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31.
本研究旨在探究饲粮蛋白质水平对藏系绵羊瘤胃真菌菌群结构及功能的影响。试验选取18只12月龄健康、平均体重为(31.71±0.72)kg的藏系绵羊羯羊,随机分为3组,每组6只,分别饲喂代谢能相近而蛋白质含量不同(LP组,10.06%CP;MP组,12.10%CP;HP组,14.12%CP)的饲粮,试验为期120 d,包括15 d的预饲期和105 d的正试期。结果表明:1)LP组藏系绵羊的终末体重、平均日增重和平均日采食量均显著低于MP组和HP组(P<0.05),而料重比显著高于MP组和HP组(P<0.05)。2)3组18个瘤胃液样品共产生1547415条有效序列,聚类后共得到4073个OTUs。饲粮蛋白质水平并没有对藏系绵羊瘤胃真菌多样性指数产生显著性影响(P>0.05)。3)在门分类水平上,藏系绵羊瘤胃真菌优势菌门为子囊菌门、担子菌门、被孢霉亚门和新美鞭菌门等;在属分类水平上,瘤胃真菌优势菌属为青霉属、无茎真菌属、枝孢属、镰孢霉属和链格孢属等。4)采用LEfSe方法对各个分类水平上丰度有显著差异的微生物进行比较分析,共筛选到33个符合生物标记物的真菌菌群。5)基于FUNGuid对藏系绵羊瘤胃真菌群落的营养型进行功能预测,发现腐生营养型是最主要的营养型。以上结果表明,适当提高饲粮中蛋白质水平可以显著提高藏系绵羊的生长性能,但对瘤胃真菌菌群的多样性和结构组成并未产生明显的影响。 相似文献
32.
奶牛亚急性瘤胃酸中毒 《畜牧与饲料科学》2022,43(5):55-60
在奶牛养殖中,亚急性瘤胃酸中毒(subacute ruminal acidosis,SARA)是一种高发的营养代谢病。随着我国奶牛养殖集约化程度的提高,为提升奶牛生产性能饲喂大量高能谷物饲料极易诱发SARA,导致瘤胃液pH值降低,瘤胃菌群发生改变,瘤胃上皮黏膜层受损,进而影响瘤胃代谢功能。分析了奶牛不同生理阶段、择食行为以及个体差异等SARA的易感因素,探讨了SARA对奶牛瘤胃菌群变化、瘤胃上皮细胞基因表达、瘤胃屏障功能的影响,以期为阐明SARA造成瘤胃功能损伤的机制、降低奶牛发生SARA的风险提供参考。 相似文献
33.
34.
A. Werner Omazic C. Kronqvist L. Zhongyan H. Martens K. Holtenius 《Journal of animal physiology and animal nutrition》2015,99(2):258-264
This study investigated the fate of glycerol entering the rumen, in particular whether glycerol could be absorbed across the rumen epithelium. Three non‐lactating rumen‐fistulated cows were used to calculate the overall disappearance rate of glycerol in vivo and evaluate the rate of ruminal glycerol absorption. Rumen epithelial tissues isolated from sheep were used to characterise glycerol transport properties. The rate of rumen microbial degradation of glycerol was then studied in an in vitro system under anaerobic and thermo‐regulated conditions. The results showed that glycerol can be absorbed from the rumen in significant amounts. The fractional rate of absorption of glycerol was not affected by variations in glycerol concentration in the buffer solution in the in vivo study. The glycerol absorption apparently occurred largely by passive diffusion and was probably not facilitated by carriers. Glycerol also disappeared via microbial digestion and outflow from the rumen through the omasal orifice. 相似文献
35.
