丙酸镁对西门塔尔牛氮平衡和能量平衡的影响

Effects of supplemental magnesium propionate on nitrogen balance and energy balance in Simmental steer

选用4头年龄3.5岁,体况良好,体重(500±20)kg的中国西门塔尔牛阉牛。采用4×4拉丁方设计,研究日粮添加丙酸镁(100 g/d)、丙酸(87 g/d)和氧化镁(24 g/d)对西门塔尔牛氮平衡和能量平衡的影响。结果表明:日粮中添加丙酸镁、丙酸和氧化镁后,各组采食氮、采食总能、粪能、尿能、气体能、产热量、消化能/采食能差异均不显著(P>0.05);丙酸镁组粪氮较对照和氧化镁组显著降低(P<0.05);处理组尿氮较对照组显著降低(P<0.05),处理组间差异不显著(P>0.05);丙酸镁和丙酸组可消化氮和沉积氮、代谢能和沉积能较对照和氧化镁组显著提高(P<0.05),氧化镁组沉积氮较对照组显著提高(P<0.05)。丙酸镁组消化能、沉积能/消化能和沉积能/采食能较对照和氧化镁组显著提高(P<0.05)。丙酸镁降低了粪氮和尿氮,提高了可消化氮、沉积氮、消化能、代谢能、沉积能、沉积能/消化能、沉积能/采食能,改善了氮平衡和能量平衡。

Four Simmental steers[average BW（500±20）kg,aged 3.5]cannulated at the rumen were used in a 4×4 Latin square design to evaluate the effects of supplemental magnesium propionate（MgP,100g/d）,propionic acid（PA,87 g/d） and magnesium oxide（MgO,24g/d） on nitrogen balance and energy balance.The results showed that there was no significant difference between energy intake,nitrogen intake,feces energy,urinary energy,gas energy,heat and the ratio of digestible energy to intake energy when steers diets supplemented with MgP,PA and MgO（P0.05）.Feces nitrogen of MgP group was higher than that of the control group and MgO group significantly（P0.05）.Urinary nitrogen of treatment groups were higher than that of the control group significantly（P0.05）,but there was no difference between treatments（P0.05）.Digestible nitrogen,nitrogen retention,metabolizable energy and energy retention of MgP and PA group were higher than that of the control group and MgO group significantly（P0.05）.Retention nitrogen of MgO group was higher than that of control group significantly（P0.05）.Digestible energy,the ratio of retention energy to digestible energy and the ratio of energy retention to intake energy of MgP group were increased significantly comparing with control and MgO group（P0.05）.MgP decreased feces nitrogen and urinary nitrogen,but increased digestible nitrogen,retention nitrogen,digestible energy,metabolizable energy,energy retention,the ratio of retention energy to digestible energy and the ratio of retention energy to intake energy significantly.The nitrogen balance and energy balance were improved by supplementing MgP.