Letteratura scientifica selezionata sul tema "Fifty days post weaning"

AbstractAvilamycin (AGP) and zinc oxide (ZnO) are both frequently included in the post-weaning piglet diet to enhance growth performance and prevent diarrhoea. This study investigated what effect removing these compounds from the post-weaning diet would have on the growth performance and faecal microbiota of weaned piglets. Fifty-two crossbred piglets (JSR Healthbred) were allocated, at weaning, to one of two dietary treatments on the basis of weight, litter origin and gender. The diets were (i) control (no supplemented ZnO or AGP); (ii) ZnO + AGP (supplemented with 3100 mg ZnO per kg food and 40 mg avilamycin per kg food). These diets were offered ad libitum for 20 days post weaning. Thereafter, the pigs received the same non-supplemented grower and finisher diets ad libitum. All piglets were individually weighed, and faecal samples were obtained from pre-selected piglets, at various time points throughout the trial period. Ten-fold serial dilutions of faecal material were cultured on specific media to enumerate aerobes, anaerobes, Lactobacillus spp. and Escherichia coli. ZnO + AGP supplementation enhanced weaned piglet average daily food intake (ADFI) (P < 0·001), average daily live-weight gain (ADG) (P < 0·001) and food conversion ratio (FCR) (P < 0·01) during the initial 20 days post weaning. Piglets previously supplemented with ZnO + AGP gained more weight per day during the non-supplemented grower phase (days 21 to 60) than their control counterparts (741·5 v. 672·5 g per pig per day) (P < 0·01). The bacteriological data showed that ZnO + AGP piglets had lower counts of anaerobic bacteria in their faeces than control piglets (P < 0·01). These findings indicate that dietary AGP + ZnO may enhance growth by reducing gastro-intestinal bacterial populations, and that their removal from the post-weaning diet will increase days to slaughter.

Abstract Fifty-six litters standardized to 12 piglets from first-parity sows were used to determine the effects of creep and nursery diet compositions on pre- and post-weaning pig growth performance. At three days of age, litters (initial BW 2.31±0.61kg) were assigned to one of four creep feeding regimens (n=14): [1] commercial creep feed (COM), [2] liquid milk replacer (LMR), [3] pelleted milk replacer (PMR), or [4] no creep feed (NO); creep feeds contained 1.0% brilliant blue as a fecal marker. Fecal swabs were collected every 3±1 days to identify piglets that regularly consumed creep feed. At weaning (18±1 days of age), six pigs per litter that consumed creep feed were placed on either a HIGH- (contained highly digestible animal proteins) or LOW- (contained corn and soybean meal as the main protein sources) quality nursery diet (n = 7) in a three-phase feeding program over 38 days. The LMR disappeared at the greatest rate (37.7 g/pig/d; DM-basis) versus COM and PMR (10.8±1.5 g/pig/d; P &lt; 0.001). Litters that received LMR had the greatest proportion of pigs with blue fecal swabs between study days 4 and 15 (85.0 vs 59.0±0.4%; P &lt; 0.05) and LMR piglets had greater BW at weaning versus all other treatments (6.32, 6.02, 5.92, 5.67±0.14 kg, for LMR, COM, NO, and PMR, respectively; P &lt; 0.001). Over the entire nursery period, pigs that received LOW diets had reduced ADG (399 vs 485±42 g; P &lt; 0.001), ADFI (520 vs 595±37 g; P&lt; 0.001), G:F (0.77 vs 0.82±0.03; P &lt; 0.01), and BW at the end of the nursery period (21.2 vs 24.4±1.6 kg; P &lt; 0.001), with no carryover effects of creep feeding regimen. Providing supplemental nutrition during the suckling period via LMR improved pig body weight at weaning, but did not improve post-weaning growth performance, regardless of nursery diet quality.

