肉用绵羊饲粮营养物质消化率和代谢能预测模型的研究

本试验旨在建立肉用绵羊饲粮营养物质消化率和代谢能(ME)的预测模型。选用66只体重为(45.0±2.0)kg的体况良好的杜泊×小尾寒羊F1代杂交肉用羯羊,随机分为11个处理,每个处理6个重复,每个重复1只羊。采用随机区组设计,分别测定11种不同粗饲料组成的饲粮的营养物质含量,通过物质代谢试验和气体代谢试验测定这11种饲粮的营养物质消化率、消化能(DE)及ME,在分析饲粮营养物质含量、可消化营养物质、DE和ME的基础上,筛选出最佳估测因子并建立估测方程。结果表明:饲粮干物质(DM)、有机物(OM)、粗蛋白质(CP)、总能(GE)消化率与饲粮中CP、GE和OM含量呈显著或极显著正相关(P0.05或P0.01),与中性洗涤纤维(NDF)含量呈显著负相关(P0.05);饲粮NDF消化率与饲粮中DM、OM、CP、GE含量达到显著或极显著负相关(P0.05或P0.01),与NDF含量达到极显著正相关(P0.01)。利用饲粮中营养物质含量对ME进行估测的最佳方程为ME=-49.593+0.594OM-0.107NDF(R2=0.949,P0.01)。由此得出,饲粮营养物质消化率、ME与营养物质含量均有较强的相关性,可通过营养物质含量对饲粮的营养物质消化率、ME进行合理估测。

A Study on Prediction Models of Dietary Nutrient Digestibility and Metabolizable Energy of Mutton Sheep

This study aimed to establish the prediction models of dietary nutrient digestibility and metabolizable energy (ME) of mutton sheep.Sixty-six Dorper×thin-tailed Han crossbred F1 mutton sheep with the body weight of (45.0±2.0) kg were selected and divided into 11 treatments and each treatment had 6 replicates with1 sheep per replicate.According to a randomized block design, the nutrient contents of eleven diets with different roughages were determined, and the nutrient digestibility, digestible energy (DE) and ME of those eleven diets were determined using material metabolism trial and gas metabolism trial.The optimal prediction factors and the prediction equations were screened on the basis of the dietary nutrient contents, digestible nutrients, DE and ME.The results showed that dietary dry matter (DM), organic matter (OM), crude protein (CP) and gross energy (GE) digestibility were significantly positively correlated with dietary CP, GE, and OM contents(P<0.05 or P<0.01), but were significantly negatively correlated with neutral detergent fibre (NDF) content(P<0.05).Dietary NDF digestibility was significantly negatively correlated with dietary DM, OM, GP, and GE contents (P<0.05 or P<0.01), but was significantly positively correlated with NDF content (P<0.01).The optimal prediction equation for ME with dietary nutrient contents was: ME =-49.593 + 0.594OM0.107NDF (R2=0.949, P<0.01).In conclusion, dietary nutrient digestibility and ME all have a stronger correlation with dietary nutrient contents.By using dietary nutrient contents, the dietary nutrient digestibility and ME can be reasonably predicted.[Chinese Journal of Animal Nutrition, 2017, 29(2) :416-425]