The pathophysiology of the ovarian dysfunction encountered in broiler breeder hens remains poorly understood but is similar to a condition in women known as
polycystic ovary syndrome. This study reveals that
metformin may provide a cheap and effective method of improving ovarian function in broiler breeder hens.
Abstract: Broiler breeder hens, the parent stock of commercial broiler chickens, have poor reproductive efficiency associated with aberrant and excessive recruitment of ovarian follicles which results in sub-optimal egg production, fertility, and hatchability. The reproductive dysfunction observed in these hens resembles
polycystic ovary syndrome in women, a condition wherein
metformin is prescribed as a treatment. The main objectives of this study were to determine the effect of
metformin on
body weight, abdominal fat pad weight, ovarian function, and plasma
steroid hormone concentrations. Broiler breeder hens were treated with 0, 25, 50, or 75 mg/kg
body weight of
metformin mixed in the diet for 40 weeks (n = 45 hens/treatment; 2565 weeks of age). At 65 weeks of age, hens that received the highest dose of
metformin had significantly lower body and abdominal fat pad weights (P < 0.05) than the control.
Metformin treatment, at all levels, normalized the preovulatory and prehierarchical ovarian follicular hierarchy.
Metformin (50 or 75 mg/kg
body weight) significantly increased the total number of eggs laid per hen during the entire production period and these hens had significantly greater fertility and hatchability at 65 weeks of age compared to the control (P < 0.05).
Metformin treatment at all levels altered the plasma profile of reproductive
hormones, with significantly lower plasma
testosterone concentrations and a decreased
testosterone to
androstenedione ratio in hens that received
metformin (P < 0.05). Future studies should focus on the mechanisms underlying the beneficial effects of
metformin in improving the reproductive efficiency of broiler breeder hens.