Effects of Umami Enhancer on Growth Performance,Heat Stress and Serum Indexes of Holstein Calves Born in Summer
This experiment was conducted to study the effects of adding umami enhancer to starter on the growth performance,heat stress and serum indexes of Holstein calves.The single factor randomized experimen-tal design was used in this experiment.Sixty Holstein newborn female calves with similar body weight and age and fed with sufficient colostrum were randomly divided into 4 groups with 15 calves in each group.The calves in control group were fed a starter without adding umami enhancer.On the basis of the starter of control group,150,300 and 450 g/t umami enhancer were added to the starters in experimental groups Ⅰ,Ⅱ and Ⅲ,re-spectively.The trial period was 73 days,including 63 days of lactation,and continued feeding for 10 days af-ter weaning.The results showed that the average daily dry matter intake(ADDMI)of starter of calves in the first week after birth showed a quadratic variation trend with the increase of umami enhancer additive amount(P=0.07),and the increase rate was the highest when the additive amount was 300 g/t,which was 88.5％higher than that of the control group;with the increase of umami enhancer additive amount,the ADDMI of starter of calves in the 2nd,3rd,4th,7th,9th and 10th weeks after birth was linear increased(P＜0.05).Compared with the control group,the ADDMI of starter of the experimental group Ⅲ was increased by 15.17％(P＞0.05),25.69％(P＜0.05),27.34％(P＜0.05),16.98％(P＜0.05),29.76％(P＜0.05)and 26.23％(P＜0.05),respectively.The body weight of 60-day-old calves and the average daily gain(ADG)of calves at 1 to 60 days of age were increased linearly with the increase of umami enhancer additive amount(P＜0.05).At 30 and 45 days of age,the body height of calves increased linearly with the increase of umami en-hancer additive amount(P＜0.05).At 30,45 and 70 day of age,the body length of calves increased linearly with the increase of umami enhancer additive amount(P＜0.05).At 60 days of age,the chest circumference of calves increased linearly with the increase of umami enhancer additive amount(P＜0.05).The respiratory rate of calves at 16:00 in experimental groups was significantly lower than that in control group(P＜0.05).The ad-dition of umami enhancer had no significant effects on the fecal score and diarrhea rate of calves at each stage(P＞0.05).At 60 days of age,the serum glucose content in experimental groups Ⅰ and Ⅱ was significantly increased compared with the control group(P＜0.05).At 15 days of age,the serum urea nitrogen content showed a quadratic variation with the increase of umami enhancer additive amount(P＜0.05),and it reached the lowest value when the additive amount of umami enhancer was 300 g/t.In conclusion,adding umami en-hancer to the starter can alleviate the heat stress of calves born in summer,and improve the growth performance of calves by increasing starter feed intake.[Chinese Journal of Animal Nutrition,2024,36(8):5117-5129]
万方数据
维普
