To see the other types of publications on this topic, follow the link: Cystorelin.
Journal articles on the topic 'Cystorelin'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 30 journal articles for your research on the topic 'Cystorelin.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Holz, J. P., P. L. Houghton, and M. F. Spire. "Use of Cystorelin® and artificial insemination in repeat-breeding beef heifers after estrous synchronization." Kansas Agricultural Experiment Station Research Reports, no. 1 (January 1, 1993): 86–87. http://dx.doi.org/10.4148/2378-5977.2089.
Full text
2
Small, J., F. Dias, L. Pfeifer, K. Lightfoot, M. Colazo, J. Kastelic, and R. Mapletoft. "20 ADMINISTRATION OF FOLLICLE-STIMULATING HORMONE AT CIDR REMOVAL DOES NOT AFFECT THE PREGNANCY RATE IN A CIDR-BASED, COSYNCH PROTOCOL IN LACTATING BEEF COWS." Reproduction, Fertility and Development 20, no. 1 (2008): 90. http://dx.doi.org/10.1071/rdv20n1ab20.
Full textAbstract:
In previous studies, giving eCG at CIDR removal significantly increased the pregnancy rate after timed-AI in beef cows. However, eCG is not universally available. Therefore, we tested the hypothesis that giving pFSH at CIDR removal might improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows; a secondary objective was to compare pregnancy rates when GnRH v. pLH was used to synchronize wave emergence and ovulation. This work was conducted as two experiments (separate locations). All cows were given a CIDR (containing 1.9 g progesterone; Pfizer Animal Health, Montreal, QC, Canada) on Day 0 (without regard to stage of estrous cycle or cyclicity). On Day 7, CIDRs were removed, all cows were concurrently given 25 mg PGF (Lutalyse; Pfizer Animal Health, Groton, CT, USA), half were given 20 mg pFSH (Folltropin-V; Bioniche Animal Health, Belleville, ON, Canada), and all cows were timed-AI 54 h later (Day 9). In Experiment 1, 240 cows [94 � 10.8 days postpartum; body condition score (BCS: 1 = emaciated, 9 = obese; mean � SD): 5.8 � 0.4] were used; at CIDR insertion and AI, cows were allocated to receive either 100 µg GnRH (n = 160; Cystorelin, Merial Canada Inc., Victoriaville, QC, Canada) or 12.5 mg pLH (n = 80; Lutropin-V, Bioniche Animal Health). In Experiment 2, 109 cows (59.2 � 19.5 days postpartum; BCS: 5.6 � 1.1) were used; all received 100 µg GnRH (Cystorelin) at CIDR insertion and AI. In Experiment 1, three cows that lost their CIDR were excluded; pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, synchronizing treatment, and their interactions) were not different between cows given pFSH v. control cows (64.7 v. 65.2%; P > 0.80), nor between cows given GnRH v. pLH (62.7 v. 69.6%; P = 0.91). However, there was an interaction (P < 0.04) between parity and the synchronizing treatment; in primiparous cows, pregnancy rates were significantly lower in those given GnRH v. pLH (59.3 v. 83.3%). In Experiment 2, pregnancy rates after timed-AI (logistic regression, backward selection: parity, pFSH, and their interaction) were not different between cows given pFSH v. control cows (38.2 v. 42.6%; P > 0.6). In conclusion, our hypothesis was not supported; giving pFSH at CIDR removal did not significantly improve the pregnancy rate in a CIDR-based, Cosynch protocol in postpartum, suckled Bos taurus beef cows.
3
Kohram, H., V. Vahedi, S. Nasrollahi, and A. Farahavar. "Superovulation following follicular synchronization with GnRH at random stages of the oestrous cycle in heifers." Czech Journal of Animal Science 56, No. 1 (January 20, 2011): 7–14. http://dx.doi.org/10.17221/325/2009-cjas.
Full textAbstract:
The objective of this study was to develop a superovulatory program based on synchronization of follicular waves with GnRH which could be applied regardless of the stage of the oestrous cycle. 36 heifers were subjected to this experiment and GnRH (Cystorelin, 200 µg) was applied between Days 0 and 7 (n = 15), 8 and 12 (n = 8) or 13 and 20 (n = 13) of the oestrous cycle. Four days after GnRH treatment, all follicles ≥ 6 mm of heifers (n) were either punctured (n = 21) or left intact (n = 15). All heifers were superstimulated from Day 6 to Day 10 after GnRH treatment with 320 mg Folltropin-V. In parallel, 21 heifers were superstimulated in a conventional manner (Days 8 to 12) and were used as controls. The homogeneity of follicular inventories among Stage-groups occurred within 4 days of GnRH treatment for follicles ≥ 7 mm but only 2 days after follicular puncture for follicles 4 to 6 mm. In response to the follicular puncture, the mean number of follicles 4 to 6 mm increased in heifers of the punctured group (P < 0.01). Following the superstimulation, the follicular (P < 0.01) and ovulatory (P < 0.01) responses were higher in the punctured group than in the nonpunctured group. The in vivo production of transferable embryos in the punctured group was similar to that of the nonpunctured group but it was lower (P < 0.01) than in heifers of the control group. In conclusion, results from the present study indicate that regardless of the stage of the oestrous cycle, the homogeneity of follicular inventories following the follicular synchronization is obtained using GnRH treatment and follicular puncture. The in vivo production of embryos was severely compromised in the present study with heifers. Causes of such reduction in the in vivo production of embryos are still unknown.
4
Bogle, O. A., M. H. Ratto, and G. P. Adams. "221 PREPUBERTAL MOUSE BIOASSAY FOR OVULATION-INDUCING FACTOR IN SEMINAL PLASMA." Reproduction, Fertility and Development 20, no. 1 (2008): 190. http://dx.doi.org/10.1071/rdv20n1ab221.
Full textAbstract:
A substance in the seminal plasma of llamas and alpacas has been discovered that induces ovulation and growth of the corpus luteum (CL) in the female of the same species. The ovarian effects of the ovulation-inducing factor (OIF) are associated with a surge release of LH into circulation. Ultrasonographic detection of ovulation and CL development is currently the only method available for testing the bioactive effects of OIF. The purpose of this study was to determine if a superstimulatory prepubertal mouse model could be developed as an in vivo bioassay for OIF. Prepubertal female CD1 mice (n = 144), 20 days of age and weighing 20–25 g, were housed at 24�C with lights on from 0500 to 1900 h and free access to food and water. An intramuscular dose of 5 IU of eCG (Novormon, Bioniche Animal Health, Belleville, ON, Canada) was given (Day 0) for ovarian superstimulation. On Day 2, mice were assigned randomly to 4 groups (n = 36 per group) and given a single 0.1 mL intraperitoneal dose of (1) 5 IU of hCG (Chorulon, Intervet Canada, Ltd., Whitby, ON, Canada), (2) 5 µg GnRH (gonadotropin-releasing hormone: Cystorelin, Merial, Ltd., Iselin, NJ, USA), (3) llama seminal plasma, or (4) phosphate-buffered saline (negative control). On Day 3, females were euthanized by an overdose of inhaled halothane. Oviducts were collected and oocytes were counted using trans-illumination stereomicroscopy. The proportion of mice that ovulated did not differ among groups treated with hCG, GnRH, and seminal plasma (31/36, 31/36, 28/36, respectively); however, the proportion of mice that ovulated in each treatment group was greater than that in the saline-treated group (9/36) (P < 0.001). The number of oocytes counted (mean � SEM) was also similar among groups treated with hCG (25.8 � 2.9), GnRH (27.4 � 2.7), and seminal plasma (19.2 � 2.8), all of which were greater (P < 0.01) than in the saline-treated group (6.2 � 2.1). We conclude that the superstimulated prepubertal CD1 mouse model is effective as an in vivo bioassay for OIF in seminal plasma. Whether the bioassay may be used for quantitative estimates of OIF activity will require dose-response trials using serial dilutions of seminal plasma.
5
Wock, J. M., L. M. Lyle, and M. E. Hockett. "297 EFFECT OF GONADOTROPIN-RELEASING HORMONE COMPARED WITH ESTRADIOL-17β AT THE BEGINNING OF A SUPERSTIMULATION PROTOCOL ON SUPEROVULATORY RESPONSE AND EMBRYO QUALITY." Reproduction, Fertility and Development 20, no. 1 (2008): 228. http://dx.doi.org/10.1071/rdv20n1ab297.
Full textAbstract:
Success of a superstimulation protocol is largely dependent on avoiding the effects of the dominant follicle. The objective of this study was to determine if gonadotropin-releasing hormone (GnRH) would serve as a suitable alternative to the traditional estradiol-17β in a superstimulation protocol when using a CIDR. Dairy cattle (n = 411) were superstimulated using one of two treatment protocols. The GnRH-treated animals received a CIDR on random days of the estrous cycle (day 0), and GnRH was injected i.m. (100 micrograms of Cystorelin) on day 3. Porcine FSH (Folltropin-V) was administered twice daily in decreasing doses on days 5 to 8, and on day 8, CIDR were removed and 25 mg of dinoprost (PGF2α) was administered twice. The Estradiol-treated animals received a CIDR and 4 mg estradiol-17β i.m. on random days of the estrous cycle (day 0). Porcine FSH was administered twice daily in decreasing doses on days 4 to 7, and on day 7, CIDR were removed and 25 mg of PGF2α was administered twice. All animals were artificially inseminated at standing estrus and at 6-h intervals during estrus. Animals were inseminated a minimum of twice, and those with extended estrous periods were inseminated three times. Animals not showing estrus were inseminated once 48 h after CIDR removal. Seven days following estrus, embryos were collected. For data analysis, animals were divided into lactating cows, dry cows, and heifers. Dosage of FSH for each animal varied according to previous response rates; therefore, animals were further subclassified as high FSH (≥300 mg in 15 mL) or low FSH (<300 mg in 15 mL). As there were no heifers on high FSH, data analysis was done as a 5 � 2 factorial ANOVA. Total number of ova/embryos, quality, development, and fertilization rates were recorded. Analysis of data showed no statistical differences (P > 0.05) between Estradiol- and GnRH-treated groups for number ova/embryos recovered (9.8 � 0.58 v. 9.7 � 0.65), IETS-grade 1 and 2 embryos (4.7 � 0.37 v. 4.5 � 0.41), percentage fertilized (54.1 � 2.5 v. 53.2 � 2.9), and percentage grade 1 and 2 embryos (49.2 � 2.5 v. 49.3 � 2.8), respectively. No significant interactions were found between treatment and lactation status or treatment and FSH dose. Data suggest that GnRH in combination with a CiDR is an effective means of synchronizing follicle wave emergence in a superstimulation protocol. George Seidel, Josh Walker, John Hassler, and Sam Galphin.
6
Dupras, R., and Y. Chorfi. "139 NEW APPROACH FOR BOVINE EMBRYO RECOVERY." Reproduction, Fertility and Development 21, no. 1 (2009): 169. http://dx.doi.org/10.1071/rdv21n1ab139.
