Effect of photoperiod on serum hormone concentrations during the annual reproductive cycle in geese.

The poor egg-laying rate of geese hinders the development of the goose industry; therefore, the reproductive performance of geese is an important area of investigation. To evaluate the relationship between photoperiod, reproductive hormones, and reproductive activity during the egg-laying cycle in geese under natural conditions, we collected blood samples from Sichuan white geese and Xupu geese to quantify changes in prolactin (PRL), estradiol (E2), vasoactive intestinal polypeptide (VIP), follicle stimulating hormone (FSH), gonadotropin-inhibitory hormone (GnIH), and luteinizing hormone (LH). We also calculated the rate of egg laying for the two populations during the egg-laying cycle. We show that the egg-laying rate and the serum concentration of some hormones (PRL, E2, VIP, FSH, GnIH, and LH) differed significantly between the two populations during the pre-laying, laying, and ceased-laying periods. Serum LH concentrations may be associated with maturation of the ovary and oviducts, whereas FSH, PRL, and GnIH play important roles in egg laying. These results provide a useful resource for future studies examining the laying rate in geese.

Effects of feeding conditions on gene expression in chicken breast muscle.

Chicken meat quality is becoming increasingly important among breeders and consumers. To understand the effect of feeding conditions on chicken meat quality, we investigated the profiles of genes expressed in chicken breast muscle. Using RNA sequencing, we identified 336, 321, and 387 differentially expressed genes among Chengkou, Daninghe, and Qingjiaoma chickens under scatter- and captivity-feeding conditions. Twenty-two genes differentially expressed between different feeding conditions were shown to be common among the three breeds. Seven of these genes were assessed by real-time quantitative PCR, which confirmed the findings of RNA sequencing and suggested that the results were viable. The differentially expressed genes showed enrichment for a series of significant pathways, including energy metabolism, xenobiotics biodegradation and metabolism, and the immune system. These results provide a solid foundation for elucidating the molecular mechanisms underlying chicken meat quality.