【作者】 徐明；

【导师】 姚军虎；

【作者基本信息】 西北农林科技大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 一、煮玉米比例对泌乳牛产乳性能、养分消化和血液指标的影响　 试验采用 ４×４ 拉丁方设计，研究在自由采食“麦秸＋玉米秸秆青贮”的粗饲料条件下，煮玉米比例对中低产的黑白花中期泌乳牛产乳性能、养分消化和血液指标的影响。四处理组分别为 ０／３ 煮玉米组（对照组）、１／３ 煮玉米组、２／３ 煮玉米组和 ３／３ 煮玉米组。日粮中玉米全部粉碎，平均粒度为 １．４ｍｍ。煮玉米比例为处理玉米与日粮总玉米的比值。结果表明，与对照组相比，煮玉米比例不影响各类饲料采食量、ＤＭＩ、乳中脂肪、蛋白、乳糖、ＳＮＦ、固形物含量和乳密度。１／３ 煮玉米提高原乳及 ＦＣＭ 产量 ３．９％和 ４．０％（Ｐ＜０．０５），２／３ 和 ３／３ 煮玉米组不影响饲料采食量和乳产量（Ｐ＞０．０５），１／３、２／３ 和 ３／３ 煮玉米组提高了 ＤＭ、ＯＭ、能量、淀粉的全消化道表观消化率，降低了 ＮＤＦ 和 ＡＤＦ 消化率。１／３、２／３ 和 ３／３ 煮玉米对 ＣＰ 消化率的影响未达显著水平，但 ２／３ 组与 １／３ 组相比，ＣＰ 消化率下降了 ９．４％（Ｐ＜０．０５）。１／３ 煮玉米组与 ０／３、２／３ 和 ３／３ 煮玉米组相比降低了粪便含水率（Ｐ＜０．０５）。１／３、２／３ 和 ３／３ 煮玉米组分别降低血浆葡萄糖浓度 １２．１％（Ｐ＞０．０５）、１９．２％和 ２１．１％（Ｐ＜０．０５），提高尿素氮浓度 ２．４％（Ｐ＞０．０５）、１９．３％和 １７．５％（Ｐ＜０．０５）。综上，在自由采食“麦秸＋玉米秸秆青贮”的粗饲料条件下，煮沸处理中低产的黑白花中期泌乳牛日粮中 １／３ 玉米，可显著提高泌乳性能。　 二、烫玉米比例对泌乳牛泌乳性能的影响　 实施两个试验，研究烫玉米在不同粗饲料条件下对泌乳牛产奶性能的影响。日粮中玉米全部粉碎，平均粒度为 １．４mm。烫玉米比例为处理玉米与日粮总玉米的比值。试验 １：选择四头荷斯坦中期泌乳牛，采用 ４×４ 拉丁方设计，研究在自由采食“麦秸＋青贮玉米”的粗饲料条件下，烫玉米比例对产乳性能的影响。四处理组分别为 ０／３ 烫玉米组（对照组）、１／３ 烫玉米组、２／３ 烫玉米组和 ３／３ 烫玉米组。结果表明，烫玉米比例不影响 DMI 和乳中脂肪、蛋白、SNF 含量和乳密度（Ｐ＞０．０５）。２／３ 烫玉米组分别提高了原乳和 FCM 产量 ６．４％（Ｐ＜０．０５）和 ７．０％（Ｐ＞０．０５），１／３ 和 ３／３ 烫玉米组不影响原乳和 FCM 产量（Ｐ＞０．０５）。试验 ２：６ 头荷斯坦中期泌乳牛随机分为两组，每组 ３ 头，采用<WP=6>２ 重复 ３×３ 拉丁方设计，研究在每天投喂 １５ｋｇ 苜蓿青草和自由采食青贮玉米的粗饲料条件下烫玉米的效果。三个处理组分别为 ０／４ 烫玉米组（对照组）、１／４ 烫玉米组和 ２／４烫玉米组。结果表明，烫玉米比例不影响各类饲料采食量、ＤＭＩ、乳密度和乳脂、乳蛋白、SNF 含量和乳密度。１／４ 烫玉米不影响原乳和 FCM 产量，2/4 烫玉米极显著降低了原乳产量（P＜0.01），不影响 FCM 产量。结果显示，在“麦秸＋青贮”的粗饲料条件下，２／３ 烫玉米可显著改善泌乳性能；在“苜蓿青草＋青贮”的粗饲料条件下，烫玉米有降低乳产量的趋势。　 三、泡玉米和煮玉米对泌乳牛泌乳性能的影响　 8 头荷斯坦中期泌乳牛随机分为两组，每组 4 头，采用 2 个 4×4 拉丁方，分别研究在自由采食“麦秸＋青贮玉米”和每天投喂 3.5kg苜蓿干草和自由采食青贮玉米的粗饲料条件下，煮玉米和泡玉米对荷斯坦中期泌乳牛产乳性能的影响。四处理组分别为对照组、1/3煮玉米组、1/3泡玉米组和2/3泡玉米组。日粮中玉米全部粉碎，平均粒度为1.4mm。处理玉米比例为处理玉米与日粮总玉米的比值。 与对照组相比，在麦秸日粮条件下，泡玉米比例不影响 DMI，乳产量和 FCM 产量随使用比例提高而线性提高，但均未达显著水平（P>0.05）。乳脂、乳蛋白、SNF 和固形物含量和产量，及饲料利用效率不受泡玉米比例的影响。与对照组相比，1/3 煮玉米趋于提高青贮、麦秸及 DMI（P>0.05），提高乳产量 4.6%和 FCM 产量 3.8%（P<0.05），不影响乳脂、乳蛋白、SNF 和固形物含量（P>.05），提高饲料利用效率；在苜蓿干草日粮条件下，泡玉米比例不影响 DMI、乳产量、FCM 产量、乳密度，乳脂、乳蛋白、SNF 和固形物含量，及饲料利用效率（Ｐ＞０．０５）。与对照组相比，１／３ 煮玉米不影响 DMI、乳产量和 FCM 产量（Ｐ＞０．０５），趋于降低乳脂、乳蛋白、SNF 和固形物含量和乳密度，不影响饲料利用效率（Ｐ＞０．０５）。与 ２／３ 泡玉米相比，１／３ 煮玉米降低乳脂率（Ｐ＞０．０５）、乳蛋白率、SNF 和固形物含量（Ｐ＜０．０５），不影响乳密度和饲料利用效率。结果显示，在“麦秸＋青贮”的粗饲料条件下，1/3 煮玉米可提高泌乳性能；在“苜蓿干草＋青贮”的粗饲料条件下，泡玉米和煮玉米不影响泌乳性能。更多还原

