Effects Of Fermented Feed On Growth Performance And Rumen Environment Of Dairy Bulls

Recently,under the influence of climate and epidemic situation,the decrease of corn and soybean production at home and abroad has led to the rise of domestic feed raw material prices,which has caused great pressure on the feed supply of beef cattle.In this case,it has become a top priority to find cheap agricultural product processing by-products to replace corn and soybean meal and other diets.As a feed source of non-conventional feed,spraying corn husk is widely used,while bread residue is the waste produced by urban bread factory.Its low price and stable source can be used as a potential source of feed raw materials.In this experiment,Saccharomyces cerevisiae and Bacillus strains were added to bread crumbs and shotcrete corn husks for solid bulk fermentation,After production,fermented bread residue feed and fermented spraying corn husk feed replaced 30% of shotcrete corn husk in concentrate diet of beef cattle respectively as test group A and test group B,and test group C was fed with unfermented spraying corn husk to make three groups of concentrate diet.Then it was added into the diet of holstein dairy bulls in fattening period to explore the effects of different agricultural by-products on the growth performance and rumen environment of beef cattle after fermentation.The results are as follows:Experiment 1: In order to study the nutritional value and digestion characteristics of different agricultural by-products after fermentation,this study used in vitro gas production test to evaluate the nutritional value of group A:fermented bread crumbs concentrate Group B: fermented spraying corn husk concentrate group C: unfermented spraying corn husk concentrate The results showed as follows: rumen dry matter degradation rate and total gas production were significantly decreased by fermented bread crumbs and shotcreted corn husks.Compared with group C,methane production at 48 h in group A was significantly decreased(P<0.05),but hydrogen production at 48 h was significantly higher than that in groups C and B(P<0.05)Compared with group C,the total volatile acid content in group B and group B was significantly decreased(P<0.05),and the concentration of isobutyric acid in group A and group B was also significantly lower than that in group C(P<0.05).There was no significant difference in volatile fatty acid content between groups A and B(P>0.05)The two groups C were significantly higher than group A(P<0.05),and there was no significant difference in p H(P>0.05).Therefore,compared with non-fermented spraying corn bran concentrate,the concentrate made from fermented bread residue was lower in terms of feed dry matter degradation rate,and the digestive efficiency of simulated rumen feed was also lower.Experiment 2: In order to study the effects of fermented feeds made from different agricultural by-products on the growth performance and nutrient digestibility of dairy bulls,36 long-term dairy bulls were used for A 60-day growth test,which were divided into three groups: group A fermented bread residue concentrate and group B fermented spray corn husk concentrate The results showed that there was no significant difference in the weight gain index,blood biochemical index and nutrient apparent digestibility index among the three groups in terms of growth performance(P>0.05).The average daily gain(ADG)in group B was significantly higher than that in groups A and C during36-60 days(P<0.05);Dry matter intake in group B was significantly higher than that in groups A and C during 0-36d(P<0.05),but there was no significant difference in other groups(P>0.05).The feed to gain in group B was significantly lower than that in groups A and C during the whole trial period,and the economic benefit was the highest(P<0.05).In terms of blood biochemistry,the total protein albumin globulin in serum,leukocyte and red blood cell There was no significant difference in hemoglobin concentration among the three groups(P>0.05),the content of glutamic-pyruvic transaminase in group B was the highest and significantly higher than that in group A(P<0.05),the content of glutamic-oxalacetic transaminase in group A was significantly higher than that in group B(P < 0.05)urea nitrogen concentration B>A>C was significant(P <0.05),creatinine content A The total cholesterol content of group A was significantly higher than that of group B and GROUP C(P < 0.05),but the nutrient apparent digestibility of group B was in the normal range.The apparent digestibility of dry matter in group B was significantly higher than that in group A and C(P < 0.05),the apparent digestibility of crude protein in group B was significantly higher than that in group A(P < 0.05),the apparent digestibility of energy in groups A and B was significantly higher than that in group C(P <0.05),and the apparent digestibility of neutral detergent fiber in groups B and C was significantly higher than that in group A(P < 0.05).The apparent digestibility of acid detergent fiber in group B was significantly higher than that in groups A and C,but the apparent digestibility of ether extract was not significantly different among the three groups(P > 0.05).The apparent digestibility of starch in groups A and B was significantly higher than that in group C(P < 0.05),so feeding fermented bread crumbs concentrate reduced the apparent digestibility of crude protein and neutral fiber of beef cattle,and the weight gain of beef cattle also showed A decreasing trend compared with the other two groups,which was consistent with the results of in vitro fermentation evaluation.Compared with non-fermented shotcrete corn husks,the feed conversion rate of beef cattle fed with fermented shotcrete corn husks was increased,immunity was enhanced,feed to gain ratio was reduced and economic benefit was improved.Experiment 3: In order to study the degradation of agricultural by-product fermented feed in rumen of beef cattle and the effect of fermented spraying corn husk on rumen bacterial community,and to clarify the influence mechanism of fermented feed on growth performance of dairy bulls,the fermentation indexes of three groups in rumen were measured in this study.The rumen bacterial flora of spray corn husk group and fermentation spray corn husk group was analyzed by 16 Sr RNA gene sequencing method.The results showed as follows: rumen fermentation parameters had no significant change in p H before feeding(P>0.05),rumen fluid p H in group B was significantly higher than that in groups A and C after feeding(P< 0.05),and the contents of ammonia nitrogen,acetic acid and propionic acid in groups B and C were significantly increased compared with group A(P<0.05).At the level of rumen bacteria,Saccharibacteria and Tenericutes in group B were significantly higher than those in group C(P<0.05).At family level,group B significantly increased the relative abundance of Rikenellaceae and BS11 Bacteroidales＿BS11＿gut＿group and Christensenellaceae(P< 0.05).At the genus level,the relative abundance of Rikenellaceae＿RC9＿gut＿group of Rikenellaceae RC9 and Ruminococcaceae＿NK4A214＿group of Ruminococcaceae NK4A214 was significantly increased in group B(P < 0.05).Feed through to the 2.5 h tumor after the index analysis of gastric juice,bread slag concentrate reduced the rumen fermentation volatile fatty acid content,reduce the absorption of the beef cattle feed on use,not suitable for 30% level instead of unleavened guniting corn husk,compared with unleavened shortcreting corn husk feeding fermented corn husk of spray concentrate improved protein and fiber in the rumen degradation of the relative abundance of the types of bacteria,The contents of volatile acetic acid and propionic acid were significantly increased under the influence of dominant rumen bacteria,which affected the feed conversion rate.Conclusion: different fermentation feed by-products from processing of agricultural products are varying degrees of holstein bull milk,fermented bread slag to replace 30% concentrate diet,reduced the beef cattle on feed conversion rate,so the follow-up will feed exploitation to the beef cattle feed in bread slag should be to reduce the percentage of feed,and to guarantee feed through supplements in the level of protein.Fermentation guniting corn husk feed can improve protein in the rumen and non fiber carbohydrates the relative abundance of the bacteria,improve the rumen ammonia nitrogen and volatile acid concentration level,improve the body on the apparent digestibility of crude protein,crude fiber,so as to reduce the beef cattle feed weight ratio,improve the feed conversion rate,reduce feed costs,create economic benefits.