Effects Of Nutritional Compound Added Into Reconstructed Milk On Growth Performance And Rumen Microbial Flora In Calves

This study was to investigate how the two kinds of reconstructed milk influence the production performance,used feeding test,digestion test to research the growth performance,serum parameters,rumen fermentation parameters and rumen microflora of pre-and post-weaning calves in odder to provide theoretical basis for nutritional compound in calves breeding.The specific content is divided into the following two aspects:Exp.1: The aim of this study was to assess the effects of nutritional compound added to reconstructed milk on growth performance,serum indexes and nutrient digestibility of pre-and post-weaning calves.Twenty eight new-born Holstein calves with similar body weight were allotted into two treatments with 14 calves each?7 females and 7 males?.Calves were offered reconstructed milk?control group?and reconstructed milk + nutritional compound?test group?.Calves were weaned at 70 days of age and the experiment lasted 98 days.?Result?The results showed as follows: 1)for growth performance,nutritional compound significantly increased average daily weight aged from 71 to 98,birth to 98 days?P<0.05?and body weight at 98 days of nutritional compound group?P<0.05?,and significantly increased the wither height change ratio,thorax girth change ratio aged from birth to 70,birth to 98 days of nutritional compound group?P<0.05?.and significantly increased the dry matter intake,starter dry matter intake aged from birth to 70,71 to 98,birth to 98 days of nutritional compound group?P<0.05?.2)for serum indexes,nutritional compound significantly increased total protein,glucose contents,total antioxidant capacity in serum at 42 days?P<0.05?and glucose,triglyceride contents in serum at 98 days of nutritional compound group?P<0.05?.3)No significant differences were observed in nutrient apparent digestibility between groups of pre-and post-weaning calves?P>0.05?.In conclusion,nutritional compound can improve dry matter intake,average daily gain,calf body size and serum antioxidant capacity when added into reconstructed milk.Exp.2: The aim of this study was to assess the effects of nutritional compound added to reconstructed milk on rumen fermentation indexes and microbial flora diversity of pre-and post-weaning calves.The experiment designs the same as that of experiment one.The results showed as follows: 1)for rumen fermentation indexes,the test group is significantly lower than control group in pH and acetate / propionate at 98 days?P<0.05?.2)In terms of rumen microflora,at the phylum level,nutritional compound significantly increased the proportion of the firmicutes at 42 days of nutritional compound group?P<0.05?,the proportion of bacteroidetes of nutritional compound group was significantly lower than the control group?P<0.05?;At the genus level,the proportion of Prevotella₁ and Prevotella₇ in calves of nutritional compound group was significantly lower than that of control group at 42 days of age?P<0.05?.The results suggest that the addition of nutritional compound to the reconstructed milk can improve the rumen fermentation environment,change the type of ruminal fermentation and affect the rumen microflora.