肉牛过瘤胃脂肪进食量对营养物质消化、氮沉积和嘌呤衍生物排出量的影响

Influence of Supplemental Prilled Fat on Total Tract Nutrient Digestion, Nitrogen Retain and Urinary Excretion of Purine Derivatives in Steers

为研究过瘤胃脂肪对肉牛营养物质消化代谢和尿中嘌呤衍生物排出量的影响,试验选用15头西杂肉牛分成三组,试验1组和试验2组在对照组的日粮基础上每天补饲300g和500g过瘤胃脂肪粉,用全收粪法和全收尿法分别测定营养物质消化代谢和尿中嘌呤衍生物排出量,试验结果表明,日粮中补饲过瘤胃脂肪对全消化道OM、NDF、ADF消化率没有明显影响(p>0.05),补饲脂肪明显影响全消化道粗蛋白和粗脂肪的表观消化率,并随补饲脂肪增加粗脂肪消化率提高,但补饲500g脂肪明显降低日粮粗蛋白质消化率(p<0.05);补饲脂肪明显影响氮的沉积,补饲300g脂肪比不补或补饲500g脂肪有明显高的可消化氮沉积;日粮过瘤胃脂肪补饲对肉牛尿中嘌呤衍生物排出量没有明显影响(p>0.05)。关键词:肉牛;过瘤胃脂肪;消化率;氮沉积;

An experiment was conducted to determine the effects of dietary supplemental prilled fat on nutrient digestion and metabolism in steer. Fifteen crossbred （ Simmental × Chinese yellow cattle） steers （435± 20 kg） were utilized in this experiment. They were assigned randomly to one of the following three treatments： 1） control （no supplemental prilled fat plemental priUed fat 500 g a day （test 2）. The ）, 2） supplemental prilled fat 300 g a day（test 1）, and 3） supfeces and urine were collected using a total collection of successive days. The apparent digestibilities of OM, NDF, and ADF were no differences （p〈0.05） among the treaments. The apparent digestibilities of CP were lower （p〈0.05） for the diet containing 500 g priUed fat than for other diet. The apparent digestibilities of ether extract were increased （p〈0.05） for supplemental fat. The nitrogen retain were higher （p〈0.05） with supplemental priUed fat 300 g than the other treatments. However, the urinary purine derivative excretions were unaffected among the supplementation of fat. It was concluded fat supplements markedly affect nutrient digestion.