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1.
本试验旨在研究饲粮不同非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)对肉用绵羊瘤胃pH、氨态氮和挥发性脂肪酸的影响.选用(47.21±1.01)kg安装有瘤胃瘘管的杜泊羊(♂)×小尾寒羊(♀)杂交1代肉用公羊12只,采用12×4不完全拉丁方设计,试验分4期进行,每期16 d,分别饲喂NFC/NDF为0.25、0.34、0.36、0.52、0.60、0.80、0.87、1.13、1.30、1.58、2.17和2.49的12种饲粮.结果表明:随着NFC/NDF的增加,试验羊瘤胃pH极显著线性降低(P＜0.01),氨态氮浓度极显著线性增加(P＜0.01),瘤胃总挥发性脂肪酸及丁酸比例呈显著三次曲线变化(P＜0.05),总挥发性脂肪酸中的丙酸、戊酸和异戊酸比例极显著线性增加(P＜0.01),乙酸比例和乙酸/丙酸极显著线性降低(P＜0.01).由此可见,饲粮NFC/NDF对瘤胃pH、氨态氮和挥发性脂肪酸具有显著影响.  相似文献   

2.
文章旨在研究不同类型全混合日粮对肉牛生长性能、养分表观消化率及瘤胃发酵性能的影响。试验将初重为（151.26±2.21）kg的180头肉牛随机分为3组,每组5个重复,每个重复12头。在整个为期20 w的饲养试验中,对照组肉牛饲喂象草水平为30%的全混合日粮,T1组饲喂青贮象草水平为30%的全混合日粮,T2组饲喂象草水平为30%的青贮全混合日粮。结果：T2组肉牛11～20 w平均日增重及饲料效率均显著高于对照组（P＜0.05）。对照组和T1组肉牛0～10 w料重比较T2组分别显著降低23.30%和25.25%（P＜0.05）。对照组肉牛干物质表观消化率较T1组显著提高15.36%（P＜0.05）,而对照组和T2组粗脂肪表观消化率较T1组分别显著提高6.35%和5.96%（P＜0.05）。T2组肉牛粗蛋白质表观消化率较T1组分别显著提高6.88%（P＜0.05）。对照组与T1组肉牛采食后2 h氨氮浓度、挥发性脂肪酸和丙酸浓度均显著高于T2组（P＜0.05）,对照组肉牛采食前瘤胃挥发性脂肪酸和丙酸浓度显著高于T1和T2组（P＜0.05）。采食2 h后,T2组肉牛瘤胃乙酸浓度及乙酸与丙酸比值均显著高于对照组和T1组（P＜0.05）。结论：饲喂发酵全混合日粮可改善瘤胃氮代谢,用含30%青贮象草的全混合日粮或发酵含30%象草的全混合日粮可以替代普通象草全混合日粮,对整个试验期肉牛的生长性能无负面影响。 [关键词]全混合日粮|肉牛|生长性能|养分消化|瘤胃发酵  相似文献   

3.
本试验旨在研究不同营养水平全饲粮颗粒料对绵羊瘤胃液挥发性脂肪酸(VFA)浓度和比例的影响。选用3.5～4月龄,体重15 kg左右的陶赛特(♂)×藏羊(♀)杂交一代公羔15只,采用单因子完全随机试验设计,试验分A、B、C 3个处理,分别为1、0.9、0.8倍NRC水平。预试期15 d,正试期50 d。结果表明:营养水平对绵羊瘤胃液总挥发性脂肪酸(TVFA)浓度没有产生显著影响(P>0.05),说明饲喂颗粒饲料造成的食糜排出速率提高使瘤胃发酵受限制,但对各种酸的摩尔比产生了显著影响(P<0.05),采食较高营养水平饲粮绵羊瘤胃液中丙酸和其他酸的摩尔比显著较高而乙酸摩尔比和乙/丙比显著较低(P<0.05)。  相似文献   

