The poultry industry has become of great

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1 The effects of alternative forced-molting methods on the performance and egg quality of commercial layers ¹PhD student in the Animal Science Post Graduate Program of FMVZ/UNESP-Botucatu. ²Professor, Department of Animal Production of FMVZ/UNESP-Botucatu. bird s physical condition is deteriorating, becoming unable to support egg production, the maintenance of feathers and body maintenance (Ellis, 2000). It is possible, however, to accelerate this process with a program designed to stimulate the fall of feathers, with subsequent growth of new feathers and rapid resumption of the production of eggs through a process known as forced molting program that should last at most 6 to 8 weeks (Garcia, 2004). Introduction The poultry industry has become of great importance for being an activity of high technical level and high economic returns. However, as the of poultry farming techniques have developed, along with it emerged severe criticism related to the conditions of animal production by environmental groups that justified themselves for finding animal welfare impairment (Ribeiro et al., 2008). Some practices used in the poultry industry have been polemic among animal defensors groups, costumers, producers and researchers. Among them we can highlight the forced molting (Berry, 2003). This practice is used in extending the life of hens and despite its benefits, the forced molting has been a public concern in many parts of the world, implicating that the criticism is directed to methods that use fasting as the inductive stimulus, wich has been severely criticized by organizations working for animal welfare (Bell and Kuney, 2004). It is known that the feathers molting in wild birds is a natural process that occurs after the period of reproduction and that the exchange of feathers lasts about four months (Garcia, 2004). Concerning laying hens, the fall of posture and the beginning of molting are indications that the In laying hens, forced molting has as a purpose promoting a rejuvenation of the bird causing it to lose up to 30% of their body weight, returning to the weight of a chicken in early production. Simultaneously, there is the objective of pausing the egg production, promoting a rest in the reproductive tract and its regeneration, preparing it so the bird can return to a new production cycle (Garcia, 2004). Deprivation of food has been the most commonly used method for inducing molting, due to its low cost and high efficiency (Rodrigues et al., 1995). In Brazil, this technique is widely used, surpassing 22 million chickens per year submitted to forced molting process, increasing with this, the volume of eggs produced. The forced molt, when performed correctly, promotes increased rate of posture, improvement of internal quality and egg shell during the second cycle, comparing to the end of the first cycle (Lee, 1982). In the United States 90% of poultry flocks in posture are subjected to forced molting, with ages ranging between 60 and 80 weeks (Bell, 2003). According to Garcia (2005) the production in the second laying cycle is 5 to 10% lower than the first cycle and even, the younger it has changed sooner it will resume posture and achieve higher levels of production. Preferably the molting should be performed around 70 weeks of age of the lot. Methods of forced molting According to Llobet (1989), methods of 1

2 2 molting in general can be divided into three groups: Pharmacological Methods, Methods of Management and Nutritional Methods. Pharmacological methods They consist of adding to the ration certain drugs such as 2-amino-5, nitrothiazole, progesterone, anovulatory substances as chlormadinone acetate or other products that induce the birds to moult resulting in a temporary stop of egg production. However, the use of these methods is still at an experimental stage, given the difficulty of its use and the possibility of residual effects of these substances and their effects on human health. Management methods These are based on inducing the birds to various stressful situations so that the egg production ceases quickly. Usually there is a reduction of the photoperiod with the withdrawal of artificial lighting, removal of ration for a period not exceeding 14 days and sometimes withdrawal of water for a period of up to three days (which has been