Effect Of Melatonin On Laying Performance Of Laying Hens

Melatonin is a multifunctional steroid hormone,which is secreted by the pineal gland,which secretes with circadian rhythms and seasonal rhythms.The growth and development of the pineal gland is affected by many factors.The most important factor reason is the age factor.In vertebrates,the pineal gland begins to secrete melatonin from the time of birth until it reaches its peak in childhood,and then with age.the growth of the pineal gland is gradually deteriorates with age.Melatonin plays a vital role in the reproduction of animals reproduction.On the one hand,melatonin regulates reproduction through the hypothalamic-pituitary-gonadal axis.On the other hand,autocrine melatonin in the reproductive organs can directly participate in the reproductive process.At present,the important regulatory effects of melatonin on reproductive processes such as sperm production and follicular development have been well documented.There is a melatonin receptor in the hen’s ovary,so melatonin can directly affect the ovary and regulate the synthesis and secretion of gonadotropin through its receptor(so the synthesis and secretion of gonadotropin can be directly affected by melatonin though receptor)thereby affecting reproductive function.In this experiment the present study we show that,the content concentration of melatonin and important reproductive hormone,such as follicle stimulating hormone(FSH)and luteinizing hormone(LH),in laying hens were determined and correlated.At the same time,statistical analysis was carried out on the development of pineal gland and egg quality related indexes of laying hens in different laying stages(the correlation of pineal gland development and egg quality was been found though statistical analysis in different laying stages of laying hens),revealing the correlation between melatonin and laying performance of laying hens.Then Afterwards,different concentrations of melatonin were added to the feed of laying hens to detect(the changes of follicle stimulating hormone,luteinizing hormone and melatonin in each group of chickens have been detected after feeding different concentrations of melatonin in each group of laying hens),and then the effects of different concentrations of melatonin on the egg quality of laying hens were analyzed adding different concentrations of feed to add melatonin.In order to analyze the relationship between melatonin and laying performance of laying hens.The effect on the quality of egg and egg was analyzed in detail on the relationship between melatonin and laying performance of laying hens.According to the research content,this topic is divided into two parts.Part one:Correlation analysis of egg production performance,hormone and pineal gland development in laying hens during different laying periods In this part of the study,the hormonal concentration in the blood of laying hens was detected by ELISA kit,and the calcium concentration was detected by methyl thymol blue colorimetric method.The egg quality was tested by egg quality tester.The pineal gland cells of laying hens were cultured in different laying stages.The size and shape of cells were observed and the cell’s ability to synthesize melatonin was examined.The results showed that there were differences in blood hormone and egg production between laying hens in different laying periods.(The levels of melatonin,follicle-stimulating hormone and luteinizing hormone in the blood of the layering hens at the peak of egg production were higher than those at the end of egg production,which respectively high 8.1%,28.1%and 32.9%.Meanwhile,in terms of egg quality,the eggshell thickness was 8.2%higher,the eggshell strength was 15.3%higher,and the egg weight increased by 2.3%).The ability of the pineal gland development and the synthesis melatonin with cell in the end of production has been weakened compared with the peak in laying hens,then the pineal gland is only half size of the production peak,and the cell development is also poor.Part two:Effect of adding exogenous melatonin on laying performance of laying hens.Different concentrations of melatonin were added to the laying hens at the end of laying period,and four groups were set according to the different concentrations of melatonin.The changes of melatonin,follicle stimulating hormone,luteinizing hormone and egg quality in each group were detected.Surface-enhanced Raman spectroscopy was used to scan the effects of melatonin on egg composition.RT-PCR was used to detect the expression of egg-related genes in laying hens after adding melatonin,and analyze the effect of the melatonin on production performance in laying hens.The results showed that the hormone concentration and production performance of the laying hens in the end of laying period increased significantly compared with that before adding melatonin.and the increasing was most significant when 1 mg/kg of melatonin was added Compared with the control group,the melatonin concentration increased 5.3%;the luteinizing hormoneincreased 46.3%;the follicle stimulating hormone increased 56.8%;the concentrated protein height increased 26.2%;the eggshell thickness increased 4.9%;the eggshell strength increased by 20.1%and the egg weight increased 34.3%,which indicatethat the synthesis of melatonin is an important factor affecting eggs quality.This study provides theoretical basis for the improvement of production performance in laying hens.It provides a theoretical reference for the prolongation of laying hens and the application of melatonin in laying hens.It enriches the mechanism of laying eggs,provides useful reference of efficient breeding of poultry and provides useful lessons to contribute to the development of animal husbandry.