Effect of In Ovo Ascorbic Acid Injection and Thermal Manipulation During Incubation on Intestine Morphology of Broilers Reared under Cold and Heat Stress

It was investigated if pre-incubation ascorbic acid (AA) injection in fertile eggs incubated at high temperature impacts the performance, the yield of carcass and parts, and the intestine morphology of broilers reared under heat stress. Three thousand Cobb® fertile broiler eggs were randomly distributed according to weight into three incubations treatments (eggs not injected with AA and incubated at 37.5°C; eggs not injected with AA and incubated at 39°C; and eggs injected with 6 µg AA/100 µL water prior to incubation and incubated at 39ºC). The hatched birds were reared at thermoneutral, cold, and hot house temperatures. Broilers reared under hot temperature presented lower feed intake and weight gain than the broilers of the different rearing temperatures. Egg incubation at 39.0 ºC and 39.0 ºC + AA reduced broiler viability. Carcass and cut yields were not influenced by incubation and rearing procedures. Duodenal goblet cell count was lower in broilers from eggs of the treatment 39ºC + AA than in broilers from the other incubation treatments and in broiler rearing in hot temperature. In the jejunum, the goblet cell counts were higher in broilers that were reared under hot than thermoneutral temperatures. The incubation treatment of 39 ºC+AA increased the goblet cell counts in the ileum of broilers reared under cold temperatures. Rearing temperature influenced the duodenal villi counts, which were lower under cold rearing conditions than in the two other rearing temperatures. The results showed that egg incubation at 39°C, independently of ascorbic acid injection, did not produce an effective epigenetic heat adaptation in broilers.(AU)

In ovo injection of ascorbic acid and higher incubation temperature modulate blood parameters in response to heat exposure in broilers.

1. This study analysed whether in ovo injection of ascorbic acid before incubation and at high incubation temperature influenced blood characteristics and performance in broilers reared in different temperature conditions. 2. A total of 3,000 fertile eggs from broiler breeders (Cobb®) were randomly divided into three incubation treatments: no ascorbic acid injection and egg incubation at 37.5°C (control); no ascorbic acid injection and egg incubation at 39°C; in ovo ascorbic acid injection prior to incubation (6 µg AA/100 µl water) and egg incubation at 39°C. 3. Male chicks hatched from the three incubation treatments were submitted to three distinct rearing temperatures (control, cold and hot) from the third week of age onwards (540 chicks were divided into 6 treatments with 5 replicates per treatment). 4. Measurements at 42 d showed that, after egg incubation at 39°C, the haematocrit, haemoglobin values, ionised calcium and glucose concentrations were increased and base excess values were reduced. However, in ovo injection of ascorbic acid normalised all these parameters. 5. Partial CO2 and O2 pressure were higher with increased rearing temperature. Blood pH was lower when eggs were incubated at 39°C and injected with ascorbic acid. In ovo injection of ascorbic acid induced leucocytosis due to lymphocytosis and heterophilia, restored basophils rate and led to monocytopoenia. Leucocytosis was triggered by hot rearing temperature due to lymphocytosis, eosinophilia and heterophilia. 6. The results obtained in this study showed that in ovo injection of ascorbic acid before incubation may serve as a long-term stimulator and modulator of the broiler immune system, and that high incubation temperatures induce adaptations in the electrolytic balance, minimising or avoiding the occurrence of respiratory alkalosis under hot rearing temperature.

Genetic and environmental effects on tonic immobility duration of red-winged tinamou applying survival analysis

Fear behavioral studies provide knowledge on animal welfare, and fearful behaviors can be used as selection criteria of individuals adapted to intensive rearing system. The survival analysis methodology was applied to estimate tonic immobility (TI) duration, as an indicator of fear, of red-winged tinamous (Rhynchotus rufescens) reared in captivity and to determine if TI is genetically influenced. A number of 539 birds born between 2006 and 2010 were evaluated. The exploratory data analysis was performed using the Kaplan-Meier estimate (KM), and the covariates were then fit to a Cox model, considering month of observation nested within year of birth and body weight as fixed effects and the random effect of sire as frailty term. In order to predict genetic values and to estimate heritability, the model of proportional hazards was applied, using a Weibull distribution as the baseline hazard. Birds born in the last year presented shorter TI duration than those born in the previous year, as shown by the survival KM curves, indicating a decline in fearfulness from one year to the next. The Cox analysis detected that hazard function was reduced as body weight increased. The frailty term was significant (p<0.05), showing that sires induced variation in the TI duration of the offspring. Heritability estimated as 0.37, indicating the influence of additive genes. These findings suggest that the selection of for short TI duration may allow reducing fearfulness of a red-winged tinamou population after some generations.

Genetic and environmental effects on tonic immobility duration of red-winged tinamou applying survival analysis

Fear behavioral studies provide knowledge on animal welfare, and fearful behaviors can be used as selection criteria of individuals adapted to intensive rearing system. The survival analysis methodology was applied to estimate tonic immobility (TI) duration, as an indicator of fear, of red-winged tinamous (Rhynchotus rufescens) reared in captivity and to determine if TI is genetically influenced. A number of 539 birds born between 2006 and 2010 were evaluated. The exploratory data analysis was performed using the Kaplan-Meier estimate (KM), and the covariates were then fit to a Cox model, considering month of observation nested within year of birth and body weight as fixed effects and the random effect of sire as frailty term. In order to predict genetic values and to estimate heritability, the model of proportional hazards was applied, using a Weibull distribution as the baseline hazard. Birds born in the last year presented shorter TI duration than those born in the previous year, as shown by the survival KM curves, indicating a decline in fearfulness from one year to the next. The Cox analysis detected that hazard function was reduced as body weight increased. The frailty term was significant (p<0.05), showing that sires induced variation in the TI duration of the offspring. Heritability estimated as 0.37, indicating the influence of additive genes. These findings suggest that the selection of for short TI duration may allow reducing fearfulness of a red-winged tinamou population after some generations.(AU)

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.(AU)

Poultry egg incubation: integrating and optimizing production efficiency

Due to its central position in the production chain, in-ovo development is influenced by pre-incubation factors that affect the quality of embryonated eggs and incubation conditions themselves, and both may influence egg hatchability and chick quality, as well as bird survival, growth performance, and phenotype in the field. The evolution of the incubation process over the years is characterized by significant scientific and technological development. Presently, the main current focuses of research are the manipulation of thermal incubation conditions, eggshell temperature, and the integrated effects of factors that influence incubation. In this context, one of the questions that needs to be asked is how effective are the current physical conditions of incubation to promote greater hatchability and better quality chicks, and higher survival and better performance in the field under adverse conditions or not. What are the new and future prospects for incubation? The purpose of this paper was to review the role of the physical agents of incubation, such as temperature, relative humidity, O2 and CO2 concentration, and egg turning and position from an integrated perspective, considering egg incubation as the transitional link between egg and poultry production.(AU)

Poultry egg incubation: integrating and optimizing production efficiency

Due to its central position in the production chain, in-ovo development is influenced by pre-incubation factors that affect the quality of embryonated eggs and incubation conditions themselves, and both may influence egg hatchability and chick quality, as well as bird survival, growth performance, and phenotype in the field. The evolution of the incubation process over the years is characterized by significant scientific and technological development. Presently, the main current focuses of research are the manipulation of thermal incubation conditions, eggshell temperature, and the integrated effects of factors that influence incubation. In this context, one of the questions that needs to be asked is how effective are the current physical conditions of incubation to promote greater hatchability and better quality chicks, and higher survival and better performance in the field under adverse conditions or not. What are the new and future prospects for incubation? The purpose of this paper was to review the role of the physical agents of incubation, such as temperature, relative humidity, O2 and CO2 concentration, and egg turning and position from an integrated perspective, considering egg incubation as the transitional link between egg and poultry production.

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.

Incubation temperature alters thermal preference and response to heat stress of broiler chickens along the rearing phase.

The current study aimed to investigate whether embryonic temperature manipulation may alter thermal preference throughout the rearing phase of broiler chickens and how this manipulation may affect response to thermal challenge, metabolism, growth rate and feed intake rate. Eggs were exposed to a constant incubation temperature [machine temperatures: 36°C (Low), 37.5°C (Control), and 39°C (High); eggshell temperature of 37.4 ± 0.08°C, 37.8 ± 0.15°C, and 38.8 ± 0.33°C, respectively] from d 13 till hatching. Low treatment chickens showed lower plasma T3 and GH levels at d 1 of age and lower T3 level at d 42 of age compared to the Control treatment. Preferred ambient, rectal temperature, T4 level, growth rate, food intake rate, and response to thermal challenge were not altered in these chickens. On the other hand, High-treatment chickens exhibited high preferred ambient temperature and rectal temperature during the first 2 wk post-hatch, lower plasma T3 level at d 21 and 42 and a delayed increase in respiratory movement in response to thermal challenge compared to the Control treatment. However, chickens subjected to the Control and High treatments did not differ in T4 and GH level and performance. We conclude that exposure to high temperature during late embryonic development has long-lasting effects on the thermoregulatory system of broiler chickens by affecting the heat tolerance of these chickens. Moreover, the preferred ambient temperature of the chickens from heat-treated eggs correspond to those recommended for the strain under study, whereas for the cold-treated and control-chickens it was 1°C below, indicating that incubation temperature might have consequences on the ambient temperature chickens require during the rearing phase.

Incubation temperature manipulation during fetal development reduces adiposity of broiler hatchlings.

Broilers are known as an efficient source of lean meat. Genetic selection resulted in broiler strains with large body size and fast growth, but a concomitant increase in fat deposition also occurred. Other than reducing nutrient intake, there is a lack of alternative methods to control body fat composition of broilers. The present study assessed whether incubation temperature (machine temperatures: 36ºC, 37.5ºC, and 39ºC; eggshell temperatures: 37.4 ± 0.08°C, 37.8 ± 0.15ºC, and 38.8 ± 0.33°C, respectively.) from d 13 affects broiler hatchling fat deposition. We analyzed adipocyte hypertrophy and proliferation in 3 body regions; weight and chemical composition of yolk-free chicks and yolk sacs; and serum lipid profile. Increased incubation temperature reduced abdominal and cervical adipocyte size. Independently of temperature, cervical adipocytes were smaller and showed higher proliferation than adipocytes in the abdominal and thigh regions. Smaller cervical adipocytes were observed in birds from eggs incubated at 36ºC and 39ºC. With regard to weight and composition of chicks, ash content as a percentage of dry matter was the only variable affected by temperature; it was higher in chicks from eggs incubated at 36ºC than at 39ºC and showed no significant difference between chicks incubated at 39ºC and 37.5ºC. Absolute and relative weights of yolk sacs were higher from eggs incubated at 39ºC than at 36ºC, and these two treatments did not differ from the 37.5ºC control. Absolute measures of yolk sac lipids, moisture, dry matter, and crude protein content were lower in chicks from eggs incubated at 36ºC, and no significant differences were found for these variables between chicks from eggs incubated at 37.5ºC and 39ºC. Hatchlings from eggs incubated at 36°C had significantly higher cholesterol levels than chicks incubated at the other 2 temperatures, but no additional effects on blood lipids were detected. Incubation temperature manipulation during fetal development altered cervical and abdominal adipocyte size in broiler hatchlings and could become a tool in hatcheries to manipulate chick quality, although further studies are needed to evaluate its long-term effects.

Effect of Broiler Breeder Age and Glutamine Supplementation on the Development of the Intestinal Mucosa of 7-Day-Old Chicks

The aim of this study was to evaluate the possible effects of glutamine and broiler breeder age on the development of intestinal mucosa in broiler chicks during first week of age. For this purpose, 32 one-day-old broiler chicks were distributed according to a completely randomized experimental design in a 2 x 2 factorial arrangement. Treatments consisted of two broiler breeder ages (30 and 60 weeks) and two dietary glutamine supplementation levels (0% and 1%). The morphological development of intestinal mucosa, particularly villus height and crypt depth, was evaluated. The results showed that the supplementation with 1% of glutamine influenced the development of villus height in the duodenum (p=0.009), jejunum (p = 0.006), and ileum (p = 0.001), as well as crypt depth in the jejunum (p = 0.037) of 7-day-old broilers. These results suggest that the presence of glutamine influenced the development of intestinal mucosa during the first week of age, when these tissues are highly influenced by dietary components, especially by trophic agents. The results show that broiler breeder age (30 or 60 weeks) did not influence the evaluated parameters.

Effect of In-Ovo Ascorbic Acid Injection on the Bone Development of Broiler Chickens Submitted to Heat Stress During Incubation and Rearing

This experiment was conducted to evaluate the effect of in-ovo ascorbic acid (AA) injection on the bone development of broilers submitted to heat stress during incubation and rearing. One thousand (1,000) Cobb(r)fertile broiler eggs were randomly distributed according to the weight into five incubators, with 200 eggs per incubator. The incubation treatments were: eggs not injected with AA and incubated at 37.5°C; eggs not injected with AA and incubated at 39°C; and eggs injected with 6 µg AA/100 µL water prior to incubation and incubated at 39ºC. The hatched birds were reared at three different house temperatures: cold, thermoneutral, or and hot. The high incubation temperature negatively influenced broilers' bone characteristics. The femur of the birds hatched from eggs incubated at 39°C and injected with AA presented lower shaft mineral density, lower maximum force and lower elongation at maximum force. Their tibia presented reduced mineral density at the proximal and distal epiphysis. In-ovo AA injection of eggs incubated at high temperature did not minimize the negative effects of high rearing temperature on the performance andbone development of broiler chickens reared until 42 days of age.

Effect of In-Ovo Ascorbic Acid Injection on the Bone Development of Broiler Chickens Submitted to Heat Stress During Incubation and Rearing

This experiment was conducted to evaluate the effect of in-ovo ascorbic acid (AA) injection on the bone development of broilers submitted to heat stress during incubation and rearing. One thousand (1,000) Cobb(r)fertile broiler eggs were randomly distributed according to the weight into five incubators, with 200 eggs per incubator. The incubation treatments were: eggs not injected with AA and incubated at 37.5°C; eggs not injected with AA and incubated at 39°C; and eggs injected with 6 µg AA/100 µL water prior to incubation and incubated at 39ºC. The hatched birds were reared at three different house temperatures: cold, thermoneutral, or and hot. The high incubation temperature negatively influenced broilers' bone characteristics. The femur of the birds hatched from eggs incubated at 39°C and injected with AA presented lower shaft mineral density, lower maximum force and lower elongation at maximum force. Their tibia presented reduced mineral density at the proximal and distal epiphysis. In-ovo AA injection of eggs incubated at high temperature did not minimize the negative effects of high rearing temperature on the performance andbone development of broiler chickens reared until 42 days of age.(AU)

Effect of Broiler Breeder Age and Glutamine Supplementation on the Development of the Intestinal Mucosa of 7-Day-Old Chicks

The aim of this study was to evaluate the possible effects of glutamine and broiler breeder age on the development of intestinal mucosa in broiler chicks during first week of age. For this purpose, 32 one-day-old broiler chicks were distributed according to a completely randomized experimental design in a 2 x 2 factorial arrangement. Treatments consisted of two broiler breeder ages (30 and 60 weeks) and two dietary glutamine supplementation levels (0% and 1%). The morphological development of intestinal mucosa, particularly villus height and crypt depth, was evaluated. The results showed that the supplementation with 1% of glutamine influenced the development of villus height in the duodenum (p=0.009), jejunum (p = 0.006), and ileum (p = 0.001), as well as crypt depth in the jejunum (p = 0.037) of 7-day-old broilers. These results suggest that the presence of glutamine influenced the development of intestinal mucosa during the first week of age, when these tissues are highly influenced by dietary components, especially by trophic agents. The results show that broiler breeder age (30 or 60 weeks) did not influence the evaluated parameters.(AU)

Vitamin C prevents the effects of high rearing temperatures on the quality of broiler thigh meat1.

We investigated the effects of incubation temperatures and vitamin C injections into eggs (treatments: 37.5ºC, 39ºC, 39ºC+vitamin C) on resultant chick pectoralis major and sartorius muscle fiber hypertrophy, as well as their effects on the quality of breast and over-thigh meat of broilers reared under cold, control, or hot temperatures. Incubation at 39ºC increased the shear force and reduced meat redness in breast meat (P < 0.05). Vitamin C prevented these high temperature incubation effects [shear force (kgf cm(-2)): 37.5ºC = 2.34, 39ºC = 2.79, 39ºC+vitamin C = 2.44; redness: 37.5ºC = 2.64, 39ºC = 1.90, 39ºC+vitamin C = 2.30], but reduced water content (37.5ºC = 74.81%, 39ºC = 74.53%, 39ºC+vitamin C = 69.39%) (P < 0.05). Cold rearing temperatures increased breast meat redness (a*: cold = 2.78, control = 2.12, hot = 1.98), while hot rearing temperatures reduced the muscle fiber area (cold = 5.413 µm(2), control = 5.612 µm(2), hot = 4.448 µm(2)) (P < 0.05) without altering meat quality (P > 0.05). Hot rearing temperatures increased the cooking loss (cold = 30.10%, control = 33.66%, hot = 37.01%), shear force (cold = 3.05 kgf cm(-2), control = 3.43 kgf cm(-2), hot = 4.29 kgf cm(-2)) and redness (a*: cold = 4.63, control = 3.55, hot = 3.20) in the over-thigh meat of broilers from eggs incubated at 37.5ºC, increasing the area of muscle fibers, while cold rearing temperatures diminished cooking loss and shear force, reducing the muscle fiber area (P < 0.05). Incubation at 39ºC and 39ºC+vitamin C prevented the effects of hot and cold rearing temperatures, by diminishing and increasing the muscle fiber area, respectively.

Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.(AU)

Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.

Dietary fiber inclusion as an alternative to Feed Fasting to induce molting in Commercial Layers

The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers with 72 weeks of age were distributed, according to a completely randomized experimental design into five treatments with eight replicates of eight birds each, totaling 40 experimental units. Molting was induced by feeding diets with the inclusion of alfalfa or soybean husks at 80% and 60% or feed fasting. Treatments were applied for 14 days. Performance and egg quality parameters were evaluated for the second laying cycle and organ morphometrics (liver, gizzard, proventriculus, reproductive apparatus) in two different slaughter dates. The obtained data were submitted to analysis of variance using the General Linear Model (GLM) procedure of SAS statistical package (SAS Institute, 2002). Alternative molting methods promoted similar performance and egg quality results after molting were similar to those obtained by the conventional fasting method. Feeding fiber produced the expected effects in terms of organ weight regression and recovery and may be used to induce molting in commercial layers.(AU)

Dietary fiber inclusion as an alternative to Feed Fasting to induce molting in Commercial Layers

The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers with 72 weeks of age were distributed, according to a completely randomized experimental design into five treatments with eight replicates of eight birds each, totaling 40 experimental units. Molting was induced by feeding diets with the inclusion of alfalfa or soybean husks at 80% and 60% or feed fasting. Treatments were applied for 14 days. Performance and egg quality parameters were evaluated for the second laying cycle and organ morphometrics (liver, gizzard, proventriculus, reproductive apparatus) in two different slaughter dates. The obtained data were submitted to analysis of variance using the General Linear Model (GLM) procedure of SAS statistical package (SAS Institute, 2002). Alternative molting methods promoted similar performance and egg quality results after molting were similar to those obtained by the conventional fasting method. Feeding fiber produced the expected effects in terms of organ weight regression and recovery and may be used to induce molting in commercial layers.

Effect of forced-molting methods and rearing temperatures on the performance and organ biometrics of laying hens

An experiment was conducted to evaluate the biometrics of organs (ovary, oviduct, liver, proventriculus and gizzard) of laying hens submitted to different forced-molting methods of molt and maintained at three different temperature. Organs were evaluated after molting and resting period. Six hundred birds were distributed according to a completely randomized experimental design in a 5x3 factorial arrangement (forced-molting methods x environmental temperatures) into 15 treatments with 5 replicates of 8 birds each. The molting methods applied were the dietary inclusion of 90%, 70%, 50% of alfalfa, 2,800 ppm zinc oxide, or total feed restriction. Birds were kept at ±20 ºC, ±27 ºC, or ±35 ºC. Data were submitted to analysis of variance and means were compared by orthogonal and polynomial contrasts. The traditional forced-molting method (feed fasting) resulted in adequate performance. However, as the aim of the present study was to find an alternative method to feed fasting, the highest dietary alfafa inclusion level (90%) was shown to be efficient compared with other methods, particularly when hens were kept at high temperature. Therefore, this alternative forced-molting may be applied, especially when bird welfare is taken into consideration.(AU)