A new procedure for nonsurgical deep intrauterine insemination (DUI) in non-sedated sows has recently been reported (Martinez et al. 2002 Reproduction 123, 163–170). In comparison to traditional artificial insemination (AI), using this procedure, a 20-fold reduction in the number of spermatozoa inseminated can be used without a decrease in fertility when hormonally treated post-weaning estrous sows are used. The aim of the present study was to evaluate the effectiveness of DUI under field conditions. In Experiment 1, crossbred sows (2–6 parity) were weaned at 20.75 ± 0.06 days. Estrous detection was performed once per day, beginning 3 days after weaning. Sows with a weaning to estrus interval of 4–5 days were selected to be inseminated. A total of 190 sows were inseminated at 12, 24, and 36 h after onset of estrus using one of the following two regimes: (1) DUI with 150 × 106 fresh spermatozoa in 5 mL of BTS (n = 95) and (2) Traditional AI with 3 × 109 fresh spermatozoa in 100 mL of BTS (n = 95) prepared from the same semen samples used for the DUI group. Farrowing rates (FR) and litter sizes (LTS; mean ± SEM) from both groups were compared using chi-squared test and ANOVA, respectively. There was no significant difference in the FR between groups (83.2 and 86.3% for DUI and AI groups, respectively). However, a decrease (P < 0.001) in the LTS was observed in sows inseminated by the DUI procedure (9.8 ± 0.29 and 10.9 ± 0.17, respectively). In Experiment 2, seventy one natural post-weaning estrus sows were used. Fifty-five sows were DUI inseminated three times with 150 (n = 17), 300 (n = 19), or 600 (n = 19) × 106 spermatozoa in 5, 10, or 20 mL of BTS, respectively. The remaining sows (n = 16) were traditionally inseminated. On Day 6 after estrus, sows were subjected to laparotomy and the tips of both uterine horns were flushed in order to evaluate pregnancy rate (PR: percentage of sows with at least 4 viable embryos) and fertilization rate (ratio of viable embryos to the total number of embryos and oocytes). PR was similar in all the groups, ranging from 84.2% (DUI 300 × 106 spermatozoa group) to 94.7% (DUI 600 × 106 spermatozoa group). Fertilization rate and the percentage of bilateral fertilization after DUI with 600 × 106 spermatozoa did not differ from those of the AI group (97.8 and 100% vs. 98.4 and 100%, respectively), but a significant decrease in both parameters (P < 0.05; chi-square test) was observed in sows inseminated with 300 (94.3 and 87.5%) or 150 (84.4 and 66.7%) × 106 spermatozoa. In conclusion, DUI with 150 × 106 spermatozoa offers similar FR but a lower LTS in sows with natural estrus in comparison with those parameters obtained when traditional AI is used. The lower litter size could be related to the low percentage of bilateral fertilization observed in that group. This work was supported by CDTI 020003.

AbstractThe first part of the paper describes the process of weaning in domestic cats. The subjects were seven families of cats living under laboratory conditions-each family consisting of a mother and her two kittens, living in their own large indoor pen. Observations were carried out at regular intervals from the third week after birth until the kittens were 10 weeks old. Weaning is viewed as the period during which the rate of milk transfer from mother to offspring drops most sharply. According to this definition, weaning commenced when the kittens were four weeks old and was largely completed by the time they were seven weeks old. During the weaning period mothers made suckling progressively more difficult for their kittens by increasingly adopting body postures that blocked access to their nipples. The amount of suckling declined sharply from four weeks after birth and seldom occurred after seven weeks. Kittens were first seen to eat solid food during the fifth week, and this was associated with a large increase in the variability of their daily weight gain. Prior to the start of weaning, mothers' food intake was approximately double that of non-lactating females. Male kittens grew more rapidly than their sisters and were significantly heavier. However, there was no evidence that males suckled more than females prior to the start of weaning. In general, weaning was characterised by a gradual reduction in the ease with which kittens could suckle, rather than by any overt rejection or aggression by the mother. The absence of any obvious weaning conflict is thought to be related to the favourable housing conditions (small litter size, ad libitum food, freedom from disturbances, etc.) used in this study. The second half of the paper describes the results of an experiment in which maternal lactation was interrupted during the first week of weaning. Seven Experimental (E) mothers were injected with the lactation-blocking drug bromocriptine on days 28, 30 and 33 post partum, each injection being sufficient to interrupt lactation for about 18-24 h. In the period immediately following the injections (days 29-46), E mothers and their kittens were more active than the controls, and E mothers washed their kittens more. Later on (days 47-70), E kittens suckled more than the controls-notably in the eighth week after birth, at a time when suckling would normally be rare. E mothers appeared to be more willing to let their kittens suckle during this period, as they adopted a fully accessible posture more often, and a blocking posture less often, than controls. The overall pattern of results is interpreted in terms of an initial withdrawal from the kittens in the period immediately after lactation was interrupted, followed by a later resumption of maternal care and a postponement of the end of weaning. Perhaps as a result of this continuation of suckling, the experimental treatment had no overall effect on the kittens' growth, although the Experimental kittens did grow more slowly in the week of the injections. One tentative hypothesis is that the apparent postponement of weaning represents a compensatory response to the earlier reduction in the rate of parental investment.