4.
本试验旨在探讨在高精料饲粮条件下,添加烟酸对锦江黄牛瘤胃乳酸、挥发性脂肪酸浓度及相关酶活性的影响.选用3头平均体重为(275±20)kg、安装有永久性瘤胃瘘管的锦江黄牛,采用精料比例逐步提高来诱导酸中毒的试验方法,试验分4期,每期10 d,第Ⅰ、Ⅱ、Ⅲ期依次饲喂精料比例分别为60％、70％、80％的饲粮;第Ⅳ期饲喂精料比例80％+烟酸800 mg/kg的饲粮.结果表明:1)在试验第Ⅰ、Ⅱ、Ⅲ期,未添加烟酸条件下,随精料比例的提高,瘤胃pH显著下降(P＜0.05);瘤胃中的乙酸、丙酸、丁酸、总挥发性脂肪酸浓度随着精料比例的提高而提高,60％精料比例与70％和80％精料比例之间差异显著(P＜0.05),但70％和80％精料比例之间差异不显著(P＞0.05);瘤胃中的丙酮酸、乳酸浓度及乳酸/丙酮酸也随着精料比例的提高而提高,60％与70％精料比例之间差异不显著(P＞0.05),80％精料比例与60％、70％精料比例之间差异显著(P＜0.05);各精料比例对瘤胃氧化型烟酰胺腺嘌呤二核苷酸(NAD+)、还原型烟酰胺腺嘌呤二核苷酸(NADH)浓度和NADH/NAD+没有显著影响(P＞0.05),但NAD+浓度随着精料比例的提高有降低的趋势,而NADH浓度和NADH/NAD+有提高的趋势.2)在试验第Ⅲ、Ⅳ期,精料比例为80％条件下,与未添加烟酸相比,添加烟酸显著提高了瘤胃pH及丙酸、总挥发性脂肪酸浓度(P＜0.05),显著降低了丙酮酸、乳酸浓度及乳酸/丙酮酸(P＜0.05),而乙酸、丁酸浓度及乙酸/丙酸差异不显著(P＞0.05);与未添加烟酸相比,添加烟酸对瘤胃中总脱氢酶活性、NAD+、NADH浓度及NADH/NAD+均无显著影响(P＞0.05),但有提高NAD+浓度,降低NADH浓度及NADH/NAD+的趋势.3)第Ⅰ、Ⅱ、Ⅳ期瘤胃中均未检出乳酸脱氢酶活性,而在试验第Ⅲ期,精料比例为80％(未添加烟酸)条件下,瘤胃中检出了乳酸脱氢酶,其活性为132.9 U/mL.结果提示,添加烟酸提高了瘤胃NAD+浓度,降低了NADH浓度及NADH/NAD+,抑制了乳酸脱氢酶活性和乳酸产生,从而缓解瘤胃酸应激或酸中毒.  相似文献   

5.
试验利用发酵全混合饲料(fermented total mixed ration,FTMR)和未发酵的全混合饲料(totalmixed ration,TMR)为发酵底物,探讨2种饲料在绵羊体外瘤胃培养6 h和24 h对产气量、纤维降解率、纤维降解菌数量以及瘤胃发酵特性的影响。结果表明:培养6 h后,FTMR组的气体生成量极显著低于TMR组(P0.01),乙酸、丙酸以及总挥发性脂肪酸的生成量显著高于TMR组(P0.05)。培养24 h后,FTMR组干物质和中性洗涤纤维降解率极显著高于TMR组(P0.01),pH值显著低于TMR组(P0.05),乙酸含量极显著高于TMR组(P0.01),丙酸和总挥发性脂肪酸的含量显著高于TMR组(P0.05),两种重要的纤维降解菌Ruminococcus albus和Ruminococcus flavefaciens的拷贝数极显著高于TMR组(P0.01)。说明TMR经过发酵处理后可以提升纤维降解菌数量、干物质和中性洗涤纤维降解率、促进瘤胃发酵。  相似文献   

