Optimization Of Fermentation Conditions And Evaluation Of Nutritional Value Of Cotton Stalk And Its Application In Hu Sheep Breeding

Research purposes: In this study,cotton stalks were used as raw materials to ferment by adding different proportions of beet pulp: bacterial liquid: urea.The purpose of this study was to investigate the effects of different ratios of beet pulp and cotton stalk fermentation on its nutrient composition,fermentation parameters and free gossypol content.To provide a scientific basis for improving and improving the feeding quality,safety and utilization of fermented cotton stalks.Through the feeding experiment,the effects of different feeding ratios of fermented cotton stalks on the growth performance,rumen fermentation parameters and serum biochemical indexes of mutton sheep were studied,which provided basic theoretical guidance and data support for the scientific and rational use of fermented cotton stalks in actual production.Methods: This study investigated the effects of different proportions of beet pulp and cotton stalk fermentation on its nutritional value.The design added carbon source(beet residue 10%,30%,50%),nitrogen source(urea(0.1%,0.2%,0.3%)),the bacterial liquid(complex bacteria 0.05%,0.1%,0.2%),using orthogonal test(AI),the control group only added cotton rod,salt and water,each treatment for 60 d(6replicates),determination of nutrition and Fermentation index.At the same time,the application of fermented cotton cultivars with different feeding ratios in Hu sheep was explored.The single-factor completely randomized block design was used to select 50 heads Hu sheepat with 2 months old health and similar body weight(16-18 kg).They were randomly divided into 5 groups,10 heads in each group,and the test period was60 days.During the test period,the feeds of the sheep concentrates were the same,and the coarse materials were 100% wheat straw,70% wheat grass + 30% cotton wool.stalk,50% wheat grass + 50% fermented cotton stalk,30% wheat straw + 70%fermented cotton stalk,100% fermented cotton stalk.30 sheep were selected,each group was slaughtered,the growth performance of mutton sheep,rumen fermentation parameters,serum biochemical indicators.Result:(1)The ratios of DM,NDF,ADF,ADL,pH and free gossypol increased with the increase of beet pulp content in different proportions of beet pulp and cotton stalk.The contents of CP,LA and NH3-N showed an upward trend.The contents of DM,NDF,ADF and ADL in I treatment group were significantly lower(P<0.05)than those in other treatment groups.The contents of CP and LA were significantly higher than those in other treatment groups except G and H treatment(P<0.05).Comprehensive evaluation: I treatment group in cotton straw: beet pulp: bacterialliquid: urea(50:50:0.2:0.1),the highest fermentation quality is better.(2)The 30%fermented cotton stalk group had the greatest impact on the growth performance of Hu sheep.The daily gain was 77.3 g,which was 48.94% higher than that of the control group(P<0.05),and the slaughter rate increased by 6.1%(P<0.05).The increase in the proportion of stalk feeding increased the daily weight and slaughter rate compared with the control group,and the feed-to-weight ratio increased.(3)The concentration of ammonia nitrogen and pH in the rumen of each group were in the normal range of rumen,but the lactic acid concentration in the rumen was increased,the pH value was significantly different from the group exposure(P<0.05),and the rumen fermentation function was positive.effect.(4)Compared with the control group,the serum biochemical indexes of each group increased the content of albumin and total protein in the serum of the sheep,and decreased the content of triglyceride.Conclusion:(1)Different proportions of cotton stalks: beet pulp: bacterial liquid:urea fermentation can improve the nutritional value of fermented cotton stalks,improve the palatability of fermented cotton stalks and reduce the content of free gossypol,among which cotton stalk: beet pulp : Bacterial liquid: Fermented cotton stalk fermented with urea(50:50:0.2:0.1)has the best quality.(2)Proper fermented cotton stalk feeding ratio Fully mixed ration can improve the palatability of feed,improve nutritional value,improve animal growth performance,promote rumen fermentation function,and promote the absorption and utilization of protein and cholesterol by meat sheep body.Among them,it is better to feed 30% fermented cotton rods to fully mix the diet.