不同精粗比饲粮对湖羊肉品质、血液指标和肠道发育的影响

Effects of total mixed rations with different concentration-roughage ratios on meat quality,serum indices, and intestinal tract development in Hu sheep

为分析等蛋能比下不同精粗比饲粮对湖羊肉品质、血液指标和肠道发育的影响,本研究将40只体重相近、体况良好且健康的湖羊羔羊随机分为4组,每组10只(公母各半),各试验组羊分别饲喂精粗比为70∶30(试验Ⅰ组)、60∶40(试验Ⅱ组)、50∶50(试验Ⅲ组)和40∶60(试验Ⅳ组)的全混合饲粮,试验期为70 d。结果表明,1)正试期14 d时,试验Ⅳ组羊血清尿素氮(urea nitrogen,BUN)含量显著高于试验Ⅰ组(P<0.05),而血糖(glucose,GLU)含量则显著低于第Ⅲ组(P<0.05);正试期35 d时,试验Ⅳ组羊血清BUN和总胆固醇(total cholesterol,TC)含量分别极显著(P<0.01)和显著(P<0.05)高于试验Ⅰ组;正试期56 d时,试验Ⅳ组湖羊血清BUN含量分别极显著(P<0.01)和显著(P<0.05)高于试验Ⅰ和Ⅱ组,而血糖含量则相反。2)试验Ⅰ组羊肉熟肉率极显著高于第Ⅲ组(P<0.01),而剪切力和失水率则相反;试验Ⅰ组湖羊腿肌粗脂肪比例显著高于试验Ⅳ组(P<0.05),而肉色黄度则相反。3)试验Ⅳ组湖羊十二指肠绒毛高度和绒毛高度/隐窝深度极显著或显著高于试验Ⅰ和Ⅲ组(P<0.01或P<0.05),试验Ⅲ组湖羊空肠绒毛高度和隐窝高度均显著高于试验Ⅰ(P<0.05),试验Ⅳ组湖羊空肠绒毛高度/隐窝深度显著高于试验Ⅰ(P<0.05)。综上所述,在等蛋能比下,提高饲粮精粗比能够提高湖羊肉品质,但精粗比过高不利肠道的发育,从本研究结果来看,精粗比为60∶40全混合饲粮的效果最佳。

Forty healthy Hu lambs with similar body weights and in good body condition were chosen in order to study the effects of different concentration-roughage ratios with equal protein to energy ratios on meat quality,serum indices,and intestinal tract development.Lambs were randomly divided into four groups with 10 sheep per group(5 male and 5 female).Sheep in each group were fed total mixed rations with concentration-roughage ratios of 70∶30(GroupⅠ),60∶40(GroupⅡ),50∶50(GroupⅢ),or 40∶60(GroupⅣ).The experimental period was 70 days,and consisted of a 14-day preexperiment and a 56-day experiment.The results were as follows:1)The serum urea nitrogen content was significantly higher in groupⅣlambs than in groupⅠlambs(P<0.05),whereas urea glucose content was significantly lower in groupⅣlambs than in groupⅢlambs on day 14 of the experiment(P<0.05).Serum urea nitrogen and serum total cholesterol content were significantly higher in groupⅣlambs than in groupⅢlambs(P<0.01 or P<0.05)on day 35 of the experiment(P<0.05).The serum urea nitrogen content was significantly higher in groupⅣlambs than in lambs from groupsⅠandⅡ(P<0.01 or P<0.05)on day 56 of the experiment,but glucose content showed the opposite pattern.2)Cooked meat percentage was significantly higher in groupⅠlambs than in groupⅢlambs,whereas shear force and rate of water loss were higher in groupⅢlambs than in groupⅠlambs.The percentage of crude fat in the leg muscles of groupⅠlambs was significantly higher than in groupⅣlambs,whereas the meat of groupⅠlambs was less yellow than the meat of groupⅣlambs.3)The villus height and the VH/CD of the duodenum were significantly higher in groupⅣlambs than in lambs from groupsⅠandⅢ(P<0.01).The villus and the cryptic height of the jejunum were significantly higher in groupⅢlambs than in groupⅠlambs(P<0.05).The VH/CD of the jejunum was significantly higher in groupⅣlambs than in groupⅠlambs(P<0.05).In conclusion,meat quality could be improved by increasing the concentration-roughage ratio of diets with equal protein to energy ratios.However,higher concentration-roughage ratios were detrimental to intestinal development.The total mixed ration with a concentration-roughage ratio of 60∶40 produces the optimal results in this experiment.