Full textAbstract:
The objective of this study was to evaluate the use of a second flush for bovine embryo recovery. A total of 319 clinically healthy Holstein cows (247 lactating, 53 dry, 19 nulliparous) with an average age of 5.5 ± 2.5 years were used for this experiment. Superovulation was performed according to a modified method of Baracaldo et al. (2000). On Day 0 (beginning of the experiment), each cow received 3 mg of estradiol-17β intramuscularly (i.m.) and a progesterone-releasing vaginal insert (1.9 g of progesterone, CIDR, Pfizer Animal Health, Kirkland, QC, Canada) at random stages of the estrous cycle. From Day 4 evening to Day 8 evening, the cows received a total of 380 mg of NIH-FSH-P1 (FolltropinV, Bioniche Animal Health) administered im through 9 injections of decreasing dose (from 70 to 20 mg) at 12-h intervals. On Day 7, the cows received 2 injections consisting of 500 μg of cloprostenol (prostaglandin F2α analogue Estrumate, Schering-Plough, Pointe-Claire, QC, Canada) given approximately 12 h apart and vaginal inserts were removed 12 h after the last injection. Artificial insemination was performed on Day 10 after treatment with 100 μg, GnRH im (Cystorelin, Merial Canada Inc, Baie d’Urfe, QC, Canada). Embryos were flushed from the uterus of donor cows 6 days after AI. The method consisted of using simultaneously 1 catheter (18Fr Silicone 2-way, Bioniche Animal Health) per uterine horn. Catheters were maintained in place to perform 2 flushes 1 h apart. A total of 1000 mL of flushing media (Complete flush, Bioniche Animal Health) were used, 700 mL and 300 mL for the first and the second flush, respectively. Embryos were assessed for viability immediately after collection using IETS classification. Data were analyzed using the SAS MIXED procedure (SAS Institue, Cary, NC). The mean (±SD) number of embryos collected at the first flushing was 5.87 ± 5.1, 0.92 ± 2.2 and 2.9 ± 4.4 for transferable, degenerate and unfertilized oocytes, respectively. The second flushing yielded 2.32 ± 2.6 transferable embryos, 0.28 ± 0.83 dead embryos and 1.2 ± 2.2 unfertilized oocytes. There was no significant effect of age, day in milk, or stage of lactation on transferable or degenerate embryos or nonfertilized oocytes in each flushing. The embryo recovery method used in this experiment could be used to recover more transferable embryos. The authors want to thank Dr Vincent Girard for his help in statistics.
7
Dupras, R., J. Dupras, and Y. Chorfi. "173 ESTRADIOL-17β CONCENTRATIONS IN BLOOD AND MILK DURING SUPEROVULATORY TREATMENT IN DAIRY COWS." Reproduction, Fertility and Development 22, no. 1 (2010): 245. http://dx.doi.org/10.1071/rdv22n1ab173.
Full textAbstract:
In cows, estradiol-17β is usually used to synchronize follicular wave emergence during superovulatory treatment. This approach, however, raises some concerns about the presence of estrogens in bovine products and their possible association with some human estrogen-sensitive cancers. The objective of this study was to determine estradiol-17β concentrations in blood and milk of dairy cows after i.m. injection of estradiol-17β and to compare these concentrations to those obtained during standard superovulation protocols. Six cows were used for this experiment. On Day 0, corresponding to Day 7 of their ensuing cycle, cows received 4.5 mg of estradiol-17β (Gentes et Bolduc, St-Hyacinthe, Québec, Canada) via i.m. injection and a progesterone-releasing vaginal insert (1.9 g of progesterone, CIDR, Pfizer Animal Health, Kirkland, Québec, Canada). Blood and milk samples were taken at 0, 24, 48, and 72 h after injection. From Day 4 evening to Day 8 evening, the cows received a total of 380 mg of NIH-FSH-P1 (Folltropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) administered i.m. through 9 injections of decreasing dose (from 70 to 20 mg) at 12-h intervals. On Day 7, the cows received 2 injections consisting of 500 μg of cloprostenol (prostaglandin F2 α analogue, Estrumate, Shering-Plough, Pointe-Claire, Québec, Canada) given approximately 12 h apart and vaginal inserts were removed 12 h after the last injection. Artificial insemination was performed on Day 9 and 10 after treatment with 100 μg of GnRH i.m. (Cystorelin, Merial Canada Inc., Baie Urfe, Québec, Canada). A second batch of blood and milk samples was taken at Day 8, 9, 10, and 11. Measurement of estradiol-17β was performed with an IMMULITE chemiluminescent counter using an IMMULITE Estradiol Kit (Siemens Diagnostic Products Corporation, Los Angeles, CA, USA). Concentrations of estradiol-17β in blood (37.1 ± 15.6 pg mL-1 at 24 h, 19.1 ± 14.2 pg mL-1 at 48 h) and milk (38.4 ± 29.5 pg mL-1 at 24 h, 9.3 ± 4.9 pg mL-1 at 48 h) were significantly higher after i.m. injection of 4.5 mg of estradiol-17β. In comparison, superovulation heat (Day 9 to 11) increased estradiol-17β concentrations in blood (20 ± 13.6 pg mL-1 at 24 h, 32.5 ± 16.3 pg mL-1 at 48 h) but not in milk.
8
Bartolome, J. A., A. Sozzi, J. McHale, K. Swift, D. Kelbert, L. F. Archbald, and W. W. Thatcher. "8RESYNCHRONIZATION OF OVULATION AND TIMED INSEMINATION IN LACTATING DAIRY COWS USING THE OVSYNCH AND HEATSYNCH PROTOCOLS INITIATED 7 DAYS BEFORE PREGNANCY DIAGNOSIS ON DAY 30 BY ULTRASONOGRAPHY." Reproduction, Fertility and Development 16, no. 2 (2004): 126. http://dx.doi.org/10.1071/rdv16n1ab8.
Full textAbstract:
Rapid re-synchronization of ovulation and insemination in cows found nonpregnant to a previous service is important to maintain high reproductive efficiency. The objective was to compare pregnancy rate (PR) and pregnancy losses (PL) in cows subjected to Ovsynch or Heatsynch protocols 7 days before pregnancy diagnosis by ultrasonography (U/S) on Day 30. Initiation of both protocols included administration of GnRH on Day 23, which was considered the optimal time according to the distribution of interestrus intervals in cows previously inseminated. The study was conducted in a large dairy herd located in north central Florida from March to May, 2003. Of 593 cows treated with GnRH on Day 23 (±1) after insemination and found nonpregnant at U/S on Day 30 (±1; experimental Day 0), 75% (445) had a CL (diestrus) and were sequentially assigned to the two experimental groups. Cows in the Ovsynch Group (n=225) received 25mg (i.m.) PGF2α (Lutalyse, Pharmacia, Kalamazoo, MI, USA) on Day 0, 100μg (i.m.) GnRH (Cystorelin, Merial Limited, Iselin, NJ, USA) on Day 2, and were timed inseminated 16h later. Cows in Heatsynch Group (n=220) received 25mg (i.m.) PGF2α on Day 0, and 1mg (i.m.) estradiol cypionate (ECP, Pharmacia, Kalamazoo, MI, USA) on Day 1, and were timed-inseminated 36h later. Pregnancy at Day 30 was determined by U/S and at Day 55 by rectal examination of the genital tract. Pregnancy rate and PL were evaluated using multiple logistic regression. Pregnancy rate at Day 30 for Ovsynch (64/225, 28.4%) and Heatsynch (63/220, 28.6%) and PR at Day 55 for Ovsynch (58/225, 25.8%) and Heatsynch (54/220, 24.5%) were not different. In addition, PL between Days 30 and 55 for Ovsynch (6/64, 9.4%) and Heatsynch (9/63, 14.3%) were not different. There were no effects of parity, inseminator and days in milk on PR. However, PR at day 30 was higher in lots with cooling systems (46/141, 32.6%) and lots of first calf heifers (41/135, 30.4%) compared to lots of multiparous cows late in lactation without cooling systems (32/148, 21.6%). In conclusion, Heatsynch and Ovsynch initiated 7 days before pregnancy diagnosis on Day 30 had comparable PR of 25% at Day 55 in lactating dairy cows during the period of March–May.
9
Campos, Carla Cristian, Mayara Oliveira, Renata De Freitas Ferreira Mohallem, and Ricarda Maria dos Santos. "Gonadorelina no início e/ou no final do protocolo de sincronização da ovulação a base de progesterona e benzoato de estradiol em fêmeas Nelore." Semina: Ciências Agrárias 37, no. 1 (February 29, 2016): 173. http://dx.doi.org/10.5433/1679-0359.2016v37n1p173.
Full textAbstract:
<p>Objetivou-se avaliar os efeitos da gonadorelina (GnRH) utilizada para sincronização da emergência da onda de crescimento folicular e para indução da ovulação sincronizada ou em ambos sobre a taxa de concepção (TC) de vacas da raça Nelore. O experimento foi realizado em duas fazendas no Vale do Araguaia, MT. A avaliação do escore de condição corporal (ECC) e a ultrassonografia para determinação da condição dos ovários [folículo com diâmetro < 10 mm, ? 10 mm ou presença de corpo lúteo (CL)] foram realizadas no início (Dia 0) do protocolo de inseminação artificial em tempo fixo (IATF). Vacas multíparas (n = 494) foram submetidas ao protocolo: Dia 0 – inserção do dispositivo intravaginal de progesterona (P4, DIB®, MSD) utilizado previamente por oito ou 16 dias e aplicação IM de 2,0 mg de Benzoato de Estradiol (BE, Gonadiol®, MSD); Dia 8 – remoção do dispositivo, aplicação IM de 300 UI de Gonadotrofina Coriônica Equina (eCG, Folligon®, MSD), de 1,0 mg de Cipionato de Estradiol (ECP®, Zoetis) e de 0,265 mg de Cloprostenol Sódico (PGF2?, Ciosin®, MSD); Dia 10 – IATF, realizada por um único inseminador. Os animais foram distribuídos aleatoriamente em quatro grupos: controle (n = 126), GnRH D0 (n = 123), GnRH D10 (n = 123) e GnRH D0 + D10 (n = 122), sendo que os animais tratados com GnRH receberam 50 mcg de gonadorelina (GnRH, Cystorelin®, Merial). O diagnóstico de gestação foi realizado por ultrassonografia 39 ± 10 dias após a IATF. As variáveis foram analisadas pelo procedimento GLIMMIX do programa SAS (P < 0,05). Verificou-se uma TC geral de 42,71%. Não foi detectado efeito dos tratamentos sobre a TC (P = 0,2482), que foi de 36,89% ± 0,19 (47/126) para o grupo controle, 46,08% ± 0,19 (56/123) para GnRH D0, 48,30% ± 0,18 (61/123) para GnRH D10 e de 38,48% ± 0,19 (47/122) para GnRH D0 + D10. Observou-se efeito da variável fazenda, sendo que na Fazenda A a TC foi de 47,32% ± 0,13 e na Fazenda B de 38,24% ± 0,13 (P = 0,0249). Não foi verificado efeito das interações entre fazenda e tratamento (P = 0,7662), nem entre condição ovariana e tratamento (P = 0,1225) sobre a TC. Vacas com folículos < 10 mm apresentaram menor TC (16,44% ± 0,08; P = 0,0001), quando comparadas às vacas com folículos ? 10 mm (46,15% ± 0,07) e vacas com CL (48,35% ± 0,07). Conclui-se que a utilização de gonadorelina para sincronização da emergência da onda de crescimento folicular e/ou como indutor da ovulação nos protocolos de IATF não promove incremento na taxa de concepção de vacas da raça Nelore.</p>
10
Messerschmidt, C. A., F. M. Abreu, L. H. Cruppe, M. V. Biehl, M. L. Day, C. R. F. Pinto, and M. A. Coutinho da Silva. "9 EFFECTS OF MECLOFENAMIC ACID ON LUTEAL FUNCTION OF BEEF CATTLE." Reproduction, Fertility and Development 24, no. 1 (2012): 115. http://dx.doi.org/10.1071/rdv24n1ab9.
