| Three experiments were conducted to research the design and feeding effects of amino acid balance diet on lactating dairy cows in reclamation area of ShiheziExperiment 1:The objective of this study was to evaluate the nutritive values of normal feedingstuffs for cows in Shihezi by using Cornell net carbohydrate-protein system(CNCPS).The normal feed samples surrounding Shihezi area were collected,and their conventional nutrition ingredients were analysed,and the classified analysis of carbohydrate and protein ingredient of feeds using CNCPS were carried on.The result indicated that the conventional nutrient ingredients sequence of each feed samples were certionly different,including differences in the content of CP,NDF,ADF were the largest.The proportion of NPN?SCP?NDFIP accounted for CP of feed samples were quite different.the sequence of feed samples were different by protein and carbohyrate components evaluation using CNCPS,and efficient feed utilization could obtained according to different requirements.The protein component evaluation of feed samples,soybean meal nutritional value was the highest,alfalfa hay nutritive value was the lowest.The structural carbohydrate component evaluation of feed samples,cotton seed hulls nutritional value was the highest,corn gluten meal nutritive value was the lowest;however,the non-structural carbohydrate availability evaluation of feed samples,corn gluten meal nutritional value was the highest,cotton seed hulls nutritive value was the lowest.CNCPS could evaluate the feed samples nutritive value more accurately from two aspects of protein and carbohydrates,and provide theoretical basis for more rational utilizition of feed resources.Experiment 2:This experiment was conducted to study the effect of amino acid balance diet onproductive performance,blood biochemical indexes,economic benefits analysis in dariy cows.48 healthy Holstein cows in the early lactation period were seclected,the average number of lactation(DIM)was 39.69±12.48 days,the average parity was 3.02±0.64.Principle experiments using single factor randomized experimental designby age,milk yield,parity identical or similar,the 48 Holstein cows area after pairing randomly were assigned to 4 groups each group were 12 cows.The control group of former high-yielding dairy cows were fed TMR diets(without adding any amino acid);trial group 1 cows diets were only fed rumen-protected methionine(HMBi),trial group 2 and 3 diets on the basis of group 1,respectively adding two kinds of rumen-protected lysine levels.The results showed that:comparing with the control group,the experimental group 1 and group 2 cows average daily milk yield of 4% improved 8.65% and 10.47%(P<0.05),respectively,the feeding conversion efficiency improved 10.6% and 11.3%(P>0.05),respectively,while dry matter intake had no significantly changed(P>0.05).The daily diet adding amino acid balance diet had no significantly effects on health conditions and reproductive performance in the dariy cows(P>0.05).Dietary adding rumen-protected lysine and methionine did not affect the nature of milk fat percentage,milk protein ratio,and total solids content of lactose rates and other indicators,but could significantly increase milk fat(P<0.05)and milk protein yield(P<0.01).The supply of rumen-protected methionine and lysine had no significant effects on the serum glucose,total serum triglyceride(TG),total cholesterol(TCH),The results showed that feeding the amino acid balance diets can significantly improve productive performance of dairy cows,cows with improved metabolic status of trends,providing a theoretical basis for the practical application of amino acid balance in dairy cows diets.Experiment 3:This experiment was conducted to study the effects of amino acid balance diets in dariy cows.According to paired experimental design,30 healthy firstborn Holstein cows were seclected,divided into two groups,the control group were fed the control diet,the experimental group were fed the amino acid balance TMR diets.The indicators of the milk yield,milk composition,blood biochemical indexes and reproductive performance were determined in dairy cows.The results showed that: comparing with the control group,the experimental group cows average daily milk yield of 4% improved 2.56%(P<0.05).The feeding of amino acid balance diets did not affect the nature of milk fat percentage,milk protein ratio,lactose rates and other indicators,but could significantly increase the total solids content,milk fat and milk protein yield(P < 0.05).Supplementary rumen-protected methionine and lysine had no significant effects on the serum glucose,total serum triglyceride,total cholesterol,health conditions and reproductive performance in the dariy cows(P>0.05).The results indicated that feeding the amino acid balance diets can significantly improve productive performance of dairy cows,cows with improved metabolic status of trends. |
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