| With the improvement of our people’s living standard,the demand for red mutton is increasing gradually.The production of sufficient and high-quality red mutton has become the focus of the livestock industry.Soybean isoflavone is a class of polyphenol compounds derived from leguminous plants.It is a natural,non-toxic,non-polluting,non-residual new,efficient and green feed additive.It can improve animal production performance,promote animal growth,improve feed utilization,and is of great significance in increasing yield and improving meat quality.Therefore,this study aims to study the effects of soy isoflavones on growth and development,slaughter performance and rumen microorganisms of castrated RAMS of Guanzhong dairy goats,so as to provide a theoretical basis for improving growth performance and mutton quality of dairy goats and reducing feeding costs.Experiment selected 27 only 5 months the Guanzhong dairy goats castrated ram,randomly divided into three groups,each group of nine only.Control group,trial group 1and trial group 2 were fed basal diets supplemented with 0,100 and 200 mg/d soybean isoflavones,respectively.The pre-trial period was 2 weeks and the trial period was 8 weeks.During the trial period,feed intake was measured every day;body weight was measured on0 d,14 d,28 d,42 d and 56 d;body size was measured on 0 d,28 d and 56 d.Blood samples were collected on 0 d,28 d and 56 d,and urea nitrogen(BUN),total cholesterol(TC),triglyceride(TG),total protein(TP),growth hormone(GH)and soy isoflavone(SIF)were determined.At the end of the experiment,3 sheep in each group were selected and slaughtered,a total of 9 sheep were slaughtered.Carcass and non-carcass tissues and organs,bone samples,meat physicochemical properties and other slaughter indexes were determined.Rumen fluid was extracted for 16 S r RNA sequencing.The results are as follows:1.Analysis of feeding indexes,body size traits,and blood indexes of castrated RAMS of Guanzhong dairy goats in different feeding groups showed that the average daily gain of test group 1 was significantly higher than that of control group from 28 d to 42 d of the test period.(P < 0.05).42 d to 56 d test,the two groups of daily gain,on average,significantly higher than the control group and experiment 1 group(P < 0.05).Over the course of the experiment,the mean daily food intake of test group 1 was significantly greater than that of control and test group 2 from 42 d to 56 d(P < 0.05).During the test period,the feed conversion rate of test group 1 was significantly higher than that of both the control and test groups 2 at 14 d to 28 d(P < 0.05).On day 56 of the testing period,the soy isoflavone content in the blood of the test group 1 was significantly higher than that of the control and test groups 2(P < 0.05),but soybean isoflavone had no significant effects on other blood indexes and body size traits.2.Analysis of slaughter indexes,internal organ quality and meat quality of castrated RAMS of Guanzhong dairy goats in different feeding groups showed that there were no significant differences in carcass weight,carcass length and other slaughter indexes.Kidney weight and net large intestine weight of experimental groups were significantly higher than those of control group(P < 0.05),and lung weight of experimental groups were significantly lower than those of control group(P < 0.05).In the index of cooking loss rate,experiment group 1 was significantly lower than control group(P < 0.05).3.Analysis of microbial diversity in the rumen of castrated RAMS of Guanzhong dairy goats in different feeding groups showed that Shannon index,Chao1 index and ACE index of test group 2 were significantly lower than those of control group(P < 0.05),and Shannon index of test group 2 was also significantly lower than that of test group 1(P < 0.05).αdiversity analysis showed that there was significant difference in the number of species between control group and test group 2(P < 0.05).At the phylum level,the relative abundance of Bacteroidota in test group 1 was significantly higher than that of control group.At the genus level,The relative richness of the experimental groups was improved,including Ruminobacter,Prevotellaceae UCG-001 and Lachnospiraceae NK4A136 group.In conclusion,soy isoflavone can improve average daily gain,feed intake,feed conversion rate and blood soy isoflavone content of castrated RAMS of Guanzhong dairy goats.Increased kidney weight and net large intestine weight of castrated RAMS;Promoted the growth and development of castrated RAMS;At the same time,the rumen microbial diversity of castrated RAMS can significantly improve the relative abundance of Bacteroidota.The bacterial richness of Ruminobacter,Prevotellaceae UCG-001 and Lachnospiraceae NK4A136 group was increased,and the rumen digestion function was increased.This study laid a theoretical foundation for the analysis of the physiological function of soybean isoflavones and the growth and development of dairy goats. |
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