avoided widely due to the fact that Birds excrete their metabolites in the urine and the lack of water may cause poisoning). The method of induction of molt based on bird management is the most used in Brazil, with great variations of this method, each recommended by a particular research center. The most common method is known as the Conventional Molting Method and was developed by the University of California. In the pre-molting period it must be weighed and make the selection of the lot discarding birds with low weight, out of production and weakened physical state. If necessary, you should do a gathering of the birds of the same age, but in different warehouses in order to fill all the cages of the warehouses that will be used for molting. From the first day of the period of molting, it must be removed the artificial light, leaving there only natural lighting in the classic aviaries and in the controlled environment, the photoperiod should be reduced to 6 hours daily. Birds should be fasting for a period of 10 to 14 days, so that a loss of 25 to 30% of body weight occurs, however, it can be given flour oyster shells or limestone coarse grain size (3 mm) for three to four days at the beginning of the period of fasting so that there is availability of calcium for the egg shell calcification in formation, and thus taking advantage of the eggs produced during the period of change. In addition, Brake (1993) states that calcium seems to play a central role in inducing the molting, because when calcium carbonate is supplied as the sole source of nutrients, the birds extend ovulation during forced molt and hold the pose for up to four days. This author suggested that calcium is the first limiting nutrient of ovulation, during a molt with a ration withdrawal. When finishing the period of fasting, the feeding should return, using chicken ration, corn or sorghum grain, taking care to make a readjustment of the first birds to feed. Thus, in the first day should be provided only 30% of the amount of ration that the birds consume ad libitum, the second day 60%, the third day 90%, only on the forth day the birds should receive food production in amounts recommended by the lineage manual, and that may be maintained until the twenty-eighth day of the proccess or staggered as follows: 100 g per bird per day on alternate days (every other day) until the 18 th day and from the 19 th to the 28 th day, it should be administer ration for the molting for a two days yes and one day no feeding series, also at 100 g per bird at a time. From the twenty-ninth day of the beginning of the molting birds should feed with production feed freely, and also restart a program of increasing light, similar to that used for chickens in the early stages of production. In this method does not use water fasting. The birds reach 50% of posture about 8 weeks after initiation of molting. For the expected results with the conventional changes, it is expected a mortality rate of 1.25% since the beginning of the program up to 8 weeks. From there, we expect the same mortality of the first production cycle. In relation to the size of eggs, there is a tendency to produce eggs of similar size to those that were being produced before the changes. As in the first cycle of production, there is an increase of egg size according with the age of the birds, and it is expected in the second cycle that the eggs are, on average, larger than the first cycle. For the production of eggs, with fasting occurred during the start of the molting, production falls rapidly reaching zero between 4 and 6 days. As the birds start to feed on the posture feed and receive light stimulus, the production restarts quickly. The shape of the production curve of the 2º cycle is similar to 1º, however with productivity rates 5-10% lower. These curves also decline to a greater degree. There are variants of this method of molting, which are known as Quick Molting Method and the Molting with a Short Fasting Period Method.