6.
本研究以全混合日粮为基础日粮,研究了玉米颗粒大小对荷斯坦肉牛瘤胃发酵性能和血液代谢产物的影响,为肉牛玉米适宜的粉碎粒度提供基本数据。试验选择4只体重为(592±29.9)kg装有瘤胃瘘管的荷斯坦奶牛,以全混合日粮为基础饲料,分别置于自动温湿度可调节的房间(温度24℃,相对湿度60%,22h/d)。在4×4拉丁方设计中,处理分别为全混合基础日粮组(对照组)、基础日粮+全珠玉米(处理1组)、基础日粮+粗粉玉米(处理2组)、基础日粮+细粉玉米(处理3组)。处理组中玉米替代全混合日粮的20%。为了测定瘤胃pH、氨氮和挥发性脂肪酸浓度,在早晨饲胃后每隔1h通过瘤胃插管采集瘤胃消化液,以确定瘤胃发酵特性,瘤胃消化后经颈静脉采血用于测定血液代谢物。玉米干物质摄入量受体重1.66%的限制,不同粉碎粒度玉米组干物质摄入量无显著差异(P 0.05)。不同玉米颗粒大小对平均氨氮和总挥发性脂肪酸浓度无显著影响(P 0.05),而与处理1和3组相比,处理2组瘤胃pH及乙酸与丙酸比例显著降低(P 0.05),丙酸盐浓度显著升高(P 0.05)。不同颗粒大小的玉米日粮对血液代谢物浓度无显著影响(P 0.05),但处理3组较对照组和其他处理组显著提高了血清甘油三酯浓度(P 0.05)。结果表明,荷斯坦肉牛饲喂粗粉碎玉米可提高瘤胃对饲料的消化能力,而饲喂细粉碎玉米对瘤胃微生物养分降解时间明显不足。  相似文献   

7.
本试验旨在研究马铃薯淀粉渣和玉米秸秆混合青贮料对肉牛瘤胃内环境及血清生化指标的影响.选择4头平均体重(455.00±19.50)kg的健康秦川杂交肉牛,随机分配到4×4拉丁方试验设计中.4组分别为:1)对照组,40％精料+60％玉米秸秆黄贮料;2)S25组,40％精料+45％玉米秸秆黄贮料+15％马铃薯淀粉渣和玉米秸秆混合青贮料;3)S50组,40％精料+30％玉米秸秆黄贮料+30％马铃薯淀粉渣和玉米秸秆混合青贮料;4)S75组,40％精料+15％玉米秸秆黄贮料+45％马铃薯淀粉渣和玉米秸秆混合青贮料.结果表明:各组肉牛平均日增重、干物质采食量和蛋白质摄入量均差异不显著(P＞0.05).S25、S50和S75组肉牛瘤胃液氨态氮浓度均高于对照组(P＞0.05),分别提高了58.96％、36.35％、26.17％.各组乙酸、丙酸、丁酸、戊酸、总挥发性脂肪酸浓度和乙酸、丙酸、丁酸、戊酸比例及乙酸/丙酸、(乙酸+丁酸)/丙酸均无显著差异(P＞0.05).各组间血清总蛋白、尿素氮和葡萄糖含量均无显著差异(P＞0.05).由此可知,马铃薯淀粉渣和玉米秸秆混合青贮料替代部分玉米秸秆黄贮料能提高肉牛瘤胃液氨态氮浓度,对瘤胃液挥发性脂肪酸含量和血清生化指标无影响.马铃薯淀粉渣和玉米秸秆混合青贮料可以替代肉牛饲粮中75％的玉米秸秆黄贮料.  相似文献   

