Dietary Supplementation with Ferula Improves Productive Performance, Serum Levels of Reproductive Hormones, and Reproductive Gene Expression in Aged Laying Hens

This study investigated the effects of dietary Ferula supplementation on productive performance, egg quality, follicular development, serum levels of reproductive hormones, and reproductive gene expression in aged laying hens. A total of 300 Dawu pink laying hens (65 weeks old) were assigned to four treatments with six replicates per treatment and 10 hens per replicate. The birds were individually housed in wire cages and fed a corn-soybean meal-based diet with added Ferula at doses of 0, 50, 100, and 200 mg/kg for 12 weeks. The results showed that the laying rate in the 100 mg/kg Ferula-supplemented group was higher than in birds of the control group during weeks 1 to 12 (p<0.05). The average egg weight in the 100 mg/kg Ferula-supplemented group was significantly higher than in the other groups (p<0.01), while the feed-to-egg ratio was significantly lower than in other groups (p<0.01). The numbers of small yellow follicle, middle white follicle, and small white follicle were higher in the 100 mg/kg Ferula-supplemented birds than in the other groups (p<0.01). On weeks 69, the serum levels of estradiol, follicle-stimulating hormone, and luteinizing hormone were significantly higher in the 100 mg/kg Ferula-supplemented group than in the other groups (p<0.05). Additionally, expressions of ER alpha, FSHR, and LHR in the ovarian tissue were up-regulated by Ferula supplementation, especially in the 100 mg/kg group (p<0.01). These results indicate that the Ferula supplementation can significantly improve productive performance, egg quality, reproduction of hormonal profile, and reproductive gene expression of aged laying hens.