共查询到19条相似文献，搜索用时 218 毫秒
1.
蛋白质摄入量对牛奶尿素氮影响的评价 总被引：4，自引：0，他引：4
本文分析了奶牛瘤胃降解蛋白(RDP)、瘤胃非降解蛋白(RUP)日摄入量和泌乳净能(NEL)日摄入量对牛奶尿素氮(Milk Urea Nitrogen,MUN)值直接影响的程度大小,结果是RUP摄入量的影响程度最大(P<0.001),RDP摄入量次之(P=0.001),NEL摄入量的影响最小(P=0.414)。NEL摄入量对MUN的影响主要是通过RDP和RUP的摄入量来对MUN产生间接影响。用RDP摄入量(X1)和RUP摄入量(X2)估测MUN(Y)的多元回归方程:Y=0.50×X1+0.65×X2-14.82(R2=0.92,P<0.001) 相似文献
2.
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. 相似文献
3.
4.
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。 相似文献
5.
可降解蛋白及非蛋白氮对模拟瘤胃体外发酵、营养物质降解率的影响 总被引：5，自引：0，他引：5
以11.85%和8.38%两个水平的可降解蛋白(RDP)及非蛋白氮(NRN)作为试验因子,进行2×2试验设计。应用体外短期发酵技术,研究了RDP及RDP与非蛋白氮组合对模拟瘤胃发酵及营养物质降解率的影响。结果表明:添加NPN处理组的pH、NH3-N浓度显著(P<0.05)高于未添加NPN处理组。高RDP水平pH值、NH3-N浓度、细菌N与低RDP水平的相比,高RDP处理组显著(P<0.05)高于低RDP处理组,说明日粮中RDP水平显著提高瘤胃内pH值、NH3-N浓度和细菌N的产量。同时发现,RDP与NPN互作对瘤胃发酵影响不显著。对瘤胃发酵营养物质降解率的研究发现,反刍动物日粮中添加适量的NPN,有利于优化瘤胃内环境,提高物质成分在瘤胃中的降解率。RDP水平对模拟瘤胃发酵时干物质(DM)、酸性洗涤纤维(ADF)降解没有显著影响,但显著提高了中性洗涤纤维(NDF)的降解率。 相似文献
6.
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。 相似文献
7.
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%(中)1、0.5%(高)三个水平,RUP设45%CP(低)、55%CP(高)两个水平,共6个处理组,饲喂相同基础日粮,精粗比为3:7,预饲期10 d,饲喂后2、4、8、12、24 h从食道采集瘤胃液2 d,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水平对瘤胃液氨氮浓度的影响极显著(P<0.01),对BCP及VFA的含量影响较小,总体而言,9%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。本试验条件下,日粮中CP(9%)和RUP(55%CP)可在一定程度上改善瘤胃代谢。 相似文献
8.
9.
试验旨在研究发酵0、3、7、15、30 d的全混合日粮(TMR)对瘤胃降解特性以及小肠消化率的影响。选用3头体重为550 kg左右、安装有永久性瘤胃瘘管的荷斯坦奶牛,采用尼龙袋法和三步体外法测定发酵全混合日粮(FTMR)的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)的瘤胃降解率以及瘤胃未降解蛋白(RUP)的小肠消化率。结果表明:随着发酵时间的延长,FTMR饲料的DM含量显著降低(P<0.05);随着发酵时间的延长,显著提高FTMR的DM、CP、NDF的瘤胃降解率(P<0.05)和CP、NDF的快速降解部分(P <0.05);同时发酵显著降低RUP的小肠消化率(P <0.05)。综上可知,全混合日粮提高了DM、CP和NDF在瘤胃中的瘤胃降解率,15、30 d的FTMR各营养成分的瘤胃降解性较好;RUP的小肠消化率随发酵时间的延长开始逐渐降低,7d之后降低最为明显。因此,应控制好TMR的发酵时间,以便更有效地利用饲料资源。 相似文献
10.
