全饲粮颗粒料对羔羊瘤胃代谢产物浓度变化的影响

将 2 7只陶塞特 (♂ )与藏羊 (♀ )的杂交一代 (3 5～ 4月龄 )公羔分为 3个试验组 (A、B、C) ,每只为一个重复 ,研究了1、0 9、0 8倍NRC能量、蛋白质水平的全饲粮颗粒料 ,对肥育羔羊的瘤胃氮代谢参数及血清尿素氮浓度的影响。结果表明 :各组间瘤胃液pH平均值差异不显著 (P >0 0 5 ) ;A组瘤胃液总氮平均含量显著高于C组 (P <0 0 5 ) ,有高于B组的趋势 (P =0 0 6 1) ;A组瘤胃液氨氮、血清尿素氮平均含量显著低于B、C组 (P <0 0 1或P <0 0 5 ) ;A组瘤胃液蛋白氮平均含量显著高于B、C组 (P <0 0 5 ) ;A组瘤胃液尿素氮平均含量明显高于B组 ,有高于C组的趋势 (P =0 0 6 0 )。可看出 ,A组瘤胃氮代谢状况优于B、C组 ,B组也比C组为好。     

日粮蛋白质水平对湖羊胃肠道pH、氨态氮及尿素氮的影响

本试验用装有永久性瘤胃瘘管、十二指肠近端T型瘘管的3只湖羊(35±5)kg作为试验动物,按3×3拉丁方试验设计方案,研究了日粮蛋白质水平分别为8.4%(A)、11.2%(B)、14.0%(C)时对湖羊瘤胃和十二指肠pH值、氨态氮、尿素氮浓度的影响。结果表明:①瘤胃pH为6.31~6.43,各组间差异不显著(P>0.05);十二指肠pH为2.64~2.70,各组间差异不显著(P>0.05)。②瘤胃氨态氮浓度(3.24~11.99)mg/100mL,C组极显著高于A、B组,B组极显著高于A组(P<0.01);十二指肠氨态氮浓度(3.01~7.88)mg/100mL,C组极显著高于A、B组,B组极显著高于A组(P<0.01)。③瘤胃尿素氮浓度(13.81~17.51)mg/100mL,C组极显著高于A、B组(P<0.01),B组显著高于A组(P<0.05);十二指肠尿素氮浓度(4.1~5.91)mg/100mL,B、C组极显著高于A组(P<0.01),B组与C组差异不显著(P>0.05)。     

不同蛋白质饲料对陕北绒山羊瘤胃内环境的影响

为了研究不同蛋白质饲料对陕北绒山羊瘤胃内环境和瘤胃微生物区系的影响,试验选择4只装有永久性瘤胃瘘管的陕北绒山羊,采用4×4拉丁方设计,分别饲喂棉籽粕(A组)、玉米蛋白粉(B组)、豆粕(C组)和菜籽饼(D组)4种蛋白质日粮,测定瘤胃液pH值、氨态氮浓度、精料蛋白质降解率、瘤胃微生物蛋白浓度以及微生物群体结构。结果表明:各组瘤胃液pH值均在6.07～6.63之间,各组间差异不显著(P>0.05);氨态氮浓度变化范围为99.1～265.6 mg/L,A组与D组差异不显著(P>0.05),其他各组间不同时间段均差异显著(P<0.05)或极显著(P<0.01);各组粗蛋白降解率均随着时间的延长呈上升趋势,其中C组的消化率最高;在饲喂后随着时间的延长,瘤胃微生物蛋白量呈先降低再升高再降低的趋势,在采食前各组间差异不显著(P>0.05),采食后C组处于较高水平,与其他3组差异极显著(P<0.01);通过对原虫蛋白与细菌蛋白的比较,发现4种不同蛋白质饲料对瘤胃内微生物结构的影响不显著(P>0.05)。     