AbstractFive hundred and eighty-four Pannon White kits of 73 newborn litters were submitted to one of five treatments. Control litters (SS) were nursed once a day for 35 days post partum (traditional method of nursing). DD litters were raised by two does and the kits were nursed both in the morning and in the evening until day 35 post partum. DS litters were nursed twice a day for 23 days, and then once a day until weaning at 35 days. Part of the DS litters were nursed at 08:00 and 20:00 h (i.e. every 12 h, DS12), the rest were nursed at 08:00 and at 16:00 h (DS8). Kits of the fifth treatment (D0) were nursed twice a day until day 23, and then immediately weaned.Rabbit kits that were nursed twice a day (DD, DS12, DS8, D0) consumed on average 1·89 more milk compared with SS individuals until day 23 (overall treatment effect P < 0·001). The 21-day body weight of these young was 1·7 times greater than that of the SS kits (overall P < 0·001). D0 rabbits were weaned early and their growth curve showed a slight break at this point. However, they compensated for this lag by the end of the fattening period. SS rabbits and DD ones were respectively the first and the last to start consuming solid food. The food consumption of DS rabbits was similar to that of DD until day 23 and from then until day 35 it was not significantly different from that of SS. After having been weaned on day 23, D0 kits consumed only very small quantities of pellets for 2 days. Afterwards their food intake increased abruptly. Rabbits that were nursed twice a day (DD, DS12, DS8 and D0) consumed more food as compared with the SS individuals throughout the total period of fattening (157 v. 137 g/day; P < 0·05). The weight at 10 weeks of age was 2·49 v. 2·88 kg (overall P < 0·001), respectively for SS and doublenursed (DD, DS, D0) rabbits. Nursing twice a day did not affect dressing proportion but the proportion of the carcass in the front part of the body decreased slightly (318 v. 323 g/kg; P < 0·05) while that in intermediate part increased (321 v. 307 g/kg; P < 0·05). Nevertheless, rabbits that were nursed twice a day had more (P < 0·05) perirenal + scapular fat and produced heavier livers. Total fat content of the empty body, however, was not significantly higher, with the one exception of the DD rabbits which had higher levels than any other group. The results of our experiment show clearly that the growth potential of rabbit kits is strongly limited by the milk availability during the first weeks post partum.

AbstractA total of 77 heifers (3⁄4 Charolais crossbred) completed a study which examined the effects of parity number on growth, changes in size of the carcass, carcass composition and meat quality. The experiment had a factorial design based on the factors: parity and level of finish. The parities were: 0 (maiden), 1, 3 and 5. At each parity animals were slaughtered at medium (EU fat class 3) and high (EU fat class 4H) levels of finish. All data were analysed by analysis of variance using individual animal observations, and linear, quadratic and asymptotic trends were explored. Where appropriate, regression equations were derived using individual animal values to describe the relationships between key parameters and the parity status of the finished animal. Animals calved at turn-out to grass in spring (April/May) and the cows were housed at weaning in mid October (mean lactation length of 163 days) and all pregnant animals were given a diet of grass silage without concentrate supplementation during the winter period. The medium level of finish animals were slaughtered 24 days after commencement of the breeding programme for parity 0 or at the end of lactation for the remaining parities, except for parity 1 animals which had a short finishing period. For the high level of finish treatment, parity 0 heifers had a longer finishing period, while all bred animals had a post-weaning finishing period. The high finish animals were finished on a diet of grass silage and concentrates. Birth weights of calves increased until the fourth parity, while weaning weights increased linearly until the fifth parity. Mean daily milk yield increased until the third lactation. Live weight, carcass weight and weights of saleable beef, separable lean and separable fat all followed asymptotic patterns of rapid initial increase and then tended to plateau with increase in parity. The asymptote values for live weight and carcass weight were 723·0 and 383·2 kg respectively. Statistically significant asymptotic relationships with parity number were obtained for live weight and various tissue weights. Nominal mature weight was assumed to be 0·99 of the asymptote and nominal mature weights for live weight, carcass weight, saleable beef, separable lean and separable fat were attained at parity (age, years) 4/5 (6·1), 3/4 (5·3), 4/5 (6·2), 3/4 (4·7) and 1/2 (2·7) respectively. The proportion of high-priced joints declined with increase in parity (linear trend P 0·01) thus indicating a reduction in relative growth of the main muscle groups of the hind limb. Shear value measurements on cooked muscle from the maiden and first parity animals indicated very tender meat, but tenderness declined with increase in parity (asymptotic trend P 0·001). Taking animals to the higher level of finish effected increases in carcass weight and separable fat in the carcass of 55·1 kg (P 0·001) and 72 g/kg (P 0·001) respectively, while separable lean declined by 53 g/kg (P 0·001). Cooked muscle from the high finish animals was less tender than from the medium finish animals (P 0·05). It was concluded that slaughtering cows at the third parity would enable a self replacing closed herd to be operated, while obtaining 0·97 of the potential maximum output of saleable beef from the cow, but there may be some compromise in the tenderness of the meat for some consumers by the third parity.