Full textAbstract:
The objective of this study was to determine the effects of meclofenamic acid, a nonsteroidal anti-inflammatory, on luteal function of beef cattle. A total of 18 Angus cows, aged between 2 and 3 years old, were enrolled in the experiment. All cows were synchronized using a 5-day CIDR protocol. Briefly, cows received 100 μg of gonadorelin diacetate tetrahydrate (GnRH; Cystorelin®, Merial, Athens, GA, USA) and a controlled internal drug release insert (CIDR; Eazi-BreedTM CIDR®, Pfizer Animal Health, New York, NY, USA). Five days later, the CIDR was removed and 50 mg of dinoprost (Lutalyse®, Pfizer Animal Health) was administered intramuscularly. Oestrus was determined by twice daily observations of mounting behaviour and tail painting scores (day of oestrus = Day 0). At 72 h after dinoprost, a second dose of gonadorelin (100 μg, IM) was administered. On Day 14, cows were randomly assigned to the following treatment groups: 1) control: 10 mL of saline solution administered IM; 2) systemic: 2 g of meclofenamic acid administered IM; and 3) oral: 2 g of meclofenamic acid administered orally. Cows were treated once daily for 11 days (i.e. until Day 24) and no adverse reactions were observed. Blood sampling and ovarian ultrasonography were performed every 72 h from Day 0 until Day 12 and then every 48 h until the end of the study. Serum progesterone concentrations were determined by radioimmunoassay and were used to determine functional luteolysis (i.e. progesterone <1 ng mL–1). Ovaries were evaluated for the presence of a corpus luteum and to evaluate follicular growth and subsequent ovulation. One-way ANOVA was used to compare the day of peak progesterone concentration, lifespan of the corpus luteum and the length of the oestrous cycle between groups. Significance was set at P < 0.05 and data are presented as means ± standard error of the mean (Table 1). There were no effects of meclofenamic acid administration on any of the parameters evaluated (P > 0.05). In conclusion, meclofenamic acid administration did not affect luteal function in our study. Potentially, higher doses of meclofenamic acid may be necessary to inhibit prostaglandin synthesis and prevent luteolysis. Table 1.Effects of meclofenamic acid administration on the day of peak progesterone concentration, lifespan of the corpus luteum (CL) and the length of oestrous cycle in beef cows (mean ± standard error of the mean) Funding was provided by The Ohio State University, College of Veterinary Medicine, USDA-Animal Health Formula Funds. The authors are also grateful to the staff at the OSU Beef Center Facility for helping with animal handling and care.
11
Colazo, M. G., F. C. Dias, K. Lightfoot, O. Dochi, J. P. Kastelic, and R. J. Mapletoft. "8 PREGNANCY RATE FOLLOWING TIMED AI IN BEEF HEIFERS TREATED WITH CUE-MATE AND pLH OR GnRH." Reproduction, Fertility and Development 19, no. 1 (2007): 122. http://dx.doi.org/10.1071/rdv19n1ab8.
Full textAbstract:
The objective was to investigate the use of Cue-Mate and porcine LH (pLH) or GnRH with or without presynchronization on pregnancy rate following timed AI (TAI) in Angus heifers (n = 462). Approximately half of the heifers (Control; n = 236) were treated at random stages of the estrous cycle, and the other half (Presynch; n = 226) received two injections of 500 �g cloprostenol (PGF: Estrumate�; Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) 14 days apart; synchronization treatments were initiated 11 days after the second injection of PGF. On Day 0, heifers received an intravaginal progesterone device (Cue-Mate; Bioniche Animal Health, A/Asia Pty, Armidale, Australia) and were treated with 100 �g GnRH IM (Cystorelin�; Merial Canada Inc., Victoriaville, Quebec, Canada; n = 233) or 12.5 mg pLH (Lutropin-V�; Bioniche; n = 229). On Day 7, Cue-Mates were removed and heifers were given PGF IM. GnRH or pLH (same as the first treatment) was given concurrently with TAI on Day 9 (54–56 h after PGF) with frozen–thawed semen of one of 3 sires. Ultrasonographic examinations were performed in a subset of 182 heifers on Days 0 and 7 for CL and follicle development, and in all heifers on Days 41 to 49 for confirmation of pregnancy. Data were compared using CATMOD procedures in the Statistical Analysis System (SAS Institute, Inc., Cary, NC, USA). The proportion of cycling heifers on Day 0 was 90.7% (165/182). Pregnancy rate tended to differ among bulls (46.7, 56.9, and 61.4% for Bulls A, B, and C, respectively; P≤ 0.1). Heifers that ovulated in response to the first GnRH or pLH injection had a higher pregnancy rate than those that did not ovulate (66.3 vs. 51.9%; P ≤ 0.03). In addition, heifers treated with GnRH tended to have a higher ovulatory response to the first treatment and a higher pregnancy rate to TAI than those treated with pLH (60.9 and 60.5% vs. 50.0 and 52.4%, respectively; P ≤ 0.09). Although ovulatory response to the first GnRH or pLH treatment was 46.5 and 63.5% for Control and Presynch groups, respectively (P ≤ 0.02), pregnancy rates did not differ (59.8 vs. 53.1%; P ≥ 0.2). However, there was an interaction between presynchronization treatment and ovulatory response to the first injection of GnRH or pLH on pregnancy rates (P ≤ 0.02). The pregnancy rate was higher in Control heifers that ovulated (77.5%) to the first injection of GnRH or pLH than in Control heifers that did not ovulate (52.2%) or Presynch heifers that did (59.0%) or did not (51.4%) ovulate. In summary, Cue-Mate-treated heifers that ovulated in response to the first GnRH or pLH treatment had higher pregnancy rates to TAI. Although presynchronization with PGF increased the ovulation rate, it did not significantly affect the pregnancy rate.
12
Schafer, D. J., J. F. Bader, D. C. Busch, F. N. Kojima, M. R. Ellersieck, M. C. Lucy, M. F. Smith, and D. J. Patterson. "208 FOLLICULAR DYNAMICS, ESTRUS, AND OVULATION IN COWS SYNCHRONIZED TO OVULATE FIRST OR SECOND WAVE DOMINANT FOLLICLES USING SHORT- OR LONG-TERM MELENGESTROL ACETATE- OR EAZI-BREED CIDR INSERT-BASED PROTOCOLS." Reproduction, Fertility and Development 17, no. 2 (2005): 254. http://dx.doi.org/10.1071/rdv17n2ab208.
Full textAbstract:
The objective of this experiment was to determine the feasibility in substituting EAZI-BREED CIDR inserts (CIDR; Pfizer Animal Health, Groton, CT, USA) for melengestrol acetate (MGA) in progestin-based protocols to synchronize estrus in beef cows. Follicular dynamics, timing of estrus, and ovulation were compared in beef cows synchronized to ovulate first or second wave dominant follicles using short- or long-term MGA- or CIDR-based protocols. The study was conducted with 48 nonsuckled, estrous cycling, crossbred beef cows assigned to one of four treatments (T1 to T4; n = 12/T) by age and body condition. Cows were synchronized to ovulate first wave (T1 and T2) or second wave (T3 and T4) dominant follicles based on assignment to treatment. Cows in T1 were fed MGA (0.5 mg h−1 d−1) for 7 days, and were injected with PGF2α (PG; 25 mg Lutalyse; Pharmacia Animal Health, Kalamazoo, MI, USA) on Day 7, GnRH (100 μg Cystorelin; Merial, Athens, GA, USA) on Day 11, and PG on Day 18. Cows in T2 had CIDR (1.38 g progesterone) inserted for 7 days, and were injected with PG on Day 7, GnRH on Day 9, and PG on Day 16. Cows in T3 were fed MGA for 14 days, and were injected with GnRH on Day 26, and PG on Day 33. Cows in T4 had CIDR inserted for 14 days, and were injected the GnRH on Day 23, and PG on Day 30. Transrectal ultrasonography was performed daily to monitor follicular dynamics from GnRH to estrus after PG; and every 4 h from 20 h after the onset of estrus until ovulation. Estrus detection was performed continuously using the HeatWatch® estrus detection system (DDx, Denver, CO, USA). Blood samples for progesterone (P4) were collected daily beginning one day prior to the initiation of treatment and continuing through ovulation following PG. Data were analyzed using the General Linear Models procedure of SAS (SAS Institute, Inc., Cary, NC, USA) and are summarized in the following table. Animals that responded to treatment and were included in the analysis were those that initiated a new follicular wave after administration of GnRH and that displayed estrus within 144 h after PG. Although estrous response was similar among treatments, there were differences in follicular dynamics, steroid secretion patterns, and timing of events that culminated in differences in timing and synchrony of estrus and ovulation among the short- and long-term groups. These differences may be important in relation to fixed-time AI programs. These data suggest that in situations that are not conducive to feeding MGA, substituting CIDR inserts into MGA-based protocols to synchronize estrus may be feasible. This work was supported by USDA-NRI grant 2000-02163; Pfizer Animal Health, New York, NY; and Merial, Athens, GA, USA.
13
Small, J. A., M. G. Colazo, J. P. Kastelic, D. R. Ward, O. Dochi, and R. J. Mapletoft. "18 THE EFFECTS OF CIDR AND eCG TREATMENTS IN A GnRH-BASED PROTOCOL FOR TIMED AI OR EMBRYO TRANSFER ON PREGNANCY RATES IN LACTATING BEEF COWS." Reproduction, Fertility and Development 19, no. 1 (2007): 127. http://dx.doi.org/10.1071/rdv19n1ab18.
Full textAbstract:
Two experiments were conducted to determine the effects of the addition of a progestin, equine chorionic gonadotropin (eCG), or both, in a GnRH-based protocol for timed AI (TAI) or timed embryo transfer (TET). In both experiments, Angus, Gelbvieh, and Simmental cross-bred cows were randomized by breed and postpartum interval [50 � 10 days (mean � SD); range, 27 to 89] into 4 groups in a 2 � 2 factorial design. All injections were given IM. In Experiment 1, 288 cows (89.6% cycling) were given 25 mg dinoprost (PGF; Lutalyse�; Pfizer Animal Health, Montreal, Quebec, Canada) on Day –11; on Day 0, they were given 100 �g GnRH (Cystorelin�; Merial Canada, Pointe-Claire, Quebec, Canada), with or without concomitant insertion of a CIDR (1.9 g progesterone; Pfizer Animal Health, Montreal, Quebec, Canada). On Day 7, CIDR inserts were removed and cows were given PGF, with or without concomitant injection of 400 IU of eCG (Pregnecol�; Bioniche Animal Health, Belleville, Ontario, Canada). On Day 9 (54-56 h after PGF), TAI was done, with concomitant injection of 100 �g GnRH. Ultrasonographic examination of 147 cows on Day 7 revealed that 62.4% had ovulated in response to the first GnRH. Pregnancy rates (ultrasonographic examination) on Day 38 did not differ between cows with or without a CIDR (52.9 and 51.4%, rspectively; P ≥ 0.64), with or without eCG treatment (53.5 and 50.7%, respectively; P ≥ 0.28), in cycling vs. anestrous cows (51.6 vs 56.7%, respectively; P ≥ 0.76), and in cows that had ovulated (58.1%) or did not ovulate (50.0%) after the first GnRH treatment (P ≥ 0.58). In Experiment 2, 151 cows were given 500 �g cloprostenol (PGF; Estrumate�; Schering–Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day –12, 100 �g GnRH on Day 0, with or without concomitant insertion of a CIDR. On Day 3, half of the cows were given 400 IU eCG. On Day 7, CIDRs were removed and cows were given PGF; on Day 9 (54–56 h after PGF), all cows were given 100 �g GnRH. On Day 15, ultrasonography was done to select suitable recipients for transfer of frozen–thawed embryos on Day 16 (part of another experiment, balanced across synchronization groups). Recipient selection rates did not differ whether cows received or did not receive a CIDR (93.4% vs 85.5%, respectively; P ≥ 0.27) or eCG (91.0 vs 87.8%, respectively; P ≥ 0.67). In addition, pregnancy rates on Day 43 did not differ whether cows received or did not receive a CIDR (32.3 vs 32.4%, respectively; P ≥ 0.52) or eCG (35.2 and 29.2%, respectively; P ≥ 0.21). In summary, the addition of a CIDR or eCG to a GnRH-based synchronization protocol initiated after PGF presynchronization in lactating beef cattle yielded no improvement in pregnancy rates following TAI, or recipient selection and pregnancy rates following TET.