牛至油对绵羊瘤胃发酵特性及饲粮营养物质瘤胃降解率的影响

本试验旨在研究牛至油对绵羊瘤胃发酵特性和饲粮营养物质瘤胃降解率的影响。试验选用4只平均体重为(40.83±4.11) kg的4周岁新疆细毛羊×杜泊羊杂交的安装永久瘤胃瘘管的绵羊,采用4×4拉丁方试验设计,对照组饲喂基础饲粮(不添加牛至油),试验组分别饲喂在基础饲粮中添加0.015%、0.030%和0.045%牛至油的试验饲粮。试验共分为4期,每期12 d,其中预试期10 d,正试期2 d。第1天于早餐采食后2、4、6及10 h采集瘤胃液,测定瘤胃液pH、挥发性脂肪酸、总氮、氨氮和尿素氮浓度,第2天利用尼龙袋法测定基础饲粮的营养物质瘤胃降解率。结果表明:1)添加牛至油对饲粮干物质、中性洗涤纤维和酸性洗涤纤维的瘤胃降解率均未产生显著影响(P0.05); 2)添加牛至油对各组在各时间点的绵羊瘤胃液pH、总氮、氨氮和尿素氮浓度均未产生显著影响(P0.05); 3) 0.030%和0.045%组绵羊瘤胃液4 h的总挥发性脂肪酸浓度显著低于对照组(P0.05); 0.015%组绵羊瘤胃液0、2、6 h乙酸比例显著低于其余各组(P0.05),6 h的乙酸/丙酸显著低于其余各组(P0.05),而2 h丙酸比例显著高于除了对照组外的其余各组(P0.05)。由此可知,饲粮中添加牛至油不影响饲粮营养物质的瘤胃降解率,对瘤胃氮浓度也无显著影响,但会影响瘤胃内挥发性脂肪酸浓度,以添加0.015%牛至油效果最好。     

饲喂燕麦-箭筈豌豆捆裹青贮对绵羊瘤胃pH与氮代谢参数的影响

选用6只装有永久瘤胃瘘管的羯羊作为试验动物,采用3×3拉丁方设计,研究了A(100%燕麦—箭筈豌豆捆裹青贮料,简称青贮料),B(80%青贮料+20%玉米)和C(63%青贮料+37%玉米)3种饲粮处理对绵羊瘤胃内环境的影响。结果表明,瘤胃液pH值为A>B>C,但A的瘤胃液总氮含量平均值显著低于处理C(P<0.05);除食前1 h处理间NH3-N浓度差异接近显著(P=0.085)外,其他时段A,B和C差异显著或不显著(P<0.05或P>0.05);瘤胃液中尿素氮仅B和C食后8 h的测值和平均值显著(P<0.01或P<0.05)高于A;C的瘤胃液蛋白氮含量平均值显著高于A(P<0.05),但3种处理差异不显著。因此,3种饲粮试羊的瘤胃液pH值和微生物蛋白合成状况间没有显著差异。     

日粮不同CP及RUP水平对奶牛瘤胃发酵的影响

试验旨在研究不同水平的粗蛋白(CP)及瘤胃非降解蛋白(RUP)的日粮对奶牛瘤胃代谢的影响。试验选择18头健康、体重相近的荷斯坦奶牛作为试验动物,随机分为6组,每组3头。采用2×3因子完全随机试验设计,其中CP设7.5%(低)、9.0%(中)、10.5%(高)3个水平,RUP设45%CP(低)、55%CP(高)2个水平,共6个处理组,饲喂相同基础日粮,精粗比为3∶7,预饲期10d,饲喂后2、4、8、12、24h从食道采集瘤胃液2d,测定瘤胃液pH值,NH3-N、微生物蛋白质(BCP)、挥发性脂肪酸(VFA)含量。结果表明,日粮CP水平对瘤胃液NH3-N浓度的影响极显著(P<0.01),对BCP及VFA的含量影响较小,总体而言,9.0%CP水平组对奶牛的瘤胃发酵略好于其他两组;日粮中高RUP(55%CP)可以显著降低瘤胃pH值且有降低NH3-N浓度的趋势,同时,对瘤胃BCP及VFA的合成有一定的促进作用。该试验条件下,日粮中CP(9.0%)和RUP(55%CP)可在一定程度上改善瘤胃代谢。     

