0～56日龄舍饲肉用羔羊前胃功能发育研究

Functional development of forestomach in confined lambs at the age of 0-56 d

选用甘肃肉用绵羊新品种选育群公羔(单羔)45只,分为9组,每组5只,分别于0,7,14,21,28,35,42,49和56 d屠宰、取样,测定与前胃功能发育相关的内容物相对重量、pH值及瘤胃内容物VFAs、主要微生物消化酶等指标的变化规律。结果表明,羔羊瘤网胃内容物相对重量(%全胃内容物重量)在0～35 d呈线性增加(R2=0.93,P=0.00),在28 d时为61.54%,35 d时为76.87%;瘤胃、网胃和瓣胃均具有较低的pH值,分别为5.30～6.03,5.37～6.42和5.39～6.15;瘤胃以乙酸发酵类型为主导,内容物A/P为2.18～3.82,丙酸含量较高;瘤胃内容物中微生物蛋白酶、α-淀粉酶和纤维素酶活性较高的日龄分别出现在21,7和14 d。在本试验条件下,羔羊在28 d时前胃功能发育已基本完成。舍饲并于7 d开始补饲的饲养方式下,于35 d或提早至28 d对羔羊开展早期断奶可行。

Forty-five male lambs（Gansu modern breeding sheep group） were divided into 9 treatments（5 animals in every treatment）,killed and sampled at 0,7,14,21,28,35,42,49 or 56 d respectively.The relative weight and pH value of contents in every compartment of forestomach,concentration and Molar proportion of volatile fatty acids,and activity of microbic enzymes of rumen contents were measured.The relative weight of contents（%total weight of content in stomach） in reticulorumen were linearly increase during 0 to 35 d（R2=0.93,P=0.00）,and was 61.54% and 76.87% at 28 and 35 d respectively.There was lower pH value in contents of rumen,reticulum and omasum,it was changed between in 5.30 to 6.03,5.37 to 6.42 and 5.39 to 6.15 respectively.It was mainly acetic acid fermentation type,and the ratio of acetic to propionic（A/P） was changed between 2.18 to 3.82 in rumen contents,and there was higher propionic concentration.The higher activity of protease,α-amylase,cellulase in rumen contents was respectively appeared at 21,7 and 14 d.The functional development in forestome was preliminarily completed at 28 d in the conditions of this trial.With confined raising and supplying the suited supplementary diet from 7 d age in days,the early weaning technology may be used at 35 or 28 d after birth in lambs.