Articles de revues : « Defaunated sheep »

1

Hegarty, R. S., C. Shands, C. Harris et J. V. Nolan. « Productivity and pasture intake of defaunated crossbred sheep flocks ». Australian Journal of Experimental Agriculture 40, n^o 5 (2000) : 655. http://dx.doi.org/10.1071/ea99091.

Texte intégral

Résumé :

From a flock of pregnant crossbred ewes, 63 were established as protozoa-free by treatment with alkanate 3SL3 and 64 ewes were maintained as controls. The controls included 20 ewes, which had been defaunated and subsequently re-inoculated with protozoa. After lambing, both flocks were grazed in a 6-paddock rotation until weaning at 20 weeks of age. Defaunated ewes were heavier than control ewes throughout lactation and had a higher urinary allantoin concentration than the control ewes. Intake and apparent digestibility of pasture dry matter by ewes did not differ between groups although these estimates were confounded by differences in pasture composition between the paddocks used. Both groups selected a diet with digestibility approximately 10% units higher than the bulk digestibility of pasture on offer. Control ewes selected a higher proportion of white clover in their diet than was available in the pasture (24% v. 2%) but defaunated ewes did not exhibit preferential selection for clover. Lambs from defaunated ewes were heavier at birth, remained heavier until weaning and grew more wool than lambs from control ewes. Contamination of fauna-free ewes and lambs with protozoa was first observed at weaning and protozoa were detected in 41 out of 60 lambs, 4 weeks after contamination was first detected. Study of defaunated ewes returned to a flock of untreated ewes confirmed rapid spread of contamination into defaunated ewes with small entodiniomorph protozoa establishing first.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Fenn, PD, et RA Leng. « The effect of bentonite supplementation on ruminal protozoa density and wool growth in sheep either fed roughage based diets or grazing ». Australian Journal of Agricultural Research 41, n^o 1 (1990) : 167. http://dx.doi.org/10.1071/ar9900167.

Texte intégral

Résumé :

In penned sheep offered a mainly roughage diet, supplementation with 30, 50 or 60 g/day bentonite consistently increased the density of ruminal protozoa. The effect of 15 g/day bentonite administered via the drinking water to pregnant grazing ewes that were either normally faunated or had been defaunated for 6 months was studied. The wool growth of defaunated sheep at pasture was 25% greater (P < 0.05) than that of faunated animals. The wool growth of the latter was increased 17% (P < 0.15) by the addition of 15 g/day bentonite to their drinking water, while a similar addition of bentonite to defaunated sheep had no effect on wool growth. In this field study, supplementation with bentonite increased the population densities of protozoa free in the ruminal fluid of faunated sheep by 51% (5.6 X 105 v. 3.7 X 105, P<0.07). It is suggested that this allows a greater flow of protozoal protein from the rumen to the intestines, leading to increased wool growth in response to supplements of bentonite.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Cottle, DJ. « Effects of defaunation of the rumen and supplementation with amino acids on the wool production of housed Saxon Merinos. 2. Methionine and protected methionine ». Australian Journal of Experimental Agriculture 28, n^o 2 (1988) : 179. http://dx.doi.org/10.1071/ea9880179.

Texte intégral

Résumé :

In experiment 1, 6 groups, each of 10 superfine Merino wethers, were individually penned indoors and hand-fed oats, wheat straw and whole lupins, either alone or with 2 g/day of DL-methionine or 6.6 g/day of fatty acid coated methionine (Ketionin) for 23 weeks. Following shearing the 6 groups were hand-fed lucerne-chopped hay in experiment 2 either alone or with hydroxymethyl-methionine (Mepron) or Ketionin for 23 weeks. In both experiments the rations were fed at maintenance level and were offered 3 times a week. Half of the sheep had no rumen ciliate protozoa following treatment in a previous trial. In experiment 1, defaunated sheep produced an additional 6.5%clean wool on the supplemented oats plus lupins rations. Inclusion of Ketionin in the ration of defaunated sheep resulted in an 11% increase in clean wool growth, without affecting wool quality. In experiment 2 defaunated sheep produced an additional 6% clean wool on the lucerne-chopped hay ration. No responses to defaunation occurred on the supplemented rations. Inclusion of both forms of protected methionine in the ration (providing 2 g methionine/sheep.day) resulted in 23% and 13% higher clean wool production in the faunated and defaunated sheep respectively. Fibre diameter of wool was increased by 0.7 pm in sheep receiving Mepron and 0-5 pm in sheep receiving Ketionin. The wool grown by suppiemented sheep remained suitable for the 'Sharlea' trade (< 17.5 �m). It is concluded that wool growth responds more to defaunation on high energy-low protein diets. Wool growth responses to supplementation with protected methionine were greater on 100% roughage diets than on high grain diets. Further study is needed before an optimal ration for superfine wool production is formulated.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Ushida, K., J. P. Jouany et P. Thivend. « Role of rumen protozoa in nitrogen digestion in sheep given two isonitrogenous diets ». British Journal of Nutrition 56, n^o 2 (septembre 1986) : 407–19. http://dx.doi.org/10.1079/bjn19860121.

