不同精粗比全混合日粮对湖羊生长性能、血清激素浓度和屠宰性能的影响

Effects of Total Mixed Ration with Different Concentration-Roughage Ratios on Growth Performance,Serum Hormone Concentrations and Slaughter Performance of Hu Sheep

本试验旨在研究不同精粗比全混合日粮对湖羊生长性能、血清激素浓度和屠宰性能的影响。选择体重相近、体况良好且健康的湖羊羔羊40只,随机分为4组,每组10只(公母各占1/2)。4组试验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)的全混合日粮。试验期为70 d,其中预试期为14 d,正试期为56 d。结果显示:1)正试期第14天和第35天,试验Ⅰ组羔羊平均日增重(ADG)极显著高于试验Ⅲ和Ⅳ组(P<0.01);正试期第35天和第56天,试验Ⅱ组羔羊体重(BW)显著高于试验Ⅳ组(P<0.05)。2)正试期第14天,试验Ⅱ组羔羊体斜长以及试验Ⅰ组羔羊胸围和管围均显著高于试验Ⅳ组(P<0.05);正试期第35天,试验Ⅰ组羔羊胸围和管围均显著高于试验Ⅳ组(P<0.05),试验Ⅰ组羔羊血清瘦素(LEP)浓度显著高于试验Ⅱ组(P<0.05);正试期第56天,试验Ⅰ组羔羊血清生长激素(GH)和四碘甲状腺原氨酸(T4)浓度显著高于试验Ⅳ组(P<0.05),试验Ⅱ组羔羊血清三碘甲状腺原氨酸(T3)浓度显著高于试验Ⅲ和Ⅳ组(P<0.05)。3)试验Ⅱ组羔羊宰前活重、胴体重、屠宰率、后腿重和背膘厚均极显著高于试验Ⅳ组(P<0.01),试验Ⅱ组羔羊肋肉厚、心脏和肝脏重量均显著高于试验Ⅳ组(P<0.05)。综上所述,在本试验条件下,育肥湖羊饲喂精粗比为60∶40的全混合日粮可获得最佳的生长性能和屠宰性能。

The purpose of this experiment was to study the effects of total mixed ration with different concentration-roughage ratios on growth performance,serum hormone concentrations and slaughter performance of Hu sheep. Forty healthy Hu lambs with similar body weight and good body condition were randomly divided into four groups with ten sheep per group (half of male and female). Sheep in four groups were fed total mixed rations with concentration-roughage ratio of 70 ∶ 30 (group Ⅰ),60 ∶ 40 (group Ⅱ),50 ∶ 50 (group Ⅲ) and 40 ∶ 60 (group Ⅳ),respectively. The experimental period was 70 days containing 14-day pre-experiment and 56-day formal experiment. The results showed as follow: 1) the average daily gain of sheep in group Ⅰ was significantly higher than that in groups Ⅲ and Ⅳ on day 14 and 35 of formal experiment ( P <0.01);the body weight of sheep in group Ⅱ was significantly higher than that in group Ⅳ on day 35 and 56 of formal experiment ( P <0.05). 2) The body length of sheep in group Ⅱ,the chest circumference and cannon-bone circumference of sheep in group Ⅰ were significantly higher than those in group Ⅳ on day 14 of formal experiment ( P <0.05);the chest circumference and cannon-bone circumference of sheep in group Ⅰ were significantly higher than those in group Ⅳ and the serum leptin concentration of sheep in group Ⅰ was significantly higher than that in group Ⅳ on day 35 of formal experiment ( P <0.05);the concentrations of growth hormone and tetraiodothyronine in serum of sheep in group Ⅰ were significantly higher than that in group Ⅳ( P <0.05) and the concentration of triiodothyronine in serum of sheep in groupⅡ was significantly higher than that of groups Ⅲ and Ⅳ on day 56 of formal experiment ( P <0.05). 3) The live weight before slaughter,carcass weight,dressing percentage,hind leg weight,backfat thickness,rib meat thickness,heart weight and liver weight of sheep in group Ⅱ were significantly higher than those of group Ⅳ( P <0.01 or P <0.05). In conclusion,the growth performance and slaughter performance of Hu sheep fed total mixed ration with concentration-roughage ratio of 60 ∶ 40 is optimum under this experiment condition.