14
Giordano, J. O., J. L. Edwards, G. M. Schuenemann, N. Rohrbach, and F. N. Schrick. "13 STRATEGIES TO INCREASE OVULATORY FOLLICLE SIZE AND REDUCE OVULATION TIME IN LACTATING DAIRY COWS." Reproduction, Fertility and Development 20, no. 1 (2008): 87. http://dx.doi.org/10.1071/rdv20n1ab13.
Full textAbstract:
In vitro exposure of oocytes to elevated temperatures hastened oocyte maturation; furthermore, performing IVF of heat-stressed oocytes 5 h earlier than the usual 24 h resulted in blastocyst development similar to that of non-heat-stressed controls (Edwards et al. 2005 J. Dairy Sci. 88, 4326–4333). If elevated ambient temperatures in vivo alter oocyte maturation in a similar fashion, then new strategies are needed to induce earlier release of the oocyte from the ovulatory follicle. Current objectives were to examine follicular growth after FSH administration and examine whether treatment with FSH and an exogenously induced LH surge would hasten ovulation. On Day 0 (8 to 9 days after estrus) of the experimental period, lactating Holstein cows (n = 31; 65–115 days in milk; 1–6 lactations) received an EAZI-BREED CIDR (Pfizer Animal Health, New York, NY, USA) plus 100 µg of gonadotropin-releasing hormone (GnRH, IM; Cystorelin, Merial Ltd, Iselin, NJ, USA). On Day 7, CIDRs were removed and cows were administered 500 µg cloprostenol (IM; Estrumate, Schering-Plough Animal Health, Union, NJ, USA). Concurrently, cows were randomly allocated to receive either 80 mg FSH (FSH; n = 15; Folltropin-V, Bioniche Animal Health, Belleville, ON, Canada) or 4 mL of sterile saline (SAL; n = 16). Forty-eight h later (Day 9), cows within the FSH and SAL groups were randomly subdivided to receive either a 100-µg dose of Cysterolin (GnRH) or 3000 IU of hCG (hCG, IM; Chorulon, Intervet Inc., Millsboro, DE, USA) generating 4 treatment combinations (FSH/GnRH, n = 3; FSH/hCG, n = 7; SAL/GnRH, n = 8; and SAL/hCG, n = 8). Ovarian activity was assessed by ultrasonography to evaluate growth of the ovulatory follicle. Following CIDR removal, frequent ultrasonography was utilized to confirm ovulation (disappearance of the dominant follicle). Data were analyzed using the MIXED procedure of SAS (SAS Institute, Inc., Cary, NC, USA). Five cows from the FSH group were removed from the combination treatment due to ovulation occurring before 48 h post-CIDR removal. Size of the ovulatory follicle at time of GnRH or hCG administration was not different between FSH or SAL groups (16.7 � 0.7 v. 17.5 � 0.6 mm, respectively). Total growth of the ovulatory follicle from CIDR removal to ovulation did not differ between FSH (3.04 � 0.7 mm) and SAL (2.75 � 0.7 mm)-treated cows. As calculated from time of CIDR removal, ovulation occurred earlier in FSH (63.6 � 4.5 h) than in SAL (77.2 � 4.4 h; P < 0.05)-treated cows. Combination of FSH/GnRH produced the earliest ovulation (74 � 1.2 h) which was different only from FSH/hCG (78.6 � 0.8 h; P < 0.05), but not from SAL/GnRH or SAL/hCG (77 � 0.8 and 78 � 0.8 h, respectively). Regardless of FSH or SAL treatment, cows treated with GnRH ovulated earlier than those treated with hCG (75.5 � 0.7 v. 78.3 � 0.6 h, respectively; P < 0.05). In conclusion, while FSH was unable to increase the size of the ovulatory follicle, earlier ovulation occurred when given alone or in combination with GnRH.
15
Blevins, B. A., D. L. Armstrong, and N. M. Loskutoff. "153 THE EFFECT OF CONTINUOUS EXOGENOUS GONADOTROPIN TREATMENT ON OVARIAN ACTIVITY IN TIGERS (PANTHERA TIGRIS SPP.)." Reproduction, Fertility and Development 21, no. 1 (2009): 175. http://dx.doi.org/10.1071/rdv21n1ab153.
Full textAbstract:
Tigers are seasonally polyestrus, induced ovulators and can show breeding behavior for 7 days or more. The aim of this study was to determine the optimal time to trigger ovulation to induce a normal luteal phase. Previously, naturally cycling tigresses (n = 5) were observed for estrus and treated with gonadotropin-releasing hormone (GnRH) agonist. It appeared from ovarian laparoscopic examinations, fecal estrogen, and progesterone measurements, that Day 4 of estrus was optimal for timing the ovulation trigger. One of the tigresses had three 10 to 12 mm follicles and three ovulation sites on her ovaries and produced a live cub after intra-uterine laparoscopic artificial insemination using fresh semen. To control the cycle and further pinpoint the timing for ovulation, a study was conducted on three tigresses using purified pFSH, previously shown to be effective in tigers (Crichton et al. 2003 Biol. Reprod. 68, 105–113) delivered in an implantable osmotic pump (Alzet, Palo Alto, CA, USA) and GnRH agonist delivered on Day 4 of estrus. None of the females ovulated as determined by fecal progesterone measurements, which is consistent with previous anecdotal reports that GnRH agonists are effective in natural cycles but not in stimulated cycles in felids. To overcome this problem, a study was conducted on 6 tigresses (n = 11 cycles) using 210 mg pFSH (Folltropin-V, Bioniche, Belleville, ON, Canada) delivered at 1.25 U pFSH/h and the tigresses were treated on Day 4 of estrus (7 days after pFSH implantation) with 50 μg GnRH agonist (Cystorelin, Merial, Victoriaville, QC, Canada) in addition to 10 000 IU of hCG (Profasi, Serono, Rockland, MA, USA), the latter previously shown to be effective in felids (Donoghue et al. 1993 J. Zoo Wild. Med. 24, 185–189). Fecal samples were collected and analyzed for estradiol and progesterone and ovarian responses were examined laparoscopically. Results were compared using Student’s t-tests. Discrepancies in reported sample numbers were due to limited sample availability. Concentrations of fecal estradiol were similar (P > 0.05) between females treated with pFSH and natural cycles (172.5 ± 14.9 ng g–1, n = 8 v. 204.8 ± 4.1 ng g–1, n = 4; respectively). Females responded to hormonal stimulation with a significant increase (P < 0.05) in the number of large follicles (>9 mm) to CL stages compared to naturally cycling females (11.8 ± 1.9, n = 11 v. 4.0 ± 0.1, n = 5; respectively). There was no difference (P > 0.05) in the average duration of the luteal phase between stimulated and natural cycles (32.9 ± 0.1d, n = 7 v. 33.3 ± 1.4d, n = 3; respectively). Luteal phase progesterone concentrations were significantly higher (P < 0.05) after GnRH and hCG treatments than in naturally ovulating tigresses (6.3 ± 1.0 μg g–1, n = 10 v. 2.8 ± 0.6 μg g–1, n = 4; respectively). In summary, while follicular development was increased, exogenous hormone administration resulted in fecal estradiol concentrations and luteal phase duration similar to that of naturally cycling tigresses. Nevertheless, progesterone concentrations were significantly higher and follicular phase duration tended to be longer in the stimulated cycles.
16
Rabaglino, M. B., C. A. Risco, M. J. Thatcher, J. E. P. Santos, and W. W. Thatcher. "38 APPLICATION OF A FIVE-DAY PROGESTERONE-BASED SYNCHRONIZATION PROTOCOL FOR TIMED AI WITH SEXED SEMEN IN DAIRY HEIFERS." Reproduction, Fertility and Development 22, no. 1 (2010): 177. http://dx.doi.org/10.1071/rdv22n1ab38.
Full textAbstract:
It is expected that pregnancy per AI with sexed semen would be 70 to 75% of that with conventional semen, and the use of sexed semen with timed AI (TAI) protocols is discouraged (DeJarnette et al. 2009 Theriogenology 71, 49-58). It was hypothesized that the 5-day Co-Synch + CIDR (controlled internal drug-release) protocol with 1 injection of PGF2α would be an acceptable reproductive management program for TAI of dairy heifers with sexed semen. The objectives were to compare pregnancy per TAI (P/TAI) using conventional or sexed semen for the first TAI (experiment 1), and to evaluate P/TAI of a reproductive management program with sexed semen for the first TAI and sexed or conventional semen for the second TAI (experiment 2). A total of 1,000 Holstein heifers between 13 to 14 months of age were synchronized with the 5-day Co-Synch + CIDR protocol, that consisted of an administration of GnRH (100 μg i.m. Cystorelin®, Merial Ltd., Iselin, NJ, USA) and a CIDR insert containing 1.38 g of progesterone inserted at Day 0; on Day 5 the CIDR was removed and one injection of PGF2α (25 mg, i.m. Lutalyse®, Pfizer Animal Health, New York, NY, USA) administered; on Day 8 a second injection of GnRH was administered concurrent with TAI. In experiment 1, 198 heifers were assigned randomly to be TAI with conventional (n = 98) or sexed (n = 100) semen for the first TAI. Commercial straws with sexed or conventional semen were obtained from 2 sires. In experiment 2, a total of 802 heifers received TAI to the first service with sexed semen. For the resynchronized TAI, nonpregnant heifers at 32 days after the first TAI were resynchronized with the 5-day Co-Synch + CIDR and were TAI with either sexed semen (n = 114) or with conventional semen (n = 373). Pregnancy per TAI to first and second TAI was analyzed by logistic regression using the GLIMMIX procedure of SAS (SAS Version 9.1 for Windows, SAS Institute, Cary, NC, USA) with heifer treated as a random effect. In experiment 1, P/TAI was 51.0% and 42.0% at 45 days for conventional and sexed semen, respectively (P = 0.1). Pregnancy per TAI with sexed semen was 82.3% of conventional semen. In experiment 2, P/TAI at first service with sexed semen was 35.9% at 45 days after TAI. For the second TAI, P/TAI was 40.4% with sexed semen at 45 days and 59.2% with conventional semen at 60 days (P < 0.001). As expected, P/TAI was lower with sexed compared to conventional semen. Nevertheless, the application of the 5-day Co-Synch + CIDR protocol with one injection of PGF2α, as a reproductive management program for TAI of dairy heifers, achieved an acceptable P/TAI with sexed semen. We conclude that sexed semen can be used with TAI to effectively manage reproduction in dairy heifers by removing the challenges of detection of estrus and increase the number of females born.