Texte intégral

Résumé :

1. The effect of protozoa on digestion in the rumen was studied using either defaunated or faunated sheep.2. Six wethers, each fitted with rumen and simple duodenal cannulas, were given two isonitrogenous diets containing either lucerne (Medicago sativa) hay (diet L) or sodium hydroxide-treated wheat straw (diet S). The diets were given in eight equal portions per day at 3-h intervals. The mean intake of dry matter, 53 g/kg body-weight0.75per d, was similar for the two diets and each diet had a similar digestible organic matter content. Diet L promoted a large protozoal population and was rich in nitrogen sources of low rumen-degradability, while diet S supported a smaller protozoal population and was rich in rumen-degradable N.3. Digesta flow at the duodenum was estimated by means of a dual-marker technique using chromium-mordanted lucerne hay and polyethylene glycol as markers. The microbial flow at the duodenum was estimated using diaminopimelic acid (DAPA), nucleic-acid purine bases (PB) and35S incorporation simultaneously. The different microbial markers were compared in the defaunated sheep. Protozoal N contribution was estimated in faunated sheep.4. Defaunated sheep had lower rumen ammonia concentrations and molar proportions of butyric acid than faunated sheep, but they had higher molar proportions of propionic acid.5. Rumen organic matter digestion was reduced by defaunation, but this decrease was compensated for by increased intestinal digestion.6. There was a net increase of N flow (approximately 10 g/d) between mouth and duodenum in defaunated sheep. This was explained by increases in both microbial and dietary N flows from the rumen compared with faunated sheep.7. The influence of protozoa on solid- and liquid-phase retention times in the rumen is discussed, as well as the protozoal contribution to microbial N flow in the duodenum of faunated sheep.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Rowe, J. B., A. Davies et A. W. J. Broome. « Quantitative effects of defaunation on rumen fermentation and digestion in sheep ». British Journal of Nutrition 54, n^o 1 (juillet 1985) : 105–19. http://dx.doi.org/10.1079/bjn19850097.

Texte intégral

Résumé :

1. Studies on the quantitative significance of protozoa on carbon and nitrogen digestion and metabolism in the rumen were carried out in sheep given a diet of pelleted concentrate (500 g/d) and chopped hay (500 g/d).2. Measurements were made of apparent digestibility; flows of organic matter and dietary and microbial non-ammonia N (NAN) (using 15NH+4) to the duodenum; and rates of production, interconversion and metabolism of the major C fermentation end-products (from mathematical modelling of 14C isotope values).3. The population density of bacteria in the rumen increased as a result of defamation (28.6 compared with 8.2 x 10° organisms/ml). This high density was associated with greater utilization of volatile fatty acids (VFA) within the rumen.4. The rate of irreversible loss (IL) of bicarbonatefcarbon dioxide from the rumen was greater in the defaunated animals (98.5 v. 57.2 g C/d) but the IL from the blood was greater in the faunated group (138.6 v. 106.1 g C/d). This is consistent with the hypothesis that the high population density of bacteria found in the rumen fluid of defaunated animals may result in increased fermentation of rumen VFA and digestible dietary carbohydrate, thereby increasing the output of CO2 from the rumen and reducing the quantity of VFA (hence energy) available to the host.5. There was no difference in the flow of organic matter (OM) to the duodenum but there was a higher faecal excretion of OM in defaunated animals (apparent OM digestibility: 0.72 in faunated, 0.67 in defaunated).6. Defamation did not significantly increase the flow of NAN to the duodenum, the percentage of duodenal NAN of bacterial origin or the quantity of microbial NAN synthesized/g organic matter fermented. Faecal excretion of NAN was higher in defaunated animals (5.3 v. 3.6 g N/d).

Styles APA, Harvard, Vancouver, ISO, etc.

6

Enev, E., A. Petkov, N. Oblakov et N. Todorov. « Some Aspects of Carohydrate Metabolism in Defaunated Sheep ». Asian-Australasian Journal of Animal Sciences 2, n^o 3 (1 septembre 1989) : 471–72. http://dx.doi.org/10.5713/ajas.1989.471.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

7

Ushida, K., C. Kayouli, S. De Smet et J. P. Jouany. « Effect of defaunation on protein and fibre digestion in sheep fed on ammonia-treated straw-based diets with or without maize ». British Journal of Nutrition 64, n^o 3 (novembre 1990) : 765–75. http://dx.doi.org/10.1079/bjn19900078.

Texte intégral

Résumé :

Using a defaunating method which preserved bacteria and fungi in the rumen, the effect of protozoa on protein and fibre digestion was studied in six adult wethers in relation to the nature of the diet. Sheep were given daily, 42 g dry matter (DM)/kg metabolic body-weight (W0.75), one of two isonitrogenous diets: one contained ammonia-treated wheat straw as the only energy source (diet S) and the other was supplemented with maize grain pellets (diet SM). Mean daily intakes (g/d) of nitrogen, neutral-detergent fibre and acid-detergent fibre were respectively 22, 573 and 373 for diet S and 23, 450 and 334 for diet SM. Elimination of protozoa increased duodenal non-ammonia-nitrogen flow. This result was mainly due to an increase in microbial protein flow and, to a lesser extent, to a higher dietary protein flow. Defaunation markedly increased the efficiency of microbial protein synthesis. Maize-grain supplementation had a net positive effect on this variable in defaunated sheep, but not in faunated sheep. Cell-wall carbohydrates were less well digested in the defaunated rumen, and the negative effect of defaunation was greatest with the diet SM. Intestinal fibre digestion increased in the defaunated sheep especially in those fed on diet SM, but not enough to compensate for the decrease in rumen digestion.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Santra, A., S. Parthasarathy et S. A. Karim. « Effect of defaunation on body conformation changes, wool yield and fibre characteristics of growing lambs in a hot semiarid environment ». Australian Journal of Experimental Agriculture 47, n^o 7 (2007) : 789. http://dx.doi.org/10.1071/ea05106.

