| Silky chickens are well-known as medicinal rare birds,which have high nutritional value and medicinal value.However,silkies breed aquatics are limited because of the large individual differences,and the farming scale is small and more development space for the silky market.There has always been a hot topic on how to improve the production performance of laying hens and improve the economic benefits.Coated sodium butyrate(CSB)is a kind of short-chain fatty acids and was used as a additive due to varieties of physiological functions,especially the extended releasing and contribution to the full absorption of the intestinal epithelium.In addition,CSB can help maintaining the health of intestine and promoting the immune function.However,the study of CSB is mainly focused on the piglets and chickens.Few researches are concentrated on the impacts of CSB on the health of silkies.The aim of present study was to investigate the effect of CSB on the growth and reproduction performance of silky breeding hens,and the effect on the lipid metabolism and antioxidant properties,in order to improve the health of hens,and provide a theoretical basis for the use of CSB as an additive in the production of silkies.1.Effects of coated sodium butyrate on the growth performance and production performance of silky breeding hens512 25-week-old silky breeding hens were selected for experimental purpose,randomly assigned to two groups:Control group fed with basal diet,hens in experimental group were fed CSB(add to 500 mg/kg in Premix)for 20 weeks.According to the physiological characteristics of hens,the experimental period was divided into three stages,25?28 weeks old was early laying period,29?36 weeks old was the peak laying period,37?44 weeks old was the later laying period.The number of feed,death hens,laying eggs,broken eggs,soft eggs and abnormal eggs were noted every day.Each group were randomly assigned to 8 hens to weigh every week,The results showed that:Compared with control group,from 25?28 weeks old hens,body weight,the rate of death were not significantly different in the CSB group.Egg weight,egg production rate and broken egg rate as well.Feed intake and egg Haugh unit value were significantly increased.It improved the quality of the eggs in the period.Dietary supplementation of 500 mg/kg coated sodium butyrate did not significantly alter the growth performance and laying performance of the period from 29-36 weeks old hens,but the egg Haugh unit value were significantly increased.For the silky breeding hens in the period from 37?44 weeks old,average feed intake and hatchable egg rate were significantly increased and death culling rate were decreased.2.Effects of coated sodium butyrate on tissues and organs of silky breeding hensThe same design of experiment as number experiment 1.Respectively,each group slaughtered 8 hens for samples collection and determination after feeding hens in the 28 weeks old,36 weeks old,44 weeks old,collecting organ tissues(heart,oviduct,liver,spleen and ovary).The result showed that:Compared with the control group,the addition of CSB had little effect on the heart index,liver index,ovary index and oviduct index during the whole test period of silky breeding hens,but at the 44 weeks old,the spleen index were decreased in the CSB group and the morphological structure of the the fallopian tube enlargement,isthmus,uterus of oviduct were not significantly different in the SCE groups Above all results showed that the addition of 500 mg/kg CSB for 20 weeks had no significant effect on the organ index of hens,but also had no significant effect on the shape of tubal tissue May be related to age added.3.Effects of feeding coated sodium butyrate on serum biochemical parameters,antioxidation stress and lipid metabolism of silky breeding hensThe same design of experiment as number experiment 1.At the same time,the blood(2 ml)were taken at 28 weeks old,36 weeks old,and 44 weeks old.The result showed that:Compared with control group,the addition of CSB did not have a significant effect on the liver function and antioxidant stress of the 28-week-old silky breeding hens,in this period,LDL-C levels in the serum were significantly decreased which promoted the transport of cholesterol to the ovaries,and had a positive effect on the accumulation of yolk in the ovaries of hens.BUN content in serum were decreased in CSB group,but the difference was not significant.Contrary to the expectation,AKP in the CSB group were decreased,possibly due to the shorter addition of diets.For the 36 weeks old hens,dietary supplementation of CSB in the diet were significantly reduced the levels of ALT and MDA in the serum of the 36-week-old silky breeding hens,and the level of CAT were decreased at the same time in CSB group.In addition,the content of BUN were significantly decreased in CSB group,which may be at the peak of laying hens in the body of protein loss is greater.Dietary addition of CSB did not significantly affect the lipid metabolism of 44-week-old silky breeding hens,but the level of CAT in the serum were significantly increased and the activity of AST in the serum were significantly reduced.The hens had better ability of antioxidant stress feeding coated sodium butyrate during the period.During the whole trial period,the level of estrogen in serum were significantly increased in CSB group,and the levels of CAT in the liver increased slightly,but the difference was not significant.The above results indicate that the addition of 500 mg/kg of coated sodium butyrate to the 25-week-old silky breeding hens increased the estrogen levels in the serum and promoted synthesis of lipid transport from liver to the ovary at the age of 28 weeks.Ii is good for the accumulation of hens egg material.And when the hen age reached to 44 weeks,coated sodium butyrate increased the immune level and antioxidant stress of silky breeding hens. |
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