| Low energy and pelleting technology are important factors which restrict the use of bran in broiler feed percentage.It is one of the most effective methods to raise effective energy value and cultivate active metabolites by bran fermentation.In this experiment,two kinds of bran fermentation materials were used as experimental materials,and no bran fermentations were used as control.The effective utilization rate of nutrients and energy in bran starter for commercial broilers were studied,and the feasibility of improving the production performance and meat production performance of broilers with bran starter were discussed.This study will lay a theoretical foundation for the use of bran starter in commercial granulated feed for broiler chickens.Test 1: In order to explore the feasibility of using bran starter in the diet of commercial broiler chickens,a single-factor completely randomized design was adopted in this study.240 AA commercial broiler chickens with similar weight and age of 21 days were selected and randomly divided into 4 treatments,6 replicates for each treatment and 10 chickens for each repetition.Treatment 1,the control group was feeded wity a diet without bran,and the nutritional level was prepared according to the NRC recommended nutritional level.In treatment 2,3 and 4,5% bran,bran starter A and bran starter B were used to replace the diet of the control group respectively.The results showed that the daily weight gain,feed intake,feed weight ratio,42d-body weight,semi-clean chamber rate,full clean chamber rate,abdominal fat rate,chest muscle rate,leg muscle rate,digestive tract weight,empty field thickness and ileum thickness of broilers were not significantly affected by the bran and two kinds of bran fermentation diets(P > 0.05).However,the diet fed with bran starter increased the thickness of duodenal wall(p = 0.016),and it showed a trend of increasing in the length of digestive tract(p = 0.079).Moreover,the results showed that the production performance,meat production performance and digestive tract development of broiler chickens were increased.Bran starter can promote the development of the digestive tract of broiler chickens,and may change the efficiency of feed,improve the performance of production and meat production.The results showed that the bran starter had more economic benefit than the unadded on.Test 2: In order to determine the effective utilization rate of nutrients and energy in bran starter for commercial broilers,this test adopts the method of full fecal-urine collection.A total of 100 healthy AA broiler chickens with the same weight at the age of 21 days were selected and randomly divided into 5 treatments,10 replicates for each treatment and 2chickens for each repetition.Treatment 1,base diet(no bran);Treatment 2,unfermented bran starter diet,15% unfermented bran starter diet +85% base diet;Treatment 3,bran starter A diet,15% bran starter A+85% base diet;Treatment 4,bran starter B diet,15% bran starter B+85% base diet;Treatment 5 was used as the endogenous blank control.The results showed that all nutrients(dry matter,organic matter,crude fat,crude protein,crude fiber and nitrogen free extract)and total energy apparent and true utilization rate of bran starter A and B were significantly higher than those without bran(p < 0.001),and there was no significant difference between the two bran starters(p > 0.05).The nutrient utilization rate of bran was100%.The dry matter,organic matter,crude fat,crude protein,crude fiber,nitrogen free extract and total energy apparent metabolic rate of bran starter A were increased by 3.7%,4.2%,3.9%,6.2%,6.7%,4.2% and 5.7%,respectively.The dry matter,organic matter,crude fat,crude protein,crude fiber,nitrogen free extract and total energy apparent metabolic rate of bran starter B were increased by 3.9%,4.2%,3.9%,6.3%,9.3%,4.2% and 5.7%,respectively.The nutrient utilization rate of bran was 100%,and the true metabolic rate of dry matter,organic matter,crude fat,crude protein,crude fiber,nitrogen free extract and total energy of bran starter A were improved by 4.8%,5.4%,5.4%,5.1%,8.1%,7.2%,5.4% and 5.5%,respectively.The true metabolic rate of dry matter,organic matter,crude fat,crude protein,crude fiber,nitrogen free extract and total energy of bran fermentation B was increased by4.8%,5.4%,5.4%,5.1%,8.2%,9.6%,5.4% and 5.5%,respectively.It seems that the bran starter had a higher nutrient utilization rate,and the bran starter B seemed to have a better fiber utilization rate.The available values of bran and bran starter components and energy can be used as the basis of effective nutrient design.Test 3: To study the bran yeast for commodity feed water retention properties,nutrition index and the study of the influence of grain shape,this experiment choose 1.5 mm and 2.0mm,2.5 mm and 4.0 mm four grinding fineness,with no added fermented feed to the control group,3% bran A yeast,5% bran yeast,3% B bran yeast,5% bran yeast for group B,each packet powder commodities of feed,particle feed two processing,each processing three repetition.The moisture,Ca,CA,EE,CF,P,CP,ADF,NDF and other indexes in the feed were detected by near infrared spectroscopy,and the hardness index method was used todetermine the hardness of the pellet feed.The results showed that :(1)there was no significant difference in particle hardness and particle diameter between the four grinding fineness degrees of 1.2mm,2.0mm,2.5mm and 4.0mm(P > 0.05).The moisture content,Ca,CA,EE,CF,P,CP,ADF and NDF of commercial feed were significantly different with different grinding fineness(P < 0.001).(2)the addition of bran starter A and bran starter B had significant effects on the indexes of water,Ca,CA,EE,CF,P,CP,ADF,NDF and particle hardness of commercial feed(P < 0.05).There was no significant difference in water content,Ca,CA,EE,CF,P,CP,ADF,NDF,particle size between different kinds of bran starter A and B(P > 0.05).(3)adding 3% bran yeast,5% bran pitchforks and not add bran yeast goods feed moisture,Ca,CA,EE,CF,P and CP,ADF,NDF,grain hardness index exists significant difference(P < 0.05),with the increase of adding ratio,higher feed water retention,5% bran yeast adding ratio is the highest water retention in the three groups.With the increase of the proportion of bran starter,the hardness of the granule decreased,and the hardness of the control group was the highest,and that of the 5% starter group was the lowest.There was no significant difference in the particle size of commercial pellets with different proportions of fermented feed(P > 0.05).The bran starter had significant effect on the water and nutrition index of commercial feed,so the balance nutrition should be paid attention to when using the bran starter in commercial feed.The hardness of pellet feed could be softened by adding bran starter and decreased with the increase of adding proportion.The fineness of grinding has an effect on the water-retaining property of the bran starter,and the best water-retaining property is obtained when grinding at 4.0mm. |
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