Texte intégral

Résumé :

The efficacy of sodium laurel sulfate as a defaunating agent, as well as effect of defaunation on body confirmation changes, wool yield and fibre characteristics, were evaluated in growing lambs in a 90-day feeding experiment. Forty-five Malpura male weaner (90-day old) lambs were divided into three equal groups: defaunated, refaunated and faunated. The lambs of defaunated and refaunated groups were defaunated by oral administration of sodium laurel sulfate at the rate of 8 g/100 kg liveweight as a 10% aqueous solution. Six days after defaunation, all the lambs of the refaunated group were refaunated by inoculation of 100 mL rumen content per lamb drawn from a normal faunated sheep. All the experimental lambs were maintained under stall feeding on a complete feed containing 50 : 50 Pala (Ziziphus nummularia) leaf and concentrate. Treatments did not differ in intake of dry matter, digestible crude protein or digestible energy. Body height and paunch girth were greater (P < 0.01) in defaunated compared to refaunated and faunated lambs. With similar dry matter intake in the three experimental groups, liveweight gain, feed conversion efficiency and wool yield were higher (P < 0.01) in defaunated lambs. The wool fibre diameter and medullation percentage were higher (P < 0.01) in defaunated than refaunated and faunated lambs. It was concluded from the study that, with similar dry matter intake and plane of nutrition, the growth rate, feed conversion efficiency and wool yield were higher in defaunated lambs, as compared to refaunated and faunated lambs. Higher paunch girth in defaunated lambs resulted in a pot-bellied appearance of the animals.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Frumholtz, P. P., R. J. Wallace, C. J. Newbold et E. R. Ørskov. « Long-term changes in rumen fermentation in defaunated sheep ». Proceedings of the British Society of Animal Production (1972) 1991 (mars 1991) : 77. http://dx.doi.org/10.1017/s0308229600020274.

Texte intégral

Résumé :

The removal of ciliate protozoa, or defaunation, results in the establishment of a new ecosystem in the rumen, consisting only of bacteria and fungi. Although extensive research has been done on ciliate-free ruminants, the role of protozoa in the rumen still provokes considerable debate. The diversity of experimental design, such as animal species, defaunation method, and diet could account for many of the differences observed between defaunation studies. Also it is important to examine the stability of the ciliate-free ecosystem. The aim of this study was to investigate changes in rumen fermentation of ciliate-free sheep over a period of one year.Eight male castrated sheep, weighing 60-70 kg, received twice daily 700 g of a diet of hay, barley, molasses, fish meal and vitamins/minerals (500, 299.5, 100, 91 and 9.5 g/kg DM respectively). Four sheep were defaunated by the rumen washing technique (Jouany and Senaud, 1979) and kept in isolated pens while the other four were left faunated with a mixed type A ciliate protozoa population. Rumen samples were withdrawn via the rumen cannula and blood samples were taken from the jugular vein -1, 0, 1, 2, 4 and 6 h after feeding. There were three sampling periods: one month, six months and one year after defaunation.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Van Nevel, C. J., S. De Smet et D. I. Demeyer. « Digestion in defaunated and refaunated sheep fed soybean oil hydrolysate or crushed toasted soybeans ». Netherlands Journal of Agricultural Science 41, n^o 3 (1 septembre 1993) : 205–19. http://dx.doi.org/10.18174/njas.v41i3.620.

Texte intégral

Résumé :

Defaunated then refaunated sheep were given diets containing soyabean oil hydrolysate (SOH: 70 g/day) or an equivalent amount of lipids administered as crushed toasted soyabeans (TSB). Defaunation increased molar percentage of propionate in the rumen, while butyrate decreased. SOH caused a similar effect in both the defaunated and refaunated rumen, while the effect on acetate proportions was variable. Protozoal counts were lower after feeding SOH. Crushed toasted soyabeans had a minor effect on rumen fermentation pattern. Rumen digestibility of organic matter was decreased by both defaunation and SOH feeding, with a concomitant shift in digestion to the lower intestinal tract. Total tract digestibility was not affected. Both treatments increased nonammonia N flows at the duodenum, but this was only significant with defaunation. Total tract digestion of N remained almost constant. Defaunation resulted in more microbial protein reaching the duodenum. Except for the TSB diet, total lipid leaving the rumen equalled intake. Total tract digestibility of total lipid was much higher with SOH and TSB than with controls. Defaunation almost doubled microbial growth efficiency and this value tended to increase by SOH feeding. The decrease of protozoal count or even elimination of protozoa after lipid feeding could not entirely explain the change in rumen metabolism, as additional changes in defaunated sheep were shown.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Coleman, G. S. « The distribution of carboxymethylcellulase between fractions taken from the rumens of sheep containing no protozoa or one of five different protozoal populations ». Journal of Agricultural Science 106, n^o 1 (février 1986) : 121–27. http://dx.doi.org/10.1017/s0021859600061827.

