日粮添加不同剂量南瓜粉对育肥牛体外模拟瘤胃发酵参数、生长性能及血液指标的影响OA

This research aimed to investigate the effects of different doses of pumpkin powder in ration on in vitro rumen fermentation,growth performance and blood indicators in fattening cattles.In the in vitro fermentation experiment,six healthy fattening cattles of similar weight and age as rumen fluid donors.The control group used total mixed ration as the basal diet,while the experimental group added 4％,8％and 12％pumpkin powder to the basal diet,respectively.Following a 48-hour in vitro cultivation,gas production volume and rumen fermentation indices were determined.In the feeding experiments,twenty-four healthy fattening cattle aged 13 months with similar body weights were selected and randomly assigned to four groups,with six replicates set in each group.The control group was provided with a basal diet,whereas the experimental groups were fed the basal diet incorporated with 30,60 g/head,and 90 g/head of pumpkin powder,respective.The experimental period was 35 days.The results of the in vitro simulation experiment showed that compared with the control group,the cumulative gas production of the experimental groups after 48 hours of in vitro fermentation tended to increase,but there was no significant difference(P＞0.05);the dry matter degradation rate of experimental groups 1,2 and 3 was 4.41％,6.76％and 7.93％higher than that of the control group,respectively(P＞0.05).The NH3-N content of experimental groups 1,2 and 3 was 10.55％,18.92％and 16.29％higher than that of the control group,respectively(P＜0.01).The results of the animal experiment showed that the final body weight of fattening cattle in experimental groups 2 and 3 was 3.03％and 0.89％higher than that of the control group,respectively(P＞0.05).The NH3-N content of experimental groups 1,2 and 3 was 10.55％,18.92％and 16.29％higher than that of the control group,respectively(P＜0.01).The butyric acid and acetic acid to propionic acid ratio in experimental group 3 was significantly higher than that in the control group by 28.03％and 7.63％,respectively(P＜0.01).Feeding pumpkin powder significantly increased the serum antioxidant indicators of blood routine,such as blood urea nitrogen(BUN)and C-reactive protein coefficient of variation(P＜0.05).On the 14th day of the experiment,the BUN content in the serum of experimental group 3 was 18.29％higher than that of the control group(P＜0.01).On the 28th day of the experiment,the BUN content in the serum of experimental groups 1,2 and 3 was 38.91％,21.82％and 34.55％higher than that of the control group,respectively(P＜0.01).In conclusion,the supplementation of pumpkin powder could improve the in vitro rumen fermentation characteristics,growth performance,and serum indicators of fattening cattles.It was recommended that the levels of pumpkin powder was 60 g/herd.