Treatment of tropical forages with exogenous fibrolytic enzymes: effects on chemical composition and in vitro rumen fermentation
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A. Díaz M. J. Ranilla L. A. Giraldo M. L. Tejido M. D. Carro 《Journal of animal physiology and animal nutrition》2015,99(2):345-355
The effects of three treatments of fibrolytic enzymes (cellulase from Trichoderma longibrachiatum (CEL), xylanase from rumen micro‐organisms (XYL) and a 1:1 mixture of CEL and XYL (MIX) on the in vitro fermentation of two samples of Pennisetum clandestinum (P1 and P2), two samples of Dichanthium aristatum (D1 and D2) and one sample of each Acacia decurrens and Acacia mangium (A1 and A2) were investigated. The first experiment compared the effects of two methods of applying the enzymes to forages, either at the time of incubation or 24 h before, on the in vitro gas production. In general, the 24 h pre‐treatment resulted in higher values of gas production rate, and this application method was chosen for a second study investigating the effects of enzymes on chemical composition and in vitro fermentation of forages. The pre‐treatment with CEL for 24 h reduced (p < 0.05) the content of neutral detergent fibre (NDF) of P1, P2, D1 and D2, and that of MIX reduced the NDF content of P1 and D1, but XYL had no effect on any forage. The CEL treatment increased (p < 0.05) total volatile fatty acid (VFA) production for all forages (ranging from 8.6% to 22.7%), but in general, no effects of MIX and XYL were observed. For both P. clandestinum samples, CEL treatment reduced (p < 0.05) the molar proportion of acetate and increased (p < 0.05) that of butyrate, but only subtle changes in VFA profile were observed for the rest of forages. Under the conditions of the present experiment, the treatment of tropical forages with CEL stimulated their in vitro ruminal fermentation, but XYL did not produce any positive effect. These results showed clearly that effectiveness of enzymes varied with the incubated forage and further study is warranted to investigate specific, optimal enzyme‐substrate combinations. 相似文献
36.
Effect of Mediterranean saltbush (Atriplex halimus) ensilaging with two developed enzyme cocktails on feed intake,nutrient digestibility and ruminal fermentation in sheep
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Haidy Alsersy Abdelfattah Z. M. Salem Borhami E. Borhami Jaime Olivares Hany M. Gado Maria D. Mariezcurrena Mohamed H. Yacuot Ahmed E. Kholif Mounir El‐Adawy Saul R. Hernandez 《Animal Science Journal》2015,86(1):51-58
The aim of this study was to assess the effects of feeding Atriplex halimus (AH) silage treated with two developed enzyme cocktails to sheep on feed intake, nutrient digestibility and ruminal fermentation. The AH silage was treated without or with 2 L of ZAD1® or ZAD2®/1000 kg with 5% molasses and ensiled for 30 days. Barley grain (300 g/head/day) was fed as an energy supplement once daily at 10.00 hours and AH silage with or without enzyme treatment was offered ad libitum to animals twice daily at 09.00 and 16.00 hours. Sheep were fed on four experimental forage diets comprised of AH silage and barley (D1), AH silage treated with ZAD1® and barley (D2), AH silage treated with ZAD2® and barley (D3) and AH silage treated with a combination of ZAD1® and ZAD2® (1:1) and barley (D4). Ensiling AH with enzymes reduced its contents of neutral detergent fiber and acid detergent fiber. The dry matter intake of AH of D2, D3 and D4 decreased (P < 0.001) as compared to D1. However, enzyme‐treated diets had greater total digestible nutrients intake (P < 0.001) as compared to D1. The nutrients digestibility for D2, D3 and D4 were higher than those for D1 (P < 0.001), and were higher for D3 as compared to both D2 and D4. Sheep fed on D3 had highest (P < 0.001) ruminal total volatile fatty acids concentration, ammonia nitrogen concentration and microbial protein yield. It could be concluded that AH silage treated with ZAD1® or ZAD2® improved digestibility and rumen fermentation in sheep. 相似文献
37.