Texte intégral

Résumé :

SUMMARYThe distribution of carboxymethylcellulase (CMCase) between various rumen fractions has been determined at three times after feeding in sheep containing no ciliate protozoa or five different protozoal populations. The total rumen CMCase was lowest in defaunated animals and tended to be higher in animals containing the amylolyticEntodinium caudatumor a natural mixed protozoal population and highest in sheep containing single cellulolytic species. In animals containing the cellulolytic species,Epidinium ecaudatum caudatumorEudiplodinium maggii, 70% of the CMCase was associated with the protozoal fraction whereas less than 15% was present in a fraction prepared in the same way from sheep containing no protozoa or onlyEntodinium caudatum. The activity associated with the free bacteria was higher in sheep containing onlyEntodinium caudatumthan in defaunated animals or those containing the cellulolytic species. Similar results were obtained 1·5, 6·5 or 24 h after feeding. Almost no activity was present in the cell-free rumen liquor under any condition. A variable amount of CMCase (up to 25% of the total) was associated with the plant debris in the rumen and the specific activity of the enzyme released by sonication was often higherthan that released from the free bacteria under the same conditions.

Styles APA, Harvard, Vancouver, ISO, etc.

12

KOBAYASHI, Yasuo, Toshiki NAKAGAWA, Sadao HOSHINO et Rudoif A. PRINS. « Variations in Ruminal Characteristics between Defaunated and Protozoa-inoculated Sheep ». Nihon Chikusan Gakkaiho 62, n^o 3 (1991) : 297–300. http://dx.doi.org/10.2508/chikusan.62.297.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

13

Nguyen, Son Hung, Huyen Duong Thi Nguyen, Graeme Bremner et Roger Stephen Hegarty. « Methane emissions and productivity of defaunated and refaunated sheep while grazing ». Small Ruminant Research 161 (avril 2018) : 28–33. http://dx.doi.org/10.1016/j.smallrumres.2018.02.004.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

14

Morgavi, D. P., J. P. Jouany et C. Martin. « Changes in methane emission and rumen fermentation parameters induced by refaunation in sheep ». Australian Journal of Experimental Agriculture 48, n^o 2 (2008) : 69. http://dx.doi.org/10.1071/ea07236.

Texte intégral

Résumé :

Elimination of protozoa or defaunation is known to reduce methane emission by ruminants. However, the long-term efficacy of this practice is not well documented. In this work methane and other end products of fermentation were monitored in five adult, rumen-cannulated wethers that had been kept defaunated for two years (Def1) and successively refaunated (Fau, 12 weeks) and defaunated (Def2) during a 6-month-long experiment. Methane was measured for periods of 4 days at about 4-weekly intervals using the SF6 tracer technique, and rumen content samples were taken regularly throughout the experiment. Refaunation was performed by single administration of a mixed protozoal inoculum (103 cells). A noticeable protozoal population was observed at 12 days after inoculation, which was followed by an exponential increase that peaked at 12 ± 3 × 105 cells/mL rumen fluid at 4 weeks and decreased thereafter to 8 ± 4 × 105 cells/mL at the end of the 12-week Fau period. Production of methane, which was 33 ± 8 L/animal.day in Def1, increased (P < 0.05) up to 42 ± 5 L at the end of the Fau period and dropped back at the end of Def2 to 35 ± 7 L (Def1 v. Def2, P > 0.05). Even though protozoal numbers were comparable to conventional animals 20 days after inoculation, the increase in methane production was observed later, at 8 weeks, suggesting that protozoa are not the only microbial factor favouring methanogenesis and that the ecosystem needs a relatively long adaptation time following protozoal introduction to optimise this function. The presence of protozoa did not affect total volatile fatty acids and acetate concentration in the rumen but increased butyrate, while decreasing propionate concentration (Fau v. Def1, Def2, P < 0.05). These results show that the decrease in methane emissions induced by defaunation in sheep was stable for a period of up to 2 years. In the absence of protozoa, methane decreased by ~20% in both short- and long-term defaunated animals.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Morgavi, D. P., J. P. Jouany, C. Martin et M. J. Ranilla. « Archaeal community structure diversity in the rumen of faunated and defaunated sheep ». International Congress Series 1293 (juillet 2006) : 127–30. http://dx.doi.org/10.1016/j.ics.2006.01.019.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

16

Jouany, J. P., Y. Papon, B. Lassalas et M. Ivan. « Effects of Isotricha, Eudiplodinium, Epidinium + Entodinium and a mixed population of rumen protozoa on the in vitro degradation of fish meal, soybean meal and casein ». Canadian Journal of Animal Science 72, n^o 4 (1 décembre 1992) : 871–80. http://dx.doi.org/10.4141/cjas92-099.

Texte intégral

Résumé :

An in vitro rumen simulation system was used to study effects of different types of rumen protozoa (Isotricha, Eudiplodinium, Epidinium + Entodinium, total mixed fauna) on the degradation of three feed proteins (fish meal, soybean meal, casein). A comparison of the fermentations containing different feed proteins was made with the control fermentations containing no added feed protein. Rumen contents used in the fermentations originated from defaunated sheep, or from sheep containing a single genus of protozoa (Isotricha spp. or Eudiplodinium spp.), a mixture of genera Entodinium spp. and Epidinium spp., or a total mixed fauna. In the presence of the total mixed fauna the degradabilities were 82.0, 51.1 and 26.5% for casein, soybean meal and fish meal, respectively. The absence of protozoa resulted in decreased (P < 0.05) degradation of fish meal and soybean meal but had no effect (P > 0.05) on casein. The single genus Isotricha spp. decreased (P < 0.05) the degradation of all three protein sources compared with the defaunated fermentations or those containing the total mixed fauna. Eudiplodinium did not affect (P > 0.05) fish meal or soybean meal, but it decreased (P < 0.05) the degradation of casein compared with the defaunated fermentations. However, when this organism was compared with the total mixed fauna the degradability of fish meal was not affected (P > 0.05), but that of soybean meal or casein was decreased (P < 0.05). The combination of Epidinium + Entodinium decreased (P < 0.05) the degradation of all three protein sources when compared with the total mixed fauna. When compared with the defaunated fermentations, the protozoal combination had no effect on fish meal (P > 0.05), but the degradation of soybean meal and casein was decreased (P < 0.05). Total volatile fatty acid (VFA) production was systematically reduced (P < 0.05) by the sole presence of Isotricha. The presence of other genera or the total mixed fauna had variable effects on the production of VFA or gases for different sources of protein. It was concluded that the mode of action of a single species or genus of protozoa on nitrogen metabolism in the rumen is different from that of total mixed fauna. The protozoal effect on protein degradation varies according to the type of protozoa present and the nature of the protein. Key words: Protozoa, in vitro degradation, fish meal, soybean meal, casein, rumen

