【作者】 张婷；

【导师】 陈宇光；

【作者基本信息】 湖南农业大学 ， 特种经济动物饲养， 2015， 硕士

【摘要】 本研究以农副产品玉米秸秆为主要粗饲料来源,选用玉米青贮与能乳发调整低、高能量水平,普通玉米与蒸汽压片玉米作为不同加工方式,采用2x2因子试验设计,参照NRC(2001)奶牛营养需要配制4种饲粮：玉米秸秆和普通玉米组成的低能玉米组(LEGC),玉米秸秆和蒸汽压片玉米组成的低能压片玉米组(LESFC),秸秆、普通玉米、玉米青贮和能乳发组成的高能玉米组(HEGC)以及秸秆、压片玉米、玉米秸秆青贮和能乳发组成的高能压片玉米组(HESFC)。通过开展3个试验：CNCPS体系、体外产气试验及动物饲养试验,研究不同加工方式玉米及能量水平饲粮对奶牛泌乳性能的影响。试验I：旨在通过CNCPS体系研究4种饲粮及其原料的营养价值,以便了解不同原料搭配后的4种饲粮在营养水平上是否满足预期。结果表明：玉米青贮CNSC、CA与CB1部分高于玉米秸秆,CB2与CC部分小于玉米秸秆；蒸汽压片玉米CNSC、CA与CB1部分也高于玉米、CB2与CC部分小于玉米。所以由玉米青贮与玉米秸秆组合的高能组饲粮CNSC、CA、CB1高于低能组。蒸汽压片玉米组的CB1(果胶和淀粉)高于玉米组。试验Ⅱ：旨在采用体外产气法,研究不同能量水平与不同加工玉米的饲粮对瘤胃体外发酵参数的影响。采用3头体况良好且装有永久性瘤胃瘘管的荷斯坦奶牛作为瘤胃液的供体动物,结合动态产气实时记录技术,记录样品48 h累积产气量、发酵动力学参数和瘤胃发酵特性指标。结果表明：高能组饲粮的理论最大产气量、48 h总产气量、干物质降解率均显著高于低能组(P<0.05),普通玉米高能组的乙酸、丙酸含量显著高于低能组(P<0.05)。同一能量水平下,蒸汽压片处理组的48 h总产气量均显著高于普通玉米组(P<0.05)；而低能条件下蒸汽压片组的总挥发酸、丙酸含量显著高于普通玉米组(P<0.05)。不同饲粮营养水平与体外产气参数相关性分析表明48 h总产气量与中性洗涤纤维(NDF)呈显著的负相关(P<0.05),与中性洗涤可溶物(NDS)、非纤维性碳水化合物(NFC)与NDS/CP呈显著正相关(P<0.05)。因此,通过使用蒸汽压片玉米和提高饲粮能量水平均可以显著增加体外发酵48 h总产气量；低能水平下,蒸汽压片玉米对改善瘤胃的发酵特性更为明显。试验Ⅲ：旨在采用饲养消化代谢试验,研究不同能量水平与不同加工玉米的饲粮对奶牛全肠道消化率和泌乳性能的影响。将8头试验奶牛随机分成4组,每组2头,采用4×4拉丁方设计,分别饲喂上述4种饲粮。试验共4期,每期21 d,预饲期14 d,采样期7 d。在每个采样期连续3天采集饲料样与剩料样,乳样、全收粪样。除此之外,每周采集2次奶样,每天记录产奶量。结果表明：各处理组间DMI、OMI和CPI均以高能组极显著高于低能组(P<0.01),DM、OM、CP、NDF、ADF全肠道表观消化率均以高能组极显著高于低能组(P<0.01)。低能水平下,蒸汽压片玉米组OM、 CP全肠道表观消化率极显著高于低能组(P<0.01)。高能组的乳产量、乳蛋白产量和乳糖产量均极显著高于低能组(P<0.01),在普通玉米组中,高能组乳脂肪极显著高于低能组(P<0.01)。低能水平下,蒸汽压片玉米组乳产量、乳蛋白产量均极显著高于普通玉米组(P<0.01)；上述结果表明：在以玉米秸秆为主要粗饲料来源的饲粮中,通过补充能量水平可以提高奶牛泌乳性能,在低能水平下,通过使用蒸汽压片玉米代替普通玉米可以提高奶牛泌乳性能。更多还原

