Effects Of Different Roughage Sources On Growth Performence,Nutrient Digestibility And Rumen Bacterial Flora Of Holstein Calves

In this paper,the effect of different roughage sources on the growth performance,nutrient digestion and rumen bacterial flora of Holstein dairy bulls was studied through the following experiments.The feasibility of peanut rattan and mulberry branch replacing oat grass as roughage for calves was discussed,which provided theoretical basis for the development of new type of calf roughage resources.The test content is divided into the following aspects:Experiment 1: To study the effects of different forage sources on growth performance,serum physiological and biochemical indexes,rumen bacterial flora and diversity of suckling male calves.The results are as follows:1)in lactation,the dry matter intake of oatmeal group at 7-14 days was significantly higher than that of mulberry branch group(P < 0.01),while that of peanut and rattan group at 14-21 days was significantly lower In the group of Yanmai grass and Sangzhi(P < 0.01),the intake of dry matter in the group of peanut rattan during lactation was significantly lower than that in the group of oat grass and Sangzhi(P < 0.05);the feed cost in the group of peanut rattan was significantly lower than that in the group of oat grass and Sangzhi(P < 0.01);the serum Ig G concentration in the group of mulberry branch was significantly higher than that in the group of peanut rattan and Yanmai grass(P< 0.05);on weaning day,the calf in the group of peanut rattan The body length was significantly lower in oat grass group and mulberry branch group(P < 0.05).2)During lactation,the serum Ig G concentration of Sangzhi group was significantly higher than that of the other two groups(P < 0.05),while the total cholesterol concentration of Arachis and Sangzhi group was significantly higher than that of oat grass group(P < 0.05).3)There was no significant difference in p H value and ammonia nitrogen content between the three groups(P > 0.05).4)The abundance of unidentified bacteroideae in Arachis group was significantly higher than that in oat grass group and mulberry branch group(P < 0.05);the relative abundance of ruminococceae in Arachis group was significantly higher than that in oat grass group and mulberry branch group(P < 0.05).The results showed that oat grass group had the best growth performance and economic benefit,peanut rattan could improve rumen microorganism,and mulberry branch could improve immune function of calves.Experiment 2: this experiment studied the effects of different forage sources on growth performance,nutrient digestion,blood biochemical index and rumen bacterial flora of Weaned Dairy male calves.The results were as follows:1)after weaning,the dry matter intake of oat grass group was significantly higher than that of the other two groups(P < 0.05)at 21-28 days,and the chest circumference growth of oat grass group was significantly higher than that of peanut and rattan group and mulberry branch group(P < 0.05)Group A(P < 0.05).2)After weaning,the serum immunoglobulin Ig G concentration in Sangzhi group was significantly higher than that in Arachis group and oat grass group(P < 0.05).3)After weaning,the apparent digestibility of ADF in Arachis group was significantly different from that in oat grass group and mulberry branch group(P < 0.05),while the other indexes were not significantly different.4)There was no significant difference in p H value and ammonia nitrogen content between the three groups(P > 0.05).5)The Firmicutes in oat grass group was significantly higher than that in peanut vine group(P < 0.05).The relative abundance of Bacteroides in Arachis group was significantly higher than that in oat grass group and mulberry branch group(P < 0.05);the relative abundance of prevotellaceae in Arachis group was significantly higher than that in oat grass group and mulberry branch group(P < 0.05),and the relative abundance of acidaminoccaceae in mulberry branch group was significantly higher than that in Arachis group(P < 0.05).The results showed that the growth performance of high quality oat grass was the best and rumen flora could be regulated after weaning,and the immune function of calves could be improved by feeding mulberry branch.In conclusion,oat grass is the high-quality roughage for calves.Although the feeding effect of peanut rattan and mulberry branch is not as good as oat grass,they will not affect the health of calves,and they have their own advantages.Adding a proper amount of peanut rattan is conducive to the rumen development of lactating calves,and adding mulberry branch can improve the rumen flora,so peanut rattan and mulberry branch can partially replace oat grass as the roughage for calves.