Styles APA, Harvard, Vancouver, ISO, etc.

17

Broudiscou, L., C. J. van Nevel et D. I. Demeyer. « Effect of soya oil hydrolysate on rumen digestion in defaunated and refaunated sheep ». Animal Feed Science and Technology 30, n^o 1-2 (juillet 1990) : 51–67. http://dx.doi.org/10.1016/0377-8401(90)90051-9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

18

Ankrah, P., S. C. Loerch et B. A. Dehority. « Occurrence of 2-Aminoethylphosphonic Acid in Feeds, Ruminal Bacteria and Duodenal Digesta from Defaunated Sheep ». Journal of Animal Science 67, n^o 4 (1 avril 1989) : 1061–69. http://dx.doi.org/10.2527/jas1989.6741061x.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

19

Cottle, DJ. « Effects of defaunation of the rumen and supplementation with amino acids on the wool production of housed Saxon Merinos. 1. Lupins and extruded lupins ». Australian Journal of Experimental Agriculture 28, n^o 2 (1988) : 173. http://dx.doi.org/10.1071/ea9880173.

Texte intégral

Résumé :

Six groups, each comprising 10 superfine Merino wethers ('Sharlea'), were individually penned indoors and hand-fed oats and wheat straw, either alone or with 10% (w/w) crushed lupins or extruded lupins. The rations were fed at maintenance level and were offered 3 times a week. Half of the sheep were defaunated by drenching with Alkanate 3SL3. Wool growth rates and wool quality were measured during a 5-month trial period. Defaunation resulted in a 6.5% increase in clean wool production, with a 3% higher sulfur content. The quality of the wool grown was unaffected by defaunation. Inclusion of lupins or extruded lupins in the ration resulted in a 10% increase in clean wool growth. Wool quality was largely unaffected, though a lower resistance to compression was apparent. It was concluded that a reasonable diet for 'Sharlea' production was 500g oats, 50g wheat straw, 50g lupins, 10.5g vitamin, mineral mix per sheep per day. This diet may be further improved by additional ingredients and defaunation of the sheep.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Hsu, J. T., et G. C. Fahey. « Effects of Centrifugation Speed and Freezing on Composition of Ruminal Bacterial Samples Collected from Defaunated Sheep ». Journal of Dairy Science 73, n^o 1 (janvier 1990) : 149–52. http://dx.doi.org/10.3168/jds.s0022-0302(90)78658-4.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

21

Cottle, DJ. « Effects of defaunation of the rumen and supplementation with amino acids on the wool production of housed Saxon Merinos. 4. Cottonseed meal, analogues of methionine and avoparcin ». Australian Journal of Experimental Agriculture 28, n^o 6 (1988) : 707. http://dx.doi.org/10.1071/ea9880707.

Texte intégral

Résumé :

Ten groups, each of 6 superfine Merino wethers were individually penned indoors and hand-fed at maintenance level a ration of 70% oats and 30% chopped lucerne hay (w/w). The groups of sheep were fed 3 different supplementary pellets rotationally during three 9-week periods. Each group received 3 of the following 7 pellets: (1) control, (2) cottonseed meal (CSM), (3) CSM plus hydroxymethyl-methionine (MEP), (4) CSM plus methionine hydroxy analogue (MHA), (5) CSM plus avoparcin (AV), (6) CSM plus MEP plus AV, and (7) CSM plus MHA plus AV. The rations were offered 3 times a week. Half of the sheep had no rumen ciliate protozoa. Wool production was measured during the 7-month period. Defaunation resulted in a 6.9% increase in greasy fleece weight and a 7.7% increase in clean wool production. Average wool fibre diameter increased by 0.6 pm in defaunated sheep. The clean wool growth responses compared with sheep fed the control pellets were 4, 5, 12, 0, 3 and 9% respectively for sheep fed pellets 2-7. The most cost-effective supplement was the CSM plus MHA pellet, which increased clean wool production by 0.5 glday compared with sheep fed the CSM pellet but did not significantly affect wool quality. It was concluded that supplements containing MHA could be economically fed to housed superfine Merino wethers ('Sharlea'), but MHA appears to be relatively inefficient in supplying methionine to the intestines.

Styles APA, Harvard, Vancouver, ISO, etc.

