不同粒度豆粕对绵羊瘤胃发酵及其外流速度的影响

Effect of different particle size of soybean meal on fermentation and outflow rate in rumen of sheep

试验采用4×4拉丁方设计，观察其4种粉碎粒度豆粕（细粉豆粕、中粉豆粕、未粉豆粕和粗粉豆粕）对绵羊瘤胃发酵和豆粕瘤胃外流速度（铬标记方法）的影响。试验结果表明，不同粉碎粒度豆粕对瘤胃液pH没有显著影响。瘤胃NH3-N浓度具有随着豆粕粉碎粒度增大而降低的趋势，但统计差异不显著。细粉豆粕在瘤胃中的分解速度快于粗粉和未粉豆粕（P〉0．05），未粉豆粕组NHrN浓度在采食6h后比其它3组低10．35％～15．60％，而粗粉豆粕组瘤胃NH，-N浓度在采食8h后比其它3组高6．28％～13．07％。细粉豆粕、中粉豆粕、未粉豆粕和粗粉豆粕通过瘤胃的速度分别为每小时5．8％、4．5％、5．0％和4．8％，前3组羊粪中Cr2O.浓度高峰出现时间为饲喂后40h，而粗粉豆粕在44h。未粉豆粕在瘤胃中的外流速度适中，而蛋白质分解量较少，未粉豆粕可直接利用在反刍动物生产中。

Four mature male Merino sheep with rumen cannula with a 4×4 Latin square design were fed 4 diets to measure the effect of 4 particles （thin, mid, no crush and thick） of soybean meal （SB） on fermentation and outflow rate （Cr2O3 marker） in rumen. Results showed that there was not clear effect of different size of soybean particles on pH values in rumen. There was a trend of that NH3-N concentration in rumen decreased with increasing of SB particle （P〉0.05）. Thin SB in rumen degrade little faster than no crush and thick SB （P〉0.05）. NH3-N concentration in rumen of sheep fed no crush soybean diet after 6 h feeding was 10.35%-15.60% lower than that of other 3 SB diets, and that of thick SB diet at 8 h after feeding was 6.28%-13.07% higher. The Cr2O3 pinnacle concentrations in feces of sheep fed thin, mid and no crush soybean diets were found at 40 h after feeding, that of sheep fed thick SB diet at 44 h after feeding, outflow rate from rumen of thin, mid, no crush and thick SB was 5.8%, 4.5%, 5.0% and 4.8% per hour respectively. It would be conclude that no crush SB meal could be used directly in production of ruminants because less protein degradation and feasible outflow rate in rumen.