3 In the case of the quik molting, the process of molting is similar to the conventional, however, without the feeding period with diets of low nutritional value, ie, without the rest period. This process allows the birds to reach 50% of production 5 to 6 weeks after the beginning of the molting. The Molting with a Short Fasting Period Method is also similar to conventional molting methods, however, it includes the reduction of fasting for 4 to 6 days and eliminating the resting period. With that, the birds can return to 50% of production 3 weeks after the beginning of the molting. The choice of the program to be adopted will depends on the objective of the producer and the market situation of eggs. Nutritional methods The Nutritional Methods modify the dietary concentration of certain ions that influence egg production, such as calcium, phosphorus, sodium, potassium, iodine and zinc. These methods can be used separately or together, their results vary, however, and gained special attention for avoiding the purchase of ingredients making it easy to use and applicability. As nutritional methods of inducing molting, you can still highlight the use of alternative ingredients in the diet, of common use or not. Among them we may mention the ration of corn or high-energy, low-energy ration, ration of low nutrient density, sorghum, wheat bran, defatted jojoba meal, alfalfa, cotton, rice hulls, brewers rice and rice bran. A qualitative food restriction for molt induction was the subject of study by Andreotti et al., (2005) that compared the fasting to the restriction of nutrients in relation to a basic diet for laying hens, using for this purpose a dilution of the diet with rice hulls at 50 and 75%. It was found a loss weight of 25% at 20 and 10 days for the dilution of diets with 50 and 75%, respectively, concluding that the dilution of the production ration by up to 50% can be used for induction of molt without causing severe stress, thus providing the birds a greater welfare. of fasting followed by a supply of grape pomace containing 10 ppm of thyroxine; corn at will (with and without 10 ppm of thyroxine); a day of fasting followed by a supply of corn at will (with and without 10 ppm of thyroxine), two days of fasting followed by a supply of corn at will (with and without 10 ppm of thyroxine). The birds that had fasted and the ones that had a treatment with a day of fasting followed by a supply of grape pomace containing 10 ppm thyroxine lost 30% of body weight with 14 and 16 days respectively and were able to cease production of eggs. The other treatments reached this loss only at 28 days, but did not stop the production of eggs. During the period of after laying, the percentage on laying in fasting treatment was the largest and the ones in corn treatments at will and the ones in a day of fasting followed by a supply of corn at will was the smallest. Still within the innovation in the search for alternative methods of forced molting, Willis et al., (2008) evaluated the effect of extract of mushroom (L. edodes) and extract of Fitolaca (Phytolacca americana), alone or in combination with alfalfa or production ration for 10 days to induce molting, and he concluded that the treatments with the use extracts combined with alfalfa presented results of weight loss during the molting and egg production after changes similar to those obtained with conventional treatment in conventional molting through fasting. Another method that has received much attention in foreign countries is the provision of alfalfa, as studied by Kim et al., (2008) who worked with the inclusion of alfalfa in the diet of laying hens (90, 80 and 70%) for nine days for induction of molting compared to the conventional method by fasting. Birds of the fasting treatments and 90% inclusion of alfalfa ceased egg production to six days and had weight loss of 28 and 25% respectively, while the birds of treatment with 80% inclusion of alfalfa had zeroed the production to five days and had weight loss of 20%, the treatment with inclusion of 70% was not enough to promote the stop of the production of eggs up to nine days and reached 19% loss of body weight. In the search for new methods of inducing molting, in addition to the commonly used alternatives, such as the reduction of certain ions from the diet or decreasing the density of the same, some authors studied less usual methods, but with good results, as Keshavarz et al., (2002) who tested several methods in the same experiment, working with fasting to a loss of 30% of body weight; 1 day It is common to find researches in the which more than one molting induction method is found, like Onbasilar and Erol (2007) that compared conventional fasting, a diet high in zinc (10,000 mg / kg) for 10 days and grain whole barley for 10 days and observed weight loss of 20, 8 and 18%, respectively. During the molting period (28 days) only the birds that had fasted ceased egg 3