8.
试验旨在应用Rusitec系统研究不同粒度日粮对绵羊瘤胃发酵特性的影响。试验分为两个处理组,日粮颗粒分别为5和0.45 mm,每个处理4个重复,适应期10 d,采样期2 d,测定不同时间发酵液总产气量、甲烷产量及发酵参数。结果显示,5 mm颗粒组的总产气量极显著高于0.45 mm颗粒组（P＜0.01）,甲烷产量不受粒度的影响（P＞0.05）;5 mm颗粒组投料后6 h的pH、6和9 h的乙酸、6 h的异丁酸、12 h的乙酸/丙酸、0和12 h的总挥发性脂肪酸、6和9 h的总氮均显著或极显著大于0.45 mm颗粒组（P＜0.05;P＜0.01）,而5 mm颗粒组12 h的丙酸及3、6、9、12 h戊酸则显著或极显著小于0.45 mm组（P＜0.05;P＜0.01）,不同粒度对其余指标没有显著影响（P＞0.05）。由此可知,人工瘤胃试验中日粮的不同粒度可影响发酵特性,较大颗粒有较高的总产气量、乙酸、乙酸/丙酸、总挥发性脂肪酸和总氮含量。  相似文献   

9.
采用单因子设计,应用瘤胃持续动态模拟装置(Rusitec-S),研究葡萄渣含量分别为0%、6%、8%、10%、12%、14%和16%的日粮对人工瘤胃发酵的影响。结果表明,随葡萄渣添加比例的增加,人工瘤胃发酵液中NH3-N浓度极显著降低(P<0.01),pH值无显著变化(P>0.05),总挥发性脂肪酸浓度、乙酸摩尔比、丙酸摩尔比、丁酸摩尔比和乙酸/丙酸随着葡萄渣比例的增加变化趋势不同。随萄萄渣含量的增加,发酵罐日粮残渣干物质降解率呈下降趋势,粗蛋白降解率0%组极显著高于14%组和16%组(P<0.01),显著高于D组和E组(P<0.05)。  相似文献   

10.
文章旨在探讨日粮添加不同水平碎米替代木薯对肉牛生长性能、养分消化、瘤胃发酵及胴体性状的影响。试验将平均体重接近的144头肉牛随机分为3组,每组6个重复,每个重复8头。3组肉牛在为期26周的饲养试验中分别饲喂碎米替代木薯水平为0、50%和100%的全混合日粮。结果：碎米替代木薯水平对肉牛的体重、采食量及大部分养分消化无显著影响（P＞0.05）,碎米完全替代木薯可以显著提高肉牛日增重和粗蛋白质表观消化率（P＜0.05）,显著降低肉牛料重比（P＜0.05）。100%碎米组肉牛瘤胃挥发性脂肪酸总量、丙酸和戊酸浓度均显著高于木薯组（P＜0.05）,但乙酸浓度及乙酸与丙酸比值均显著低于木薯组和50%碎米组（P＜0.05）。木薯组肉牛瘤胃异丁酸浓度显著高于50%和100%碎米组（P＜0.05）。100%碎米组肉牛背膘厚度显著高于50%碎米组（P＜0.05）,同时50%碎米组肉牛大理石花纹评分显著低于木薯组和100%碎米组（P＜0.05）。结论：全混合日粮用碎米完全替代木薯可以改善粗蛋白质表观消化率,提高瘤胃挥发性脂肪酸和丙酸浓度,进而改善肉牛生长性能。 [关键词]碎米|木薯|肉牛|生长性能|瘤胃发酵|胴体性状  相似文献   

11.
本试验旨在探讨不同精粗比日粮对奶山羊瘤胃液pH值、VFA以及血液中VFA含量的影响。选择8只安装永久性瘤胃瘘管的奶山羊作为试验动物,采用完全随机分组试验设计随机分为2组,分别饲喂精粗比为6∶4和4∶6的日粮,预饲期15 d,采样期3 d。结果表明,高精料组(HC组)瘤胃液pH值显著低于低精料组(HR组)(P<0.05);在采食后3 h,HC组与HR组瘤胃液pH值均下降至最低值,分别为5.71和6.08。除了乙酸含量外,HC组瘤胃液丙酸、异丁酸、丁酸、异戊酸、戊酸以及总挥发性脂肪酸(TVFA)含量分别比HR组提高4.99%、5.58%、21.81%、17.95%、18.27%、1.66%。HC组血浆中各种VFA的含量均高于HR组,其中丙酸、丁酸含量两组间差异达到显著水平(P<0.05)。HC组瘤胃液以及血浆中乙酸与丙酸比值均低于HR组,但两组间差异均不显著(P>0.05)。HC组瘤胃液乙酸、丙酸、TVFA浓度在采食后2 h达到最大值,HR组在采食后3 h达到最大值,两组日粮血浆中VFA浓度均在采食后2 h达到最大值,然后逐渐恢复到采食前水平。结论:高精料日粮导致瘤胃液pH值显著降低,瘤胃液和血浆中VFA含量增加;瘤胃液VFA生成速率HC组高于HR组。  相似文献   