A study was conducted on indigenous unselected Sokoto Red (SR) and Sahel (SH) goats in National Animal Production Research Institute, (NAPRI), Ahmadu Bello University, Shika- Zaria, Kaduna State, Nigeria. The study was carried out to understand how birth, pre- weaning and post-weaning weights in the SR and SH goats can be used to improve their productivity. Thirty kids (10 males and 20 females) of SR and thirty kids (10 males and 20 females) of SH breeds of goat were utilised for this study. Results obtained showed that the coefficient of variation (CV) was very low. There were no significant differences (P>0.05) among mean bodyweight at birth, 30 days pre-weaning, 60 days pre-weaning, 90 days post- weaning and 120 days post-weaning weights of SR and SH goats except at 150 days post- weaning weight. Highly positive phenotypic correlations existed in the SR goats between 90- day weaning weight and 120-day post weaning; 90-day weaning weight and 150-day post weaning.120-day post weaning weight and 150-day post weaning.The birth weight of the SH goats were highly significant (P<0.05) and positively correlated with body weight at 30, 60, 90, 120 and 150 days old. It was observed that the sampled population was homogeneous for all traits. The 90-day weight of the SR can be utilised to improve for body weight at 30-, 120- and 150- days of age while in the SH goat, selection for high birth weight would enhance improvement for high body weight at later stages of growth.

Seventy-five Angus x MARC II crossbred heifers were used to assess the effects of age at weaning on calf performance and blood constituents. Calves were weaned at 150, 210, or 270 days of age with comparisons made to their non-weaned counterparts. Changes in blood chemistry and hematology (cortisol, glucose, T3, total proteins, packed cell volume and the differential white blood cell count) were recorded on the day of weaning (day-0), and at 2, 7, 14, and 28 days post-weaning. Calves weaned at 210 days of age presented the highest plasma cortisol, glucose, and total protein concentrations during their early post-weaning period. Calves weaned at 150 days of age had significantly lower plasma T3 values. Packed cell volume and differential white blood cell counts showed no relationship to age at weaning. Calves weaned at 210 days of age presented the most rapid post-weaning growth performance, relative to the 150 or 270 days of age weaned calves.

Context Betaine supplementation has been reported to increase insulin-like growth factor 1 (IGF-1) in pigs. Betaine is not generally added to weaner pig diets due to a lack of knowledge on the duration of supplementation and effect on targeted bodyweight class. Light-weight weaners, known for their inferior growth performance, may benefit from betaine supplementation during the early days post-weaning. Aims This experiment aimed to identify the timing of betaine supplementation over the weaner phase (early (0–7 days) or late (7–35 days) post-weaning periods) and targeted weaning weight class (light vs normal). Methods The experiment followed a 2 × 2 × 2 factorial arrangement for studying the effects of 0.1% betaine supplementation during early (0–7 days post-weaning) and late (7–35 days post-weaning) weaner phase in light-weight and normal-weight weaners. One hundred and forty-four pens (18 pigs/pen) of weaned pigs (26 days age) were allocated into a 2 × 2 × 2 factorial arrangement on the basis of weaning weight class ((light (3.6 ± 0.75 kg, mean ± s.d.) vs normal (6.6 ± 0.84 kg, mean ± s.d.)), early weaner phase diet (control vs 0.1% betaine) and late weaner phase diet (control vs 0.1% betaine). Basal diets contained sufficient methionine and choline as per industry practice. Growth performance during early, late and whole weaner phase were recorded. Blood IGF-1 was measured at 7 days and 35 days post-weaning. Key results Supplementing 0.1% betaine during the early weaner phase reduced (P &lt; 0.05) growth rate over the early post-weaning period (0–7 days) in both light- and normal-weight weaners, although blood IGF-1 concentration (7 days post-weaning) was not affected. Betaine supplementation during early or late weaner phase did not affect growth performance over the late weaner phase (7–35 days), whole weaner phase (0–35 days) or blood IGF-1 concentration (35 days) of light- or normal-weight weaners. Light-weight weaners had a lower feed intake, and a lower average daily gain than did the normal-weight weaners during the early, late and whole post-weaning periods (all P &lt; 0.01). Conclusions Light-weight weaners had inferior production performance during the weaner phase, which was not improved by betaine supplementation. Implications Betaine supplementation is not recommended in the weaner phase when other dietary methyl donors are sufficient.

