不同全株玉米青贮饲喂量对妊娠期母牛体况、血液指标及后代犊牛的影响

Effects of Whole Corn Silage Feeding Amount on Body Condition, Blood Index of Gestational Cows and Calf Growth

试验旨在研究全株玉米青贮饲喂量及精粗饲料配比对妊娠期母牛体况、血液指标及后代犊牛的影响。选用40头体重相近、2岁、1胎的妊娠期7个月左右的西门塔尔母牛,随机分为4组,每组10头,试验期3个月。Ⅰ组每头每天饲喂全株玉米青贮14 kg、燕麦秸1 kg、精料补充料3 kg,Ⅱ组每头每天饲喂全株玉米青贮19 kg、燕麦秸1 kg、精料补充料1 kg,Ⅲ组每头每天饲喂全株玉米青贮19 kg、燕麦秸2 kg,Ⅳ组每头每天饲喂全株玉米青贮22 kg、燕麦秸1 kg。产犊后各组母牛统一更换为泌乳料,母牛带犊哺乳,6月龄断奶。结果表明:Ⅳ组的干物质摄入量低于Ⅰ组(P<0.05);Ⅲ组和Ⅳ组的氮摄入量低于其他组(P<0.01),Ⅰ组最高(P<0.01);Ⅲ组的纤维摄入量高于其他组(P<0.01);各组体况评分无差异;妊娠期7月末,Ⅳ组血液锰含量低于其他组(P<0.05);妊娠期9月末,Ⅲ组和Ⅳ组的血清尿素氮含量低于其他组(P<0.01);Ⅳ组母牛所产犊牛的胸围低于Ⅰ组和Ⅱ组(P<0.05),且有3头因生长缺陷被淘汰;6月龄时,各组犊牛体况指标无差异。综上,推荐肉牛能繁母牛妊娠后期每日提供全株玉米青贮19 kg、燕麦秸1~2 kg、精料补充料0~1 kg。

This study investigated the effect of whole corn silage feeding amount and ratios of concentrate to coarse feed on body condition,blood index of gestational cows and calf growth.Forty Simmental cows of approximately seven month gestation with similar weight,age(two years old)and parity(first parity)were randomly allocated into four dietary treatments with ten cows each for a three-month trial period.Cows in the first group fed 14 kg whole corn silage,1 kg oat straw and 3 kg concentrate supplement per day,the second group fed 19 kg whole corn silage,1 kg oat straw and 1 kg concentrate supplement per day,the third group fed 19 kg whole corn silage and 2 kg oat straw per day,the fourth group fed 22 kg whole corn silage and 1 kg oat straw per day,respectively.After calving,the diets of all cows were changed to lactation feed.Calves suckled with cows and were weaned at the age of 6 months.Results showed that the dry matter intake of cows in group 4 was lower than that of group 1(P=0.027).The nitrogen intake of cows in groups 3 and 4 were lower than that in other groups and cows in group 2 showed the highest nitrogen intake(P<0.001).Cows in group 3 had the highest fiber intake as compared with that of other groups(P<0.001).No differences were observed in body condition score of cows among groups(P>0.05).The blood Mn concentration of cows in group 4 was lower than that of other groups in gestation age at the end of seventh month.While in gestation age at the end of ninth month,the serum urea nitrogen contents of cows in groups 3 and 4 were lower than that of the other groups(P<0.001).Calves born by cows in group 4 exhibited smaller chest girth in comparison with that of groups 1 and 2(P=0.043),and three calves in group 4 were eliminated because of growth defect.Six months after birth,body condition indices of calves were almost the same among groups(P>0.05).In conclusion,the appropriate diets for late-gestating beef cows are 19 kg of whole corn silage,1~2 kg of oat straw and 0~1 kg concentrate per day under the current experimental condition.