日粮不同CP及RUP水平对奶牛瘤胃发酵的影响

试验旨在研究不同水平的粗蛋白(CP)及瘤胃非降解蛋白(RUP)的日粮对奶牛瘤胃代谢的影响.试验选择18头健康、体重相近的荷斯坦奶牛作为试验动物,随机分为6组,每组3头.采用2×3因子完全随机试验设计,其中CP设7.5％(低)、9.0％(中)、10.5％(高)3个水平,RUP设45％CP(低)、55％CP(高)2个水平,共6个处理组,饲喂相同基础日粮,精粗比为3∶7,预饲期10d,饲喂后2、4、8、12、24h从食道采集瘤胃液2d,测定瘤胃液pH值,NH3-N、微生物蛋白质(BCP)、挥发性脂肪酸(VFA)含量.结果表明,日粮CP水平对瘤胃液NH3-N浓度的影响极显著(P＜0.01),对BCP及VFA的含量影响较小,总体而言,9.0％ CP水平组对奶牛的瘤胃发酵略好于其他两组;日粮中高RUP(55％CP)可以显著降低瘤胃pH值且有降低NH3-N浓度的趋势,同时,对瘤胃BCP及VFA的合成有一定的促进作用.该试验条件下,日粮中CP(9.0％)和RUP(55％CP)可在一定程度上改善瘤胃代谢.     

不同阴阳离子水平饲粮对绵羊瘤胃内环境参数的影响

采用4×4拉丁方试验设计,将8只装有瘤胃瘘管绵羊分为4组;饲粮DCAB采用、(Na K -CI-)meq/100gDM公式计算,按DCAB水平不同分为4个处理,即A(25)、B(35)、C(45)、D(55),结果表明:(1)各处理瘤胃液pH值均在6.21～6.94之间变动,(P>0.05),各组在喂后3h下降到最低点.(2)B、C、D处理瘤胃液氨氮浓度各时间段平均值显著低于A处理(P<0.05);B处理喂后1h、3h、5h、7h NH3-N浓度显著低于A处理(P<0.05);处理NH3-N浓度变化于4.47～49.67mg/100mL之间.(3)B处理瘤胃液尿素氮各时间段浓度平均值显著高于A、C、D处理(P<0.05).(4)各处理瘤胃液乙酸、丙酸、丁酸、TVFA浓度及乙酸/丙酸值各时间段平均值问差异不显著(P>0.05);B、D处理丙酸浓度高于A、C处理(P=0.08),A处理丁酸浓度高于B、C、D处理(P=0.06),B、D处理乙酸/丙酸值低于A、C处理(P=0.07).综合考虑,35 meq/100gDM DCAB水平有利于绵羊瘤胃发酵,该组合为最佳日粮.     

不同SC/NSC日粮对徐淮白山羊瘤胃发酵的影响

选取4只体况良好、体重(30±2.5)kg的徐淮白山羊,并安装永久性瘤胃瘘管,按4×4拉丁方设计,饲喂4种结构性碳水化合物(SC)与非结构性碳水化合物(NSC)比例不同的日粮(SC/NSC3.52、2.06、1.28、0.84),分别为A、B、C、D组,研究徐淮白山羊瘤胃发酵规律.结果表明D组瘤胃液pH值极显著低于其他3组(P＜0.01);D组瘤胃液氨氮浓度(NH3-N)极显著高于A、B组(P＜0.01);A组微生物蛋白(MCP)浓度极显著低于其他3组(P＜0.01);瘤胃液总挥发性脂肪酸(VFA)、乙酸及丙酸浓度,C组最高,但差异不显著(P＞0.05);D组丁酸浓度极显著高于A、B、C三组(P＜0.01);乙酸与丙酸之比差异不显著(P＞0.05).结果表明,SC/Nsc为1.28时徐淮白山羊瘤胃发酵最佳.     

不同蛋白质结构日粮对山羊瘤胃内环境的影响

安装永久性瘤胃瘘管的山羊4只,采用4×4拉丁方设计,选用不同比例稻草、苜蓿干草、羊草与配合精料组成4种日粮,研究对瘤胃内环境的影响。结果表明:瘤胃液pH值、氨氮浓度和尿素氮浓度在5.94～6.43、16.42～29.82、0.48～0.78mg/100ml内波动,各组间差异不显著;4组瘤胃液FAA浓度为25.58～26.86mg/100ml,组间差异不显著(P>0.05);PAA中,A组(22.82mg/100ml)极显著低于B组(24.25mg/100ml)和D组(25.73mg/100ml)(P<0.01),B组和C组(23.53mg/100ml)显著低于D组(P<0.05)。     