17
Sanchez, J. M., V. Maillo, L. Molina, C. C. Perez-Marin, P. Lonergan, and D. Rizos. "12 EFFECT OF HUMAN CHORIONIC GONADOTROPIN (hCG) ADMINISTRATION ON DAY 2 OR DAY 5 AFTER OESTRUS ON PREGNANCY RATE IN HIGH-YIELDING DAIRY COWS." Reproduction, Fertility and Development 27, no. 1 (2015): 98. http://dx.doi.org/10.1071/rdv27n1ab12.
Full textAbstract:
In cattle, ~40% of embryonic loss occurs in the period from Day 8 to Day 16 of pregnancy. A significant proportion of embryo loss may be due to inadequate circulating progesterone (P4) concentrations. Low P4 concentrations have also been implicated as a causative factor in the low pregnancy rates (PR) observed in high-yielding dairy cows. Administration of hCG during the early luteal phase stimulates hypertrophy of the original corpus luteum (CL) and, depending on the day of administration, induces ovulation of the first-wave dominant follicle and formation of a functional accessory CL, which increases circulating P4 concentrations. The aim of this study was to examine whether administration of hCG on Day 2 or Day 5 after oestrus after timed AI (TAI) would lead to an increase in pregnancy rates in dairy cattle. Lactating Holstein cows (n = 194) from 12 commercial dairy herds in Southern Spain (37.8833° N, 4.7667° W) with an average milk production at 37.8 L/cow per day and typically with a PR to first AI of ~30% were randomly assigned based on their body condition score (2.65 ± 0.05; mean ± SEM), parity (2.60 ± 0.09), and days in milk (75.06 ± 0.63) to 1 of 3 treatments and administered a single intramuscular injection of 3000 IU of hCG (4 mL of Veterin Corion) either (1) on Day 2 = 36 h after TAI (n = 65; hCG2 group), (2) Day 5 = 108 h after TAI (n = 64; hCG5 group), or (3) 4 mL of saline on Day 2 = 36 h after TAI (n = 65; control group). Cows were synchronized using a 7-day Ovsynch TAI protocol that included a P4-releasing intravaginal device (PRID DELTA 1.55 g). First, gonadotropin-releasing hormone (Cystorelin 100 mg) treatment was administered at PRID insertion (Day 0) followed by 25 mg Dinoprost (prostaglandin F2α: Enzaprost T) on Day 7 at PRID withdrawal. Then, 56 h later, the second gonadotropin-releasing hormone (100 mg) treatment was administered and all cows were inseminated 16 h later. Pregnancy was diagnosed by ultrasonography 28 to 32 days after TAI. Logistic regression model and chi-squared test were used to analyse data. Pregnancy rate to AI was significantly higher in the hCG2 and hCG5 groups than in the control group (43.1 and 45.3%, v. 27.7%; P < 0.05). A treatment-by-parity interaction was observed; while pregnancy rate for primiparous cows was not affected by treatment, multiparous cows from the hCG2 group had greater pregnancies per AI than those in the control group (47.2% v. 21.1%, respectively; P < 0.05). In conclusion, these preliminary results suggest that hCG administration on Day 2 and 5 after oestrus increases PR at first postpartum AI in Holstein cows. In addition, hCG on Day 2 increases the fertility in multiparous cows.This study was funded by the Spanish Ministry of Science and Innovation (AGL2012–37510) and partially supported by Ceva Salud Animal S.A., Spain – synchronization protocol and DFV, Spain – hCG treatments.
18
Colazo, M. G., J. A. Small, D. R. Ward, N. E. Erickson, J. P. Kastelic, and R. J. Mapletoft. "11THE EFFECT OF PRESYNCHRONIZATION ON PREGNANCY RATE TO FIXED-TIME AI IN BEEF HEIFERS SUBJECTED TO A COSYNCH PROTOCOL." Reproduction, Fertility and Development 16, no. 2 (2004): 128. http://dx.doi.org/10.1071/rdv16n1ab11.
Full textAbstract:
The objective was to investigate the effect of presynchronization with PGF prior to a Cosynch protocol on estrus synchrony, CL and preovulatory follicle diameters and pregnancy rate following timed-AI (TAI) in beef heifers. Cycling beef heifers (n=148) were treated with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day 0, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day 7, and GnRH concurrent with TAI on Day 9 (54h after PGF). Half of the heifers (Control) received the first GnRH treatment at random stages of the estrous cycle, while the other half (Presynch) received two injections of PGF 11 days apart, with the first injection of GnRH 11 days after the second injection of PGF. Estrus detection was done between the first GnRH and 12h after PGF, and heifers detected in estrus were inseminated (and considered nonpregnant to TAI), while all other heifers were TAI. Heifers were examined by transrectal ultrasonography for CL and follicle development, and confirmation of pregnancy. Data were compared between groups using Student’s t-test and chi-square procedures. The numbers of heifers in estrus early (after first GnRH and before TAI) was higher in the Control group than in the Presynch group (18/74 v. 2/74, respectively; P<0.0001). Mean (±SD) diameters of the dominant follicle (12.1±3.1 v. 14.2±2.5mm) and CL (17.3±5.5v. 20.5±4.3mm) at first GnRH injection were smaller (P<0.0001) and more variable (P<0.03) in Control than Presynch heifers, but diameters of the preovulatory follicle (P=0.3) and CL (P=0.1) at TAI did not differ. Although the diameter of the preovulatory follicle was more variable (P<0.004) in Control (5 to 19mm) than Presynch (8 to 17mm) heifers, pregnancy rate to TAI did not differ (P=0.4; 29.7 v. 36.5%, respectively). Overall pregnancy rates were 45.9 and 37.8% for Control and Presynch groups, respectively (P=0.3). Pregnancy rate tended (P<0.08) to be affected by diameter of the preovulatory follicle at the time of TAI (0, 23.1, 45.7, 41.4, and 60.0% pregnant for diameters of <9, 9–11, 12–14, 15–17, and >17mm, respectively). Regardless of treatment, diameter of the preovulatory dominant follicle (P<0.02) and CL (P<0.03) 7 days after TAI was smaller, and CL diameter was more variable (P<0.004), in open than in pregnant heifers (12.7±2.6v. 13.8±2.1mm, and 16.5±4.4v. 18.0±3.0mm, respectively). In summary, presynchronization with PGF prior to a Cosynch protocol reduced the proportion of heifers in estrus before TAI, suggesting that this approach may be useful in the successful application of Ovsynch or Cosynch programs in heifers. However, pregnancy rate to TAI did not differ between groups in this study. Diameter of the preovulatory follicle tended to positively affect pregnancy rate, regardless of treatment.
19
Small, J., M. Colazo, D. Ambrose, R. Mapletoft, J. Reeb, and J. Kastelic. "183PREGNANCY RATE FOLLOWING TRANSFER OF IN VITRO- AND IN VIVO-PRODUCED BOVINE EMBRYOS TO LH-TREATED RECIPIENTS." Reproduction, Fertility and Development 16, no. 2 (2004): 213. http://dx.doi.org/10.1071/rdv16n1ab183.
Full textAbstract:
The objective was to evaluate the effect of pLH treatment on pregnancy rates in recipients receiving in vivo- or in vitro-produced bovine embryos. Heifers (n=37) and lactating (n=28) and non-lactating (n=150) beef cows were treated at random stages of the cycle with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day −9, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day —2 and GnRH on Day 0 (66h post-PGF; without estrus detection). Cattle were placed at random, by class, into three groups: no further treatment (Control; n=71), or 12.5mg pLH (Lutropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) on Day 5 (n=72) or on Day 7 (n=72) after the second GnRH. On Day 7, cattle with a CL >10mm in diameter (determined ultrasonically) received in vivo-produced, fresh (Simmental) or frozen (Holstein), or in vitro-produced frozen (Holstein) embryos (embryo type balanced among groups). Embryos were cryopreserved in 10% ethylene glycol; in vivo-produced frozen embryos were thawed 5 to 10s in air, 15s in a water-bath at 30°C and then “direct-transferred” nonsurgically. In vitro-produced frozen embryos (donated by IND Lifetech Inc., Delta, British Columbia, Canada) were thawed in a water-bath at 27°C for 10s and placed in ViGro Holding Plus medium (AB Technology, Pullman, WA, USA) at room temperature, evaluated and then transferred nonsurgically. Pregnancy was determined by ultrasonography on Day 35. Data were analyzed with CATMOD, chi-square and GLM procedures (SAS Institute, Cary, NC, USA.). Twenty cattle (9.3%) did not receive embryos; five heifers had cervical problems, and five heifers and 10 cows did not have a CL >10mm. Overall, 7.1% of the recipients had two CL on the day of embryo transfer. There was no effect (P>0.05) of treatment, embryo type (or interaction) or class of recipient on pregnancy rate (overall, 44.1%, 86/195; Table 1). Similarly, mean (±SD) CL diameter and luteal area did not differ (P>0.05) among groups or between pregnant and open recipients (overall, 22.0±3.4mm and 352.0±108.7mm, respectively). However, recipients with a CL diameter ≥18mm tended (P<0.1) to have a higher pregnancy rate (45.8 vs 25.0%). In a subset of 40 recipients examined ultrasonically on Day 12, 50% of those treated on Day 5 and 70% of those treated with pLH on Day 7 had two CL. In summary, overall pregnancy rate in GnRH-synchronized recipients receiving in vitro- or in vivo-produced embryos by nonsurgical transfer was 44.1%. Embryo survival to Day 35 was not affected by type of embryo or treatment with pLH 5 or 7 days after ovulation. Table 1 Pregnancy rate in recipients on Day 35 based on pLH treatment and embryo-type
20
Thatcher, W. W., C. A. Risco, J. Larson, M. J. Thatcher, F. Lima, and S. A. Woodall. "21 DEVELOPMENT OF A TIMED INSEMINATION PROGRAM IN DAIRY HEIFERS AS A PLATFORM TO DETERMINE IF FLUNIXIN MEGLUMINE IMPROVES PREGNANCY RATE AND EMBRYO SURVIVAL." Reproduction, Fertility and Development 20, no. 1 (2008): 90. http://dx.doi.org/10.1071/rdv20n1ab21.
