Effects of restricted feeding molt diet on induction of molt and energy intake in laying hens

Abstract

This experiment aimed to determine the effects of restricted feeding a molt diet on molt induction in laying hens. Single Comb White Leghorn hens (age, 61 wk) were housed in individual cages and randomly divided into 3 groups (2 treatments and 1 control group). After a 4-wk preliminary period, the control group was continuously fed a layer ration based on corn and soybean meal ad libitum. Molting was induced in the treatment groups by starvation (MS) or with feeding (MF). In the MS group, the feed was withdrawn for 2 wk; this was followed by feeding of the layer ration skip-a-day for 1 wk and then ad libitum. The MF group was fed a low-protein and low-energy diet comprising corn, wheat bran, and corn gluten feed 60 g/hen/d for 4 wk; this was followed by ad libitum feeding of the layer ration. Egg production, egg quality, and feed intakes were measured throughout the experimental period; serum estradiol-17β concentration, heterophil: lymphocyte (H:L) ratio, ovary and oviduct weights, and ME1, intake were measured during the molting period. During molting, body weights of the MS and MF groups were significantly (P < 0.01) reduced than that of the control group. On d 10 of molting, the H:L ratio of the MF group was significantly (P < 0.01) lower than that of the MS group. On d 14, the ovaries and oviducts of the MS and MF groups were distinctly (P < 0.01) lighter than those of the control. On d 6, serum estradiol-17β of the MS and MF groups decreased regardless of the treatment. The energy intake for the MF hens was lower than requirement level and just enough for the basal metabolism. Therefore, the MF hens also completely went out of production during the molting period and arrest period was the same in the MS and MF groups.