6种饲料原料瘤胃降解特性和瘤胃非降解蛋白质的小肠消化率 总被引：3，自引：0，他引：3
本试验旨在研究新疆地区玉米青贮、棉籽壳、苜蓿草粉、苜蓿干草、葡萄籽粕、蕃茄酱渣6种奶牛饲料原料的瘤胃降解特性和瘤胃非降解蛋白质(RUP)的小肠消化率(Idg)。选用3头装有永久性瘤胃瘘管的泌乳荷斯坦奶牛,采用尼龙袋法和改进三步体外法测定饲料原料的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解特性以及RUP的Idg和小肠可消化粗蛋白质(IDCP)含量。结果表明:1)苜蓿草粉和玉米青贮的DM有效降解率最高,显著高于次之的苜蓿干草、番茄酱渣(P0.05),葡萄籽粕、棉籽壳最低,显著低于其他原料(P0.05);CP有效降解率为番茄酱渣苜蓿草粉玉米青贮苜蓿干草棉籽壳葡萄籽粕,各原料间差异显著(P0.05);NDF有效降解率为玉米青贮苜蓿草粉棉籽壳苜蓿干草番茄酱渣葡萄籽粕,各组饲料原料间差异显著(P0.05);ADF有效降解率为玉米青贮棉籽壳苜蓿干草番茄酱渣苜蓿草粉葡萄籽粕,各组饲料原料间差异显著(P0.05)。2)苜蓿草粉RUP的Idg和IDCP含量最高,Idg显著高于依次降低的苜蓿干草、玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05),IDCP含量与苜蓿干草差异不显著(P0.05),显著高于依次降低的玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05)。综上所述,不同饲料原料具有不同的瘤胃降解特性,进入小肠IDCP的含量也不同。玉米青贮的DM、NDF和ADF在瘤胃的有效降解率较高,苜蓿草粉RUP的Idg较高,苜蓿草粉和苜蓿干草的IDCP含量较高。 相似文献
11.
Effect of dietary crude protein level and degradability on ruminal fermentation and nitrogen utilization in lactating dairy cows 总被引：1，自引：0，他引：1
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. 相似文献
12.
M. Jahani‐Moghadam H. Amanlou A. Nikkhah 《Journal of animal physiology and animal nutrition》2009,93(6):777-786
Effects of different dietary rumen undegradable (RUP) to degradable (RDP) protein ratios on ruminal nutrient degradation, feed intake, blood metabolites and milk production were determined in early lactation cows. Four multiparous (43 ± 5 days in milk) and four primiparous (40 ± 6 days in milk) tie‐stall‐housed Holstein cows were used in a duplicated 4 × 4 Latin square design with four 21‐day periods. Each period had 14‐day of adaptation and 7‐day of sampling. Diets contained on a dry matter (DM) basis, 23.3% alfalfa hay, 20% corn silage and 56.7% concentrate. Cows were first offered alfalfa hay at 7:00, 15:00 and 23:00 hours, and 30 min after each alfalfa hay delivery were offered a mixture of corn silage and concentrate. Treatments were diets with RUP:RDP ratios of (i) 5.2:11.6 (control), (ii) 6.1:10.6, (iii) 7.1:9.5 and (iv) 8.1:8.5, on a dietary DM% basis. Different RUP:RDP ratios were obtained by partial and total replacement of untreated soybean meal (SBM) with xylose‐treated SBM (XSBM). In situ study using three rumen‐cannulated non‐lactating cows showed that DM and crude protein (CP) of SBM had greater rapidly degradable fractions. The potentially degradable fractions were degraded more slowly in XSBM. Treatment cows produced greater milk, protein, lactose, solids‐non‐fat and total solids than control cows. Increasing RUP:RDP reduced blood urea linearly. Feed costs dropped at RUP:RDP ratios of 6.1:10.6 and 7.1:9.5, but not at 8.1:8.5, compared with the 5.2:11.6 ratio. Intake of DM and CP, rumen pH, blood glucose, albumin and total protein, faecal and urine pH, changes in body weight and body condition score, and milk lactose and solids‐non‐fat percentages did not differ among treatments. Results provide evidence that increasing dietary RUP:RDP ratio from 5.2:11.6 to 7.1:9.5 optimizes nitrogen metabolism and milk production and reduces feed costs in early lactation cows. Reduced blood urea suggests reprodutive benefits. 相似文献
13.