Full textAbstract:
The objectives of the present series of experiments were to develop a timed artificial insemination (TAI) program for dairy heifers and to utilize a TAI program to evaluate the effect of flunixin meglumine (Banamine�; Schering-Plough Animal Health Corp., Atlanta, GA, USA), a prostaglandin H synthase (PGHS)-2 inhibitor, on pregnancy rate and embryo survival. In Experiment 1, 247 heifers were assigned randomly to a prostaglandin F (PGF)/gonadotropin-releasing hormone (GnRH) TAI [i.e., 2 injections of Lutalyse� (25 mg, IM; Pfizer Animal Health Inc., Groton, CT, USA) given 14 days apart in the PM; 60 h after the 2nd Lutalyse injection, heifers received a GnRH injection (Cystorelin�; 100 µg, IM; Merial, Duluth, GA, USA) and were TAI] or a 5-day CIDR/Synch TAI [intravaginal insertion of a CIDR� device (Pfizer Animal Health Inc.) and an injection of GnRH in the AM; 5 days later in the AM, the CIDR insert was removed and Lutalyse was injected, followed by a 2nd injection of Lutalyse� 12 h later; heifers were TAI and injected with GnRH at 72 h after CIDR removal]. Blood samples for progesterone analyses were taken 7 days apart prior to initial PGF or CIDR insertion from the respective groups to determine cycling status. The CIDR/Synch TAI heifers tended to have greater Day 32 (53.1, >46.2%) ultrasound pregnancy rate (USPR) and Day 42 (50.8, >43.7%) rectal palpation (RPPR) than PGF/GnRH heifers (P = 0.10); 4/9 non-cycling heifers of the CIDR/Synch TAI group conceived v. 0/3 of the PGF/GnRH TAI group. In Experiment 2, 176 heifers underwent the CIDR/Synch TAI protocol. However, 2 injections of cloprostenol [500 µg AM/PM; Estrumate�, Schering-Plough Animal Health Corp.) were used to regress the CL at CIDR removal. Heifers at initiation of the CIDR/Synch TAI protocol were assigned randomly to receive injections of Banamine (400 mg IM) at Day 15.5 and at Day 16.0 or no injections (control). Banamine treatment failed to alter either Day 32 USPR (59.6% Banamine v. 59.8% control) or Day 46 RPPR (59.6% Banamine v. 58.6% control). Overall, 4/11 non-cycling heifers conceived. In Experiment 3, 147 heifers underwent a UsedCIDR/Synch TAI protocol utilizing cloprostenol as in Experiment 2. A 5-day used CIDR was employed. Heifers at initiation of the UsedCIDR/Synch TAI protocol were assigned randomly to receive injections of Banamine (400 mg IM) at Day 15.5 and at Day 16.0 or no injections (control). Banamine treatment failed to alter either Day 32 USPR (60.5% Banamine v. 62.0% control) or Day 46 RPPR (59.2% Banamine v. 60.6% control). Pooled overall analyses of pregnancy rates for dairy heifers receiving the CIDR/Synch TAI treatments (n = 451), adjusted for experiments, were 58.3% at Day 32 (USPR) and 57.6% at Day 46 (RPPR). In conclusion, Banamine failed to improve pregnancy rate and/or late embryo survival in dairy heifers, and a CIDR/Synch TAI program is very effective for optimizing the pregnancy rate in dairy heifers. This work was supported by the Florida-Georgia Milk Check-off program.
21
Farin, P. W., K. M. Dowdall, J. E. Hicks, C. E. Farin, and C. S. Whisnant. "293 SUBCUTANEOUS ADMINISTRATION OF FOLLICLE STIMULATING HORMONE FOR SUPEROVULATION OF HOLSTEIN COWS." Reproduction, Fertility and Development 21, no. 1 (2009): 243. http://dx.doi.org/10.1071/rdv21n1ab293.
Full textAbstract:
Follicle stimulating hormone (FSH) is usually administered in a series of intramuscular (IM) injections to induce multiple ovulations for embryo production in cattle and other species. The objective of this study was to determine the superovulatory response of dairy cows to subcutaneous (SC) administration of FSH using a reduced number of injections in combination with a progesterone-releasing device. Eighteen non-lactating Holstein cows initially received 25 mg Prostaglandin F2α IM (PGF; Lutalyse; Pfizer Animal Health, Groton, CT, USA) on Day –7. All cows then received an intravaginal progesterone-releasing device (CIDR-B, 1.38 mg progesterone; Pfizer Animal Health) on Day 0, and 100 μg GnRH IM (Cystorelin; Merial Ltd, USA) on Day 2. Cows were randomly assigned to receive a total of 400 mg (20 mL) of FSH (Folltropin-V; Bioniche Animal Health, USA) either by IM injection (IM Group, n = 9 cows) given at 12 h intervals on Days 4 (60 mg, 60 mg), 5 (55 mg, 55 mg), 6 (45 mg, 45 mg) and 7 (40 mg, 40 mg), or by SC injection (SC Group, n = 9 cows) given at 24 h intervals on Days 4 (140 mg), 5 (140 mg) and Day 6 (120 mg). On Day 7, CIDR-B inserts were removed and cows received two 25 mg PGF IM injections given 12 h apart. Cows were artificially inseminated at 12 and 24 h after standing estrus. Blood samples were obtained from all cows at 0, 2, 4, 8, 12, 24, 36, 48, 60, 72, and 84 h after the first FSH injection for determination of serum FSH concentrations. Ovarian follicles and CL were monitored using ultrasonography on Days 4, 7, and 16. Embryos were recovered non-surgically on Day 16 (7 days after estrus). The effects of treatment on follicular response and embryo yield were analyzed by Wilcoxon test, and the response of cows to treatment was analyzed by chi-square test. The effects of treatment on concentrations of serum FSH were analyzed using ANOVA for repeated measures. There was no effect (P > 0.05) of route of FSH administration on the concentrations of serum FSH at any time point. The superovulatory response of cows to treatment, defined as greater than 2 CL per cow, did not differ (P > 0.05) between the IM (77.8%, 7/9 cows) and SC (88.9%, 8/9 cows) Groups. There was also no difference (P > 0.05) between the IM and SC Groups for the number of 5 to 10 mm follicles prior to FSH treatment (mean ± SEM; 0.6 ± 0.2 v. 0.9 ± 0.4), the total number of follicles after FSH treatment (12.4 ± 1.6 v. 12.7 ± 2.2) or the number of CL at embryo recovery (6.4 ± 1.5 v. 10.4 ± 2.1). Similarly, there were no differences (P > 0.05) between the IM and SC Groups for total number of oocytes/embryos (5.6 ± 2.6 v. 13.0 ± 4.3), transferable embryos (Grade 1, 2, 3; 3.0 ± 1.4 v. 6.1 ± 2.9) or Grade 1 embryos (2.9 ± 1.4 v. 4.3 ± 2.5). In conclusion, administration of FSH using 3 SC injections in combination with a progesterone-releasing device was an effective method for superovulation of Holstein cows. Supported by USDA Animal Health Formula Funds and the State of North Carolina.
22
Bas, S., A. Hoet, P. Rajala-Schultz, D. Sanders, and G. M. Schuenemann. "10 EFFECT OF USING PROTECTIVE AI COVER SHEATHS ON FERTILITY OF LACTATING DAIRY COWS." Reproduction, Fertility and Development 22, no. 1 (2010): 163. http://dx.doi.org/10.1071/rdv22n1ab10.
Full textAbstract:
An adequate and clean artificial insemination (AI) technique is recommended to maximize reproductive outcomes in dairy cattle. The objective of this study was to evaluate the effectiveness of using protective sheaths (PS; Continental Plastic Inc., Delavan, WI, USA) to minimize contamination of the AI catheter (AIC) on pregnancies per AI (P/AI) in lactating dairy cattle. A previous study reported no improvement on cattle fertility when using PS during first service AI (King et al. 1984 Can. Vet. J. 25, 327). Lactating cows housed in free-stall barns on a commercial dairy farm with a rolling herd milk production average of 10.140 kg were presynchronized with 2 injections of PGF2α (25 mg; Lutalyse, Pharmacia & Upjohn, Kalamazoo, MI, USA) given 14 days apart (starting at 26 ± 3 d postpartum) followed by Ovsynch [OV; GnRH-7 d-PGF2α-56 h-GnRH-16 h-timed-AI(TAI)] 12 days later. Cows presenting signs of standing heat any time during the protocol received AI, whereas the remaining animals were subjected to TAI16 h after second OV GnRH (100 μg; Cystorelin, Merial, Duluth, GA, USA). At the moment of AI (one AI technician), 996 services from lactating dairy cows were randomly assigned to 1 of the 2 groups; with (TRT, n = 487) or without (CON, n = 509) the use of PS. In the TRT group, the AIC protected with a PS was introduced into the vagina; once in the cranial portion of the vagina adjacent to the cervical os, the PS was pulled back and only the AIC was manipulated through the cervix into the uterine body for semen deposition. In the CON group, cows received AI without the PS. Additionally, sterile cotton swab (BD, Franklin Lakes, NJ, USA) samples were taken from AIC (n = 51) after AI from both treatment groups. Pregnancy diagnosis was determined by ultrasonography 42 ± 3 d after AI. Data analyses were performed using GLIMMIX (P/AI) and FREQ (culture) procedures of SAS (SAS Institute Inc., Cary, NC, USA). Cultured swab samples revealed that the use of PS was effective in minimizing contamination of the AIC (bacterial growth on AIC; TRT = 57.7% v. CON = 100%; P < 0.0002). Overall, the proportion of cows pregnant (all services) was greater (P = 0.03) for cows in TRT (42.7 ± 2.2%) compared with CON group (36.1 ± 2.1%). For first services postpartum, P/AI did not differ (P = 0.87) between CON (43.01 ± 4.4%) and TRT (43.8 ± 4.6%) groups. However, P/AI for second or greater services (≥2S) were greater (P = 0.007) in TRT (43.8 ± 2.9%) than in CON cows (32.3 ± 2.6%). Results from this study suggested that the use of PS during AI improved P/AI for ≥2S in lactating dairy cows. Performing a clean AI technique through the use of PS may be a cost-effective strategy to improve reproductive outcomes in dairy cattle. Further investigation is needed under various reproductive management conditions to confirm and determine the underlying mechanisms for these findings. Authors thank Coba/Select Sires Inc. (Columbus, OH, USA) for the donation of the AI protector sheaths, Meerland Dairy for providing the animals and Brian Alkire (Coba’s AI technician).
23
Hinshaw, R. H., M. L. Switzer, R. J. Mapletoft, and G. A. Bó. "351 A COMPARISON OF 2 APPROACHES FOR THE USE OF GnRH TO SYNCHRONIZE FOLLICLE WAVE EMERGENCE FOR SUPEROVULATION." Reproduction, Fertility and Development 27, no. 1 (2015): 263. http://dx.doi.org/10.1071/rdv27n1ab351.
Full textAbstract:
Although oestradiol has been used successfully to synchronize follicle wave emergence for superovulation, it cannot be used in many countries. Attention has turned to alternatives, including the use of GnRH to induce ovulation of a dominant follicle, which will be followed by emergence of a new follicular wave in 1 to 2 days. However, GnRH synchronizes follicular wave emergence only when it induces ovulation and administration of GnRH at random stages of the oestrous cycle results in ovulation in less than 60% of animals. The objective of the study was to compare superovulatory response and ova/embryo production following synchronization of follicle wave emergence for superovulation with GnRH administered 2 days after insertion of a progestin device, with a protocol in which GnRH is administered 7 days after administration of prostaglandin F2α and a progestin device. Beef donors of various breeds were placed at random into 1 of 2 groups and superstimulated by replicate so that one cow in each group had ova/embryos collected on the same day. Sixty-six superstimulations were performed in this study; 26 were performed in 13 donors that were superstimulated twice in a crossover design, and 40 donors were superstimulated once (i.e. 20 donors in each treatment group). Cows in group 1 received CIDR devices (Zoetis Animal Health, USA) on Day –2 and 100 μg of GnRH (Cystorelin, Merial USA) on Day 0; FSH treatments were initiated on Day 2 with 288 mg of Folltropin-V (Vetoquinol, Canada) given in twice-daily decreasing doses for 4 days. Prostaglandin F2α (PGF; 35 mg dinoprost, Lutalyse, Zoetis) was given with the last 2 injections of Folltropin-V and CIDR were removed with the last Folltropin-V administration (i.e. Day 6). Donors received a second GnRH at the onset of oestrus and were AI 8 and 20 h later. Donors that were still in standing oestrus at the second AI were AI again at 30 h. Ova/embryo collections were done on Day 14 and embryos were classified according to the IETS manual. Cows in group 2 received an injection of PGF and a CIDR on Day –7 and 100 μg of GnRH on Day 0; FSH treatments were initiated on Day 2 and the remainder of the treatment protocol was as in group 1. Data (total ova/embryos collected and transferable embryos) were analysed by ANOVA for mixed models, using treatment as a fixed variable and cow (i.d.) as a random variable. The group 1 cows produced a mean (± s.e.m.) of 18.6 ± 1.9 total ova/embryos of which 12.7 ± 1.5 were of transferable quality (7.2 ± 1.3 grade 1). Cows in group 2 produced a mean (± s.e.m.) of 19.5 ± 1.7 total ova/embryos, of which 14.8 ± 1.5 were of transferable quality (8.9 ± 1.2 grade 1). Although 2 more transferable embryos were obtained in group 2, differences were not significant (P > 0.3). At the same time as this experiment was done, 214 other cows were superstimulated in this practice, yielding an average of 7.9 transferable embryos per donor. Results suggest that both approaches are efficacious for the superstimulation of beef cows.Special thanks to Vetoquinol/Bioniche Animal Health, USA for support.