22

., Chandramoni, C. M. Tiwari ., N. Haque ., Murari Lal ., S. B. Jadhao . et M. Y. Khan . « Energy Balance in Faunated and Defaunated Sheep on a Ration High in Concentrate to Roughage (Good Quality) Ratio ». Pakistan Journal of Nutrition 1, n^o 1 (15 décembre 2001) : 31–33. http://dx.doi.org/10.3923/pjn.2002.31.33.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

23

Broudiscou, L., C. J. Van Nevel et D. I. Demeyer. « Incorporation of soya oil hydrolysate in the diet of defaunated or refaunated sheep : Effect on rumen fermentationin vitro ». Archiv für Tierernaehrung 40, n^o 4 (avril 1990) : 329–37. http://dx.doi.org/10.1080/17450399009430929.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

24

Wina, Elizabeth, et Stefan Muetzel. « EFFECT OF LERAK (SAPINDUS RARAK) EXTRACT IN HIGH ROUGHAGE DIET ON RUMEN MICROBIAL PROTEIN SYNTHESIS AND PERFORMANCE OF SHEEP ». Indonesian Journal of Agricultural Science 21, n^o 2 (29 décembre 2020) : 89. http://dx.doi.org/10.21082/ijas.v21n2.2020.p89-97.

Texte intégral

Résumé :

Secondary compounds containing plant extract as feed additive may improve the performance of livestock consuming high roughage diet. An in vivo trial was conducted to investigate the effect of Sapindus rarak extract (SRE) on ruminal fermentation products, microbial protein synthesis, and growth performance of sheep. Sheep (male, 28 heads) fed high roughage diet were arranged in a completely randomized design with four treatments: addition of SRE to the diet at 0, 4, 8 and 12 g head-1 day-1. The experiment was conducted for 105 days with 2 weeks adaptation period. At the end of the experiment, total faeces was collected for 1 week and rumen liquor was taken. Variables measured were ruminal fermentation products, microbial protein synthesis, daily intake, digestibility, N retention, body weight, and average daily gain. Protozoal numbers were significantly decreased with increasing SRE dose. The ruminal NH3 concentration tended to reduce by SRE addition (P = 0.06). SRE significantly increased propionate and efficiency of microbial protein synthesis from 6.4 to 10.5 g N kg-1 DOMR. SRE significantly improved average daily gain of sheep during the first 70 days of experiment without affecting intake and digestibility. SRE did not alter carcass percentage but tended to lower pancreas and liver weights (P<0.1). In conclusion, SRE has a significant role in partially defaunated rumen microflora, hence, increased microbial protein synthesis and propionate production in the rumen. Addition of SRE is useful to increase daily gain of sheep fed high roughage diet in 70 days of feeding.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Jouany, J. P., F. Mathieu, J. Senaud, J. Bohatier, G. Bertin et M. Mercier. « Effect of Saccharomyces cerevisiae and Aspergillus oryzae on the digestion of nitrogen in the rumen of defaunated and refaunated sheep ». Animal Feed Science and Technology 75, n^o 1 (septembre 1998) : 1–13. http://dx.doi.org/10.1016/s0377-8401(98)00194-1.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

26

Sénaud, J., JP Jouany, B. Lassalas et J. Bohatier. « Digestion of a dehydrated lucerne/barley diet (70:30) in defaunated, Isotricha-monoinoculated and mixed-fauna-inoculated rumen in sheep ». Reproduction Nutrition Development 35, n^o 3 (1995) : 249–66. http://dx.doi.org/10.1051/rnd:19950302.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

27

Ni, Zhen, Xiumin Yan, Liang Chang, Xin Sun, Donghui Wu et Bing Zhang. « Habitat preferences rather than morphological traits affect the recovery process of Collembola (Arthropoda, Hexapoda) on a bare saline–alkaline land ». PeerJ 8 (21 juillet 2020) : e9519. http://dx.doi.org/10.7717/peerj.9519.

Texte intégral

Résumé :

The Songnen Plain of China was once an important grassland used for sheep grazing, but it has largely been degraded to bare saline-alkaline land (BSAL). BSAL consists of plant-free areas characterized by high soil pH values (up to 10) and salt and alkali (e.g., Na+ and Ca2+) contents, as well as low soil organic matter and water contents; thus, very few soil faunal species can survive on BSAL. The recovery of degraded ecosystems provides a great opportunity to investigate the reconstruction of belowground soil faunal communities. Collembola are a class of widespread and abundant soil fauna that can colonize this harsh environment. Habitat changes on BSAL promote aboveground revegetation, which greatly facilitates the recovery of Collembola. A soil transfer experiment on the BSAL of the Songnen Plain was conducted to study the effects of habitat and Collembola morphological traits on the recovery process of Collembola. Defaunated and with-fauna soil blocks were transferred among three habitats: BSAL, reclaimed arable land, and naturally revegetated grassland. The recovered Collembola in the transferred soil blocks were compared two, seven, and 12 weeks after the start of the experiment. The results showed that (1) the majority of the Collembola, regardless of their morphological traits, recovered in the defaunated soil blocks within 2 weeks; (2) generalists and habitat-preferring species recovered faster than specialists; (3) the average total abundance, species richness, and community composition of Collembola recovered to the natural levels in 2 weeks; and (4) 12 weeks after replacement, the highest average total abundance and species richness of Collembola were found in the arable land. Our results indicate that the majority of Collembola in this study, regardless of their dispersal type, which is related to their morphological traits, are fast dispersers, and their recovery speeds are mainly affected by habitat preferences. We suggest that the reclamation of BSAL to arable land rather than its natural recovery to grassland aids in the recovery of Collembola in degraded grassland systems.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Hsu, J. T., G. C. Fahey, J. H. Clark, L. L. Berger et N. R. Merchen. « Effects of urea and sodium bicarbonate supplementation of a high-fiber diet on nutrient digestion and ruminal characteristics of defaunated sheep. » Journal of Animal Science 69, n^o 3 (1991) : 1300. http://dx.doi.org/10.2527/1991.6931300x.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

