| In this paper,Magang goose is taken as the research object,around the hypothalamus-pituitary-gonadal axis regulation,the follicular development,serum reproductive hormone levels,and reproduction-related gene expression of goose during different reprodution periods were studied,in order to reveal the main regulatory factors and related regulatory mechanisms in the seasonal reproduction of the Magang Goose and in the regulation of the cyclical changes of egg production-the nest,and also provide the scientific basis for the improvement of poultry reproduction control theory.At the same time,we analyze and compare the flora of the intestine microorganisms of Magang goose in different breeding stages under different production modes,to explore the effects of different intestinal microflora composition on reproductive physiology of Magang Goose,and to reveal the effect of counter-season reproductive production on the intestinal microflora of female geese and the breeding performance of gooses.This study provided scientific basis and objective data for the improvement of the production technical level of geese.Experiment 1: Study the follicular development,hormone levels and related gene expression of female geese during different breeding periods(eg,laying,nesting,and cease).The results showed that the ovaries were in atrophic state during the cease and the nesting period,and the ovary was fully developed during the laying period.The numbers of LYF,SYF and LWF were 4.42±0.20,5.31±0.83 and 11.14±2.21,respectively.The concentrations of E2,P4,LH and MT during the cease period were significantly lower than the breeding period(the nesting and laying period)at 109.78±13.11 pg/mL and 1.76±0.08,68.62±5.20,and 37.91±1.86 ng/L,respectively(p<0.05).Gn IH concentration during the cease period was 249.01±15.42 pg/mL,which was significantly higher than that during the breeding period(p<0.05).There was no significant difference in the above hormones between the laying period and the nesting period.GnIH expression in the pituitary and Gn IHR expression in the hypothalamus were significantly higher than those in the laying and cease period(p<0.05 and p<0.01);GnIHR expression in the graded follicle F3 was significantly higher than that in the F1,F5 and laying period,rest period(p<0.05).The expression levels of PRL and VIP showed the same trend,which highest expressed in cease period and lowest expressed in laying period.The expression of GnRH in hypothalamic and pituitary was highest in the laying period,and in the pituitary GnRH expression level was significantly higher than that in the nesting period(p<0.05).The level of Mel-1a expression in the hypothalamus was not significantly different in each breeding period and was highest in the F5-dominant follicles in the ovary,which was significantly higher than other follicles and in the nest and cease period(p<0.05).The expression of Mel-1b in the hypothalamus was significantly higher than that in the laying period(p<0.05),and the expression of Mel-1b in the pituitary was the highest in the laying period,which was significantly higher than that in the cease period and the nesting period(p<0.01).There was no significant difference in the expression of Mel-1b in the ovary during each breeding period and in all follicles,with a slightly lower maturation period.The expression of Mel-1c was highest in the hypothalamus and pituitary in the nesting period,and the expression in the hypothalamus was significantly higher in the nesting stage than that in laying period(p<0.05).In the ovary,the expression level of Mel-1c in the cease period was the highest and significantly higher than the nesting stage and all grades of developmental follicles(p<0.01).The results showed that GnRH/GnIH plays an important role in the regulation of reproductive activities of Magang Goose.GnRH can promote the reproductive activity and follicular development by promoting the secretion of FSH and LH,while GnIH exerts an inverse inhibitory effect.Melatonin promote or inhibit reproductive activity and follicular development of Magang Goose through binding with different receptor subtypes.Experiment 2: To study the characteristics of the intestinal microflora at different breeding seasons in Magang Goose under normal seasonal breeding and out-of-season breeding.A total of 24 species of bacteria and 335 strains were obtained.At the gate level,the proportion of thick-walled bacteria is the highest(40%~97%),and it is higher in the cease period than that in the nesting and laying period,and in the counter-season production is higher than that in normal season.The proportion of Bacteroidetes is higher in the nesting period than that in the cease and the laying period,and is generally lower in the out-of-season production than that in normal season.The proportion of Proteobacteria and the Fusobacterial genus are both highest in the laying period,and the lowest in the cease period.At the genus level,in both modes of production,the proportion of Romboutsia spp.is lowest in laying period.Both Bacillus spp.and Lactococcus lactis are lowest in the nesting stage and highest in the laying period,while Staphylococcus is opposite to them.Bacillus spp.and Lactococcus lactis are higher in the out-of-season than that in the normal season.The intestinal micro-organisms of different reproductive stages have different group characteristics,and they are quite different between out-of-season and normal season.These results showed that under the condition of natural reproduction,the intestinal microbiota characteristics of Magang goose have different characteristics at different stages of reproduction,and out-of-season production could affect the characteristics of intestinal microflora. |
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