24
Rozner, A., and J. Verstegen. "314 RELATIONSHIP BETWEEN SERUM ANTI-MULLERIAN HORMONE (AMH), OVARIAN RESERVE, AND EMBRYO PRODUCTION IN SUPEROVULATED HOLSTEIN COWS." Reproduction, Fertility and Development 25, no. 1 (2013): 304. http://dx.doi.org/10.1071/rdv25n1ab314.
Full textAbstract:
The relations between serum anti-Mullerian hormone (AMH), oocyte numbers, and in vivo embryo production in Holstein heifers were evaluated. The AMH levels of 15 unstimulated cows were followed at weekly intervals during their oestrous cycles and monthly for 4 months. Forty-one superovulated heifers were evaluated at ovum pick-up (OPU) performed 20 h after cystorelin administration, and 125 others were evaluated at embryo recovery. Animals were followed over 3 consecutive cycles induced using a modified Ovsynch protocol with 4 days of FSH (Pluset H, Minitube of America, Verona, WI, USA). Blood samples were collected in serum tubes and spun within 2 h. The samples were stored at –20°C until evaluation using the Minitube of America AMH-bovine specific immunoassay (AMH Fertility Assay™). The statistical analyses (ANOVA and data correlation) were performed using Statview 5 with P < 0.05. Serum AMH ranged from 43 to 960 pg mL–1. The average AMH level of all cows was stable during the oestrous cycle and for each of the 4 monthly measurements. There was a high correlation between all values per animal (r2 = 0.9077; P < 0.01), suggesting that AMH levels are consistent during the cycle and for at least 4 consecutive months. Animals that were repeatedly stimulated showed decreasing AMH levels (509 ± 295, 299 ± 210, 211 ± 119) and a decrease in recovered embryos (7.4 ± 4, 5.6 ± 3.8, 4.2 ± 3.2; P = 0.02). The number of oocytes was not altered by multiple stimulations (10.4 ± 9.8, 11.3 ± 6.2, 8.5 ± 7.6; P = 0.75). As AMH and embryo numbers decreased after multiple stimulations, only the first AMH value and results of the first OPU or flush were used to establish following correlation. Serum AMH showed a positive correlation to the number of oocytes (r2 = 0.245) and embryos collected (r2 = 0.27).When separated into AMH categories, low (<100), normal (100–400), and high (>400 pg mL–1), high-AMH OPU animals yielded significantly higher numbers of oocytes than the animals in the normal or low AMH groups (13.8 ± 9.2 v. 9.2 ± 5.2 and 5.6 ± 3.9; P = 0.001). Flushed animals with high AMH levels had significantly higher numbers of embryos than those with low AMH (10.9 ± 7.9 v. 5.7 ± 5; P = 0.002). Comparison of the first AMH value to the average number of oocytes or embryos collected over the course of 3 collections/animal showed a positive correlation to the average number of oocytes/collection from individual OPU donors (r2 = 0.436) and a positive correlation to the average number of embryos/collection from individual donors (r2 = 0.176). When separated into AMH groups, high-AMH flushed animals had significantly higher numbers of embryos than the normal- or low-AMH animals (9.3 ± 3.1 v. 5.7 ± 3.4 and 4.5 ± 2; P = 0.0001). As OPU animals with low AMH were used only once, average oocyte/collection data was not available for this category. A significant difference was observed between the high- and normal-AMH categories (12 ± 3.6 v. 7 ± 2; P = 0.0001). Circulating AMH is stable over time in unstimulated animals but decreases in repetitively stimulated animals. Anti-Mullerian hormone is highly associated with superovulation response and oocyte and embryo production, and its use should improve animal selection to achieve improve efficiency of multiple-ovulation embryo transfer.
25
Colazo, M., M. Rutledge, J. Small, J. Kastelic, L. Siqueira, D. Ward, and R. Mapletoft. "13 EFFECTS OF PRESYNCHRONIZATION WITH A USED CIDR, AND TREATMENT WITH eCG ON FERTILITY IN LACTATING COWS SUBJECTED TO A COSYNCH PROTOCOL." Reproduction, Fertility and Development 17, no. 2 (2005): 156. http://dx.doi.org/10.1071/rdv17n2ab13.
Full textAbstract:
The objectives were to investigate the effects of pretreatment with a used CIDR on follicle size and ovulation rate in cows after an injection of GnRH, and treatment with eCG at the time of PGF on preovulatory follicle size and fertility in cows subjected to a Cosynch protocol. Lactating crossbred beef cows (n = 292), 2 to 12 years of age were allocated to two groups to receive either a used CIDR (Bioniche Animal Health; Belleville, Ontario, Canada) for 15 days or no treatment (Control). At CIDR removal (Day 0), all cows received 100 μg of GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada). On Day 7, all cows received 500 μg of cloprostenol i.m. (PGF; Estrumate, Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) and were further allocated to receive either 400 IU of eCG i.m. (Pregnacol; Bioniche Animal Health) or no treatment (2 × 2 factorial design; n = 73 per group). On Day 9 (54 h after PGF), cows were given 100 μg of GnRH i.m., concurrent with timed AI (TAI). Transrectal ultrasonographic examinations were done on a subset of approximately 40 cows in each group on Days −15, 0, 7, and 9 to assess ovarian structures, and on all cows on Day 37 to confirm pregnancy. Data were analyzed by SAS CATMOD and ANOVA. Overall, 53% of cows had a CL present on Day −15 (P = 0.23). At first GnRH (Day 0), fewer CIDR-treated cows than Control cows had a CL (15.2 vs. 85.0%, respectively; P < 0.001), while mean (± SEM) diameters of the dominant follicle were larger in CIDR-treated cows (18.2 ± 0.4 vs. 13.8 ± 0.4 mm, respectively; P < 0.001). Moreover, the proportion of cows that ovulated following the first GnRH was higher (P < 0.001) in CIDR-treated (75.0%) than Control (48.7%) cows. Eight (10.0%) cows presynchronized with a CIDR did not ovulate and had a luteinized follicle (31.7 ± 1.9 mm) at the time of PGF. Although CIDR-treated cows had larger (P < 0.002) dominant follicles than Control cows on Day 9 (16.6 ± 0.3 vs. 15.2 ± 0.3 mm), presynchronization did not affect fertility (53.4 vs. 54.1%, respectively). However, diameter of the dominant follicle at TAI in cows that became pregnant was smaller in CIDR-treated vs. Control cows (15.3 ± 0.3 vs. 16.6 ± 0.3; P < 0.005). Treatment with eCG on Day 7 did not affect (P = 0.17) the diameter of the dominant follicle at TAI, but tended (P = 0.06) to increase pregnancy rate (58.9 vs. 48.6%). Furthermore, pregnancy rate tended to be higher (P = 0.08) in Control cows given eCG (47/73, 64.4%) than in the Control- (32/73, 43.8%), CIDR- (39/73, 53.4%) or CIDR/eCG- (39/73, 53.4%) treated cows. In addition, pregnancy rate was affected by parity; 2-yr-old cows had a lower (P < 0.04) pregnancy rate than older cows (42.9, 58.7, and 58.2% for 2, 3–4, and >5 years, respectively). Treatment with eCG increased pregnancy rate by 33% (P < 0.03) in 2-yr-old Control cows. In summary, presynchronization with a used CIDR prior to a Cosynch protocol increased the proportion of cows responding to the first GnRH. Although CIDR-treated cows had a smaller dominant follicle at TAI, pregnancy rate was not affected. Treatment with eCG increased fertility in Control cows; eCG may be useful in GnRH-based protocols in lactating beef cows.
26
Mapletoft, R., M. Colazo, L. Siqueira, J. Small, M. Rutledge, D. Ward, and J. Kastelic. "18 STRATEGIES TO IMPROVE FERTILITY WITH COSYNCH-CIDR PROTOCOLS IN BEEF CATTLE." Reproduction, Fertility and Development 17, no. 2 (2005): 159. http://dx.doi.org/10.1071/rdv17n2ab18.
Full textAbstract:
Two experiments were designed to evaluate strategies to improve fertility with Cosynch-CIDR protocols in cattle. The first experiment investigated the effect of low levels of progesterone prior to a Cosynch-CIDR protocol. On Day 0, lactating beef cows (n = 34) and heifers (n = 37) were placed in two groups to receive 500 μg cloprostenol (PGF; Estrumate, Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada) or a twice-used CIDR (Bioniche Animal Health, Belleville, Ontario, Canada) for 5 days (Pretreatment) or no treatment (Control). On Day 5, used CIDRs were removed and all cattle received a new CIDR (Pfizer Animal Health, Montreal, Quebec, Canada) and 100 μg GnRH (Cystorelin, Merial Canada Inc, Victoriaville, Quebec, Canada). On Day 12, CIDR were removed and PGF was given. A second GnRH was given concurrent with timed AI (TAI) on Day 14 (54–56 h after PGF). Cattle were examined by transrectal ultrasonography for CL and follicle development, and for confirmation of pregnancy (Days 42 to 49). Diameter of the dominant follicle on Day 5 was larger and more variable in cows than in heifers (15.5 ± 5.6 vs. 11.4 ± 3.5 mm, respectively; means, P < 0.001; variance, P < 0.003), and tended to be larger in the Pretreatment group (14.3 ± 4.9 vs. 12.6 ± 5.2 mm; P = 0.13). More Pretreated (60.0%) than Control (36.1%) cattle (P < 0.005), and more cows (64.7%) than heifers (32.4%; P < 0.03) ovulated following the first GnRH. At the time of TAI, 5 (13.5%) heifers had already ovulated (P < 0.03). Diameter of the preovulatory follicle was affected by parity (P < 0.001), but not Pretreatment (P = 0.4), and tended to be larger in heifers that became pregnant (P = 0.13). Pregnancy rate was not affected by parity (P = 0.71), or pretreatment (P = 0.34); pretreatment tended to increase pregnancy rate in heifers (63.2 vs. 38.9%; P = 0.19). The second experiment evaluated the use of eCG in a Cosynch-CIDR protocol in beef heifers. Beef heifers (n = 127) were fed 0.5 mg/head/day of MGA (Pfizer Animal Health) for 15 d; 12 d after the last feeding (designated as Day 0) heifers received a CIDR and 100 μg GnRH. On Day 7, CIDR were removed, and heifers received PGF, and were randomly placed in 2 groups to receive 300 IU of eCG (Pregnacol; Bioniche Animal Health) or no treatment (Control). On Day 9 (54–56 h after PGF), all heifers received 100 μg GnRH, concurrent with TAI. Ultrasonographic examinations were done as in the first experiment. Overall, 79.5% of the heifers had a CL, and 9.4% had a luteinized follicle on Day 0. Seventy-eight heifers (61.4%) ovulated following the first GnRH, and those that ovulated had a less variable preovulatory follicle size than those that did not (13.7 ± 1.7 vs. 13.8 ± 2.3 mm; means, P = 0.76; variance, P < 0.01). However, there was no difference in preovulatory follicle size (P = 0.63), or pregnancy rate (49.2 vs. 53.1%; P = 0.7) for eCG-treated vs. Control heifers. In summary, pretreatment with a twice-used CIDR plus PGF increased the proportion of cattle that ovulated to the first GnRH, but not preovulatory follicle size or fertility in cows; fertility tended to be improved in heifers. Treatment with eCG did not increase preovulatory follicle size or fertility in heifers subjected to an Cosynch-CIDR protocol.