【Abstract】 This study com silage and rumen protected fat were selected to regulate the low and high energy level, ground com and steam-flaked com were used as different com processing based on com stover for the main forage resources in 2*2 factorial experiment. Diets were com stover and ground com for LEGC; Com stover and steam-flaked com for LESFC; Com stover, ground com, com silage and rumen protected fat for HEGC; com stover, Steam-flaked com, com silage and rumen protected fat for HESFC. Though established three trials at the follows:CNCPS system, in vitro gas production and animal feed test to evaluate the effects of different energy level and com processing on lactation performance of dairy cows.Trial 1 This part was to evaluate the nutrition level of 4 diets which combined by different material in CNCPS system. The result showed that CNSC, CA and CB1 of com silage were higher than com stover,CB2 and CC of com silage were lower than corn stover; CNSC, CA and CB1 of steam-flaked com were higher than ground com. Therefore, high energy diets which combined the com silage and com stover have more degradable carbohydrate than low energy. CB1 of steam-flaked com was higher than ground com.Trial 2 The experiment was designed to research the effect of different energy level and com processing diets on rumen fermentation parameters in vitro.3 Holstein cows fitted with permanent ruminal cannulas were selected as fumenfluid donor animal, combined the dynamic gas production real-time recording technology, recorded 48 h cumulative gas production and fermentation kinetic parameters, analyzed rumen fermentation indexes. The result demonstrated that theoretical maximum gas production,48 h total gas production, dry matter degradability(DMD) of high-energy diets were higher than the low energy (P<0.05), acetate and propionate of high-energy were greater than the low-energy in ground corn(P<0.05). Under the same energy level,48 h total gas production (GP) deal with steam-flaked com were higher than ground com (P<0.05) just under low-energy level, total volatile fatty acid(TVFA) and propionate of Steam-flaked com were higher than ground corn(P<0.05). Correlation between different diets chemical compositions and fermentation parameters in vitro analysis showed that 48 h total gas production was a significant negative (P<0.05) related to neutral detergent fiber (NDF), both had a significant positive correlation (P<0.05) to neutral detergent soluble (NDS), non-fiber carbohydrate (NFC) and NDS/CP. Steam-flaked corn and high-energy level diets which increased the 48 h total gas production in vitro fermentation. Steam-flaked corn improved the ruminal fermentation more evidently in low-energy level.Trial 3:This part was to evaluate the effect of different energy level and corn processing diets on total-tract apparent digestibilities and lactation performance though animal feed test. Eight multiparous Holstein dairy cows were randomly assigned to 2 of 4 treatments feeding the above 4 diets,and were used in 4 replicated 4*4 Latin squares with 21-d periods, with the first 14-d for adaptation, the last 7-d for taking samples about TMR(Total Mix Ration) and ort diets, milk sample, total feces lasted three days. Beside, taken milk sample two times per week and recorded milk yield per day. The result showed that DM.OM and CP of dry matter intake were highly significant higher in cows fed diets of high energy than diets of low energy (P<0.01). DM,OM,CP,NDF and ADF of total-tract apparent digestibilities in high energy were highly significant higher than low energy (P<0.01). Under low energy level, OM and CP of total-tract apparent digestibilities in steam-flaked corn were highly significant higher than in ground corn (P<0.01). Milk yield, milk protein content and protein percentage were highly significant higher in high energy diets than in low energy(P<0.01),milk fat was highly significant lower in high energy diets than in low energy (P<0.01); Under the low energy, fed steam-flaked corn with highly significant higher milk yield, milk and protein percentage than in ground corn (P<0.01).It is indicated that supplement energy in diets based on corn stover as the main roughage source could improve lactation performance; steam-flaked corn substituted with ground corn could improve lactation performance in low energy.更多还原