采食量影响绵羊瘤胃微生物蛋白质产量机理的研究

Affection of Intake Level on sheep 's Ruen ─-A Studv on the Mechanism of Microbial protein Yield

四只安有永久瘘管，体重约４５ｋｇ的去势杂种绵羊（Ｂｌａｃｋｆａｃｅ×Ｓｕｆｆｏｌｋ），在四个试验期根据４×４拉丁方设计，分别饲喂１００、８００、１２００和１６００ｇ／头／日ＣＰ配合伺料，用聚乙二醇（ＰＥＧ，分子量４０００）和三氧化二铬浸润麦桔作液相和固相指示剂，后两个试验期，用尼龙袋法测定干物质在瘤胃中的降解率。结果表明：瘤胃容积和排空速度随采食量上升而提高；当采食量升高到２１．１８ｇＤＭ／ｋｇＢＷ时，瘤胃固相容积似乎达到极限，固相排空速度的提高开始加快。瘤胃微生物蛋白质产量与瘤胃固相和液相排空速度之间都呈直线相关，其相关系数分别为０．９８７（Ｐ＜０．０１）和０．９４２（Ｐ＜０．０５）。

Four rumen-fistu lated sheep Blackface x suffolk)with 4 5 kg as BW were given400,800,1 200and 1 600/d of GP diet accotding to a 4×4 Latin Square design for 4-experimentperiods,Polyethylen glycol(PEG MW 4 0 0 0 )and chromium mordanted straw were used as the markersfor the liquid phase and solid phase of rumen digesta,The degradability of the G D diet was examinedwith nylon bags for the next two experimental perifor, The reault showed that the pool size and dilutionrate of rumen were increased alons with the chanse of intake level.The solid pool size seemed to havercached a plateau at 2 1.1 8gDM/ kg BW of intake levpl,then the solid dilution rate begsan to increasequickly. The rumen microbial protein yield was linearly related to both solid and liquid dilution rates,and the correlation coefficients were0.987(P<0.01)and0.942(P<0.05)respectively;Thedegradability of the GP diet was reduced from 64.4 to 57.3%(P<0. 05)in result of intake levelincreased,It appears to be owed to compensative digestability in stomach and intestines that apparentdigesability was not-significantly effected by intake level.