摘要
本试验旨在研究不同能量水平日粮对淘汰荷斯坦育成母牛生长性能和屠宰性能的影响。选取24头健康状况良好、平均体重为466kg左右、体型相近的淘汰荷斯坦育成母牛,随机分为3组,每组8头,分别为Ⅰ组(低能量组)、Ⅱ组(中能量组)和Ⅲ组(高能量组),饲喂不同能量水平的日粮。试验分为前期和后期2个阶段,前期3组日粮的粗蛋白质含量均为12.50%,综合净能分别为6.80、7.00、7.20 MJ/kg;后期3组日粮的粗蛋白质含量均为12.00%,综合净能分别为6.90、7.10、7.30MJ/kg。整个试验期共100d,正试期为90d。结果显示:(1)Ⅱ组淘汰荷斯坦育成母牛的平均日增重最高,分别较Ⅰ、Ⅲ组提高了4.76%(P>0.05)、43.48%(P<0.05);Ⅱ组平均干物质采食量最高,料重比最低,且与Ⅲ组差异极显著(P<0.01)。(2)提高日粮能量水平可显著提高血清中葡萄糖、胆固醇的含量(P<0.05),极显著降低β-羟丁酸的含量(P<0.01)。(3)Ⅲ组荷斯坦育成母牛屠宰率、净肉率、大理石花纹和背膘厚度最高,屠宰率较Ⅰ、Ⅱ组差异显著(P<0.05);大理石花纹和背膘厚度与Ⅰ组差异显著(P<0.05),与Ⅱ组无显著差异(P>0.05)。综上所述,提高日粮能量水平可显著提高淘汰荷斯坦育成母牛的平均日增重和屠宰率,降低料重比,促进脂肪沉积,改善肉品质。综合考虑得出:在本试验条件下,淘汰荷斯坦育成母牛育肥以中等能量水平饲喂较适宜,前期:综合净能7.00 MJ/kg,粗蛋白质12.50%;后期:综合净能7.10 MJ/kg,粗蛋白质12.00%。
This experiment was aimed to explore the effects of diets with different energy levels on growth performance and slaughter performance of culling Holstein heifers.Twenty-four selected culling Holstein heifers in healthy condition with 466 kg average body weight and similar shape were randomly divided into three groups with eight heads per group：Group Ⅰ（low energy level）,group Ⅱ（medium energy level）and groupⅢ（high energy level）.The three groups were fed diets with different energy levels.The experiment was consisted of earlier stage and later stage,and the crude protein of three groups in earlier stage were 12.50%,and energy levels were（NEmf）6.80,7.00 and 7.20 MJ/kg,respectively,while the crude protein was 12.00%,and energy levels（NEmf）were 6.90,7.10 and 7.30 MJ/kg in later stage.The experiment was lasted for100 d.The results showed that：（1）The average daily gain of group Ⅱ was the highest,increased by 4.76%（P〈0.05）and 43.48%（P〈0.05）than groupsⅠandⅢ,respectively.And the average dry matter intake of group Ⅱ were the highest and the F/G was the lowest,which were extremely significantly different from that of groupⅢ（P〈0.01）.（2）The increase of dietary energy levels could significantly increase the content of glucose and cholesterol in serum（P〈0.05）,reduce the content of beta hydroxybutyric acid（P〈0.01）.（3）The slaughter rate,net meat rate,marbling and backfat thickness of groupⅢ were the highest.There was a significant difference of slaughter rate when compared with other groups（P〈0.05）.The marbling and back fat thickness of groupⅢ were significantly different with that of groupⅠ（P〈0.05）,but there was no significantly difference between group Ⅲ and group Ⅱ（P〈0.05）.In cluclusion,improving the energy levels of diets could significantly increase the average daily gain and slaughter rate of culling Holstein heifers,and it also helped to decrease F/G,promote the fat deposition and improve the meat quality.Under the conditions of this experiment it was more appropriate to feed the culling Holstein heifers according to the standard of groupⅡ（medium energy level）.The appropriate energy and protein levels：In the earlier stage,NEmf7.00 MJ/kg and CP 12.50%;In the later stage,NEmf7.10 MJ/kg and CP 12.00%.
出处
《中国畜牧兽医》
CAS
北大核心
2018年第2期392-399,共8页
China Animal Husbandry & Veterinary Medicine
基金
国家肉牛牦牛产业技术体系建设项目(CARS-37)
关键词
淘汰荷斯坦育成母牛
能量
生长性能
养分表观消化率
血液指标
屠宰性能
culling Holstein heifers
energy
growth performance
apparent nutrient digestibility
blood parameters
slaughter performance
