Feed Withdrawal Methods Research Articles

Effect of zinc oxide, potassium iodide and withdrawal diet as alternative moulting methods on performance of commercial laying hens

ABSTRACT The aim of this study was to compare applicability of the non-feed removal method with the feed withdrawal method by using zinc Oxide and potassium iodide in moulting on productive performance. A total of 240 84-week-old Lohmann Selected Leghorn (LSL-Lite) laying hens were randomly distributed in 40 cages (ten treatments and four replicates per treatment). The results showed that crop pH and Ilium pH were similar among treatments. Moulting method affected body weight reduction and feed consumption (P < 0.05), maximum body weight reduction from 1 to 16 days during moulting was observed in T3. Feed consumptions for hens fed ZnO diets (T4) were lower, with hens fed the KI diet being intermediate (P < 0.05). During the second laying cycle no significant effect was found for egg weight and feed intake. Organ characteristics (weight organs and length oviduct) of hens fed a zinc-supplemented diet were lower than those non-moulted and hens fed a KI-supplemented diet. In conclusion, that each moulting method differently influenced various parameters studied for post moulting performance. Indicating that non-fasting moulting methods, which are better for animal welfare, are effective alternatives to fasting method.

Yumurtacı Tavuklarda Kekik (Oregano) ve L-karnitin’in Yem Katkısı Olarak Alternatif Zorlamalı Tüy Dökümü Programında Kullanılması

This research was carried out in order to determine the effects of forced molting programs induced by feeding the hens an alfalfa based and low Na-Ca induction feed as an alternative to forced molting program with feed withdrawal and the effect of L-carnitine and Oregano plant in powder form as feed additives on the induction period parameters. A total of 1170 birds were divided into 13 groups. The trial was continued for a total of 36 days, with the first 14 days of adaptation and 22 days of force molting. A negative control group ( K ) which was neither forced molted nor provided with any feed additive substances in their diets Moreover, other three treatment groups ( M : Marbel powder, Y : Alfalfa, F : Low Ca-Na diet), were forced molted and one withhold feeding group was used for the study; the forced molted groups were supplied L-carnitine ( C ) (100 ppm) and dried oregano leaves ( O ) (5%) as a feed additive in designed individual diets ( MC, AC , FC, MO, AO, FO ) alone and in combination (50 ppm; 2.5%) in groups ( MCO, ACO, FCO ). In the light of this data it could be said that the live weight loss achieved with qualitative alfalfa meal feed restriction exceeds 30% and exceeds the live weight loss ensured by an 11 day feed withdrawal. Based on these parameters it is concluded that supplementing feed additives into alfalfa meal could be an alternative to the feed withdrawal method and alfalfa meal with a combination of L-carnitine and oregano plant has a positive impact on performance.

Alternative induced molting methods for feed withdrawal and their effect on post molt egg quality parameters of White Leghorn hens

Forced molting were practiced using the flock of hens by promoting a second laying cycle. In the present study, the effectiveness of induced molting method was studied in comparison to conventional feed withdrawal in terms of egg quality parameters. Layer chicken (160), 72–week-old were divided into 4 groups and were subjected to induce molting for a period of 14 days. The first group that received ad lib. water with complete feed withdrawal served as a control. The birds of the second group received ad lib. layer ration without calcium fortified with organic zinc (20,000 ppm) along with organic copper (600 ppm/kg of feed). The third group was provided with organic zinc (20,000 ppm) along with organic cobalt (150 ppm/kg of feed). The fourth group was provided with organic zinc (20,000 ppm) with organic chromium (500 ppm/kg of feed). Egg and shell weight were significantly different among different treatments; whereas, in shell thickness, egg production and body weight reduction, no significant difference was observed. The feed withdrawal treatment resulted in lower egg weight than other treatments. In conclusion, mineral supplemented methods could be substituted for conventional feed withdrawal method of induced molting.

