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Abstract
Research in mammals indicates that nesfatin (or NUCB2) and visfatin are protein hormones involved in regulating energy balance. Broiler breeder hens are feed restricted during rearing and production to control body weight. Ad libitum feeding during either the rearing or production phase decreases reproductive performance. Implementation of feed restriction programs typically results in the birds being fed a limited amount once every other day during rearing and once a day during production. This feeding schedule results in significant fast periods between feedings which can be detrimental to follicular development. Therefore, in the current research, the ovarian mRNA expression of nesfatin and visfatin was examined in hens that had been fed daily or fasted for 72 hours. Theca and granulosa tissue was isolated from individual F1, F2, F3 and F4 follicles, a pool of small yellow follicles (SYF) and a pool of large white follicles (LWF). The isolated theca and granulosa tissue from each follicle size was combined from 2 birds, and 3 replicate samples of each tissue type for each follicle size within each feeding treatment were obtained. Total RNA was isolated from each sample for real time PCR that utilized specific Taqman MGB probes and primers for detecting nesfatin, visfatin and GAPDH (endogenous control). The mRNA for nesfatin and visfatin was detected in granulosa and theca tissues from all follicle sizes examined. The expression of nesfatin and visfatin mRNA was greater in granulosa tissue than in theca tissue in hierarchical follicles. Fasting had no effect on granulosa visfatin or nesfatin mRNA expression, but decreased theca visfatin mRNA expression. The results indicate that local production of visfatin and nesfatin could influence follicular development. The decrease in theca expression of visfatin during fasting should be further investigated to determine its possible role in follicular atresia induced by the lack of nutrient intake.