AbstractLeptin has an important rôle in the control of appetite and energy expenditure. Several studies have reported the effects of leptin in ruminants. However, little is known about changes in circulating leptin concentrations in neonates of ruminant species, or the effects of weaning on plasma leptin concentrations. The main objectives of this experiment were: to examine plasma leptin concentrations in lambs, in the period from just after birth through to weaning; to examine the effect of weaning on plasma leptin concentrations, and to compare leptin concentrations measured using a ‘multi-species’ leptin radio-immunoassay (RIA) kit and a specific ovine RIA in lambs during the 6-month period after weaning. In a previous paper, we reported leptin concentrations using a commercial RIA during the post-weaning period. However, we were not able to measure plasma leptin concentrations from just after birth to weaning as they were apparently below the level of sensitivity of the assay. In the present study, five crossbred lambs were removed from their dams within 2 days after birth, and bottle-fed on milk replacer at a level sufficient to meet a 1•2 times maintenance metabolizable energy intake. Lambs were weaned 45 days after birth, and housed individually in pens. The lambs were offered timothy hay, rolled barley and soya-bean meal to meet a 200 g daily gain during the post-weaning period. During the pre-weaning period, blood samples were collected within 5 h of birth and thereafter at 09:00 h; every day from 2 to 6 days of age; at 2-day intervals from 6 to 14 days of age; and at 3-day intervals from 14 to 45 days of age. During the post-weaning period, blood samples were collected before and 3 and 6 h after the morning meal at the ages of 0•5, 1, 2, 3, 4, 5 and 6 months. Plasma leptin concentrations slightly increased (P < 0•05) just after birth and then remained constant until 45 days old (P > 0•05). Additionally, plasma leptin concentration was not significantly changed following weaning. During the post-weaning period, plasma leptin concentrations were compared using two RIA systems. The correlation between plasma leptin concentrations measured by the ‘multi-species’ leptin RIA kit and specific ovine RIA was poor (r = 0•41). These findings are consistent with other reports and suggest that the ‘multi-species’ leptin RIA kit is not suitable for estimating leptin plasma concentrations in ruminants.

This study evaluated the changes in body composition, glycogen tissue reserves, visceral organ growth, and small intestine morphology in the young pig. A total of 96 crossbred pigs were euthanized at birth (pre-suckle), days 1, 2, 3, 5, 7, 14 postpartum, weaning at day 21, and days 1, 2, 3, 5, 7, 14, 28, and 42 post-weaning. Body composition of the pig had increasing dry matter and fat, decreasing ash, calcium and phosphorus, and relatively static protein percentage over the course of the study. Liver and muscle glycogen was greatest at birth. Following birth and weaning there was a distinct decrease in the amount of liver glycogen, while there was only a clear decrease in muscle glycogen at birth. Absolute measures of the visceral organs increased in a variety of manners (linear, quadratic and/or cubic); relative measures of visceral organs responded in different manners to increasing age. In the suckling period, villous height, villous height:crypt depth ratio, and goblet cell count was greater than in the post-weaning period. Crypt depth continued to increase through the entire study. Villi measurements of the middle and distal portion of the small intestine taken via scanning electron microscope, revealed different responses to increasing age, but numerically, villi width increased, villi density, enterocyte width, and microvilli density decreased, and microvilli diameter was relatively static. Villi, on average, increased the absorptive area of the small intestine 18 fold and microvilli increased the surface area on average 400 fold. This study provided a vast amount of biometric information on the development of the young pig from birth to 42 d post weaning.