12.
Three rumen fistulated wethers consumed a roughage (1200 g artificially dried grass) or a concentrate/roughage diet (600 g concentrate, 400 g dried grass per animal and day). The diets were unsupplemented or 0.5, 1 or 2 g choline per animal and day were added. After a 14-day feeding period, samples of rumen liquid were taken 0, 1, 2, 3, 4 and 6 h after morning feeding. In a second experiment, untreated and ammonia-treated wheat straw were incubated in nylon bags for 6, 12, 24, 48 and 72 h in rumen of 5 sheep fed on 1.2 kg dried grass and without or with 1 g choline per day. Choline supplementation decreased the total concentration of volatile fatty acids in rumen liquid in both types of diet (roughage: 106, 83, 89 and 87; concentrate/roughage: 142, 114, 91 and 106 mmol/l for 0, 0.5, 1 and 2 g choline per day resp.). Concentration of acetate and branched chain fatty acids in both diets and butyrate in concentrate/roughage diet was reduced as total acids. Butyrate in roughage diet was increased by added choline. Molar propionate concentration was not significantly influenced by choline (P greater than 0.05). Choline resulted in a little increase (P greater than 0.05) of dry matter degradability in rumen, especially when NH3-treated straw was incubated. The effect of choline on milk fat production of cows fed with diets rich in concentrate is probably not related to changes in rumen fermentation and digestion.  相似文献   

13.
Three rumen fistulated sheep were fed with roughage (1200 g artificially dried grass) or a concentrate/roughage diet (600 g concentrate, 400 g artificially dried grass per animal and day). The diets were unsupplemented or 0.5, 1 and 2 g niacin per animal and day were added. After a 14-day adaptation period samples of rumen liquid were taken 0, 1, 2, 3, 4 and 6 h after morning feeding. In a second experiment untreated and NH3-treated wheat straw were incubated in nylon bags for 6, 12, 24, 48 and 72 h in the rumen of 5 sheep fed with 1.2 kg artificially dried grass and unsupplemented or supplemented with 1 g niacin per day. Niacin did not significantly influence the total concentration of volatile fatty acids, acetate and branched chain fatty acids in both types of diet (P less than 0.05). 0.5 and 1 g niacin in the roughage and 0.5 g niacin in concentrate/roughage diet increased the propionic acid concentration and reduced the butyric acid concentration in rumen liquid of sheep (P less than 0.05). Niacin resulted in a small decrease (P greater than 0.05) of dry matter degradability in rumen. After 48 h incubation time, the dry matter disappearance of untreated and NH3-treated wheat straw amounted to 35.4 and 46.2% resp. The effects of niacin on rumen fermentation may be useful in avoiding ketogenic situations in dairy cows.  相似文献   

