不同能量水平玉米秸秆青贮饲料对郏县红牛表观消化率、血清生化指标、屠宰性能及肉品质的影响

Effects of Corn Stalk Silage with Different Energy Levels on Apparent Digestibility,Serum Biochemical Indexes,Slaughter Performance and Meat Quality of Jia County Red Bull

为研究不同能量水平玉米秸秆青贮饲料对郏县红牛表观消化率、血清生化指标、屠宰性能及肉品质的影响,选取体重、月龄相近的健康郏县红牛60头(公母各半),按照单因素完全随机区组设计分成A(低能组)、B(中能组)、C(高能组)共3组,每组20个重复,每个重复1头试验牛。试验分成7 d预试期、120 d正试期,其中正试期包括40 d前期、40 d中期和40 d末期三个阶段。前期A、B、C组饲粮粗蛋白(CP)水平均为12.0%,综合净能(NE_(mf))分别为6.21、6.52、6.83 MJ/kg。中期A、B、C组饲粮CP水平均为11.58%,NE_(mf)分别为7.14、7.45、7.76 MJ/kg。末期A、B、C组饲粮CP水平均为11.02%,NE_(mf)分别为8.07、8.38、8.69 MJ/kg。结果显示,B组平均日增重、干物质采食量最高,均显著高于C组(P<0.05),料重比最低,但组间无显著差异。B组粗脂肪、粗蛋白、酸性洗涤纤维、中性洗涤纤维、钙、总磷含量最高,组间差异不显著。C组胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇含量均显著高于A组(P<0.05)。屠宰率、胴体产肉率、眼肌面积和背膘厚度随着能量水平提高而增加,组间无显著差异,C组背膘厚度显著高于A组(P<0.05)。能量水平对pH、蒸煮损失、失水率、剪切力和肉色均无显著影响,能量水平增加有改善牛肉品质的趋势。增重经济效益以B组最高。说明适宜的饲粮能量水平可以提高郏县红牛生产性能、改善肉品质、增加经济效益;中能量的郏县红牛生产性能、养分表观消化率、血清生化指标和肉品质效果最佳,且养殖经济效益最高。

In order to study the effects of corn stalk silage with different energy levels on apparent digest⁃ibility,serum biochemical indexes,slaughter performance and meat quality of Jia county red bull.Sixty healthy Jia county red bulls(half male and half female)with similar body weight and month age were se⁃lected and divided into three treatment groups:A(low energy group),B(middle energy group)and C(high energy group)according to the single factor random block design,with 20 replicates in each group and 1 cow in each replicate.The experiment is divided into 7 d pre-trial period and 120 d posi⁃tive trial period,in which the positive trial period includes three stages:the early 40 d,the middle 40 d and the end 40 d.The crude protein(CP)level of group A,B and C was 12.0%,and the average comprehensive net energy(NE_(mf))was 6.46,6.37 and 6.47 MJ/kg,respectively.In the middle stage,the dietary CP levels in groups A,B and C were all 11.58%,and the average NE_(mf) was 6.58,6.64 and 6.62 MJ/kg,respectively.At the end of the period,the dietary CP levels in groups A,B and C were all 11.02%,and the average NE_(mf) was 6.73,6.83 and 6.93 MJ/kg respectively.The results showed that the average daily gain and dry matter intake of group B were the highest,which were signifi⁃cantly higher than those of group C(P<0.05),and the feed-to-weight ratio was the lowest,but there was no significant difference between the groups.The crude fat,crude protein,acidic detergent fiber,neutral detergent fiber,calcium and total phosphorus in group B were the highest,and there was no significant difference between groups.Cholesterol,low density lipoprotein cholesterol and high density lipoprotein cholesterol in group C were significantly higher than those in group A(P<0.05).Slaughter rate,carcass meat yield,eye muscle area and back fat thickness increased with the increase of energy level,and there was no significant difference between groups.The back label thickness of group C was significantly higher than that of group A(P<0.05).Energy level has no significant effect on pH,cooking loss,water loss rate,shear force and meat color,and the increase of energy level has a tendency to improve beef quality.The economic benefit of weight gain was the highest in group B.The results showed that appro⁃priate dietary energy level could improve the production performance,meat quality and economic ben⁃efits of Jia county red bull.In this study,group B with medium energy has the best effect on production performance,apparent digestibility of nutrients,serum biochemical indexes and meat quality of Jia county red bull,and the economic benefit of breeding is the highest.