Thesis (MPhil)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: The primary objective of today's pig producer is to maximize profit received per unit of pig space provided in a given facility. There are certain management strategies that a farmer can implement to ensure this. The goals of such strategies include maximizing performance and implementing proper pig flow schedules and to make sure current facilities are performing at maximum capacities or are better utilized. Labour in South Africa is still relatively inexpensive, but time is money. Feeding and cleaning small pens are time consuming and expensive to maintain (more feeders and water nipples, gates, walls and heating). Proper management of facility space is vital to remain competitive in today's pig industry. The amount of floor and feeder space provided within an animal's environment could vastly influence pig performance and profitability. Crowding pigs has a negative effect on Average Daily Gain (ADG) and overall performance. Conversely, facility cost per pig increases as additional space is provided, therefore, in the interest of pen efficiency, the space that allows for maximum individual performance may not be optimal for maximizing profit. Factors such as cleaning and cleaning time also have an effect on profitability. Another concerning factor associated with maximizing performance and maintaining the pig flow of a facility is that of Body Weight (BW) variation. Having uniform pigs at 70 day, post-weaning has been a major goal to ensure maximum performance in finishers. Numerous contradictions regarding the growth of piglets post-weaning (especially the effect of group size and floor space allowance) still exist in literature. Also, in South Africa, the majority of pig producers still believe that individual litters or small groups of pigs in the growers perform better and are the most economical production method. Therefore, this trial was performed to investigate the raising of large groups (200-450 pigs/group) compared to small groups (10-20 pigs/group) on their performance until 70 days when they were moved to growers. Over a period of two years, data was collected on a commercial 1200 sow unit in the Western Cape, South Africa. Crossbred pigs (n=14657; Landrace x Large White; both gilts and barrows) weaned at 19 to 24 days with average weaning weight of 5.11 kg were randomly divided into different group sizes. Groups of 10, 20, 200 and 450 were grouped together and were all given the same feed ration. The groups were housed in different buildings naturally ventilated with no artificial heating and with solid flooring. Pelleted diets were formulated (Startrite followed after two weeks with Expresweaner) by Meadows Feed Mills (Paarl, Western Cape) for weaned piglets and fed to all the piglets. The animals received the diets and water ad lib. All the piglets were weighed before being placed into the different pens (initial weight). After 69 - 72 days the piglets were weighed again (final weight). The pigs were weighed as a group and not individually. The data was statistically analysed by determining averages and standard deviations for each house. The results of this trial clearly indicate that raising piglets in larger groups does not negatively affect the performance of the piglet in terms of ADG and mortality. In larger groups, the less time (labour time) spent cleaning and the fewer feeders needed, also results in lower production costs. In today's economical environment, the producer that can lower his production cost while maintaining production standards has a significant advantage. Therefore, it is believed that by grouping pigs in larger groups, labor time (in terms of cleaning) can be reduced, and will lower production cost without reducing production standards.
AFRIKAANSE OPSOMMING: Die hoofdoel van vandag se varkprodusente is om maksimum wins per eenheid vark spasie te maak. Daar is sekere produksietegnieke wat 'n produsent kan volg om dit te verseker. Die doel van die tegnieke is om te verseker dat maksimale produksienorme en doeltreffende vark vloei gehandhaaf word asook dat huidige fassiliteite optimum benut word. Arbeid is nog relatief goedkoop in Suid-Afrika (SA), maar tyd is geld. Die voeding en skoonmaak van klein hokke is tydrowend en duur om te onderhou (meer voerbakke, waternippels, hekke, mure en verhitting). Om koste-effektief te boer, moet goeie bestuur van oppervlakte toegepas word. Die hoeveelheid oppervlakte en voerspasie beskikbaar, het 'n groot invloed op die produksievermoë en winsgewendheid van die varkies. Om te veel varkies per area aan te hou, het 'n negatiewe effek op die Gemiddelde Daaglikse Toename (GOT) en algehele prestasie. Soos die vloerspasie per varkie vergroot, neem die produksiekoste ook toe en is die area wat benodig word om varkies maksimaal te laat produseer, nie altyd die winsgewenste nie. Skoonmaak en skoonmaaktyd het ook 'n invloed op winsgewendheid. Die ideaal is om uniforme varkies op 70 dae te produseer. 'n Variasie in gewig is rede tot kommer, aangesien dit die produksie in die groeiafdeling beïnvloed. Verskeie teenstrydighede aangaande die groei van varkies naspeen (veral die effek van goepgrootte en vloerspasie) bestaan steeds in die literatuur. In SA is die meeste produsente ook nog onder die indruk dat klein groepe varkies beter presteer as groot groepe en die mees ekonomiese metode is om te boer. Daarom is 'n proef geloods om vas te stel hoe die produksie verskil tussen klein groepe (10 - 20 varkies per groep) teenoor groot groepe (200 - 450 varkies per groep) tot 70 dae ouderdom wanneer hulle na die groeiafdeling skuif. Oor 'n periode van twee jaar is data gekollekteer op In kommersiële 1200 sog-eenheid in die Wes-Kaap, Suid-Afrika. Kruisgeteelde varke (n=14657; Landras x Groot Wit; beide beertjies en soggies) is gespeen tussen 19 en 24 dae, met 'n gemiddelde speen gewig van 5.11 kg en ewekansig verdeel in verskillende groepgroottes. Groepe van 10, 20, 200, en 450 varkies was saamgegroepeer en het almal dieselfde dieet ontvang. Die groepe is in verskillende geboue gehuisves en al die geboue het soliede vloere gehad en was natuurlik geventileerd met geen kunsmatige verhitting nie. 'n Verpilde dieet is deur Meadows Voermeule (Paarl, Wes-Kaap) geformuleer (Startrite vir twee weke en dan Expresweaner vir die res van die proef). Die varke het die dieet en water ad lib ontvang. AI die varkies is geweeg voordat hulle in die verskillende hokke geplaas is (aanvangsmassa). Na 69 - 72 dae is die varkies weer geweeg (eindmassa). Die varkies is as 'n goep en nie individueel geweeg nie. Die data is statisties verwerk deur gemiddeldes en standaard-afwykings vir elke huis te bepaal. Die resultate van hierdie proef het duidelik aangetoon dat die grootmaak van varkies in groter goepe nie die produksie van die varkies (i.t.v. GOT of mortaliteit) nadelig beïnvloed het nie. In groter goepe is minder tyd nodig om die hokke skoon te maak en is minder voerders nodig. Dit lei tot 'n verlaging in produksiekoste. Deesdae het die produsent wat sy produksie koste kan verlaag, sonder om produksiestandaarde in the boet, 'n aansienslike voorsprong. Die gevolgtrekking word dus gemaak dat deur varkies in groter groepe aan te hou, arbeid (in terme van skoonmaak) verminder kan word en dus kan produksiekoste verminder sonder dat produksie self afneem.