29

Mathieu, F., J. Sénaud et JP Jouany. « Effect of the addition of mixed B-type protozoa in defaunated rumen of sheep on the degradation and fermentation of different proteins ». CrossRef Listing Of Deleted DOIs 44, Suppl. 1 (1995) : 226. http://dx.doi.org/10.1051/rnd:199505art0194.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

30

Mathieu, F., JP Jouany, J. Sénaud, J. Bohatier, G. Bertin et M. Mercier. « The effect of Saccharomyces cerevisiae and Aspergillus oryzae on fermentations in the rumen of faunated and defaunated sheep ; protozoal and probiotic interactions ». Reproduction Nutrition Development 36, n^o 3 (1996) : 271–87. http://dx.doi.org/10.1051/rnd:19960305.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

31

Mathieu, F., J. Sénaud et JP Jouany. « Effect of the addition of mixed B-type protozoa in defaunated rumen of sheep on the degradation and fermentation of different proteins ». Annales de Zootechnie 44, Suppl. 1 (1995) : 226. http://dx.doi.org/10.1051/animres:199505194.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

32

Williams, Alan G., et Susan E. Withers. « Changes in the rumen microbial population and its activities during the refaunation period after the reintroduction of ciliate protozoa into the rumen of defaunated sheep ». Canadian Journal of Microbiology 39, n^o 1 (1 janvier 1993) : 61–69. http://dx.doi.org/10.1139/m93-009.

Texte intégral

Résumé :

Changes in the microbial populations, their activities, and the ruminal fermentation were monitored for 50 d following the reintroduction of ciliate protozoa into four defaunated sheep. A protozoal population was reestablished successfully in each recipient, using a washed inoculum containing approximately 103 cells, although there were between-animal differences in the rates of recolonization and genus establishment. Entodinium spp. predominated in the initial stages of the refaunation period and had an apparent maximal generation time of 9–10 h. Bacterial and fungal numbers did not decline following the reintroduction of protozoa and a small transient increase in the numbers of amylolytic and xylanolytic bacteria and fungal zoospores occurred in the early stages of refaunation when the protozoal population was < 105/g ruminal contents, but these subsequently declined as the protozoa established. Although the fibrolytic bacterial population was lowest in period 3 (> 105 protozoa/g), the in sacco ruminal digestion of Lolium perenne hay and polysaccharolytic enzyme activities in the solids-associated populations were either maintained or increased when protozoa were present confirming the important contribution of protozoa to fibre breakdown in the rumen. Significant changes in ruminal microbial activities occurred after protozoal reinoculation but before the rumen had refaunated completely. Arylamidase activities in the liquor-phase population and ruminal ammonia concentrations increased significantly within 48 h of transfaunation; the magnitude of the effects became more pronounced as the protozoal population developed. However, volatile fatty acid formation and ruminal pH were not affected after the reintroduction of protozoa.Key words: rumen, sheep, ciliate protozoa.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Chandramoni, S. B. Jadhao, C. M. Tiwari, N. Haque, Murarilal et M. Y. Khan. « Energy Metabolism and Methane Production in Faunated and Defaunated Sheep Fed Two Diets with Same Concentrate to Roughage Ratio (70:30) but Varying in Composition ». Asian-Australasian Journal of Animal Sciences 14, n^o 9 (1 septembre 2001) : 1238–44. http://dx.doi.org/10.5713/ajas.2001.1238.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

34

Jouany, Jean-Pierre, Frédérique Mathieu, Jean Senaud, Jacques Bohatier, Gérard Bertin et Mariette Mercier. « The effect of Saccharomyces cerevisiae and Aspergillus oryzae on the digestion of the cell wall fraction of a mixed diet in defaunated and refaunated sheep rumen ». Reproduction Nutrition Development 38, n^o 4 (1998) : 401–16. http://dx.doi.org/10.1051/rnd:19980405.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

35

Morgavi, Diego P., Cécile Martin, Jean-Pierre Jouany et Maria José Ranilla. « Rumen protozoa and methanogenesis : not a simple cause–effect relationship ». British Journal of Nutrition 107, n^o 3 (18 juillet 2011) : 388–97. http://dx.doi.org/10.1017/s0007114511002935.

Texte intégral

Résumé :

