饲用油菜生物量与营养成分测定及其发酵全混合日粮饲喂湖羊效果

在饲用油菜的生长期测鲜质量,烘干后测常规营养成分,分析鲜质量和营养成分的动态变化,用终花期油菜配制发酵全混日粮(fermented total mixed ration,FTMR)。200头湖羊随机分成2组,一组饲喂油菜FTMR,另一组饲喂由青贮玉米为主原料配制的全混日粮(total mixed ration,TMR)。试验结束时每组选择10头公羊屠宰,测定屠体和肉质性状。结果表明:饲用油菜的苗期、蕾薹期和花期分别为8~98、99~146和147~180d,油菜鲜质量在终花期(180d)时达最大值,粗蛋白和粗脂肪在此时也达最高值,根据这两个营养成分计算的收获价值也在180d时达最大值。饲喂油菜FTMR的湖羊体质量增量、屠宰率、胴体瘦肉率、背膘厚和眼肌面积与饲喂青贮玉米TMR组没有显著差异,但油菜FTMR组湖羊采食量远低于青贮玉米组,其饲料转化效率和净收益显著高于青贮玉米组(P0.01)。综上所述,饲用油菜在湖北省的最佳刈割期为终花末期(约180d),用其制作成FTMR饲喂湖羊可显著降低饲养成本,同时可缓解肉羊养殖中冬春季饲料不足的现状。

Biomass,nutrition of forage rape and effect of its fermented total mixed ration on growth,carcass and meat quality in Hu sheep

The above-ground parts of forage rape were collected,weighed and dried to measure the general nutritional ingredients at the seedling,bolting and flowering stages. Forage rape were harvested at the end of the flowering stage and ensiled to produce fermented total mixed ration (FTMR). Two hundred 2-month-old Hu sheep were randomly divided into two groups. One group were fed with forage rape FTMR and the other were fed with maize silage TMR. Ten rams were slaughtered to assess carcass characteristics and meat quality after three months. The results showed that the seedling,bolting and flowering period were from 8 to 98 d,99 to 146 d,and 147 to 180 d,respectively. The fresh weight reached the peak at 180 d. The crude protein and fat content increased during forage rape development,reached the top value at 180 d,making the peak harvest value of forage rape at 180 d. The weight gain,dressing percentage,carcass meat rate,backfat thickness,and eye muscle area of rams fed with forage rape FTMR were not different from those fed with maize silage TMR. However,feed conversion ratio (FCR) and profit of the forage rape group was significantly higher than that of the maize silage group. In conclusion,the best harvest time of forage rape was at 180 d in Hubei Province and the forage rape FTMR had no negative effect on growth and carcass characteristics of Hu sheep,and cost lower compared with maize silage TMR. Therefore,the forage rape can be applied in finishing lambs,which is beneficial for relieving stress of shortage feed in winter and reducing feed cost.