Comparison of different molting methods and evaluation of the effects of postmolt diets supplemented with humate and carnitine on performance, egg quality, and profitability of laying hens

SUMMARY The aim of this study was to compare the applicability of the non-feed removal method with the feed withdrawal method by using alfalfa meal and barley in molting. Moreover, the effects of humate (2 g/kg), carnitine (0.1 g/kg) and humate (2 g/kg) + carnitine (0.1 g/kg) supplementation to the diets during postmolt period along with the different molting methods on production performance, egg quality, and profitability in laying hens were compared. In the study, 192 Bovans white laying hens, 75 wk old, were used. The lowest BW loss (21.08%) for the first 10 d was found in the barley + feed (B+F) method. The earliest onset of egg production was observed in B+F method which is followed by alfalfa meal + feed (A+F) and feed withdrawal + barley + feed (FW+B+F) groups. In the postmolt period, heavier eggs were obtained from the B+F and A+F method groups. Egg specific gravity was found to be higher in the groups molted by the A+F and B+F methods. Feed efficiency, egg shell thickness, and Haugh unit were unchanged in the A+F and B+F methods compared with the FW+B+F method. In the postmolt period, supplementation of humate to diet increased the egg weight; supplementation of carnitine increased the egg shell thickness and Haugh unit. Consequently, the use of molting methods without fasting (A+F and B+F) could be an alternative to conventional molting methods without causing any economic losses.

Effects of Hen Age and Force Molting Programs on Body Weight Loss and Heterophil: Lymphocyte Ratio during Molt Period in Laying Hens

The aim of this study was to determine the effects of hen age and force molting programs on body weight loss, egg production cease and heterophil:lymphocyte ratio during molt period. The experiment was conducted using 320 Hy-Line W36 hens randomly assigned to experimental groups (five replicates of 8 hens for each treatment). The experimental design of the study was a 2 × 4 factorial arrangement of a completely randomized design. Eight treatments were compared in a 2 x 4 factorial arrangement with 2 age treatment (63 and 75 week of age) and 4 force molting treatments [feed withdrawal (FW), 100% alfalfa (A), 50% alfalfa and 50%oat (AO), and 100% oat (O)]). The hen age had no significant effect on BW loss, cease egg production and H: L ratio during molt period. The FW had significantly (P<0.01) higher BW loss than AO and O treatments and it was similar to A treatment. Egg production for all treatments ceased completely by day 6. H: L ratio were significantly higher for FW treatment when compared with nonfeed withdrawal treatments. The results indicated that alfalfa or oat appears to be alternatives to FW methods for force molting.

Using different ratios of bitter vetch (Vicia ervilia) seed for moult induction and post-moult performance in commercial laying hens

1. The applicability of different ratios of bitter vetch seed as a new method for moult induction in laying hens was studied. The effectiveness of bitter vetch seed on post-moult production and post-moult egg quality was also investigated. 2. A total of 120 Single Comb White Leghorn hens, 78 weeks of age, were used in this study. The hens were randomly assigned to 5 treatment groups of 24 birds each. The treatments were 30% bitter vetch seed (BV30) diet, 60% bitter vetch seed (BV60) diet, 90% bitter vetch seed (90BV) diet, feed withdrawal method (FW) and full-fed non-moulted control (CON). 3. Egg production ceased first in FW and BV90 treated hens and last in BV30 treated hens. As the percentage of bitter vetch seed increased in the moulting ration, feed intake decreased and body weight loss increased during the 10-d moult induction period. Time to first egg production was significantly greater in hens exposed to the FW and BV90 diets. 4. FW and BV90 treatment hens had significantly higher hen-d egg production than non-moulted control hens. Egg weight was significantly higher in BV30 and BV90 treatments. There were no differences in egg mass, feed intake and mortality among experimental treatments during the post-moult period. 5. No significant improvements were observed in exterior or interior egg quality in moulted hens, except for Haugh units, which were significantly higher in moulted hens when compared to the non-moulted control hens. 6. In conclusion, the present study showed ad libitum feeding of a layer ration with 90% of bitter vetch seed for 10 d proved to be effective for inducing moult, increasing post-moult egg production and improving some internal egg quality parameters.

Effect of Induced Moulting in Male and Female Line Broiler Breeder Hens by Zinc Oxide and Feed Withdrawal Methods on Post Molt Performance Parameters

Effect of Induced Moulting in Male and Female Line Broiler Breeder Hens by Zinc Oxide and Feed Withdrawal Methods on Post Molt Performance Parameters

Effect of Molting Method and Dietary Energy on Postmolt Performance of Two Strains of Single Comb White Leghorn Hens

