不同粗饲料来源饲粮对断奶牦牛犊牛生长性能和免疫器官发育的影响

Effects of Different Roughage Source Diets on Growth Performance and Immune Organs Development of Weaned Yak Calves

本试验旨在探讨不同粗饲料来源饲粮对断奶牦牛犊牛生长性能和免疫器官发育的影响。试验选取遗传背景、日龄(45日龄左右)和体重[(36.47±0.99) kg]相近的21头大通牦牛犊牛(公牛),随机分为3组,每组7头牛。苜蓿干草组(AT组)在饲喂代乳粉和开食料的基础上添加苜蓿干草,燕麦干草组(OT组)在饲喂代乳粉和开食料的基础上添加燕麦干草,苜蓿干草和燕麦干草组(AOT组)在饲喂代乳粉和开食料的基础上添加苜蓿干草和燕麦干草(苜蓿干草∶燕麦干草=1∶1)。预试期21 d,正试期120 d。结果表明,1)与AT组和OT组相比,AOT组的终末体重显著升高(P<0.05),料重比显著降低(P<0.05)。2)与AT组和OT组相比,AOT组的脾脏中红髓和白髓界限明显,白髓半径较大,并且脾脏中促吞噬素、干扰素-β和肿瘤坏死因子-α含量显著升高(P<0.05)。3)与AT组和OT组相比,AOT组的胸腺中皮质面积大,并且胸腺中胸腺素β-4、前胸腺素α、胸腺肽、免疫球蛋白G、白细胞介素-1β含量显著升高(P<0.05)。综上所述,相比单一饲喂苜蓿干草或燕麦干草,二者混合饲喂更有利于提高饲料转化率,促进断奶牦牛犊牛的生长发育;同时,苜蓿干草和燕麦干草混合饲喂可以促进脾脏和胸腺器官的发育,提高断奶牦牛犊牛免疫功能。

The aim of this experiment was to investigate the effects of different roughage source diets on growth performance and immune organs development of weaned yak calves.Twenty⁃one Datong yak calves(male)with similar genetic background,days of age(about 45 days of age)and body weight[(36.47±0.99)kg]were selected and randomly divided into 3 groups with 7 yak calves in each group.The alfalfa hay group(AT group)group was fed milk replacer and starter supplemented with alfalfa hay,the oat hay group(OT group)was fed milk replacer and starter supplemented with oat hay,and the alfalfa hay and oat hay group(AOT group)was fed milk replacer and starter supplemented with alfalfa hay+oat hay(alfalfa hay∶oat hay=1∶1).The pre⁃experimental period lasted for 21 days,and the experimental period lasted for 120 days.The results showed as follows:1)compared with AT and OT groups,the final body weight of AOT group was signifi⁃cantly increased(P<0.05),and the feed to gain ratio was significantly decreased(P<0.05).2)Compared with AT and OT groups,the AOT group had a clear boundary between red medulla and white medulla in spleen,and a larger radius of white medulla;and the contents of tuftsin,interferon⁃βand tumor necrosis fac⁃tor⁃αin spleen were significantly increased(P<0.05).3)Compared with AT and OT groups,the AOT group had a larger cortical area in thymus;and the contents of thymosinβ⁃4,prothymosinα,thymosin,immuno⁃globulin G and interleukin⁃1βin thymus were significantly increased(P<0.05).In summary,compared with single feeding of alfalfa hay or oat hay,the mixed feeding of alfalfa hay and oat hay is more conducive to im⁃prove the feed conversion rate and promoting the growth and development of weaned yak calves.Meanwhile,the mixed feeding of alfalfa hay and oat hay can promote the development of spleen and thymus organs and im⁃prove the immune function of weaned yak calves.