【Abstract】 Effects of Percentage of Boiled Corn on Lactational Performance, NutrientDigestibility, and Contents of Plasma Glucose and Urea Nitrogen ofLactating Cows Four midlactation Holstein cows were used in a 4×4 Latin square design to determine theeffects of the percentage of boiled corn(BC) on lactational performance, nutrient digestibility,and contents of plasma glucose and urea nitrogen in roughage of wheat straw and corn silage.Four treatments were 0/3 boiled corn, 1/3 boiled corn, 2/3 boiled corn and 3/3 boiled cornrespectively. All corn in diets was cracked with mean particle size of1.4mm. Processing cornpercentage was the proportion of processing corn to all corn in diet. DMI, percent of milk fat,protein, lactose, and SNF, and milk density were not affected by treatments. Compared to0/3BC, 1/3BC increased 3.9% of milk yield and 4.0% of FCM yield (P<0.05), and 2/3BC and3/3BC did not affect yield of milk and FCM, 1/3BC, 2/3BC and 3/3BC increased total tractdigestibility of DM, OM, energy and starch, and decreased total tract digestibility of NDF andADF. Compared to 0/3BC, 1/3BC, 2/3BC and 3/3BC did not affect total tract digestibility ofCP (P>0.05), but relative to 1/3BC, 2/3BC decreased 9.4% of total tract digestibility of CP(P<0.05). Compared to 0/3BC, 2/3BC and 3/3BC, 1/3BC decreased the moisture of feces(P<0.05). Relative to 0/3BC, 1/3BC, 2/3BC and 3/3BC decreased 12.1% (P>0.05), 19.2% and21.1% (P<0.05) of plasma glucose concentration, and increased 2.4%(P>.05), 19.3% and17.5% (P<0.05) of urea nitrogen concentration, respectively.Effects of Percentage of Scalded Corn on Lactational Performance ofLactating Cows<WP=8>Two experiments were conducted to investigate the effects of the percentage of scaldedcorn (SC) on lactational performance of lactating cows. All corn in diets was cracked withmean particle size of 1.4mm. Processing corn percentage was the proportion of processingcorn to all corn in diet. Trial 1: Four midlactation Holstein cows were used in a 4×4 Latinsquare design to determine the effects of the percentage of SC on lactational performance inroughage of wheat straw and corn silage. Four treatments were 0/3 SC, 1/3 SC, 2/3 SC and3/3 SC. The results show that: DMI, percent of milk fat, protein and SNF, and milk densitywere not affected by treatments; compared to 0/3BC 2/3BC increased 6.4% of milk yield（P<0.05）and 7.0% of FCM yield (P>.05), and there are no significant difference of milkyield and FCM yield among 0/3BC, 1/3SC and 3/3SC (P>0.05).　Ｉn trail 2: six midlactationHolstein cows were used in two replicate 3×3 Latin square design to determine the effects ofthe percentage of SC on lactational performance in roughage of green alfalfa and corn silage.Three treatments were 0/4 SC, 1/4 SC and 2/4 SC. The results show that: DMI, percent ofmilk fat, protein and SNF, and milk density were not affected by treatments; compared to0/3BC, 1/4SC did not affect milk and FCM yield (P>0.05), but 2/4SC decreased significantlymilk yield （P<0.01）and did not affect FCM yield (P>.05). In conclusion, the optimalpercentage is 2/3, and 2/3SC increased lactational performance the in roughage of wheatstraw and corn silage, but SC tended to decrease lactational performance in forage of greenalfalfa and corn silage.Effects of Percentage of Socked Corn on Lactational Performance ofLactating Cows Eight midlactation Holstein cows were allotted to 2 groups, and were used in two 4×4Latin square design to determine the effects of boiled corn(BC) and socked corn (SKC) onlactational performance of lactating cows in forage of wheat straw and corn silage and inforage of alfalfa hay and corn silage, respectively. Four treatments were control, 1/3 BC, 1/3SKC and 2/3 SKC. All corn in diets was cracked with mean particle size of 1.4mm.Processing corn percentage was the proportion of processing corn to all corn in diet. In forageof wheat straw and corn silage, compared to the control, 1/3SKC and 2/3SKC did not affect<WP=9>DMI, per更多还原