早期断奶对湖羊体尺、屠宰性能以及内脏发育的影响

Effect of Early Weaning on Body Size,Slaughter Performance and Visceral Development of Hu Lambs

为研究湖羊羔羊28日龄断奶是否可行,选用48只出生重接近(3.51±0.57)kg的湖羊公羔,随机均分为2组,分别为早期断奶组(28日龄断奶)和对照组(56日龄断奶)。从第7日龄开始补饲开食料,60日龄同时逐渐换生长羔羊颗粒料。分别在28、42、56、70、84日龄测定羔羊体重、体尺,每组分别在42、56、70、84日龄各屠宰6只,测定各组内脏重量、胴体重量,计算屠宰率。结果表明:(1)各时间点两组羔羊体尺差异不显著(P>0.05);(2)早期断奶组70日龄胴体重和宰前活重显著高于对照组(P<0.05),其余时间点两组的胴体重、宰前活重、屠宰率均无显著差异(P>0.05);(3)70日龄早期断奶组心脏、肺脏、脾脏、肾脏、肝脏重量早期断奶组显著高于对照组(P<0.05),42、56、70日龄胰脏重量早期断奶组显著高于对照组(P<0.05),其余时间点各内脏两组间差异不显著(P>0.05)。综合分析认为,本试验条件下,28日龄断奶可促进湖羊羔羊消化器官早期发育,且不影响84日龄体尺指标,28日龄断奶可行。

Forty-eight Hu lambs with birth weight of 3.51±0.57 kg were randomly and evenly divided into two groups in order to study the feasibility of 28 dweaning strategy.Lambs in early-weaned group and control group were fed starter from 7dof age and weaned at 28 dand 56dseparately.Growing diet was gradually introduced since 3dafter weaning of control group in both groups.Lambs in both groups were slaughtered and sampled on 42,56,70,84 dfor measuring of weight,volume of compartments of gastrointestinal tract,and length of intestinal tract.The results showed as follows：1）Body size at all time points in both groups were not significantly different（P〉0.05）.2）There were no significant differences in carcass weight,liveweight before slaughter,dressing percentage between two groups at all time points（P〉0.05）except that carcass weight and liveweight before slaughter of early-weaned were significantly higher than those in control group at 70d（P〈0.05）.3）Weight of heart,lung,liver,spleen,kidney in early-weaned group were higher at 70d（P〈0.05）,pancreas weight was significantly higher than those in control group during 42~70d,no significant differences in the rest periods（P〉0.05）.It is concluded that weaning at 28 dis a feasible strategy for promoting visceral development and there revealed no influence of body size at 84 dof Hu lambs in this experimental condition.