丙三醇对牛瘤胃发酵、尿嘌呤衍生物、消化率、能量代谢及氮平衡的影响

 【目的】研究丙三醇对西门塔尔牛瘤胃发酵、尿嘌呤衍生物含量、日粮养分表观消化率、能量代谢及氮平衡的影响。【方法】选用8头体重450 kg、年龄3岁、装有永久性瘤胃瘘管的西门塔尔牛阉牛，采用4×4重复拉丁方设计，对照组饲喂基础日粮，处理组分别在基础日粮上添加丙三醇100、200和300 g?d-1。【结果】日粮添加200 g?d-1和300 g?d-1丙三醇，瘤胃pH、乙酸/丙酸比例和氨态氮浓度显著低于对照组和100 g?d-1组（P＜0.05），瘤胃总挥发性脂肪酸浓度、丙酸和丁酸摩尔比显著高于对照组和100 g?d-1组（P＜0.05）;200 g?d-1和300 g?d-1丙三醇组玉米秸秆DM、OM、NDF、ADF和混合精料DM、OM降解率显著高于对照组（P＜0.05），200 g?d-1组和300 g?d-1组混合精料CP降解率显著低于对照组和100 g?d-1组（P＜0.05）;200 g?d-1组和300 g?d-1组尿囊素和尿嘌呤衍生物含量显著高于100 g?d-1组和对照组（P＜0.05）;200 g?d-1组和300 g?d-1组OM、EE、CP、NFE、NDF和ADF表观消化率显著高于对照组（P＜0.05）。200 g?d-1组和300g?d-1组消化能和代谢能显著高于对照组（P＜0.05）;200 g?d-1组和300 g?d-1组沉积能显著高于100 g?d-1组和对照组（P＜0.05）;200 g?d-1组和300 g?d-1组沉积氮显著高于对照组和100 g?d-1组（P＜0.05）。【结论】丙三醇的适宜添加水平为200 g?d-1。

Effects of Glycerol on Rumen Fermentation, Urinary Excretion of Purine Derivatives, Digestibility, Energy Metabolism and Nitrogen Balance in Simmental Steer

【Objective】The objective of this study was to evaluate the effects of glycerol supplementation on rumen fermentation, urinary excretion of purine derivatives, nutrients digestibility, energy metabolism and nitrogen balance of steers.【Method】 Eight ruminal cannulated Simmental steers were used in a replicated 4 × 4 Latin square experiment and fed with basic diet and added with glycerol at 0, 100, 200 and 300 g per steer per day, respectively. 【Result】 The results showed that ruminal pH, ratio of acetate to propionate and ammonia nitrogen of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were lower than steers supplemented with glycerol at 100 g?d-1 and the control significantly (P＜0.05). Total VFA concentration, the molar proportions of propionate and butyrate of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than steers supplemented with glycerol at 100 g?d-1 and control significantly (P＜0.05). Ruminal DM, OM, NDF and ADF degradation of corn straw, and ruminal DM and OM degradation of concentrate of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than the control significantly (P＜0.05). Ruminal CP degradation of concentrate of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were lower than steers supplemented with glycerol at 100 g?d-1 and the control significantly (P＜0.05). Allantoin concentration and urinary excretion of purine derivatives of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than steers supplemented with glycerol at 100 g?d-1 and control significantly (P＜0.05). Dietary OM, EE, CP, NFE, NDF and ADF digestibilities of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than the control significantly (P＜0.05). Digestible energy and metabolizable energy of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than the control significantly (P＜0.05). Retenion energy of steers supplemented with glycerol at 200 g/d and 300 g/d were higher than the control and supplemented with glycerol at 100 g?d-1 significantly (P＜0.05). Retenion nitrogen of steers supplemented with glycerol at 200 g?d-1 and 300 g?d-1 were higher than steers supplemented with glycerol at 100 g?d-1 and the control significantly (P＜0.05). 【Conclusion】 These results indicated that the optimum dose of glycerol supplementation was 200 g?d-1.