Effects of massive ovulation on oxidation state and function of the ovaries in laying hens

Authors : Yu CHANG, Jinghai FENG, Minhong ZHANG, Liwen JIANG, Lili ZHAI, Xiaolan YANG

Pages : 161-166

View : 10 | Download : 4

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Modern laying hens show fast reduction in egg production rate after 60 weeks of age, which is associated with the decline in ovarian function. The aim of this study was to examine the influence of massive ovulation on the oxidation state and ovarian function in hens. In total, 48 Jing Hong hens aged 17 weeks were randomly divided into high ovulation insert ignore into journalissuearticles values(HO); and low ovulation insert ignore into journalissuearticles values(LO); groups. The LO hens were exposed to 6 h of light per day insert ignore into journalissuearticles values(6 L:18 D); up to 32 weeks to delay the initiation of egg production and then were switched to 16 L:8 D. The HO hens were reared at 16 L:8 D from 19 weeks. The treatment effects were analyzed by the independent samples t-test using SAS 9.0 software insert ignore into journalissuearticles values(SAS Institute, Cary, NC, USA);. At 36 weeks, there were no significant differences in body weight insert ignore into journalissuearticles values(P > 0.05); between the two groups and the egg production rate of both groups reached 98%; however, the cumulative egg number in the HO group was much higher than that in the LO group insert ignore into journalissuearticles values(71.3 versus 18.5, respectively; P < 0.001);. The following parameters decreased in the HO hens compared with the LO hens: the number of small yellow follicles insert ignore into journalissuearticles values(SYFs, P < 0.001); and large white follicles insert ignore into journalissuearticles values(LWFs, P < 0.01);, mRNA expression of luteinizing hormone receptor insert ignore into journalissuearticles values(P < 0.001);, and follicle-stimulating hormone receptor insert ignore into journalissuearticles values(P < 0.001);, while the atretic rates of SYFs and LWFs increased insert ignore into journalissuearticles values(P < 0.001 and P < 0.01, respectively);. In addition, compared with the LO group, the HO hens had reduced activity of superoxide dismutase insert ignore into journalissuearticles values(plasma: P < 0.01; liver: P < 0.001; ovary: P < 0.001); and glutathione peroxidase insert ignore into journalissuearticles values(plasma: P < 0.01; liver: P < 0.01; ovary: P < 0.01);, while the levels of methane dicarboxylic aldehyde insert ignore into journalissuearticles values(plasma: P < 0.01; liver: P < 0.001; ovary: P < 0.001); and mRNA expression of mitochondrial transcription factor A insert ignore into journalissuearticles values(P < 0.001); in granulosa cells were higher. These results indicated that massive ovulation aggravated oxidative stress and had adverse effects on ovarian function in laying hens.
Keywords : Laying hens, massive ovulation, ovarian function, oxidative stress