14.
The interaction of retention time in the rumen and concentrate diet on methane production in vitro and acetate:propionate ratio was examined. Twenty-four fistulated sheep were used in a complete factorial design with the sheep randomly divided into 4 groups. The sheep had a 5-wk acclimatization period on an oaten chaff diet, followed by two 3-wk diet phases. Two of the 4 groups were maintained on the oaten chaff diet for the duration of the experiment, with pot scrubbers added to the rumen of 1 of the 2 groups. The remaining 2 groups were offered a low-grain diet (35% grain) in the first diet phase followed by a high-grain diet (70% grain) in the second diet phase. Pot scrubbers were also added to the rumen of 1 of these 2 groups of grain-fed sheep. Pot scrubbers in combination with a low-grain diet decreased the amount of methane produced in vitro from 4.25 to 3.71 mmol/mL of digesta when compared with oaten chaff-fed sheep without pot scrubbers (P < 0.05). The acetate:propionate ratio was 1.6 in sheep fed a high-grain diet with pot scrubbers compared with 2.4 in sheep fed a high-grain diet without pot scrubbers in their rumen (P < 0.05). At high levels of grain, when employing a multivariate statistical analysis including all data, sheep given the combined treatment of grain and pot scrubbers were different from all other sheep groups in this experiment (P < 0.05). Furthermore, sheep fed a high-grain diet were different from sheep receiving the oaten chaff diets with and without pot scrubbers (P < 0.01 and P < 0.05, respectively). In conclusion, pot scrubbers combined with grain alter the rumen fermentation, and introducing pot scrubbers into the rumens of livestock consuming low levels of grain may be a way to lower methane emissions.  相似文献   

15.
本试验旨在明确燕麦干草与全株玉米青贮按不同比例组合对绵羊瘤胃发酵的影响。选用9头体重为(70.24±2.03)kg、体况相似且装有永久性瘤胃瘘管的杂种(美利奴×蒙古羊♀)公羊作为试验动物,按过渡期称重结果分成3组,每组3只。按燕麦干草和全株玉米青贮占粗饲料比例(干物质基础)将饲粮分为A1(100%全株玉米青贮)、A2(50%全株玉米青贮+50%燕麦干草)和A3(100%燕麦干草)3种,3种饲粮精粗比均为35∶65。采用3×3拉丁方设计,进行3期试验,每期22 d(预试期15 d,正试期7 d),正试期最后3 d采样。结果显示:1)与100%全株玉米青贮相比,以50%全株玉米青贮+50%燕麦干草或100%燕麦干草为粗饲料对绵羊瘤胃液p H和总氮浓度平均值没有产生显著影响(P0.05),但显著降低了瘤胃液氨态氮(NH3-N)、尿素氮和血浆尿素氮浓度平均值(P0.05),同时以50%全株玉米青贮+50%燕麦干草为粗饲料还显著提高了瘤胃液蛋白氮浓度平均值(P0.05)。此外,A2组的瘤胃液p H和总氮浓度平均值稍高于A3组,瘤胃液蛋白氮浓度平均值较A3组增加了8.97%,瘤胃液和血浆尿素氮浓度平均值稍低于A3组,但差异均不显著(P0.05),而瘤胃液NH3-N浓度平均值则显著低于A3组(P0.05)。2)粗饲料中燕麦干草的加入并未显著改变绵羊瘤胃液总挥发性脂肪酸浓度和丙酸摩尔比平均值(P0.05),升高了瘤胃液乙酸、丁酸摩尔比以及乙酸/丙酸平均值,且A3组与A1组差异显著(P0.05)。由此可知,在精料相同、精粗比为35∶65的条件下,用50%全贮玉米青贮和50%燕麦干草混合作为粗饲料可以改善绵羊的瘤胃内环境而适宜瘤胃微生物生长,提高瘤胃微生物活性及其对氨(NH3)的利用率,有助于微生物蛋白的合成,升高瘤胃乙酸的摩尔比及乙酸/丙酸。  相似文献   