SUMMARY This experiment was a 4 × 2 × 2 factorial arrangement of 4 dietary energy levels (2,767, 2,806, 2,846, and 2,886 kcal of ME/kg), 2 molting methods (feed withdrawal and the low-salt diet), and 2 strains (Bovans White and Dekalb White). The objective of this study was to determine the effect of dietary energy and molting method on postmolt performance of 2 strains of commercial White Leghorns. Before the molt, Bovans and Dekalb hens were randomly divided into 2 groups. Feed was withdrawn from half of the hens (66 wk of age) for 9 d. A molt feed was fed from d 10 to 28. The other half of the hens was fed a low-salt diet for 28 d. After the molt, Bovans White hens (n = 720) and Dekalb White hens (n = 720) at 70 wk of age were randomly divided into 16 treatments (6 replicates of 15 birds per treatment). Bovans hens had significantly lower egg weight, percent of eggshell, egg specific gravity, and Haugh units than Dekalb hens, whereas Bovans hens had significantly higher egg production than Dekalb hens. Increasing dietary energy had no significant effect on any parameter other than yolk color. As dietary energy increased, feed conversion improved numerically from 2.13 to 2.05, resulting in a 3.8% improvement of feed conversion. With increasing dietary energy, hens adjusted feed intake, according to egg mass, to achieve the quantities of dietary energy (5.8 to 5.9 kcal) intake per gram of egg. An ideal dietary energy level for optimal postmolt performance and profits could not be determined for hens during phase 1 of the second cycle. Other than slightly reduced egg production and egg specific gravity during phase 1, feeding the low-salt diet to induce molt could be used as an alternative for the conventional feed withdrawal method.

Effect of Force Molting on Postmolt Performance of Laying Hens

An experiment was conducted using 6168 Hyline White hens (79 wk of age) randomly assigned to two dietary treatments. The treatments included high dietary zinc (Zn) and Feed Withdrawal (FW) methods. In the Zn method, hens were fed a layer ration containing 20,000 ppm of zinc as zinc oxide for 10 d and the light was reduced to 12 h/d. At day 11, hens were returned to the control layer ration and received 16 h of light/d. In FW method, feed deprivation was continued for 5 d, water was provided for ad libitum intake and the photo period was reduced to 12 h/d. On day 6, were returned to the control layer ration and received 16 h of light/d. Data were analyzed using student's T-test procedure of SAS. The hens subjected to Zn and FW methods lost 5 and 20% of their initial body weight by 11 and 6 days of the experiment, respectively. The FW treatment resulted in total cessation of egg production within 7 d and the birds remained out of production until 16 d of the experiment. Hens subjected to Zn treatment ceased egg production by 8 day of the experiment and remained out of production until day 29. The mortality percentage throughout the entire experiment for Zn and FW were 0.057 and 0.032%, respectively which was significantly different. No differences were observed between feed removal treatment and nonfeed removal treatment for postmoult hen day production, egg weight, feed intake, feed efficiency and internal Zn of the eggs laid after Zn treatment. Our results indicated that nonfeed removal method is as effective as feed removal method on postmolt performance, although it caused significantly more mortality.

Reproductive tissue regression: Involvement of caspases, inducible nitric oxide synthase and nitric oxide during moulting in White Leghorn hens

Moulting is a natural physiological process where the reproductive system of birds undergoes complete remodeling in preparation for the next laying cycle. In domestic chickens, moulting is artificially induced by feed withdrawal to recycle the old laying flock for best profit margins. This has received severe criticism from animal welfare organizations, forcing several countries to stop this practice. Several alternative methods to feed withdrawal methods were developed but were found to produce inconsistent results. Understanding the actual mechanism of moulting would help in designing a new animal welfare friendly method. The present investigation attempted to study the molecular mechanism of moulting in White Leghorn hens. Eighty-four layers (75 weeks) were divided into two groups. The birds in the first group were subjected to moulting by feed withdrawal (FW) while the other group received high dietary Zn (ZnF) treatment for 10 days. Six birds from each group were sacrificed on 0, 1–4, 6 and 10 days of moulting and mRNA expression of caspases-1, -2 and iNOS, along with the apoptotic ladder pattern and nitric oxide (NO) in the ovary and oviduct, was investigated. The mRNA expression of iNOS was upregulated with a corresponding increase in NO levels. Caspases-1 and -2 were differentially upregulated in the ovary and oviduct of moulted birds. A constant decline in serum estradiol and progesterone levels was also observed. It can be concluded that the pattern of reproductive regression during moulting by the two methods is different, as the expression of genes studied in the present investigation is different.

