Exogenous leptin advances the recovery of regressed ovary in fasted layers

The present study was undertaken to examine the effect of recombinant mouse leptin administered to fasted mature chickens of a layer strain on feed intake, ovarian development and body weight. Twenty-five Hy-Line Gray commercial hens were randomly divided into five groups: (I) ad libitum control group; (II) fasted control group; (III) fasted+low concentration of leptin; (IV) fasted+middle concentration of leptin; (V) fasted+high concentration of leptin. All four fasted groups fasted for 2 days and then ad libitum and the hens were treated with leptin at dose of 0, 50, 200 and 400 μg/kg/d. on day 3-5. The body weight of FC, F+L, F+M, F+H hens were 86.45%, 91.81%, 86.89% and 91.15% compared with initial body weight respectively on the day of 6. Feed intake, water intake and excretion of FC and F+H groups were lower compared with control group (P<0.05). A middle dose of leptin treatment significantly increased the plasma E2 levels, follicular development and ovary weight, accompanied by decreased body weight. In conclusion, recombinant mouse leptin can promote the recovery of the regressed ovaries in fasting hens during the re-feeding period, which was reflected by higher ovary weight, better follicular development and higher plasma E2 level. Improved recovery of the ovary was accompanied by decreased the body weight.