16.
A 4 × 6 Youden square design was used to study manipulating effect of Yucca schidigera with or without nisin on rumen fermentation characteristics and microbial protein synthesis in sheep fed silage‐ and hay‐based diets. Four ruminally canulated wethers were given isonitrogenous diets of timothy silage and concentrate (85:15) (S), and timothy hay and concentrate (60:40) (H), on DM basis. The six experimental diets were: (i) S; (ii) S + 240 ppm of Yucca schidigera (SY); (iii) S + 240 ppm of Yucca schidigera + 6 mg/kg bodyweight (BW)0.75 of nisin (SYN); (iv) H; (v) H + 240 ppm of Yucca schidigera (HY); and (vi) H + 240 ppm of Yucca schidigera + 6 mg/kg BW0.75 of nisin (HYN). Rumen pH was higher (P < 0.01) in sheep fed SYN diet than those fed S diet. Concentration of ammonia‐N (NH3‐N) was significantly lower (P < 0.05) in sheep fed SY, SYN, HY, HYN than those of S and H. Total volatile fatty acids concentration was significantly lower (P < 0.05) in HYN than in H diet and tended to be higher in sheep fed H diets than those fed S diets. There was a significantly higher (P < 0.01) efficiency of microbial nitrogen synthesis in the rumen of sheep fed on HY diet than those fed on H diet.  相似文献   

17.
本试验采用尼龙袋法研究不同精粗比饲粮中添加甘露寡糖(MOS)对绵羊瘤胃养分降解率的影响。选取6只安装永久瘤胃瘘管的羯羊(白萨福克×小尾寒羊♀),采用4×6双因子析因试验设计,共设饲粮精粗比和MOS添加水平2个因子,其中饲粮精粗比分别为20∶80(A1)、30∶70(A2)、40∶60(A3)和50∶50(A4),MOS添加水平分别为0(B1)、0.4%(B2)、0.8%(B3)、1.2%(B4)、1.6%(B5)和2.0%(B6)。结果显示:饲粮精粗比对不同时间点绵羊瘤胃干物质(DM)、有机物(OM)和粗蛋白质(CP)的降解率、降解参数[DM、OM:快速降解部分(a)、慢速降解部分(b)和可降解部分(a+b);CP:a、b和b的降解速率(c)]及有效降解率均产生了显著影响(P0.05),其变化规律均为随饲粮精料比例的升高而升高,在A4组达到最高;MOS添加水平仅对不同时间点绵羊瘤胃CP的降解率及降解参数a+b产生了显著影响(P0.05),其变化规律均为随MOS添加水平的增加先升高后降低,在B5组达到最高。饲粮精粗比和MOS添加水平对绵羊瘤胃养分降解率没有产生显著的交互作用(P0.05)。由此得出,饲粮精粗比为50∶50时绵羊瘤胃干物质、有机物和粗蛋白质的有效降解率最高,MOS添加水平达到1.6%时绵羊瘤胃粗蛋白质的降解率最高。  相似文献   

18.
The influence of type of diet and time after feeding on concentration of isoacids in rumen fluid of 6 fistulated sheep were investigated. The concentration of isoacids in rumen fluid was higher in diets rich in concentrate and protein (5.6) than in roughage diets (3.4) or in straw-starch-urea diets poor in native protein (highest concentration: 2.1 mmol/l rumen fluid). Feeding of roughage diet or straw-starch-urea-diet effected a significant decrease of concentration of isoacids in the rumen fluid after morning feeding, but concentrate-roughage diet, increased the isoacids-concentration. Reasons for decreased concentration of isoacids may be a shortage of corresponding amino acids and a high activity of cellulolytic microbes. Infusion of isoacids (3 g per day) in the rumen of sheep fed with a straw-starch-sugar-urea diet did not significantly influence the in sacco dry matter degradability of untreated wheat straw, but increased the dry matter loss of ammonia treated wheat straw from 16.0; 26.6; 39.4; 54.0 and 58.8% to 17.3; 29.7; 43.1; 56.3 and 63.0% after 6; 12; 24; 48 and 72 h rumen incubation time respectively. Further experiments seem to be necessary. The effect of isoacids may be expected to occur with poor quality feeds, rich in fibre low in protein and hence low in branched-chain amino acids.  相似文献   

19.
Abstract

Three rumen fistulated and catheterized sheep were meal-fed and used to study ruminal and arterial concentrations of short-chain fatty acids (SCFA) as well as portal appearance rates of SCFA and irreversible loss rate (ILR) of acetate in 24 h periods on a hay and a concentrate/straw diet, respectively.