The aim of this thesis was to investigate how fiber growth of goats is determined by genotype, (purebred Angora and crossbred between Angora and Boer goat), physiological stages of the females from mid pregnancy until fifty days after the kids had been weaned and the plane of nutrition. Twelve Angora (pure bred) and ten Angora x Boer goat doe's with an initial mass of 28.70±4.42, between three and five years of age were used. Half of them received 120% NRC energy requirements and the other half received 80% requirements. Mohair patches of 100cm2 were collected from the animals at parturition, mid-lactation, weaning and fifty days post weaning. The fiber greasy weight started declining with commencement of lactation in crossbred animals of both high and low nutrition. The greasy mass again increased from the period of weaning until fifty days post weaning suggesting that crossbred animals do not produce a lot of fiber at the expense of fetal and kid growth. Since fiber production from the crossbred animals is lower, I recommend that the Angora genotype be increased to gain more fiber and further research be done on the topic.
Dissertation (MInstAgrar)--University of Pretoria, 2010.
Animal and Wildlife Sciences
unrestricted

For eight days in March 1970, over 200,000 postal workers staged an illegal "wildcat" strike--the largest in United States history--for better wages and working conditions. Picket lines started in New York and spread across the country like wildfire. Strikers defied court injunctions, threats of termination, and their own union leaders. In the negotiated aftermath, the U.S. Post Office became the U.S. Postal Service, and postal workers received full collective bargaining rights and wage increases, all the while continuing to fight for greater democracy within their unions. Using archives, periodicals, and oral histories, Philip Rubio shows how this strike, born of frustration and rising expectations and emerging as part of a larger 1960s-1970s global rank-and-file labor upsurge, transformed the post office and postal unions. It also led to fifty years of clashes between postal unions and management over wages, speedup, privatization, automation, and service. Rubio revives the 1970 strike story and connects it to today's postal financial crisis that threatens the future of a vital 245-year-old public communications institution and its labor unions.

This chapter looks into the Democratic National Convention that returned to Chicago in 1996. It describes the Convention as the first presidential-nominating convention to be held in Chicago since the infamous and nationally televised 1968 Democratic National Convention. The chapter mentions Michael Bilandic, a shy, careful, competent, and hardworking lawyer, who succeeded Richard J. Daley as mayor of Chicago in 1976. It investigates how Bilandic kept Chicago on a straight course, even if he did not provide dynamic leadership. It also recounts Bilandic's undoing due to the fabled Blizzard of 1979, in which record-breaking snowstorms hit Chicago and caused a cold spell that kept the snow on the ground for fifty days.

March 1919 . Somebody killed the trader at Cedar Springs. The murderer also set fire to the trading post, and soon the dried-out floor planks and the roof beams and split-cedar ceiling erupted in smoke and flame. Except for its sandstone walls, the building would have burned to the ground. The next day a plume of smoke still hung in the Arizona sky, and people from miles around came to see what was the matter. Few automobiles had reached the windy expanses of the Navajo Reservation in those days, and men and women of all ages filed in by foot and horseback and in their buggies and buckboards. The first ones to arrive found the corpse of Charley Hubbell. Cedar Springs was less than a crossroads, not really a hamlet. It stood within a circle of rough-sided buttes a few miles east of the main road between Hopi and Winslow. It consisted of a combined general store, trading post and post office, plus various pens and corrals. Navajos from a considerable distance came to exchange sheep and handcrafts for the things they needed. Charley Hubbell lived at the trading post and presided over what went on. The people who found his body dispatched a messenger on a fast horse toward Ganado, fifty miles northeast, to find Charley’s nephew Lorenzo, who was known throughout Navajo country. A man of giant girth and matching gravitas, Juan Lorenzo Hubbell had bought the Ganado trading post forty years earlier. With acumen and persistence he built a string of almost thirty such establishments from one end of Navajo country to the other. In many cases he appointed members of his large, mixed Anglo and Hispanic family to run them. The post near Ganado, to which the messenger was sent, served as his home and headquarters. Together with its broad sprawl of barns, corrals, and storage sheds, it is preserved today as Hubbell Trading Post National Historic Site, a unit of the National Park System.

From a remote outpost of global warming, a summons crackles over a two-way radio several times a week: . . . Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! . . . In a little brick building on the lip of a frigid gray lake fifteen thousand feet above sea level, Ram Bahadur Khadka tries to rouse someone at Nepal’s Department of Hydrology and Meteorology in the Babar Mahal district of Kathmandu far below. When he finally succeeds and a voice crackles back to him, he reads off a series of measurements: lake levels, amounts of precipitation. A father and a farmer, Ram Bahadur is up here at this frigid outpost because the world is getting warmer. He and two colleagues rotate duty; usually two of them live here at any given time, in unkempt bachelor quarters near the roof of the world. Mount Everest is three valleys to the east, only about twenty miles as the crow flies. The Tibetan plateau is just over the mountains to the north. The men stay for four months at a stretch before walking down several days to reach a road and board a bus to go home and visit their families. For the past six years each has received five thousand rupees per month from the government—about $70—for his labors. The cold, murky lake some fifty yards away from the post used to be solid ice. Called Tsho Rolpa, it’s at the bottom of the Trakarding Glacier on the border between Tibet and Nepal. The Trakarding has been receding since at least 1960, leaving the lake at its foot. It’s retreating about 200 feet each year. Tsho Rolpa was once just a pond atop the glacier. Now it’s half a kilometer wide and three and a half kilometers long; upward of a hundred million cubic meters of icy water are trapped behind a heap of rock the glacier deposited as it flowed down and then retreated. The Netherlands helped Nepal carve out a trench through that heap of rock to allow some of the lake’s water to drain into the Rolwaling River.

"Trait anxiety is a pervasive tendency to attend to and experience fears and worries to a disproportionate degree, across various situations. This study sought to determine if participants who undergo emotional working memory training will have significantly lower scores on the trait anxiety scales post-intervention. The study also sought to determine if emotional regulation mediated the relationship between working memory training and trait anxiety. Trait anxiety was measured using the form Y2 of the Spielberger State-Trait Anxiety Inventory (STAI-Y2). Emotion regulation was measured using the Emotional Regulation Questionnaire (ERQ). Forty-nine participants underwent 20 days of computerized emotional working memory training called Emotional Dual n-back, which involves viewing a continuous stream of emotional content on a 3x3 grid, and then remembering the location and color of items presented on the grid. The control group consisted of fifty-one participants. Participants of the treatment group had significantly lower trait anxiety compared to controls post-intervention. Mediation analysis determined that working memory training was significantly related to trait anxiety reduction as measured by the STAI-Y2. Emotion regulation was found not to mediate between working memory training and trait anxiety reduction. Results suggest that working memory training may be useful in reducing psychoemotional symptoms of trait anxiety. Moreover, it proposes for future research to further look into the mediating role of emotion regulation via neuroimaging and the development of more comprehensive measures of emotion regulation."