4 4 production. In the post molting period there was no significant difference in percentage of stance, being observed that the birds subjected to fasting during the molting had higher egg weight. Araújo et al., (2007) also evaluated methods of forced molting in laying hens: fasting for 10 days, diets containing high levels of zinc (20,000 ppm) for 10 days, diet with low levels of calcium (0.1% calcium) diet and low levels of sodium (0.05% sodium) to 14 days. After the period of changes it took place a resting period 28 days where all the birds were fed a diet containing corn supplemented with vitamins and minerals. The authors concluded that the results for the induced molting by these methods are compatible to the conventional method. An ideal program of forced molting should be of simple application, low cost, low mortality rates, and leading to an improvement in performance and quality of the eggs towards the end of the first cycle (Scherer, 2007). It should be combine all these factors to minimize the stress of the birds, and for that reason the need for further researches to meet in a single program of forced molting all the questions referring to improved performance, egg quality and animal welfare. Results obtained with alternative methods of forced molting Although the search for alternative methods of forced molting may be intensifying over the years, in Brazil it can still be considered a small number of studies in this direction. It may be noted, however, that in the Faculty of Veterinary Medicine and Animal Science (Faculdade de Medicina Veterinaria e Zootecnia - FMVZ) UNESP, Botucatu, there is a line of research developed and coordinated by Professor Edivaldo Antonio Garcia, where his team works with alternative methods of forced molting obtaining satisfactory results for over ten years (Garcia et al., 1996; Scherer et al., 2009; Molino 2010, Garcia et al., 2012; Santos et al., 2012). In one study conducted in FMVZ, Scherer et al., (2009) worked with restriction of calcium and phosphorus; calcium, phosphorus and sodium, calcium, phosphorus, sodium and amino acids, compared to the use of milled corn for 28 days and to a fasting of 14 days, followed by production ration up to 28 days. The birds subjected to fasting showed an average reduction of 30.85% over the initial body weight, while the weight losses of the other treatments did not exceed 12.4%, however, despite having lost much less than the recommended (25-30%), the authors observed during the second cycle of production that the only treatment that provided a smaller percentage of stance comparing to fasting was the production ration with constrained calcium and phosphorus. In regard to the quality of eggs, there were effects on the treatment only for Haugh unit, considering that the birds fed with the milled corn had poorer Haugh unit compared to the subjected to fasting. In another research, Molino (2010) evaluated methods of quantitative ration restriction, using five feeding restrictions (0, 15, 30, 45 and 60 g of ration / bird / day) with and without the use of limestone of thick particle size for inducing the molting and observed weight loss of 25% at 10 days for birds that had fasted, 27% at 14 days for birds that received 15g of ration / day and 25% at 21 days for birds that received 30g ration / day (regardless the supply of limestone). The other treatments did not reach 25% loss of body weight by the end of the period of molting, considering that the birds that received 45 g of ration lost 22.3% and those who received 60 g of ration lost 19.7%, all at 28 days. Like Scherer et al., (2009), one can observe that birds that had not achieved weight loss of 25% did not completely ceased egg production, which in this study resulted in worse performance results during the second cycle (Table 1). Santos et al., (2012) used alternative ingredients to induce of molting, adopting the following treatments: T1- fasting, T2-wheat bran at will, T3- rice bran at will, T4- broken rice at will, T5- alfalfa at will. All treatments weight loss reached 26% within 21 days and ceased egg production between 7 and 10 days to induce the molting. This stop on the production of eggs allowed all treatments to show the same performance results during the second production cycle compared to conventional molting induction by fasting (Table 2). In regard to the quality of eggs, there was a better result with the use of wheat bran at will to induce molting, since the eggs of birds of this treatment had a higher eggshell strength when compared to eggs from the birds subjected to fasting (Table 3). Garcia et al., (2012) evaluated the best results obtained in other surveys conducted in FMVZ and compared to the fast and to the supply of wheat bran at will, taking 14 days for the following treatments:

5 Table 1 - Performance during the second production cycle of laying hens subjected to alternative methods of forced molting. Restrictions RC 1 (g) Layin 2 (%) FC/dz 3 FC/kg 4 EW 5 (g) ME 6 (g) Mort 7 (%) 60g B 2.10 A 2.72 A 64.4 AB 40.5 B g B 2.07 A 2.79 A 62.0 B 39.5 B g B 2.07 A 2.75 A 63.0 B 40.4 B g A 1.78 B 2.26 B 65.8 A 49.1 A g A 1.79 B 2.27 B 65.8 A 49.6A 0.20 Limestone Without With CV (%) Probability Restrictions NS < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 NS Limestone NS NS NS NS NS NS NS Restriction x Limestone NS NS NS NS NS NS NS Means followed by different letters in the column differ significantly by Tukey test (p <0.05).1 - Ration consumption, 2 - Laying, 3 - Feeeding conversion per dozen eggs, 4 - Feeeding conversion per eggs mass, 5 - Weight of the eggs, 6 - Eggs mass, 7 - Mortality. NS: not significant. Table 2 - Performance of the birds in a post molting period. Treatment RC (g) EW (g) LAY (%) BE (%) ME (g) FC/kg FC/dz Fasting A AB 1.87 AB Wheat Bran AB AB 2.05 AB Rice Bran AB AB 1.87 AB Broken Rice B A 2.09 A Alfalfa AB B 1.78 B CV (%) Means followed by different letters in the column differ significantly by Tukey test (p <0.05). RC= Ration Consumption, EW= Egg wheight, LAY= Laying, BE= Broken eggs, EM= egg mass, FC/kg=Feeding conversion per kg, FC/dz= Feeding conversion per dozen eggs. Table 3 - Egg quality during the post forced molting period. Treatment SG (mg/cm 3 ) BS (gf) Thick (mm) Yolk (%) Alb (%) Shell (%) HU Color Fasting ,566B Wheat Bran ,881A Rice Bran ,673AB Broken Rice ,868AB Alfalfa ,642AB CV (%) Means followed by different letters in the column differ significantly by Tukey test (p <0.05). SG=Specific gravity, BS: breaking strength of the shell, Thick=shell thickness, Yolk= yolk percentage, Alb= albumen percentage, Shell= shell percentage, HU= Haugh unit, Cor= yolk color. 5

6 T1 -molt by fasting, T2 -supply of wheat bran at will, T3 - restricted to 50g/bird/day, T4 -rearing ration restricted to 50g/bird/day restricted to calcium and phosphorus T5 - rearing ration restricted to 30g/ bird/day; T6 - rearing ration restricted to 30g/bird/ day with the restriction of calcium and phosphorus, T7 - production ration restricted to 30g/bird/day and T8 - production ration restricted to 15g/bird/ day. The authors evaluated the percentage of ovary and oviduct in relation to body weight at first, at 14 and 28 days of trial period and the results are in Table 4. Over the first 14 days of the trial period, it was found that the fasting treatments, wheat at will and those with restricted ration equal to or less than 30 g showed a significant reduction of the ovary and oviduct and considering that from this time all the birds treatments began to be fed with production ration, to 28 days in had these percentages increased, reaching values similar to those of the beginning of the molting process. Analyzing the effects of treatments on the percentages of ovary and oviduct at 14 days, it was found that the percentage of birds ovarian treatment recreates 50g and of the oviduct of the treatments recreates 50 g and for production 30 g, and they did not show regression of these organs, equivalent to conventional treatment (fasting). However, after 28 days, no differences were observed between treatments on the percentage of these organs. The only treatments that provided 25% loss of body weight were fasting and the providing of 15g ration / bird / day. Although other treatments have not provided the weight loss of 25%, it was observed the same results in performance and quality of eggs during the second cycle (Tables 5 and 6). From the results presented in Tables 4 and 5, together with the fact that birds from all treatments had ceased egg production during the second week of the process of molting, regardless of the percentage of weight loss, it strengthens the hypothesis that more important than losing weight in inducing the molting is the rest of the reproductive tract by stopping the production of eggs. It s noted that in the research done by Santos et al., (2012), the birds were treated until they reach the recommended weight loss (26%), while the study by Garcia et al., (2012), the treatments were adopted for 14 days, and the birds returned to be fed with animal production ration at will regardless of weight loss. Although the two surveys providing wheat bran at will have provided the results of performance and quality of eggs similar to those obtained with conventional change through fasting, we emphasize that the research conducted by Garcia et al., (2012), birds subjected to fasting had a laying posture showing average of 5.95% between 21 and 28 days after the beginning of molting, while the birds fed with wheat bran at will for 14 days showed an average laying posture percentage of % in the same period. In the study by Santos Table 4 - Percentage of ovary and oviduct in relation to body weight in the 0, at 14 and 28 days of the trial period the birds subjected to alternative methods of forced molting. Treatments Ovary (%) Oviduct (%) 0 14 days 28 days 0 14 days 28 days Fasting 2.10a 0.61Bc 1.27ab 3.60a 1.16Cb 2.43ab Offspring (50g) A A 3.93 Offspring (30g) 2.10a 0.48Bb 1.95a 3.60a 1.32BCb 3.70a Offspring without CaP (50g) AB ab 2.11ABCb 3.78a Offspring wihout CaP (30g) 2.10a 0.72ABb 1.43ab 3.60a 1.76ABCb 2.34ab Production (30g) AB AB 2.65 Production (15g) 2.10a 0.78ABb 1.92a 3.60a 1.77ABCb 3.51a Wheat Bran (ad libitum) 2.10a 0.71ABb 1.80ab 3.60a 1.24BCb 2.99a C.V. (%) Prob. ns <0.01 ns ns <0.01 ns Means followed by different letters in the column differ significantly by Tukey test (p <0.05). NS: not significant. 6

7 Table 5 - Performance of laying hens subjected to alternative methods of production rest. Treatment Lay (%) RC (g) EW (g) EM (g) FC/dz FC/kg Viability (%) Fasting Offspring (50g) Offspring (30g) Offspring without CaP (50g) Offspring without CaP (30g) Production (30g) Production (15g) Wheat Bran (ad libitum) Means CV (%) Probab. ns Ns ns ns ns ns ns LAY= Laying, RC= Ration Consumption, EW= Egg wheight, EM= egg mass, FC/kg=Feeding conversion per kg, FC/dz= Feeding conversion per dozen eggs. NS: not significant Table 6 - Specific gravity (SG) breaking strength of the shell (BS), yolk color (color), Haugh unit (HU), percentage of yolk, albumen and shell, laying hens subjected to alternative methods of forced molting. Treatments SG (g/cm³) BS (gf) Color HU Yolk (%) Albumen (%) Shell(%) Fasting Offspring (50g) Offspring (30g) Offspring without CaP (50g) Offspring without/ CaP (30g) Production (30g) Production (15g) Wheat Bran (ad libitum) CV (%) Prob. ns ns ns ns ns ns ns ns: not significant. et al., (2012), birds subjected to fasting achieved weight loss of 26% at 10 days and returned to be fed with production ration which resulted in laying percentage of 31.07% between 21 and 28 days from the beginning of the molting, however, the birds fed the wheat bran at will had reached the weight loss of 26% only at 21 days, which caused no laying to the 28 days from the beginning of the molting. From the results obtained from these researches, it can be concluded that the weight loss of 25-30% for induction of molting is not the most important item for success with the method used but it is the stop in the egg production so there is a resting period with subsequent regeneration of the reproductive system in order to prepare it to support a new production cycle. Thus, it can be considered that the supply of wheat bran at will is the best method to promote forced molting, since the birds consume about 60-70g per day, not suffering stress from lack of food. Thus, we suggest changing the term molting (traumatic process that goes to the mismatch of well-being) to productive resting period (a process that promotes a break in egg production with involution and subsequent regeneration of 7

8 8 the reproductive tract without trauma, which is consistent with the welfare and prolonging the life of birds). Together with the welfare of the birds, the supply of wheat bran ad libitum for 14 days as a inductor to induce the productive resting period, provides quick stop in the production of eggs and a returning to production faster than the method of fasting and like fasting, it promotes improvement in the production and quality of eggs (shell and albumen) during the second cycle, if compared the quality obtained immediately before the molting process, besides being a simple method, since it requires no need to change formulas nor speculate the amount to be supplied; and it is also a low-cost and of easy applicability, since wheat bran is easily found on the world market. Final concerns There is an increasing pressure from entities seeking welfare in animal production due to certain practices adopted during the rearing. In laying poultry, the forced molting is also polemic among animal advocacy groups, consumers, producers and researchers, since fasting is widely the most used method to perform it. Thus, according to what was here shown, it must be considered that the practice of resting productive period with providing wheat bran ad libitum extends the productive life providing the laying hen better welfare, improving performance, egg quality and economy in the production process, which may allow its use in large scale. Moreover, using this method there is a possibility of overcoming the barriers imposed on imports of eggs from laying hens who have suffered forced molting by fasting, by importing countries. References ANDREOTTI, M.O., SOUZA, K.M., SUZUKI, F.M., RIBEIRO, S.S., ALLAMAN, I. B. and FERREIRA, J.Z. (2005) Efeito de diferentes métodos de muda forçada na redução de peso corporal de poedeiras comerciais. Congresso de Produção, Comercialização e Consumo de Ovos, 3., Indaiatuba. Anais, Indaiatuba, SP: APA. ARAÚJO, C.S.S., ARTONI, S.M.B., ARAÚJO, L.F., JUNQUEIRA, O.M., BARBOSA, L.C.G.S. and LIMA, C.G. (2007) Morfometria do oviduto de poedeiras comerciais submetidas a diferentes métodos de muda forçada. Ciência Rural 37(1): BELL, D.D. (2003) Historical and current molting practices in the U.S. table egg industry. Poultry Science 82: BELL, D.D. and KUNEY, D.R. (2004) Farm evaluation of alternative molting procedures. Journal of Applied Poultry Research 13(4): BERRY, W.D. (2003) The physiology of induced molting. Poultry Science 82: BIGGS, P.E., DOUGLAS, M.W., KOELKEBECK. K.W. and PARSONS, C.M. (2003) Evaluation of nonfeed removal methods for molting programs. Poultry Science 82(5): BRAKE, J.T. (1993) Recent advances in molt. Poultry Science 72: DALANEZI, J.A. (2007) Produção e qualidade dos ovos de poedeiras comerciais semipesadas submetidas a programas de muda forçada. Tese (Doutorado em Zootecnia) - Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu. DUNKLEY C.S., FRIEND, T.H., MCREYNOLDS, J.L., KIM, W.K., DUNKLEY, K.D., KUBENA, L.F., NISBET, D.J. and RICKE, S.C. (2008) Behavioral responses of laying hens to different alfalfa-layer ration combinations fed during molting. Poultry Science 87: ELLIS, M.R. (2008) Moulting: a natural process. Disponível em: Acesso em: 17 nov GARCIA, E.A. (1994) Avaliação dos parâmetros físicos e produtivos de poedeiras semipesadas submetidas a muda forçada e alimentadas com ração de baixa densidade por diferentes períodos. Tese (Doutorado em Zootecnia) - Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu. GARCIA, E.A., MENDES, A.A., PINTO, M.C.L. and GARCIA, S.C.R. (1996) Avaliação dos parâmetros físicos de poedeiras semi-pesadas submetidas a muda forçada. Veterinária e Zootecnia, Botucatu 8: GARCIA, E.A. (2004) Muda forçada em poedeiras comerciais e codornas. Conferência Apinco de Ciência e Tecnologia Avícolas, 22, Santos, SP, Brasil. Anais, FACTA. GARCIA, E.A. (2005) Muda forçada em poedeiras comerciais e codornas. Disciplina de Produção de Ovos do curso de mestrado do programa de pósgraduação UNESP. Botucatu: UNESP, Faculdade de Medicina Veterinária e Zootecnia. GARCIA, E.A., MONTENEGRO, A.T., MOLINO, A.B., PELÍCIA, K., MURAKAMI, E.S.F., VIEIRA FILHO, J.A., BERTO, D.A. and SANTOS, G.C. (2012) Características físicas e produtivas de poedeiras comerciais submetidas a métodos alternativos de descanso produtivo. Congresso de Produção e Comercialização de Ovos da Associação Paulista de Avicultura, 10, Ribeirão Preto, Anais... Ribeirão Preto: APA, CD ROM. KESHAVARZ, K. and QUIMBY, F.W. (2002) An investigation of different molting techniques with an emphasis on animal welfare. Journal of Applied Poultry Research 11: LEE, K. (1982) Effects of forced molt period on posmolt performance of leghorn hens. Poultry Science 61(10): LLOBET, C.J.A., PONTES, M. and FRANCO GONZALEZ, F.

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