泌乳早期乳中尿素氮含量对奶牛繁殖性能的影响 总被引：1，自引：0，他引：1
为探索奶牛泌乳早期乳中尿素氮含量对产后繁殖性能的影响,本研究选取海丰奶牛场的头胎荷斯坦牛1932头,于产犊后30d内采集乳样,测定乳中尿素氮含量,并收集试验牛只产后繁殖资料,用多因素方差分析法分析乳中尿素氮对产后繁殖性能的影响。结果表明,试验牛只产犊后1个月内乳中尿素氮含量为9．22±2．78mg／dL;乳中尿素氮含量对个体情期受胎率有显著影响（P〈0．05）,而对产后首次配种天数有极显著影响（P〈0．01）,乳中尿素氮含量大于15mg／dL的奶牛产后第一次配种天数显著高于低于此数值的奶牛,且个体情期受胎率显著低于此数值低的奶牛。同时乳中尿素氮含量与个体情期受胎率呈极显著负相关（P〈0．01）。据此认为,作为反映能氮平衡的关键指标,泌乳早期乳中尿素氮含量可作为预测奶牛产后繁殖性能的指标加以利用。 相似文献
14.
C. Wang S. W. Zhai J. L. Lai Y. M. Wu 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):100-103
Abstract Fifteen multiparous dairy cows were used in a five replicated 3×3 Latin square design to study the effects of ratio of rumendegradable-protein (RDP) and rumen-undegradable-protein (RUP) on nitrogen (N) conversion in Chinese Holstein dairy cows. Three diets were formulated isonitrogenously with varying ratio of RDP/RUP. High ratio of RDP/RUP resulted in high urinary N excretion and total N excretion, but no significant dietary effects were observed on milk yield, milk composition, and nitrogen excretion in faeces. Different protein degradability changed the partitioning of the N excretion between urine and faeces. Results indicated that reduction in ratio of RDP/RUP could improve the efficiency of N utilization in lactating dairy cows by reduced N excretion in urine and faeces without impairing milk production. 相似文献
15.
本研究以12头泌乳中期荷斯坦牛为研究对象,采用随机区组设计分为3组,在干物质进食量相似的条件下,增加瘤胃快速可发酵能量,用玉米粉颗粒替代甜菜渣颗粒,三个处理分别替换0kg、0．4kg和0．8kg,试验期61d。结果表明,日粮处理对奶牛的产奶量和乳成分没有明显影响,玉米粉颗粒替代甜菜渣颗粒饲喂奶牛后可显著降低牛奶中尿素氮（MUN）浓度,评价目粮的瘤胃能氮平衡表明为正平衡,有明显低水平的MUN。试验证明,可以用日粮瘤胃能氮平衡判断饲喂日粮对奶牛MUN的影响。 相似文献
16.
奶牛主要饲料原料蛋白质瘤胃降解率的研究 总被引：2，自引：0，他引：2
以3头安装永久性瘤胃瘘管的荷斯坦产奶牛为试验动物。用尼龙袋法研究测定了奶牛常用饲料蛋白质在瘤胃内的动态降解规律及其有效降解率。结果表明：常用蛋白质饲料中葵花粕与豆粕粗蛋白（CP）的有效降解率较高。酒糟CP降解率最低。籽实与糠麸类饲料中麸皮CP有效降解率最高，稻壳最低。常用粗饲料中苜蓿草与苜蓿草块的CP有效降解率均高于其他粗饲料，玉米秸秆的CP有效降解率最低。不同饲料蛋白质瘤胃有效降解率与蛋白质慢速降解组分呈极显著中度正相关（r=0．5013，P〈0．01），与蛋白质快速降解组分呈弱的正相关（相关性趋于显著r=0．3675。P=0．06），与非降解组分呈极显著高度负相关（r=-0．7153，P〈0．01）。 相似文献
17.
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
18.
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. 相似文献
19.
Atkinson RL Toone CD Robinson TJ Harmon DL Ludden PA 《Journal of animal science》2007,85(12):3331-3339
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. 相似文献