Researches On The Growth,Meat Quality And Gene Expression Of Growth Axis Regulated By Monochromatic Light In Yangzhou Goose

The retina and pineal gland of poultry can be stimulated by external light to activate the hypothalamus-pituitary-growth axis and regulate the growth and development of poultry.The response of goose to different color spectrum may be different.In this study,six hundred 1-day-old Yangzhou geese were randomly and uniformly reared in 4 identical houses for 70 days under white light,red light,green light and blue light,growth performance,meat quality and expression level of genes related to growth axis were compared among different groups.The findings are as follows:1.The effect of monochromatic light on the growth performance of Yangzhou geese: The average body weight of geese treated with green light was significantly higher than that treated with white light(P<0.05).The average daily food intake of green light and blue light was higher than that of white light and red light.The material weight ratio of green light treatment group was significantly lower than that of other three groups(P<0.05).2.Effects of monochromatic light on quality and histological characteristics of breast muscle in Yangzhou geese: The content of inosinic acid in the green light group was the lowest and significantly lower than that in the blue light group(P<0.05),the shear stress and the reddened value of the pectoral muscle in the white light group were significantly lower than those in the other three groups(P<0.05),and the luminance value of the pectoral muscle in the white light group was the highest,compared with the blue light group,the difference was significant(P<0.05).The contents of sweet amino acid,total amino acid and essential amino acid in green light group were higher than those in other groups,and the difference was significant(P<0.05).The area of muscle fiber in green light group was the largest,which was significantly higher than that in other three groups(P<0.05).3.Effect of monochromatic light on growth-related gene expression in Yangzhou geese: The expression of GHRH m RNA in hypothalamus of Yangzhou geese treated with blue light and green light was significantly higher than that of white light and red light(P<0.05).The expression level of 50-day-old green light group was significantly higher than that of white light group and red light group(P<0.05),and that of 70-dayold red light group was significantly lower than that of blue light and green light group(P<0.05).IGF-I m RNA expression was significantly higher in 30-day-old green light group than in the other three groups(P<0.05),and significantly higher in 50-day green light group than in white light group(P<0.05).The expression level in green light group was significantly higher than that in white light and red light group(P<0.05).There was no significant difference in the expression of IGF-IR m RNA between the 30-dayand 70-day-old Yangzhou geese breast muscle(P>0.05).The expression of IGF-IR m RNA in the 50-day-old green light group was significantly higher than that in the red light group(P<0.05).The expression of GHR m RNA was significantly higher in green light group than that in red light group(P<0.05)and white light group(P<0.05).Monochromatic green light feeding could increase the body weight,feed conversion rate,flavor amino acid content and muscle fiber area of Yangzhou geese.Monochromatic green light stimulation can also up-regulate GHRH gene expression in hypothalamus and GHR and IGF-I gene expression in breast muscle of Yangzhou geese.