27
Colazo, M., J. Small, J. Kastelic, H. Davis, D. Ward, R. Wilde, and R. Mapletoft. "11 EFFECTS OF CIDR-BASED PRESYNCHRONIZATION AND eCG ON FERTILITY FOR A GnRH-BASED TIMED-AI PROTOCOL IN BEEF CATTLE." Reproduction, Fertility and Development 18, no. 2 (2006): 114. http://dx.doi.org/10.1071/rdv18n2ab11.
Full textAbstract:
The objectives were to determine the effects of presynchronization and eCG on fertility for a GnRH-based timed-AI (TAI) protocol in beef cattle. Previously autoclaved once-used CIDR inserts (Colazo et al. 2004 Anim. Reprod. Sci. 81, 25-34) were used for experimental purposes so that all cattle had equivalent exogenous progesterone after Day 7 in Experiment 1, and to induce GnRH-responsive follicles in Experiment 2. In Experiment 1, 12-15 month old beef heifers (n = 447) were used (three locations, A, B, and C). On Day 0, half received a new CIDR insert (Pfizer Animal Health, Montreal, Quebec, Canada) and 500 �g of cloprostenol i.m. (PGF: Estrumate; Schering-Plough Animal Health, Pointe-Claire, Quebec, Canada). On Day 7, the remainder received an autoclaved once-used CIDR and all received 100 �g of GnRH i.m. (Cystorelin; Merial Canada, Inc., Victoriaville, Quebec, Canada). On Day 14, CIDR inserts were removed, PGF was given to all heifers, and heifers were given either 300 IU eCG i.m. (Pregnacol; Bioniche Animal Health, Belleville, Ontario, Canada) or no treatment (2 � 2 factorial design). On Day 16 (54-56 h after CIDR removal and PGF administration), heifers were given 100 �g of GnRH i.m., concurrent with TAI. Transrectal ultrasonography was done on Day 0 to assess ovarian structures, and on approximately Day 50 (range, 44-69) to confirm pregnancy. Overall, 72.7% of heifers were puberal on Day 0 (150/150, 5/37, and 170/260 for locations A, B, and C, respectively; P < 0.001). Pregnancy rate was affected (P < 0.001) by location (27.3, 62.2, and 51.1% for the three locations, respectively) but was not affected (P = 0.3) by puberal status at locations B and C. Pregnancy rate was not affected (P = 0.5) by presynchronization, but tended (P = 0.1) to be reduced by eCG treatment (40.4 vs. 47.7%, respectively). In Experiment 2, lactating crossbred beef cows (n = 411), 2-12 years of age were randomly allocated to receive either a previously used, autoclaved CIDR for 7 days and 25 mg of dinoprost i.m. (PGF: Lutalyse; Pfizer Animal Health) or no treatment (control; Day 0). At CIDR removal (Day 7), all cows received 100 �g of GnRH. On Day 14, all cows received PGF and were allocated to receive either 400 IU of eCG i.m. or no treatment (2 � 2 factorial design). On Day 16 (54-56 h after PGF), cows were given 100 �g of GnRH concurrent with TAI. Transrectal ultrasonographic examinations were done on approximately 65 cows in each group on Days 0, 7, and 14 to assess ovarian structures and on all cows on Day 42 to confirm pregnancy. Overall, 88.8% of cows had a corpus luteum (CL) on Day 0. Presynchronization increased both the proportion of cows that ovulated to GnRH treatment on Day 7 (76.7 vs. 55.0%; P < 0.001) and pregnancy rate (58.2 vs. 45.4%; P = 0.03) for cows that had received a CIDR vs. control cows. However, eCG treatment did not affect pregnancy rate (P = 0.3) in either group. In summary, presynchronization with a used CIDR and PGF prior to a Cosynch protocol increased ovulation rate to the first GnRH treatment and pregnancy rate in cows but not in heifers. In a GnRH-based TAI protocol, treatment with eCG had no significant effect on fertility in cows, but tended to decrease fertility in heifers.
28
Davis, H., M. Colazo, M. Rutledge, J. Small, J. Kastelic, and R. Mapletoft. "13 EFFECTS OF PLASMA PROGESTERONE CONCENTRATIONS ON LH RELEASE AND OVULATION IN BEEF CATTLE GIVEN GnRH." Reproduction, Fertility and Development 18, no. 2 (2006): 115. http://dx.doi.org/10.1071/rdv18n2ab13.
Full textAbstract:
Two experiments were conducted to determine the effects of plasma progesterone (P4) concentrations on LH release and ovulation in beef heifers and lactating beef cows given gonadotropin-releasing hormone (GnRH). Previously autoclaved, once-used CIDR inserts (Colazo et al. 2004 Anim. Reprod. Sci. 81, 25-34) were used for experimental purposes to induce differential plasma progesterone concentrations. In Experiment 1, postpubertal heifers received 25 mg of dinoprost i.m. (prostaglandin F (PGF); Lutalyse; Pfizer Animal Health, Montreal, Quebec, Canada). On Day 4 (estrus = Day 0), heifers were randomly assigned (10/group) to receive no treatment (control) or 1 or 2 autoclaved once-used CIDR (Pfizer Animal Health) inserts (1CIDR and 2CIDR, respectively). On Day 5, heifers in the 1CIDR group were given PGF twice 12 h apart. On Day 6, all heifers received 100 �g of GnRH i.m. (Cystorelin; Merial Canada, Inc., Victoriaville, Quebec, Canada). Once daily on Days 4 to 9, a blood sample was collected and ultrasonography was performed. On Day 6, heifers in the control (3.0 � 0.4 ng/mL; mean � SD) and 1CIDR groups (3.0 � 0.3 ng/mL) had lower (P < 0.01) plasma progesterone concentrations than those in the 2CIDR group (5.7 � 0.4 ng/mL). However, the diameter of the dominant follicle was larger (P < 0.001) in heifers in the control and 1CIDR groups than in the 2CIDR group (12.1 � 1.0, 11.5 � 0.7, and 10.1 � 0.7 mm, respectively). More (P < 0.01) heifers ovulated in response to GnRH in the control and 1CIDR groups than in the 2CIDR group (10/10, 9/10, and 3/10, respectively). In Experiment 2, ultrasound-guided follicular ablation (FA) was performed (to synchronize ovarian follicular wave emergence) 4 to 6 days after estrus in 20 postpubertal heifers and 20 mature lactating cows. Cattle were randomly and equally assigned to receive an autoclaved, once-used CIDR, either with no further treatment (High-P4) or with two PGF treatments 12 h apart (Low-P4) given after FA. All cattle received 100 �g of GnRH either 6 days after FA or the day after the dominant follicle reached 9 mm in diameter. Ultrasonography was performed daily (from 4 days after FA to ovulation or to 3 days after GnRH treatment). In three cows and three heifers per group, blood samples were collected every 30 min for 12 h after GnRH. The dominant follicle at GnRH treatment was larger in cows than heifers (11.0 � 1.1 vs. 10.3 � 0.9 mm, respectively; P = 0.05) and tended to be smaller in the High-P4 group vs. the Low-P4 group (10.3 � 1.0 vs. 11.0 � 1.0 mm; P = 0.06). Ovulatory response was not different (P = 0.9) between heifers (77.7%) and cows (78.9%), but combined for heifers and cows, was lower in High-P4 vs. Low-P4 cattle (61.1 vs. 94.7; P < 0.01). The GnRH-induced LH surge did not differ (P = 0.23) between cows and heifers, but it was lower and of shorter duration (P < 0.001) in the High-P4 group than in the Low-P4 group. In summary, higher plasma P4 concentrations resulted in decreased LH release and the proportion of cattle ovulating in response to GnRH treatment. There was no significant difference between heifers and cows in LH release or ovulatory response.
29
Geary, T. W., E. R. Downing, J. E. Bruemmer, and J. C. Whittier. "Ovarian and Estrous Response of Suckled Beef Cows to the Select Synch Estrous Synchronization Protocol11This research was supported by a grant from Select Sires. The authors express their appreciation to Select Sires and to Merial, Pharmacia & Upjohn, and DDx, Inc. for their generous donations of Cystorelin, Lutalyse, and HeatWatch, respectively, and to Dave Schutz and Doug Couch at the Eastern Colorado Research Center for assistance in data collection." Professional Animal Scientist 16, no. 1 (March 2000): 1–5. http://dx.doi.org/10.15232/s1080-7446(15)31653-3.
Full text
30
Al-Hamedawi, T. M. "Clinical & therapeutical study on inactive ovaries in Holstein-Friesian cows by using GnRH analogues." Al-Qadisiyah Journal of Veterinary Medicine Sciences 11, no. 3 (December 30, 2012): 19. http://dx.doi.org/10.29079/vol11iss3art210.
Full textAbstract:
This study was performed on 45 lactating Holstein – Friesian cows suffered from inactiveovaries for three months post partum and diagnosed clinically by rectal palpation in the form ofthe college of Agriculture / University of Baghdad , their ages 3-5 years during the period from2010-2012. These cows were divided randomly into 4 groups, 1st group (12 cows) were injectedwith 0.021mg (5 ml) Receptal I/M, 2nd group (12 cows) were given 500 μg (5ml) CystorelyinI/M, 3rd group (12 cows) injected with 0.5 mg (5 ml) Fertagil I/M in one dose and 4th group (9cows) without treatment (control group). The response rate was 91.8%, 83.3%, 91.6% and 66.6%for the four groups respectively. While the duration of response (from treatment to oestrusappearance) was 7.43±1.56, 10.66±2.37, 8.44±2.41 and 67.63±9.87 in the 1st ,2nd ,3rd and 4thgroups respectively, but the pregnancy rate recorded 90.9%, 80%, 81.8% and 83.3%. Thestatistical analysis showed that the 1st and 3rd group was recorded significant differences higher(p<0.01) than other groups (2nd and 4th) related with responsive animal and the duration ofresponse also but the pregnancy rate recorded higher significance (p<0.01) compared with 2nd,3rd and 4th groups. The number of services /conception was more than 1.5-2.5 for all groups ¬ significant, the days open recorded higher significant (p<0.01) in 1st, 2nd and 3rd comparedwith 4th group (control group).