Effects of supplemental ruminally degradable protein versus increasing amounts of supplemental ruminally undegradable protein on site and extent of digestion and ruminal characteristics in lambs fed low-quality forage

Four ruminally and duodenally cannulated Suffolk wether lambs (34.5 +/- 2 kg initial BW) were used in a 4 x 4 Latin square designed experiment to compare effects of supplemental ruminally degradable protein (RDP) vs. increasing amounts of supplemental ruminally undegradable protein (RUP) on ruminal characteristics and site and extent of digestion in lambs. Lambs were fed a basal diet of crested wheatgrass hay (4.2% CP) for ad libitum consumption, plus 1 of 4 protein supplements: isolated soy protein (RDP source) fed to meet estimated RDP requirements assuming a microbial efficiency of 11% of TDN (CON) or corn gluten meal (RUP source) fed at 50, 100, or 150% of the supplemental N provided by CON (C50, C100, and C150, respectively). Neither NDF nor ADF intake was affected (P >/= 0.18) by protein degradability, but they increased or tended to increase (P /= 0.26) for CON and C100, but increased (P /= 0.33) by protein degradability. However, true ruminal N digestibility was greater (P = 0.03) for CON compared with C100. Ruminal ammonia concentrations were greater (P = 0.002) for CON compared with C100 lambs, and increased (P = 0.001) with increasing RUP. Microbial N flows were not affected (P >/= 0.12) by protein degradability or increasing RUP. Likewise, neither ruminal urease activity (P >/= 0.11) nor microbial efficiency (P >/= 0.50) were affected by protein degradability or level of RUP. Total tract OM, NDF, and ADF digestibility was greater (P 相似文献   

Effect of varying ruminally degradable to ruminally undegradable protein ratio on nutrient intake, digestibility and N metabolism in Nili Ravi buffalo calves (Bubalus bubalis)

Four Nili-Ravi buffalo calves (100 ± 4 kg) were used in 4 × 4 Latin Square Design to evaluate the influence of varying ruminally degradable protein (RDP) to ruminally undegradable protein (RUP) ratio on dry matter intake (DMI), digestibility and nitrogen (N) metabolism. Four experimental diets A, B, C and D were formulated to contain RDP:RUP of 70:30, 65:35, 60:40 and 55:45, respectively. The calves were fed ad libitum. Dry matter intake by calves fed C diet was higher (P < 0.05) than those fed D diet and lower (P < 0.05) than calves fed A diet, however, it was similar to those fed B diet. There was a linear decrease (P < 0.01) in DMI with decreasing the RDP to RUP ratio. Similar trend was noticed in crude protein (CP) intake. Neutral detergent fiber (NDF) intake was significantly different across all treatment. The decrease in CP and NDF intake was due to decreasing trend of DMI. Dry matter (DM) digestibility in calves fed A and B diets was higher (P < 0.05) than those fed C and D diets. A linear decrease (P < 0.01) in DM digestibility was observed with decreasing the RDP to RUP ratio. Crude protein digestibility remained unaltered across all treatments. Neutral detergent fiber digestibility was higher in calves fed A and B diets than those fed C and D diets. Higher NDF digestibility in calves fed A and B diets was due to higher level of dietary RDP that might resulted in higher ruminal ammonia concentration which stimulate activity of cellulytic bacteria and ultimately increased NDF digestibility. The N retention (g/d) was similar among the calves fed B, C and D diets, however, it was higher (P < 0.05) than those fed A diet. Decreasing the RDP to RUP ratio resulted in linear increase (P < 0.01) in N retention. The N retention, as percent of N intake was significantly different across all treatments. Decreasing RDP to RUP ratio resulted in linear increase (P < 0.01) in N retention, as percent of N intake. A similar trend was noticed in N retention, as percentage of N digestion. Blood urea nitrogen (BUN) concentration in calves fed B diet was higher (P < 0.05) than those fed D diet and was lower (P < 0.05) than those fed A diet, however, it was not different from calves fed C diet. Decreasing dietary RDP to RUP ratio resulted in linear decrease (P < 0.05) in BUN concentrations. The decrease in BUN concentration was because of decreasing level of dietary RDP. The N retention can be increased by decreasing RDP to RUP ratio in the diet of growing buffalo calves and diet containing RDP to RUP ratio 55:45 is considered optimum regarding N retention in buffalo calves.     