Ruminal and arterial concentrations as well as portal appearance rates of SCFA and ILR of acetate were significantly affected by the intake of feed. Generally, the highest concentrations and appearance rates were obtained 2 h after feeding. The portal recovery of arterial acetate was not affected by feeding or diet. The 24 h means were 0.68 ± 0.01 and 0.67 ± 0.01 on the hay and the concentrate/straw diet, respectively. Partial correlation coefficients corrected for the effects of time, sheep, and diet were calculated for the relationships evaluated. The portal appearance rate of acetate (r = 0.52, P <0.001) and the portal net appearance rate of propionate (r = 0.68, P <0.001) were linearly related to the ruminal concentrations of the two SCFA. The logarithm of the portal net appearance rate of butyrate seemed to be linearly related to the logarithm of the ruminal concentration of undissociated butyric acid (r = 0.70, P <0.001) when the effect of time was omitted from the model. The portal appearance rate of acetate (r = 0.22, P <0.05) and the portal net appearance rate of propionate (r = 0.63, P <0.001) as well as butyrate (r = 0.55, P <0.001) were linearly related to the arterial concentration of the respective SCFA. The results show that within animal and diet the ruminal as well as arterial concentrations are good predictors of SCFA portal appearance rates in sheep fed roughage at maintenance. Ruminal and arterial concentrations of SCFA seem less reliable predictors of portal appearance rates of SCFA between diets and sheep. The portal appearance of SCFA, 5.6 ± 0.5 and 7.0 ± 0.3 mol d?1, accounted for 44 ± 4 and 43 ± 2% of the calculated metabolizable energy intake on the hay and the concentrate/straw diets, respectively.  相似文献   

20.
为研究饮用磁化水对饲喂颗粒日粮绵羊消化代谢的影响,本研究设计了2个试验:试验1:选取4只约1.5岁、体重(44.7±1.8)kg的小尾寒羊公羊,采用4×4拉丁方设计,每期每只羊分别饲喂粉碎日粮(处理1)、粉碎日粮+磁化水(处理2)、颗粒日粮(处理3)及颗粒日粮+磁化水(处理4),研究饲喂粉碎、颗粒两种日粮条件下饮用磁化水对绵羊自由采食和消化代谢的影响;试验2:选取6只约1.5岁、体重(46.3±2.1)kg的小尾寒羊空怀母羊,采用3×3拉丁方设计,每期每组饲喂相同的颗粒日粮,处理1:自由采食;处理2:在自由采食条件下饮用磁化水;处理3:在限饲(相当于处理1的喂量)条件下饮用磁化水,研究饮用磁化水时限饲对绵羊消化代谢的影响。结果显示:(1)在试验1中,饮用磁化水组绵羊的干物质自由采食量,干物质、粗蛋白质和总能表观消化率及氮保留量较饲喂粉碎日粮时分别提高14.7%(P<0.05)、2.6%(P>0.05)、2.2%(P>0.05)、2.2%(P>0.05)和22.7%(P<0.01);在饲喂颗粒日粮时分别提高14.3%(P<0.05)、4.2%(P<0.05)、4.8%(P<0.05)、6.0%(P<0.01)和14.2%(P<0.05)。(2)在试验2中,饮用磁化水时限饲母羊的干物质、有机物、粗蛋白质、纤维素、半纤维素、不可酶解纤维素和半纤维素、总能表观消化率及氮保留量较自由采食时分别提高19.1%、19.0%、9.7%、18.4%、16.2%、341.5%、226.7%、17.4%和14.8%,均差异极显著(P<0.01)。综上所述,在饲喂颗粒日粮的基础上饮用磁化水时,绵羊干物质自由采食量可进一步提高;自由采食条件下饮用磁化水不影响饲喂粉碎日粮绵羊日粮消化率,但可提高饲喂颗粒日粮绵羊干物质、粗蛋白质和能量的表观消化率,且氮保留量显著增加;限饲条件下饮用磁化水可显著提高饲喂颗粒日粮绵羊日粮营养物质消化率。  相似文献   

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