日粮中添加长链脂肪酸钙对肉牛瘤胃发酵及营养物质消化率影响的研究

EFFECT OF Ca-LCFA ON RUMEN FERMENTATION AND NUTRIENT DIGESTIBILITY IN STEERS

本试验选用4头装有永久瘤胃和真胃瘘管的阉牛 ,采用4×4拉丁方设计 ;对照组牛饲喂基础日粮 ,3个试验组在基础日粮中分别添加长链脂肪酸钙(Ca -LCFA)150g、300g 和450g。探讨日粮中添加保护油脂对肉牛瘤胃发酵及营养物质消化率的影响。结果表明 ,日粮中添加Ca -LCFA对瘤胃液pH值、乙、丙、丁酸浓度、乙酸与丙酸之比值、瘤胃内、瘤胃后及全消化道DM、OM消化率没有明显影响 ,添加150和300gCa -LCFA对总VFA浓度、瘤胃内、瘤胃后及全消化道NDF、ADF消化率无影响 ,但添加450gCa -LCFA使总VFA浓度、瘤胃内及全消化道NDF和ADF消化率显著低于对照组(P<0.05)。日粮中添加150、300及450gCa -LCFA时 ,肉牛全消化道脂肪酸的消化率分别为75.95 %、85.42 %和88.39 %,均显著高于对照组。经回归分析 ,全消化道脂肪酸消化率(Y)与Ca -LCFA添加量(X)呈线性正相关关系 ,回归方程为 :Y=63.50 +0.0624X,r=0.974,n=4。

Four steers with permanent rumen and abomasum cannulas were chosen and arranged in a 4×4 latin square trial.150g,300g and 450g of long chain fatty acids calcium was supplemented to the basal diet(control group) with concentrate and roughage ratio of 1:3.The experiment was conducted to study the effects of different levels of protected fat on rumen fermentation and nutrient digestion in beef cattle fed the high level roughage diet.The results showed as follows:The rumen fermentation characteristics such as pH value,acetate,propionate and butyrate content,and acetarte/propionate ratio,DM and OM digestibility in the rumen,small intestine and total digestive tract were not affected by supplementing Ca-LCFA.The TVFA content,NDF and ADF digestibility in the rumen and total digestive tract in steers fed 450g of Ca-LCFA were significantly decreased (P<0.05).The apparent fatty acid digestibility in total digestive tract in steers fed a diet added 150,300 and 450g of Ca-LCFA were 75.95%,85.42% and 88.39%,respectively,which were linearly higher than that in control group.The following regression equation was established:the apparent fatty acid digestibility(%)=63.50+0.0624×Ca-LCFA supplementation(g),r=0.974,n=4.