This study aimed to evaluate the e#ects of a molt diet on molt induction and the post-molt performance of laying hens. White Leghorn hens (age, 0, wk) were randomly divided into three groups (two experimental, one control). After a .-wk preliminary period, one group (control) was continuously fed a corn-soybean-based layer ration ad libitum. Molting was induced in the other groups by starvation (MS) or with feed (MF). In the MS group, the feed was withdrawn for , wk; this was followed by feeding of a layer ration on alternate days for + wk and then ad libitum. The MF group was fed ad libitum a low-protein and low-energy diet based on corn, wheat bran, and corn gluten feed for . wk; this was followed by ad libitum feeding of a layer ration. Egg production, egg quality, and feed intakes were measured throughout the experimental period; ovary and oviduct weights and heterophil: lymphocyte (H:L) ratios were measured during molting. During molting, the feed intake in the MF group was lower than that of the control; body weights of the molted groups were significantly reduced. Additionally, the MS group totally ceased egg production within 2 d; in the MF group, egg production decreased to -.2ῌ by d +*. On d +* of molting, the H:L ratio of the MF group was lower than that of the MS group. On d +., the ovaries and oviducts of the molted groups were distinctly lighter than those of the control. Throughout the post-molt period, egg production and egg shell thickness of the molted groups improved; but there were no significant di#erences. Additionally, the eggs of the MF group were heavier than those of the MS and control groups. This study suggests that feeding of a low-protein and low-energy diet e#ectively induces molting and increases post-molt production.

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This experiment aimed to determine the e#ects of restricted feeding a molt diet on molt induction in laying hens. Single Comb White Leghorn hens (age, 0+ wk) were housed in individual cages and randomly divided into -groups (, treatments and + control group). After a .-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 In the MS group, the feed was withdrawn for , wk; this was followed by feeding of the layer ration skip-a-day for + wk and then ad libitum.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 0* g/hen/d for . 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-+1b concentration, heterophil: lymphocyte (H:L) ratio, ovary and oviduct weights, and MEn intake were measured during the molting period. During molting, body weights of the MS and MF groups were significantly (Pῌ*.*+) reduced than that of the control group. On d +* of molting, the H:L ratio of the MF group was significantly (Pῌ*.*+) lower than that of the MS group. On d +., the ovaries and oviducts of the MS and MF groups were distinctly (Pῌ*.*+) lighter than those of the control. On d 0, serum estradiol-+1b 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.

This study investigated the suitable metabolizable energy (ME) level of molt diet for hens that cease producing eggs without being subjected to great stress. During the preliminary period, White Leghorn hens were fed a corn-soybean meal-based layer ration After a -wk preliminary period, the hens were randomly divided into treatment groups and control group; the control group was persistently fed the layer ration. The treatment groups were fed the following diets for wk: ( ) molt diet based on corn, wheat bran, and corn gluten feed (ME . Mcal/kg M :); ( ) molt diet with rice hull (ME . Mcal/kg M :); and ( ) molt diet with rice hull (ME . Mcal/ kg M :). During the post-molt period, the hens were returned to the layer ration. During the molting period, the heterophil: lymphocyte (H:L) ratio, ovary and oviduct weights, and ME intake were measured. Egg production, egg weight, egg quality, body weight, and feed intake were measured throughout the experiment. During the molting period, the feed intake, body weight, and ovary and oviduct weights in the molted groups were significantly ( . ) lower than those in the control group. In the M group, egg production ceased completely within d; and decreased to .by day and in the M and M groups, respectively. The H:L ratio was the highest, intermediate, and least in the M , M and M , and control groups, respectively. At , and wk, the ME intake in the M group was lower than the requirement level. Throughout the post-molt period, the egg production and quality in the molted groups improved compared to that in the control. We assume that access to low energy molt diet (ME . Mcal/kg) e ectively induces molting and increases post-molt production.: energy level, induced molting, molt diet, post-molt performance op alternatives to feed withdrawal for inducing molting (Bell, ). Since January , , all the egg producers Induced molting has become an important management that enrolled in the UEP animal care program (most US tool used by the layer industry to increase egg production shell egg producers) have discontinued the use of feed rates in older hens and to increase egg size, decrease egg withdrawal method for inducing molting (Wu breakage, and improve shell quality (Seo ). ). Several programs are currently in use for successfully We have already reported that feeding of the molting laying hens. Feed withdrawal is the primary commercial molt diet that was used in our previous expermethod used in the layer industry to induce molting and iment did not completely stop egg production during the stimulate multiple egg-laying cycles in hens (Brake, ; molting period (Hnin Yi Soe a). The energy Holt, ). In recent years, concern for the well-being of level of the diet appears to be an important factor in hens during the molting period has been expressed when causing a rapid reduction in egg production (Biggs the feed withdrawal method is employed. Holt ( ) ). Based on the results of our experiment, we considreported that birds that are molted using feed withdrawal ered the level of energy int...