不同纤维水平日粮对内蒙古白绒山羊瘤胃发酵的影响

选用2.5岁体重相近,安装永久性瘤胃瘘管的内蒙古白绒山羊羯羊18只,采用完全随机试验设计,分成6组,每组3只。分别饲喂中性洗涤纤维(NDF)水平为49%、52%、55%、59%、62%和65%日粮,预试期14d,正试期4d,正试期内每天06:00、10:00、13:00和18:00采集瘤胃液,测定pH、氨态氮浓度、瘤胃微生物蛋白(MCP)和挥发性脂肪酸(VFA)含量。结果表明:各处理组绒山羊瘤胃pH在10:00和13:00时显著下降(P<0.05),日粮不同NDF水平对瘤胃pH有影响;各处理组绒山羊瘤胃氨氮浓度在10:00时达到最高值,日粮NDF水平为52%和55%时适于微生物蛋白合成所需氨氮浓度;不同时间点间各处理组绒山羊瘤胃MCP浓度差异不显著(P>0.05),日粮NDF水平为52%和55%时MCP浓度最高;各处理组绒山羊瘤胃中乙酸、丙酸和丁酸浓度18:00都达到最低值,不同时间点各处理组VFA浓度无较大变化。本试验表明,内蒙古白绒山羊日粮NDF水平为52%和55%时有最适宜的瘤胃发酵水平。     

低淀粉饲粮条件下不同瘤胃降解淀粉水平对体外瘤胃发酵的影响

本试验旨在研究玉米作为淀粉来源的低淀粉饲粮条件下不同瘤胃降解淀粉(RDS)水平对体外瘤胃发酵的影响。以3头安装有永久性瘤胃瘘管的健康荷斯坦奶牛作为瘤胃液供体,各组分别以不同RDS水平饲粮作为发酵底物,体外产气法测定培养48 h时产气量和瘤胃发酵参数以及24 h时瘤胃微生物区系变化。结果表明:1)随着饲粮RDS水平的提高,体外培养48 h时产气量、潜在产气部分和产气速率呈线性升高(P0.05),快速发酵部分产气量呈线性下降(P0.05),干物质消失率呈线性升高(P0.05);2)随着饲粮RDS水平的提高,体外培养48 h时发酵液微生物蛋白、乙酸、丙酸、丁酸和总挥发性脂肪酸浓度呈线性升高(P0.05),pH和氨态氮浓度没有显著变化(P0.05);3)随着饲粮RDS水平的提高,体外培养24 h时发酵液中白色瘤胃球菌和嗜淀粉瘤胃杆菌的相对数量呈线性升高(P0.05),黄色瘤胃球菌、琥珀酸丝状杆菌、溶纤维丁酸弧菌、牛链球菌和溶淀粉琥珀酸单胞菌的相对数量没有显著变化(P0.05)。综合考虑,低淀粉饲粮条件下提高RDS水平有利于瘤胃发酵。     

Effects of supplemental ruminally degradable protein versus increasing amounts of supplemental ruminally undegradable protein on nitrogen retention, apparent digestibility, and nutrient flux across visceral tissues in lambs fed low-quality forage