Nonwithdrawal Molting Programs

In the commercial egg industry the management practice of using feed withdrawal to induce a flock to molt has been under extreme scrutiny. This is because animal rights groups have voiced their concern about using this practice. Thus, about 5 yr ago, the United Egg Producers (UEP) commissioned 5 universities to conduct experiments to develop alternative molting programs that used nonwithdrawal feeding programs to molt laying hens. The studies conducted to date used techniques ranging from feeding hens without added salt in the diet to using readily available, low-cost feed ingredients to develop molt diets that are low in energy level and protein content. The results of these studies indicated that molting laying hens without feed withdrawal could be done successfully. Research at the University of Illinois found that feeding laying hens diets consisting of wheat middlings, soybean hulls, and corn (low protein and low energy) were successful in providing for acceptable postmolt egg production performance and economic benefit compared with using a standard feed withdrawal method. Therefore, after 5 yr of experimenting with nonwithdrawal molting methods done in several university settings, the egg industry has successfully adopted these methods of molting laying hens. In addition, based on the finding of these experiments, the UEP has revised their recommended molting guidelines to state that only nonwithdrawal molting methods will be permitted after January 1, 2006. Thus, these guidelines will apply to approximately 82% of the US egg industry.

Utilizing different ratios of alfalfa and layer ration for molt induction and performance in commercial laying hens

Molting is a common practice used by the commercial egg industry to rejuvenate flocks for a second or third laying cycle. During this time the hens rest from production, and the reproductive organs are rejuvenated to increase production and quality during the next laying cycle. Although feed withdrawal (FW) is the most popular and effective method of molt induction, it has come under scrutiny due to food safety issues and animal welfare issues. This study involved feeding alfalfa mixed with layer ration at different ratios to hens to determine their ability to induce molt. The treatment ratios were 100% alfalfa (A100), 90% alfalfa and 10% layer ration (A90), and 70% alfalfa and 30% layer ration (A70). In addition, a fully fed (FF) nonmolted control and a FW negative control were used. Alfalfa is an insoluble, high fiber feedstuff with low metabolizable energy. Egg production for A90 and FW treatments ceased completely by d 6, whereas birds fed A100 and A70 ceased egg production by d 8. Ovary and oviduct weight of hens fed all molting diets decreased (P < 0.05) by an average of 1.5 to 2.5% (BW basis) compared with FF control during the 9-d molt induction period. As the percentage of layer ration increased, feed intake also increased and percentage of BW loss decreased during the 9-d molt induction period. Hens molted by FW lost an average of 25.8% BW, whereas A70 hens lost 18.9% BW. Nonmolted hens (FF) and A70 treatment hens had significantly lower (P < 0.05) egg production when compared with all other treatments over the 39-wk postmolt period. FF treatment hens also had lower (P < 0.05) albumen heights when compared with all other treatments. From these results, alfalfa or alfalfa mixed with layer ration appears to be viable alternatives to conventional FW methods for the successful induction of molt and retention of postmolt performance.

Differential utilization of hepatic and myocardial fatty acids during forced molt of laying hens

Feed was totally withdrawn from laying hens (n = 30, Hy-Line Brown, 608 d of age, 2.04 +/- 0.07 kg of mean BW) to induce molting. Ten birds were slaughtered on d 0 and 12, and the hepatic and myocardial triacylglycerol (TAG) and phospholipid (PL) fatty acid composition, as well as the tissue malondialdehyde (MDA) and reduced glutathione (GSH) concentrations were determined. The liver TAG and PL contents decreased by 24.3 and 16.1%, respectively, whereas the myocardial TAG content increased by 12%, and the PL decreased by 22%. Liver TAG fraction has been found to selectively retain arachidonic and docosahexanoic acids. Hepatic PL fatty acids were markedly affected by fasting; these changes reflected an altered PL metabolism, primarily degradation. Liver TAG compensated for the absence of dietary fatty acids, because we found practically no qualitative alteration in myocardial TAG. The lipid peroxide status, as measured with MDA content was, accordingly, increased in the liver tissue only. In the myocardial PL fatty acids, preferred conservation of arachidonic acid was shown, and it was hypothesized that energy deprivation of cardiomyocytes strongly improved PL degradation in fasting laying hens and influenced PL homeostasis. Generally the physiological recovery from forced molting associated with fasting is complete; however, the use of total feed withdrawal methods should be reevaluated.