不同混合青贮对西门塔尔肉牛生产性能的影响

Effects of different levels of mixed silage of alfalfa and corn straw on growth performance, slaughter performance, meat quality and breeding benefits of Simmental beef cattle

中文关键词: 苜蓿  玉米秸秆  混合青贮  肉牛

英文关键词: alfalfa  corn straw  mixed silage  beef cattle

中文摘要:

      试验旨在研究不同水平的苜蓿与玉米秸秆混合青贮对西门塔尔肉牛生长性能、屠宰性能、肉品质和养殖效益的影响。选择平均体重（380±10.25kg）健康的西门塔尔（四代）牛60 头，随机分为5组，每组12头。试验肉牛日饲喂精饲料组成相同，粗饲料由苜蓿与玉米秸秆混合青贮制作，其中Ⅰ组（对照组）、Ⅱ组、Ⅲ组、Ⅳ组、Ⅴ组苜蓿含量分别为0%、15%、25%、35%和45%。预试期15 d，正试期90 d。结果显示，Ⅴ组、Ⅳ组日均采食量分别为12.24kg和12.03kg，日均增重分别为1420g和1370g，均显著高于Ⅰ组、Ⅱ组和Ⅲ组（P<0.05）；Ⅴ组、Ⅳ组料重比分别为8.62和8.78，均显著低于Ⅰ组、Ⅱ组和Ⅲ组（P < 0.05）。各组间屠宰率、净肉率、失水率、嫩度、pH值差异均不显著（P >0.05）；Ⅴ组、Ⅳ组眼肌面积分别为84.06和83.63，显著高于Ⅰ组、Ⅱ组和Ⅲ组（P<0.05）；Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组、Ⅴ组粗蛋白质分别为22.33%、22.86%、23.73%、25.55%、26.94%，瘦肉率分别为59.66%、60.83%、61.57%、64.15%、66.37%，大理石花纹分别为2.83、3.15、3.21、3.42、3.58，Ⅰ组、Ⅱ组、Ⅲ组之间差异不显著（P>0.05），Ⅳ组和Ⅴ组之间差异不显著（P>0.05），但Ⅴ组、Ⅳ组与Ⅰ组、Ⅱ组和Ⅲ组之间差异显著（P<0.05）；日均毛利润Ⅱ组、Ⅲ组、Ⅳ组、Ⅴ组较Ⅰ组分别提高2.10元、2.34元、3.81元、4.36元。综上，不同水平的苜蓿与玉米秸秆混合青贮提高了西门塔尔肉牛的生长性能、屠宰性能、肉品质和养殖效益，其中添加35%—45%之间的苜蓿制作混合青贮饲喂肉牛效果最好，当苜蓿占比达到45%时，肉牛各项饲养指标最优。

英文摘要:

      The aim of this study was to investigate the effects of different levels of mixed silage of alfalfa and corn straw on growth performance, slaughter performance, meat quality and breeding benefits of Simmental beef cattle. 60 healthy Simmental (fourth generation) cattle with an average body weight of (380±10.25kg) were selected and randomly divided into 5 groups with 12 cattles in each group. The experimental beef cattle were fed with the same composition of the concentrate, and the forage was made by mixed silage of alfalfa and corn straw. The content of alfalfa in groupsⅠ(control group), Ⅱ, Ⅲ, Ⅳ and Ⅴ was 0%, 15%, 25%, 35% and 45%, respectively. The pre-trial period lasted for 15 days and the experimental period lasted for 90 days. The results showed that the average daily feed intake of groups Ⅴ and Ⅳ was 12.24kg and 12.03kg, and the average daily weight gain of groups Ⅴ and Ⅳ was 1420g and 1370g, respectively, which were significantly higher than those of groupsⅠ, Ⅱ and Ⅲ (P<0.05). The ratio of feed to gain in groups Ⅴ and Ⅳ was 8.62 and 8.78, respectively, which were significantly lower than that in groups Ⅰ, Ⅱ and Ⅲ (P<0.05). There were no significant differences in slaughter rate, net meat rate, water loss rate, tenderness and pH value among all groups (P>0.05). The eye muscle area of groups Ⅴ and Ⅳ was 84.06 and 83.63, respectively, which were significantly higher than that of groups Ⅰ, Ⅱ and Ⅲ (P<0.05). The crude protein in groups Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ was 22.33%, 22.86%, 23.73%, 25.55% and 26.94%, respectively, and the lean meat percentage was 59.66%, 60.83%, 61.57%, 64.15% and 66.37%, respectively. The marbling was 2.83, 3.15, 3.21, 3.42, 3.58, respectively. There was no significant difference between groups Ⅰ, Ⅱ and Ⅲ (P>0.05), no significant difference between groups Ⅳ and Ⅴ(P>0.05), but there was significant difference between groupsⅤand Ⅳ and groups Ⅰ, Ⅱ and Ⅲ (P<0.05). Compared with group Ⅰ, the average daily gross profit of group Ⅱ, group Ⅲ, group Ⅳ and group Ⅴ increased by 2.10 yuan, 2.34 yuan, 3.81 yuan and 4.36 yuan, respectively. In conclusion, different levels of mixed silage of alfalfa and corn straw can improve the growth performance, slaughter performance, meat quality and breeding benefits of Simmental beef cattle. Among them, the mixed silage made by adding 35%-45% alfalfa has the best effect on feeding beef cattle, and when the proportion of alfalfa reaches 45%, all feeding indexes of beef cattle are optimal.