Two experiments were conducted to determine effects of supplemental ruminally degradable protein (RDP) vs. increasing amounts of supplemental ruminally undegradable protein (RUP) on intake, apparent digestibility, N retention, and nutrient flux across visceral tissues in lambs fed low-quality forage. Lambs were fed a basal diet of crested wheatgrass hay (4.2% CP) for ad libitum consumption, plus 1 of 4 protein supplements: isolated soy protein (RDP source) fed to meet estimated RDP requirements (CON), or corn gluten meal (RUP source) fed at 50, 100, or 150% of the supplemental N provided by CON (C50, C100, and C150, respectively). In Exp. 1, 12 lambs (29.9 +/- 2.7 kg) were used. Forage OM intake was not affected (P = 0.46) by protein degradability or by increasing RUP (P >/= 0.31). Apparent total tract OM digestibility was not affected (P = 0.10) by protein degradability, but increased (P /= 0.40) by protein degradability or level of RUP. In Exp. 2, 16 catheterized lambs (32 +/- 5 kg) were used. Net release of ammonia-N from the portal-drained viscera (PDV) was greater (P = 0.02) for CON than for C100 and increased linearly (P = 0.002) as RUP increased. Net uptake of ammonia-N by liver was not affected (P = 0.23) by protein degradability, but increased linearly (P = 0.04) as RUP increased. Net urea-N release from liver was not affected (P >/= 0.49) by protein degradability or level of RUP. Net uptake of urea-N by PDV was greater (P = 0.02) for C100 compared with CON and increased (P = 0.04) with increasing RUP. Neither net release from PDV nor hepatic uptake of alpha-amino N were affected (P >/= 0.12) by protein degradability or level of RUP. Hepatic ammonia-N uptake accounted for 82, 38, 98, and 79% of net urea-N release from the liver for CON, C50, C100, and C150, respectively. Hepatic alpha-amino N uptake for all treatments greatly exceeded that required for the remaining urea-N release by the liver, suggesting that alpha-amino N may serve as a temporary means of storing excess N by liver between supplementation events. The pattern of net release or uptake of N metabolites between supplementation events requires further investigation.     

不同中性洗涤纤维与非纤维性碳水化合物比例日粮对山羊瘤胃和血液氮素利用的影响

试验以4只装有瘤胃瘘管和颈静脉血管留置针的徐淮白山羊(20±2)kg为试验动物,按4×4拉丁方试验设计方案,饲喂由玉米、豆粕、苜蓿干草、羊草等原料组成的中性洗涤纤维(NDF)与非纤维性碳水化合物(NFC)比例(NDF/NFC)分别为2.75(A)、1.71(B)、1.12(C)和0.74(D)组的4种日粮,研究其对山羊瘤胃和血液氮素利用的影响。结果表明:①瘤胃氨态氮浓度随日粮NDF/NFC降低而显著升高,采食1-2 h最高,然后下降。②血浆尿素氮浓度以B组最高为1 2.64 mg/dL,极显著(P<0.01)高于D组,在采食后2 h内升高而后降低,日内波动幅度以D组最大,达到4.36 mg/dL。③瘤胃液部分游离氨基酸如天门冬氨酸和谷氨酸变化显著,其浓度随NDF/NFC降低而逐渐升高。瘤胃总游离氨基酸以D组最高,极显著(P<0.01)高于A组,显著(P<0.05)高于B组。④日粮对血浆游离氨基酸浓度没有显著影响。     

Effect of dietary crude protein level and degradability on ruminal fermentation and nitrogen utilization in lactating dairy cows

The objectives of this experiment were to investigate the effects of two ruminally degradable protein (RDP) levels in diets containing similar ruminally undegradable protein (RUP) and metabolizable protein (MP) concentrations on ruminal fermentation, digestibility, and transfer of ruminal ammonia N into milk protein in dairy cows. Four ruminally and duodenally cannulated Holstein cows were allocated to two dietary treatments in a crossover design. The diets (adequate RDP [ARDP] and high RDP [HRDP]), had similar concentrations of RUP and MP, but differed in CP/RDP content. Ruminal ammonia was labeled with 15N and secretion of tracer in milk protein was determined for a period of 120 h. Ammonia concentration in the rumen tended to be greater (P = 0.06) with HRDP than with ARDP. Microbial N flow to the duodenum, ruminal digestibility of dietary nutrients, DMI, milk yield, fat content, and protein content and yield were not statistically different between diets. There was a tendency (P = 0.07) for increased urinary N excretion, and blood plasma and milk urea N concentrations were greater (P = 0.002 and P = 0.01, respectively) with HRDP compared with ARDP. Milk N efficiency was decreased (P = 0.01) by the HRDP diet. The cumulative secretion of ammonia 15N into milk protein, as a proportion of 15N dosed intraruminally, was greater (P = 0.003) with ARDP than with HRDP. The proportions of bacterial protein originating from ammonia N and milk protein originating from bacterial or ammonia N averaged 43, 61, and 26% and were not affected by diet. This experiment indicated that excess RDP in the diet of lactating dairy cows could not be efficiently utilized for microbial protein synthesis and was largely lost through urinary N excretion. At a similar MP supply, increased CP or RDP concentration of the diet would result in decreased efficiency of conversion of dietary N into milk protein and less efficient use of ruminal ammonia N for milk protein syntheses.     

