| In order to improve the level of farm production and reduce the environmental pollution,the effects of high protein and starch on the nitrogen and phosphorus emission of Xianan cattle,blood biochemistry,intestinal methane emission and rumen bacteria were investigated in this study,from the production test,nitrogen and phosphorus emission,rumen fermentation and blood biochemical indexes.Firstly,20 cattle were randomly divided into A,B,C,D four groups using single factor,5 cattle in each groups.A group(protein 13.93%,starch 24.28%)was the control group,fed with basic diet;B group was high protein group(protein15.77%,starch 24.29%),C group was high starch group(protein 13.8%,starch28.2%);group D,high protein and high starch group(protein 15.7%,starch 28.21%).The experiment was divided into four parts: metabolic test,intestinal methane emission,collection of rumen fluid and blood.The whole test period was 33 days,including pre-feeding period and trial period.During 21d~25d metabolic tests was conducted.During 26 d ~ 30 d methane emissions was measured using SF6 tracer method.On the 31 st day the experiment was conducted for the collection of rumen fluid,for the collection of blood on the 32 nd day,on the 33 rd day for weighing.Experiment 1: Three animals were randomly selected from each group of experimental animals,there were a total of 4 groups,they were similar to the growth and development condition(average weight 300 + 40kg),health and disease-free,age of 9 months old Xianan cattle for the metabolic experiments.Experimental cattle tied to a single slot feeding,fed a total mixed ration at 8:00 and 18:00 each day,free drinking water.The leftovers was cleaned up once a day in the moring before feeding.During the 21 d ~ 24 d day of the experiment,a total of 3 days of digestion and metabolism test was performed using the whole excreta collection method.The results show:The effect of dietary supplementation of high protein on nitrogen and nitrogentwo digestion significantly(P<0.05),on the fecal nitrogen,urinary nitrogen,nitrogen deposition,emissions of nitrogen and nitrogen utilization rate trend is increasing but no significant.There was no significant effect of dietary supplementation of high starch on the nitrogen metabolism of beef cattle(P>0.05).The interaction of dietary supplementation high protein and high starch had no significant effect on nitrogen metabolism(P>0.05).Dietary supplementation of high protein had a significant effect on the decrease of phosphorus and sedimentary phosphorus(P<0.05),but no significant effect on the utilization of fecal phosphorus and phosphorus(P>0.05).The interaction of dietary supplementation high protein and high starch had no significant effect on phosphorus metabolism(P>0.05).The economic benefits of the three groups were higher than the control,and B,C and D were increased by 102.76%,42.64%,respectively,than the control.Experiment 2: 12 animals(Xia Nan cattle)randomly assigned to one of three experimental treatments take the tail vein blood collection using of 5 m L EDTA anticoagulant vacuum blood vessels at 32 D 7:00-9:00 in the morning.Results show:The dietary supplementation of high protein had no significant effect on all aspects of immunity(P>0.05).The dietary supplementation of high starch had extremely significant effect on Ig M,CD3,CD4 and CD8(P>0.01),and had significant effect on Ig A 、 Ig G 、 Ig E and CD4/CD8(P>0.05).The dietary supplementation of high protein had significant effect on MDA and GSH-PX(P>0.05),and the interaction of dietary supplementation high protein and high starch had extremely significant effect on GSH-PX(P>0.01).Experiment 3: Four animals were randomly selected as a group of experimental animals,there were a total of 4 groups,their intestinal methane emissions was detected.On the 19 th day of the feeding period,permeation tube was been casted in rumen of experimental animal.Results show:The interaction of high protein and high starch in diets had significantly affect methane emissions and methane emissions per unit weight(P<0.05),the group of high protein had the best effect on methane emissions,the differences of the high protein group than in the control group had significantly affect methane emissions and methane emissions per unit weight(P<0.05).Experiment 4: 16 animals(Xianan cattle)randomly assigned to one of four experimental treatments and rumen fluid was collected from experimental cattle.Results show:The interaction of dietary supplementation high protein and high starch had no effect on rumen fermentation parameters(P>0.05),the group of 2% protein in ammonia nitrogen and microbial protein content was the highest,and had significant effect on acetic acid(P<0.01).the group of 2% protein in volatile fatty acid content was the highest.In conclusion,high protein and starch content in diets had different effects on the nitrogen and phosphorus emission,growth performance,rumen fermentation and blood parameters of beef cattle. |
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