Effect of monensin withdrawal on rumen fermentation,methanogenesis and microbial populations in cattle
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Arfan Abrar Takamitsu Tsukahara Makoto Kondo Tomomi Ban‐Tokuda Wang Chao Hiroki Matsui 《Animal Science Journal》2015,86(9):849-854
This study was designed to obtain information on the residual influence of dietary monensin on ruminant fermentation, methanogenesis and bacterial population. Three ruminally cannulated crossbreed heifers (14 months old, 363 ± 11 kg) were fed Italian ryegrass straw and concentrate supplemented with monensin for 21 days before sampling. Rumen fluid samples were collected for analysis of short chain fatty acid (SCFA) profiles, monensin concentration, methanogens and rumen bacterial density. Post‐feeding rumen fluid was also collected to determine in vitro gas production. Monensin was eliminated from the rumen fluid within 3 days. The composition of SCFA varied after elimination of monensin, while total production of SCFA was 1.78 times higher than on the first day. Methane production increased 7 days after monensin administration ceased, whereas hydrogen production decreased. The methanogens and rumen bacterial copy numbers were unaffected by the withdrawal of monensin. 相似文献
38.
Comparison of the canine corneal epithelial cell sheets cultivated from limbal stem cells on canine amniotic membrane,atelocollagen gel,and temperature‐responsive culture dish
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39.
This study explores the chemical composition, buffer N solubility, in vitro ruminal N degradability and in vitro ruminal biological activity of tannins in leaves from Gliricidia sepium, Leucaena leucocephala, Morus alba and Trichanthera gigantea trees. These tree leaves are a potential protein source for ruminants, but their site‐influenced nutritive value is largely unknown. Leucaena leucocephala leaves had the highest N content (42.1 g/kg DM), while T. gigantea leaves had the least (26.1 g/kg DM). Leucaena leucocephala had the highest buffer solubility index (20%), while 10% of the total N in leaves of the other three species was soluble. The rapidly fermentable N fraction ‘a’ was highest in M. alba leaves (734.9 g/kg DM) and least in T. gigantea leaves (139.5 g/kg DM). The rate of fermentation (c) was highest for M. alba (7%/hours) leaves. No significant correlations were recorded between buffer solubility index of N and in vitro ruminal N degradability parameters: a, b, and c. The highest response to tannin inactivation using polyethylene glycol, in terms of percentage increase in 36‐hours cumulative gas production, was recorded in M. alba (39%) and T. gigantea (38%) leaves. It was concluded that buffer solubility of N is not a good indicator of ruminal N degradation in the leaves of these tree species. Leaves of M. alba could be more valuable as a source of rapidly fermentable N when animals are offered low‐protein, high‐fibre diets compared with other tree species evaluated in the current study. However, when feeding M. alba leaves, the role of tannins must be considered because these secondary plant compounds showed significant in vitro ruminal biological activity. 相似文献
40.
A. Pérez‐Ruchel J. L. Repetto C. Cajarville 《Journal of animal physiology and animal nutrition》2014,98(6):1068-1074
Effects of NaHCO3 and MgO buffer addition on intake and digestive utilization of a pasture were studied in wethers allowed a restricted time of access to forage. Twelve wethers housed in metabolic cages and fed fresh forage (predominantly Lotus corniculatus) ad libitum for 6 h/d were randomly assigned to one of the following treatments: a control forage without buffer (C) or a forage plus buffer composed of a mixture of 750 g/kg NaHCO3 and 250 g/kg MgO at 20 g/kg dry matter intake (B). Feeding behaviour, feed and water intake and digestibility, urine output, Na urine elimination, kinetics of passage, ruminal pH and ammonia concentration, N balance and ruminal microbial N synthesis were determined in vivo, and the ruminal liquor activity was evaluated in vitro by fermentation of wheat straw. Addition of buffer increased total water intake (p = 0.05), Na urinary output (p = 0.01), purine derivative excretion in urine (p = 0.05) and tended to decrease mean total retention time in the digestive tract (p = 0.09). However, buffer addition increased ruminal pH (p < 0.001) and tended to decrease the ammonia concentration (p = 0.05). That use of buffer decreased ruminal activity was evidenced by a lower volume of gas produced in vitro (p = 0.01) possibly due to a lower microbial concentration in rumen liquor. The higher rumen dilution rate, likely due to a higher water intake, seems to have been the key driver of the actions of buffer supplementation on the rumen environment. Moreover, addition of NaHCO3 led to an increased urinary Na excretion, which should be considered due to its likely negative environmental impacts. 相似文献