Understanding the interactions between hydrogen producers and consumers in the rumen ecosystem is important for ruminant production and methane mitigation. The present study explored the relationships between rumen protozoa, methanogens and fermentation characteristics. A total of six donor sheep harbouring (F, faunated) or not (D, defaunated) protozoa in their rumens (D animals were kept without protozoa for a period of a few months (D − ) or for more than 2 years (D+)) were used inin vitroandin vivoexperiments.In vitrothe absence of protozoa decreased NH3and butyrate production and had no effect on methane. In contrast, the liquid-associated bacterial and methanogens fraction of D+ inocula produced more methane than D − and F inoculum (P < 0·05).In vivofermentation parameters of donor animals showed the same trend on NH3and butyrate and showed that D+ animals were high methane emitters, while D − were the lowest ( − 35 %). The concentration of dissolved dihydrogen measured after feeding followed the opposite trend. Methane emissions did not correlate with the relative abundance of methanogens in the rumen measured by quantitative PCR, but there was a trend for higher methanogens concentration in the solid-associated population of D+ animals compared with D − animals. In contrast, PCR-denaturing gradient gel electrophoresis profiles of methanogens' methyl coenzyme-M reductase A gene showed a clear clustering in liquid-associated fractions for all three groups of donors but fewer differences in solid-associated fractions. These results show that the absence of protozoa may affect differently the methanogen community and methane emissions in wethers.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Jouany, JP, J. Sénaud, S. Toillon, M. Ben Salah, J. Bohatier et G. Prensier. « Effect of ruminal inoculation of Isotricha alone or a mixed B-type fauna in a defaunated rumen on the digestion of a hay-maize diet (70:30) in sheep ». Reproduction Nutrition Development 35, n^o 1 (1995) : 11–25. http://dx.doi.org/10.1051/rnd:19950102.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

37

Chamberlain, D. G., P. C. Thomas, Wilma Wilson, C. J. Newbold et J. C. Macdonald. « The effects of carbohydrate supplements on ruminal concentrations of ammonia in animals given diets of grass silage ». Journal of Agricultural Science 104, n^o 2 (avril 1985) : 331–40. http://dx.doi.org/10.1017/s0021859600044002.

Texte intégral

Résumé :

SummaryA total of 15 rumen-cannulated sheep and four rumen-cannulated goats (Expt 3) were used in five latin square experiments designed to investigate the effects of carbohydrate supplements on ruminal ammonia concentration in animals given grass silage diets. In Expt 1 barley supplements were given at the same time, 1 h before or 2 h before a meal of silage. The treatments were designed to alter the synchronization between energy release from fermentation of barley and ammonia release from the degradation of silage N compounds. As compared with the unsupplemented control diet, barley supplements reduced (P < 0–05) rumen ammonia concentration and increased (P < 0–01) the number of total protozoa, but the time at which barley was given was without effect. In Expt 2 animals receiving silage or silage-barley diets were defaunated chemically. This treatment led to a 20–25 % reduction in rumen ammonia concentration. In Expt 3 supplements of maize starch, glucose and sucrose were compared. Mean ammonia concentrations were 231 mg/1 for the control unsupplemented diet and 205, 155 and 160 mg/1 (S.E. 21) for the starch, glucose and sucrose treatments. Corresponding numbers of protozoa were 7–7, 15–1, 6–1 and 6–3 x 10s/ml (S.E. 1–8). In Expt 4 the diets were unsupplemented silage or the same diet plus supplements of sucrose or xylose. Xylose reduced ammonia concentration more than sucrose, the values (mg/1) being 236 (control), 206 (sucrose) and 125 (xylose) (S.E. 19). There was no difference between the supplements in numbers of protozoa. Xylose induced a smaller reduction in pH, a higher (P < 0–05) proportion of acetate and a lower (P < 0–05) proportion of butyrate in rumen fluid than did sucrose. Effects of rumen pH were examined in Expt 5 where supplements of sucrose were given alone or together with NaHCO3. Rumen pH values were 6–38 for the control unsupplemented diet and 5–99, 6–28 and 6–55 (S.E. 0–06) for the diets supplemented with sucrose, sucrose plus 50 g NaHC03 and sucrose plus 100 g NaHCO3. Corresponding values for ruminal ammonia were 193, 151, 93 and 41 mg/1 (S.E. 10). Differences in VFA proportions between sucrose treatments were small and significant (P < 0–05) only for butyrate. It is concluded that there are important differences between carbohydrate sources in their effects on nitrogen metabolism in the rumen. Differences between starch and sugars appear to relate to the influence of the carbohydrates on the microbial population of the rumen, as was indicated by the differential effects of the carbohydrate sources on the number of total protozoa; differences between sugars appear to depend in part on the rates of sugar fermentation and the associated reduction in rumen pH.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Canul-Solis, Jorge, María Campos-Navarrete, Angel Piñeiro-Vázquez, Fernando Casanova-Lugo, Marcos Barros-Rodríguez, Alfonso Chay-Canul, José Cárdenas-Medina et Luis Castillo-Sánchez. « Mitigation of Rumen Methane Emissions with Foliage and Pods of Tropical Trees ». Animals 10, n^o 5 (13 mai 2020) : 843. http://dx.doi.org/10.3390/ani10050843.

Texte intégral

Résumé :

Methane produced by enteric fermentation contributes to the emission of greenhouse gases (GHG) into the atmosphere. Methane is one of the GHG resulting from anthropogenic activities with the greater global warming contribution. Ruminant production systems contribute between 18% and 33% of methane emissions. Due to this, there has been growing interest in finding feed alternatives which may help to mitigate methane production in the rumen. The presence of a vast range of secondary metabolites in tropical trees (coumarins, phenols, tannins, and saponins, among others) may be a valuable alternative to manipulate rumen fermentation and partially defaunate the rumen, and thus reduce enteric methane production. Recent reports suggest that it is possible to decrease methane emissions in sheep by up to 27% by feeding them saponins from the tea leaves of Camellia sinensis; partial defaunation (54%) of the rumen has been achieved using saponins from Sapindus saponaria. The aim of this review was to collect, analyze, and interpret scientific information on the potential of tropical trees and their secondary metabolites to mitigate methane emissions from ruminants.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Defaunated sheep »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres