RESUMO

Laser beak trimming is a promising alternative to conventional hot-blade beak trimming as it is less painful and provides better beak uniformity and better animal welfare. In this study, laser vs. hot-blade beak trimming were compared in 400 Hy-line Brown pullets between 2-16 weeks of age. At 7 days of age, birds were distributed according to a completely randomized design into two treatments, with 10 replicates (pens) of 20 birds each. Birds and feed offer and residues were weekly weighed to determine weight gain, feed intake, and feed conversion ratio. In weeks 4, 8, 12, and 16 weeks, one bird per experimental unit was sacrificed to measure the development of the heart development, liver, proventriculus, gizzard, small intestine, and bursa. And of the oviduct in week 16. Pullers submitted to laser beak trimming presented higher weight gain and weekly feed intake, and better feed conversion ratio during the evaluated period. There was no influence of beak trimming methods on the development of the digestive organs, bursa or oviduct. Laser beak trimming can be used as an alternative to hot-blade beak trimming of commercial brown layers.

Assuntos

RESUMO

Laser beak trimming is a promising alternative to conventional hot-blade beak trimming as it is less painful and provides better beak uniformity and better animal welfare. In this study, laser vs. hot-blade beak trimming were compared in 400 Hy-line Brown pullets between 2-16 weeks of age. At 7 days of age, birds were distributed according to a completely randomized design into two treatments, with 10 replicates (pens) of 20 birds each. Birds and feed offer and residues were weekly weighed to determine weight gain, feed intake, and feed conversion ratio. In weeks 4, 8, 12, and 16 weeks, one bird per experimental unit was sacrificed to measure the development of the heart development, liver, proventriculus, gizzard, small intestine, and bursa. And of the oviduct in week 16. Pullers submitted to laser beak trimming presented higher weight gain and weekly feed intake, and better feed conversion ratio during the evaluated period. There was no influence of beak trimming methods on the development of the digestive organs, bursa or oviduct. Laser beak trimming can be used as an alternative to hot-blade beak trimming of commercial brown layers.(AU)

Assuntos

RESUMO

Skeletal abnormalities, bone deformities and fractures cause significant losses in broiler production during both rearing and processing. Silicon is an essential mineral for bone and connective tissue synthesis and for calcium absorption during the early stages of bone formation. Performance was not affected by the addition of silicon. However, broilers receiving silicon showed a significant increase of phosphorus, zinc, copper, manganese and ash in the tibia. In conclusion, broiler performance was not impaired by adding the tested silicon product to the drinking water. In addition, bone development improved, as demonstrated by higher mineral and ash content. Further studies are required to determine the optimal concentration of silicon, including heat stress simulations, to better understand the effects of silicon on bone development.

Assuntos

RESUMO

An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxerê, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.

Assuntos

RESUMO

An experiment was conducted of the poultry facilities of La Salle Agricultural College in Xanxerê, SC, Brazil, to evaluate the effect of the administration of sodium bicarbonate, glucose and vitamin E to the drinking water during pre-slaughter feed withdrawal on carcass yield, organ relative weights (heart, liver, proventriculus, and gizzard), gizzard emptying, and meat quality of broiler chickens. The applied treatments were: water as control; 50g/L of glucose; 50g/L de glucose + 200mg/L of vitamin E; 75g/L of glucose; 75g/L + 200mg/L of vitamin E; 0.45% of sodium bicarbonate; 0.45% of sodium bicarbonate + 200mg/L of vitamin E; 0.55% of sodium bicarbonate; 0.55% of sodium bicarbonate + 200mg/L of vitamin E; 200mg/L de vitamin E. On the last day before slaughter, during the water diet period,500 birds were distributed in a completely randomized experimental design with ten treatments and ten replicates of five birds each. No difference in broiler carcass yield and organ relative weights was found. There were no significant changes in gizzard contents, in ultimate meat, cooking loss, shear force value, or in the meat color parameters L* (lightness), a* (redness) and b* (yellowness). It was concluded is that the addition of glucose, sodium bicarbonate, and vitamin E to the drinking water during pre-slaughter feed withdrawal period has no influence on carcass yield or on relative organ weight, neither on the emptying of the gizzard contents and the meat quality of broiler chickens.(AU)

Assuntos

RESUMO

This study aimed at evaluating diets containing different fiber sources and two crude protein levels on the performance, egg quality, and nitrogen metabolism of commercial layers. In total, 392 48-wk-old Isa Brown layers were distributed according to a completely randomized experimental design in a 3x2+1 (control) factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. Treatments consisted of three fiber feedstuffs (cottonseed hulls, soybean hulls, and rice hulls) and two dietary crude protein levels (12% and 16%). Cottonseed hulls associated with the high crude protein level (16%) resulted in the worst feed conversion ratio per dozen eggs. Diets with 16% crude protein resulted in the highest feed intake, egg production, egg weight, egg mass values, and improved feed conversion ratio (kg eggs/kg feed). The dietary inclusion of soybean hulls determined low yolk pigmentation, and of rice hulls, low egg specific gravity. The 16% crude protein diet with rice hulls promoted the best feed conversion ratio. Hens fed the reference diet presented higher egg mass and better feed conversion ratio per kg eggs and per dozen eggs. Hens fed the diets with low crude protein level (12%) had reduced nitrogen excretion, but presented worse egg production.(AU)

Assuntos

RESUMO

An experiment was carried out to evaluate the performance, egg quality and morphometry of the reproductive tract, liver, pancreas and tongue of laying hens submitted to different molting methods. Two hundred and eighty eight 72-week-old Isa brown layers were distributed according to a completely randomized design with six treatments (molting methods) and six replicates of eight birds each. Layers were fed diets containing 3000 ppm zinc oxide, 60 ppm or 120 ppm nicarbazin, 30 ppm or 60 ppm salinomycin, or were submitted to feed fasting. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% probability level. Molting methods alternative to feed fasting were effective to induce molting in layer and provided good performance results in the second laying cycle.(AU)

Assuntos

RESUMO

This study aimed at evaluating diets containing different fiber sources and two crude protein levels on the performance, egg quality, and nitrogen metabolism of commercial layers. In total, 392 48-wk-old Isa Brown layers were distributed according to a completely randomized experimental design in a 3x2+1 (control) factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. Treatments consisted of three fiber feedstuffs (cottonseed hulls, soybean hulls, and rice hulls) and two dietary crude protein levels (12% and 16%). Cottonseed hulls associated with the high crude protein level (16%) resulted in the worst feed conversion ratio per dozen eggs. Diets with 16% crude protein resulted in the highest feed intake, egg production, egg weight, egg mass values, and improved feed conversion ratio (kg eggs/kg feed). The dietary inclusion of soybean hulls determined low yolk pigmentation, and of rice hulls, low egg specific gravity. The 16% crude protein diet with rice hulls promoted the best feed conversion ratio. Hens fed the reference diet presented higher egg mass and better feed conversion ratio per kg eggs and per dozen eggs. Hens fed the diets with low crude protein level (12%) had reduced nitrogen excretion, but presented worse egg production.

Assuntos

RESUMO

An experiment was carried out to evaluate the performance, egg quality and morphometry of the reproductive tract, liver, pancreas and tongue of laying hens submitted to different molting methods. Two hundred and eighty eight 72-week-old Isa brown layers were distributed according to a completely randomized design with six treatments (molting methods) and six replicates of eight birds each. Layers were fed diets containing 3000 ppm zinc oxide, 60 ppm or 120 ppm nicarbazin, 30 ppm or 60 ppm salinomycin, or were submitted to feed fasting. Data were submitted to analysis of variance and means were compared by the test of Tukey at 5% probability level. Molting methods alternative to feed fasting were effective to induce molting in layer and provided good performance results in the second laying cycle.

Assuntos

RESUMO

This study was carried out to evaluate the effect of the inclusion of different linseed oil levels (0.0, 3.3, 6.6, or 9.9%) in iso-energy diets fed during the period of 21 to 56 days of age on the performance, carcass traits, and body composition of broilers. A total of 1,600 broilers were distributed according to a completely randomized experimental design consisting of four treatments with eight replicates of 40 birds per experimental unit. In the period of 21-42 days of age, weight gain increased, feed and calorie conversion ratios quadratically improved, and feed and metabolizable energy intakes linearly increased as dietary linseed oil level increased. Considering the entire experimental period, dietary linseed oil linearly increased weight gain and feed and energy intakes, and feed and calorie conversion ratios in a quadratic manner. On days 42 and 56, abdominal fat percentage and carcass yield were quadratically influenced by dietary linseed oil. Total body fat content at 56 days of age was quadratically influenced by dietary linseed levels.(AU)

Assuntos

RESUMO

O objetivo do estudo foi avaliar o efeito de níveis de silício na água de bebida de frangos de corte sobre o desempenho, o rendimento de carcaça, o metabolismo do cálcio, fósforo e nitrogênio e o perfil de ácidos graxos no músculo peitoral de frangos de corte. Foram utilizadas 1.120 pintos machos de um dia de idade da linhagem Cobb, distribuídas em um delineamento inteiramente casualisado, com quatro níveis de silício na água de bebida (0; 0,5mg; 1,0mg e 1,5mg do produto/100 kg de peso/dia), totalizando quatro tratamentos com oito repetições e 35 aves por parcela. A análise estatística dos dados foi realizada pelo método da análise de variância com o auxílio do procedimento GLM do SAS® e em caso de significância, os níveis de inclusão de silício foram estimados por intermédio dos modelos de regressão polinomial. A suplementação de silício via água de bebida promoveu efeito quadrático sobre a coxa+sobrecoxa com valor máximo de rendimento estimado em 28,87%. Com relação aos perfis de ácidos graxos observou - se efeito linear para os ácidos graxos vacênico, γ-linolênico, araquidico e palmítico e efeito quadrático para os ácidos graxos mirístico, miristoleico, palmitoleico e eicosadienoico. O silício modificou o perfil de ácidos graxos no músculo peitoral, bem como o rendimento de coxa+sobrecoxa das aves aos 49 dias de idade, podendo ser uma ferramenta importante a ser utilizada para a nutrição das aves.(AU)

The aim of this study was evaluate different levels of silicon in the drinking water of broilers on performance, carcass yield, metabolism of calcium, phosphorus and nitrogen and fatty acid profiles of pectoral muscle of broilers. A total of 1,120 one-day-old male Cobb chicks were used, distributed in a completely randomized design within four levels of silicon in the drinking water (0, 0.5 mg, 1.0 mg and 1.5 mg of silicon/100 kg/day), and eight replicates of 35 birds each . The data were analysed by the PROC GLM procedure of SAS® and in case of significance polynomial regressions were performed. Silicon supplementation in the drinking water promoted quadratic effect on thigh and drumstick with maximum yield estimated of 28.87%. For fatty acid profiles were observed linear effect for γ - linolenic, vaccenic, arachidonic and palmitic, and quadratic effect for myristic, myristoleic, palmitoleic and eicosadienoic. Silicon modified the fatty acid profiles of pectoral muscle as well as yield of thigh and drumstick of 49 days old birds, and could be an important tool to be used for poultry nutrition.(AU)

Assuntos

RESUMO

This study was carried out to evaluate the effect of the inclusion of different linseed oil levels (0.0, 3.3, 6.6, or 9.9%) in iso-energy diets fed during the period of 21 to 56 days of age on the performance, carcass traits, and body composition of broilers. A total of 1,600 broilers were distributed according to a completely randomized experimental design consisting of four treatments with eight replicates of 40 birds per experimental unit. In the period of 21-42 days of age, weight gain increased, feed and calorie conversion ratios quadratically improved, and feed and metabolizable energy intakes linearly increased as dietary linseed oil level increased. Considering the entire experimental period, dietary linseed oil linearly increased weight gain and feed and energy intakes, and feed and calorie conversion ratios in a quadratic manner. On days 42 and 56, abdominal fat percentage and carcass yield were quadratically influenced by dietary linseed oil. Total body fat content at 56 days of age was quadratically influenced by dietary linseed levels.

Assuntos

RESUMO

O objetivo do estudo foi avaliar o efeito de níveis de silício na água de bebida de frangos de corte sobre o desempenho, o rendimento de carcaça, o metabolismo do cálcio, fósforo e nitrogênio e o perfil de ácidos graxos no músculo peitoral de frangos de corte. Foram utilizadas 1.120 pintos machos de um dia de idade da linhagem Cobb, distribuídas em um delineamento inteiramente casualisado, com quatro níveis de silício na água de bebida (0; 0,5mg; 1,0mg e 1,5mg do produto/100 kg de peso/dia), totalizando quatro tratamentos com oito repetições e 35 aves por parcela. A análise estatística dos dados foi realizada pelo método da análise de variância com o auxílio do procedimento GLM do SAS® e em caso de significância, os níveis de inclusão de silício foram estimados por intermédio dos modelos de regressão polinomial. A suplementação de silício via água de bebida promoveu efeito quadrático sobre a coxa+sobrecoxa com valor máximo de rendimento estimado em 28,87%. Com relação aos perfis de ácidos graxos observou - se efeito linear para os ácidos graxos vacênico, γ-linolênico, araquidico e palmítico e efeito quadrático para os ácidos graxos mirístico, miristoleico, palmitoleico e eicosadienoico. O silício modificou o perfil de ácidos graxos no músculo peitoral, bem como o rendimento de coxa+sobrecoxa das aves aos 49 dias de idade, podendo ser uma ferramenta importante a ser utilizada para a nutrição das aves.

The aim of this study was evaluate different levels of silicon in the drinking water of broilers on performance, carcass yield, metabolism of calcium, phosphorus and nitrogen and fatty acid profiles of pectoral muscle of broilers. A total of 1,120 one-day-old male Cobb chicks were used, distributed in a completely randomized design within four levels of silicon in the drinking water (0, 0.5 mg, 1.0 mg and 1.5 mg of silicon/100 kg/day), and eight replicates of 35 birds each . The data were analysed by the PROC GLM procedure of SAS® and in case of significance polynomial regressions were performed. Silicon supplementation in the drinking water promoted quadratic effect on thigh and drumstick with maximum yield estimated of 28.87%. For fatty acid profiles were observed linear effect for γ - linolenic, vaccenic, arachidonic and palmitic, and quadratic effect for myristic, myristoleic, palmitoleic and eicosadienoic. Silicon modified the fatty acid profiles of pectoral muscle as well as yield of thigh and drumstick of 49 days old birds, and could be an important tool to be used for poultry nutrition.

Assuntos

RESUMO

O objetivo do estudo foi avaliar o efeito de níveis de silício na água de bebida de frangos de corte sobre o desempenho, o rendimento de carcaça, o metabolismo do cálcio, fósforo e nitrogênio e o perfil de ácidos graxos no músculo peitoral de frangos de corte. Foram utilizadas 1.120 pintos machos de um dia de idade da linhagem Cobb, distribuídas em um delineamento inteiramente casualisado, com quatro níveis de silício na água de bebida (0; 0,5mg; 1,0mg e 1,5mg do produto/100 kg de peso/dia), totalizando quatro tratamentos com oito repetições e 35 aves por parcela. A análise estatística dos dados foi realizada pelo método da análise de variância com o auxílio do procedimento GLM do SAS® e em caso de significância, os níveis de inclusão de silício foram estimados por intermédio dos modelos de regressão polinomial. A suplementação de silício via água de bebida promoveu efeito quadrático sobre a coxa+sobrecoxa com valor máximo de rendimento estimado em 28,87%. Com relação aos perfis de ác

RESUMO

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.

Assuntos

RESUMO

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)

Assuntos

RESUMO

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.

Assuntos

RESUMO

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)

Assuntos

RESUMO

O objetivo do estudo foi avaliar o desempenho de poedeiras comerciais durante a muda forçada submetidas a diferentes dietas e temperaturas. As aves foram distribuídas em um delineamento inteiramente ao acaso, em esquema fatorial 5x3 (dietas x temperaturas), com cinco repetições de oito aves cada. As dietas testados consistiram de inclusão de alfafa, em 90%, 70% e 50%, dieta com 2.800 ppm de zinco e o controle jejum alimentar. As temperaturas utilizadas foram: 20 ºC, 27 ºC e 35 ºC. As deitas foram fornecidas durante 14 dias. Durante o processo de muda e descanso, foram avaliadas as características de desempenho das aves. Os dados obtidos foram submetidos à análise de variância pelo programa SAS ® e as médias comparadas por meio de contrastes ortogonais e polinomiais. Os resultados indicaram que dietas com a inclusão de alfafa induziram o processo de muda em poedeiras comerciais em 3,85 dias após o fornecimento. As aves arraçoadas com alfafa apresentaram perda de peso corporal para induzir a muda de 26,88%, enquanto que para o controle (jejum alimentar) a perda de peso corporal foi de 30,26%. Aves mantidas em temperatura termoneutra, durante a muda, cessaram a produção de ovos em 2,73 dias, antes das aves mantidas nas demais temperaturas, além disso, o retorno da postura foi mais breve para aves mantidas em temperatura quente (10,47 dias) durante a muda e o descanso, com uma maior recuperação do peso corporal nesta temperatura, para as aves que receberam dietas contendo 50% de alfafa (35,66%). A inclusão de alfafa pode ser utilizada com alternativa ao método de jejum alimentar, causando uma perda de peso corporal suficiente para a indução da muda, independente da temperatura em que for realizada.(AU)

This study evaluates the performance of laying hens during molt subjected to different diets and temperatures. The birds were distributed in a completely randomized design, 5x3 factorial (diet x temperature), with five replicates of eight birds each. The diets tested to induce molt were: 90%, 70%, 50% alfalfa; added of 2,800 ppm of zinc while the last group was on full feed restriction. The temperatures used were: 20, 27 and 35ºC. Performance parameters of the birds were evaluated during the process of molt and rest. The data underwent analysis of variance by SAS® and means were compared using orthogonal and polynomial contrasts. The results indicated that diets including alfalfa induced molt in laying hens at 3.85 days after being fed. The birds fed alfalfa had weight loss of 26.88% in order to induce molt compared to 30.26% for the birds of the control group (fasting). Egg production of birds kept at neutral temperature during molt ceased at 2.73 days, earlier than the other temperatures studied. Furthermore, birds kept at warmer temperatures (10.47 days) during molt and rest returned earlier to posture while greater body weight recovery was observed at this temperature for birds fed diets containing 50% alfalfa (35.66%). The alfalfa inclusion can be used as an alternative to fasting to cause a weight loss sufficient to induce molt, independent of temperature.(AU)

Assuntos

RESUMO

O objetivo do estudo foi avaliar o desempenho de poedeiras comerciais durante a muda forçada submetidas a diferentes dietas e temperaturas. As aves foram distribuídas em um delineamento inteiramente ao acaso, em esquema fatorial 5x3 (dietas x temperaturas), com cinco repetições de oito aves cada. As dietas testados consistiram de inclusão de alfafa, em 90%, 70% e 50%, dieta com 2.800 ppm de zinco e o controle jejum alimentar. As temperaturas utilizadas foram: 20 ºC, 27 ºC e 35 ºC. As deitas foram fornecidas durante 14 dias. Durante o processo de muda e descanso, foram avaliadas as características de desempenho das aves. Os dados obtidos foram submetidos à análise de variância pelo programa SAS ® e as médias comparadas por meio de contrastes ortogonais e polinomiais. Os resultados indicaram que dietas com a inclusão de alfafa induziram o processo de muda em poedeiras comerciais em 3,85 dias após o fornecimento. As aves arraçoadas com alfafa apresentaram perda de peso corporal para induzir a muda de 26,88%, enquanto que para o controle (jejum alimentar) a perda de peso corporal foi de 30,26%. Aves mantidas em temperatura termoneutra, durante a muda, cessaram a produção de ovos em 2,73 dias, antes das aves mantidas nas demais temperaturas, além disso, o retorno da postura foi mais breve para aves mantidas em temperatura quente (10,47 dias) durante a muda e o descanso, com uma maior recuperação do peso corporal nesta temperatura, para as aves que receberam dietas contendo 50% de alfafa (35,66%). A inclusão de alfafa pode ser utilizada com alternativa ao método de jejum alimentar, causando uma perda de peso corporal suficiente para a indução da muda, independente da temperatura em que for realizada.

This study evaluates the performance of laying hens during molt subjected to different diets and temperatures. The birds were distributed in a completely randomized design, 5x3 factorial (diet x temperature), with five replicates of eight birds each. The diets tested to induce molt were: 90%, 70%, 50% alfalfa; added of 2,800 ppm of zinc while the last group was on full feed restriction. The temperatures used were: 20, 27 and 35ºC. Performance parameters of the birds were evaluated during the process of molt and rest. The data underwent analysis of variance by SAS® and means were compared using orthogonal and polynomial contrasts. The results indicated that diets including alfalfa induced molt in laying hens at 3.85 days after being fed. The birds fed alfalfa had weight loss of 26.88% in order to induce molt compared to 30.26% for the birds of the control group (fasting). Egg production of birds kept at neutral temperature during molt ceased at 2.73 days, earlier than the other temperatures studied. Furthermore, birds kept at warmer temperatures (10.47 days) during molt and rest returned earlier to posture while greater body weight recovery was observed at this temperature for birds fed diets containing 50% alfalfa (35.66%). The alfalfa inclusion can be used as an alternative to fasting to cause a weight loss sufficient to induce molt, independent of temperature.

Assuntos