瘤胃灌注不同来源淀粉对牦牛瘤胃发酵及血清生化指标的影响

本试验旨在探讨瘤胃灌注不同来源淀粉对牦牛瘤胃发酵及血清生化指标的影响.选用3头装有永久性瘤胃瘘管、体况良好、体重相近[( 244±15) kg]的去势牦牛,采用3×3拉丁方试验设计,对照组按照1.2倍维持能量水平饲喂单一燕麦草(未灌注淀粉),玉米淀粉组和抗性淀粉组分别在对照组的饲喂基础上瘤胃灌注玉米淀粉和抗性淀粉900 g/d.试验分为3期,每期试验18 d(15 d预试期和3d采样期).结果表明:与对照组相比,灌注玉米淀粉和抗性淀粉显著降低瘤胃pH(P ＜0.05),极显著降低瘤胃氨态氮含量(P＜0.01),灌注4h后显著提高瘤胃微生物蛋白质和挥发性脂肪酸含量(P＜0.05).在灌注后4和6h,玉米淀粉组和抗性淀粉组血糖含量显著高于对照组(P＜0.05),血清胰岛素、胰高血糖素和甘油三酯含量与对照组相比差异不显著(P＞0.05),血清尿素氮含量显著低于对照组(P＜0.05).结果提示,瘤胃灌注玉米淀粉和抗性淀粉,降低了牦牛瘤胃氨态氮含量,提高了微生物蛋白质和挥发性脂肪酸含量,提高了血糖含量,降低了血清尿素氮含量,说明牦牛能有效利用不同来源的淀粉.     

灌注果寡糖对生长绵羊瘤胃发酵功能的影响

采用营养灌注技术研究了果寡糖对生长绵羊瘤胃发酵功能的影响。试验选取6只安装有永久性瘤胃瘘管的内蒙古半细毛羯羊，随机分为两组，试验组一灌注1．00％果寡糖，试验组二灌注2．00％果寡糖。结果表明：灌注果寡糖可以显著（P〈0．05）降低试羊的瘤胃液相pH和瘤胃内的NH3-N浓度，显著提高（P〈0．05）瘤胃内的VFA含量和MCP含量。两个灌注水平都可以提高生长绵羊的瘤胃发酵功能。但2．00％的灌注水平仅在瘤胃NH3-N浓度的降幅方面比1．00％的灌注水平显著增大（P〈0．05），在对瘤胃液相pH值、VFA含量和MCP含量的影响方面两个灌注水平没有显著差异（P〉0．05）。     

Ruminal dynamics of ad libitum feeding in buffalo bulls receiving different level of rumen degradable protein

Four ruminally cannulated Nili-Ravi buffalo bulls were used in a 4 × 4 Latin Square Design to determine the influence of varying level of ruminally degradable protein (RDP) on dry matter intake (DMI), ruminal characteristics, digestibility, blood pH, blood urea nitrogen (BUN) and nitrogen (N) balance. Four isonitrogenous and isocaloric diets were formulated. The C diet contained 50% RDP while medium, high and very high RDP diets had 66, 82 and 100% RDP of the total crude protein (CP) and were denoted as MRDP, HRDP and VHRDP, respectively. The bulls were fed ad libitum. Nutrients intake decreased linearly with increasing the RDP proportion of total dietary CP. A quadratic effect of RDP on ruminal pH was noticed with increasing level of RDP with quadratic maxima at 66% RDP diet. Increasing level of dietary RDP also had a quadratic effect on total bacterial and protozoal count with maximum microbial count at 82% RDP diet. Increasing dietary RDP resulted in linear increase in DM digestibility. However, neutral detergent fiber digestibility was decreased linearly with increasing the level of dietary RDP. A linear increase in ruminal NH₃–N and BUN was noticed due to increasing level of dietary RDP. Higher positive N balance was noticed in bulls fed C diet compared to those fed MRDP, HRDP and VHRDP diets. The findings of this study indicated that buffalo bulls can effectively utilize 13.12% RDP of DM without any adverse effect on rumen and blood parameters.