Age, body weight and body composition requirements for the onset of sexual maturity of dwarf and normal chickens

Brody, Tom; Siegel, P. B.; Cherry, J. A.

doi:10.1080/00071668408454863

Cited by 72 publications

(38 citation statements)

References 11 publications

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“…Esse processo ocorreu primeiramente com as aves HSM, cujo acúmulo de gordura corporal foi maior nas últimas semanas da fase de crescimento, resultando na antecipação, por algumas aves, do início da postura e no aparecimento dos primeiros ovos ao final da 16 a semana, o que está de acordo com os dados observados por Brody et al (1984) e Baker (1985, sugerindo que a gordura corporal é um fator crítico para o início da puberdade das galinhas. Ressalta-se que as aves HSM não apresentaram maiores quantidades de gordura na carcaça ao término do período de crescimento, mas sim uma diferença na Tabela 6 -Estimativas dos parâmetros das equações de Gompertz e coeficientes de determinação (R 2 ) para deposição de proteína, gordura, cinzas e água corporais das linhagens de reposição estudadas PM (g) 7 8 2 6 7 8 6 5 7 5 0 9 b (por dia) (per day) 0,0220 0,0201 0,0257 0,0241 t* (dias) (days) 7 1 7 1 6 3 6 0 R 2 0,99 0,99 0,99 0,99…”

Section: Feather Depositionunclassified

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

et al. 2006

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RESUMO -Objetivou-se com este trabalho determinar as curvas de crescimento de aves de postura das linhagens semipesadas Hy Line Marrom (HLM) e Hisex Marrom (HSM) e leves Hy Line W36 (HLW36) e Hisex Branca (HSB). Foram utilizadas 300 aves de cada linhagem, distribuídas em um delineamento experimental inteiramente casualizado, com quatro repetições de 75 aves por tratamento. Semanalmente, foram avaliados o peso vivo (PV), o peso de pena (PP) e a composição corporal de proteína, gordura, cinzas e água. As curvas de crescimento foram determinadas aplicando-se os dados na função Growth curves and deposition of body components in pullets of different strains ABSTRACT -The growth curves of egg pullets of semi heavy: Hy Line Brown (HLB) and Hisex Brown (HSB) and light strains: Hy Line W36 (HLW36) and Hisex White (HSW) were evaluated. Three hundred birds of each strain were assigned to a completely randomized design with four replicates of 75 birds. Body weight (BW), feather weight (FW) and body depositions of protein, fat, ash and water were weekly measured. The growth curves were determined by Gompertz function with data collections. The semi heavy birds were later than the light ones for BW, with greater body growth rates and weights at maturity.The HLW36 were 64.23 g lighter at maturity than the HSW. Data obtained for feather growth and protein deposition were similar, but the semi heavy birds showed greater weight at maturity (WM) than the light ones. However, for these components, the birds Hy Line had larger depositions than Hisex. HLW36 strain had smaller feather rate at maturity, making it three days later than HSW. The lowest protein deposition in the end of growth period caused the deviation of energy ingested for fat deposition in HSB birds and overestimated the WM in relation to HLB birds. Hy Line birds had later body ash composition and showed greater WM than Hisex. Among the studied variables, Hy Line birds had always heavier WM, however, the body water content of Hisex birds was greater and the maximum rates at maturity were later. This fact explains the similarity in the weight gain among the studied strains, once other body components were greater for Hy Line birds.Key Words: body composition, Gompertz function, laying birds, pullets IntroduçãoAs linhagens de postura utilizadas atualmente, em virtude do constante melhoramento genético, estão aumentando continuamente a produção de ovos, diminuindo o peso à maturidade fisiológica, a idade de pico de produção, o consumo de alimento e o ganho de peso. Desta forma, os programas nutricionais destas aves devem ser reavaliados

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Section: Feather Depositionunclassified

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

et al. 2006

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“…In chickens there are age and body-weight requirements for the onset of sexual maturity (Dunnington et al, 1983 as well as particular threshold levels for components of carcass composition (Bornstein et al, 1984;Brody et at., 1984 Selection for high and low juvenile body weight in White Plymouth Rock chickens has resulted in two distinct populations differing in growth, feed consumption, and feeding behavior Dunnington et al, 1987). Differences in feed consumption concomitant to selection for juvenile body weight have been hypothesized to be associated with alterations of a satiety center in the brain (Burkhart et al, 1983).…”

Section: Introductionmentioning

confidence: 99%

Anorexia and sexual maturity in female white rock chickens. I. Increasing the feed intake

et al. 1988

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Long-term selection for low juvenile body weight has resulted in a lineof chickens where sexual maturity is retarded or prevented because of anorexia. Ad libitum-fed pullets which had not commenced egg production by 240 days of age were randomly assigned to be force-fed or fed ad libitum. Increasing food intake via force-feeding caused a significantly greater proportion of females to commence egg production than was noted for ad libitum-fed controls. Moreover, of those pullets that commenced lay, age at onset was significantly earlier in those force-fed than in those fed ad libitum.

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“…However, these instructions do not exist for quails, which makes it necessary to carry out studies that result in guidelines that help producers obtain the best possible genetic potential from these birds. The fact that the productive age start is closely related to the average body weight is well known (Brody, Siegel, & Cherry, 1984). The weight of the birds and their development during the growth phase are factors that influence the weight of the first eggs (Braz et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

<b>Productivity of japanese quails in relation to body weight at the end of the rearing phase

Filho

Garcia

Molino

et al. 2016

Acta Sci. Anim. Sci.

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ABSTRACT. Two experiments were conducted at different times with the objective of investigating how the body weight of Japanese quails at the end of the rearing period may alter the performance during the laying phase. In both experiments, the birds were distributed in five treatments according to their body weights, which were obtained at 42 and 35 days of age for the first and second experiments respectively, and the following categories were considered for said experiments: very light, light, average, heavy and very heavy. For both experiments, the treatments were distributed in a randomized block design, at eight repetitions per treatment for the first one and six for the second one, both at 18 birds per repetition. During the first experiment, sexual maturity, laying percentage, marketable egg percentage, average egg weight and egg mass, in second experiment, feed consumption, final body weight, eggs per bird present, laying percentage, average egg weight, egg mass and alimentary conversion were evaluated. The results obtained show that Japanese quails whose body weight is lower than 140 grams at 42 days of age, or lower than 120 grams at 35 days of age show significantly worse productive results during the laying phase.Keywords: body development, egg production, quail production, sexual maturity.Produtividade de codornas japonesas em função do peso corporal ao final da fase de recria RESUMO. Dois experimentos foram conduzidos para investigar como o peso corporal de codornas japonesa ao final do período de recria pode alterar os parâmetros de desempenho durante a fase de postura. Nos dois experimentos as aves foram distribuídas em cinco tratamentos em função do peso corporal, estes foram obtidos aos 42 e aos 35 dias de idade, para o primeiro e segundo experimento respectivamente. Para ambos os experimentos foram consideradas as classes: muito leves, leves, peso médio, pesadas e muito pesadas. Os tratamentos foram distribuídos em delineamento em blocos ao acaso, com oito repetições por tratamento para o primeiro experimento e seis repetições por tratamento para o segundo experimento, ambos com 18 aves por repetição. No primeiro experimento, foram avaliados a maturidade sexual, a porcentagem de postura, a porcentagem de ovos comercializados, o peso médio dos ovos e massa de ovos. No segundo experimento foram avaliados o consumo de ração, o peso corporal final, os ovos por ave presente, a porcentagem de postura, o peso médio dos ovos, massa de ovos e a conversão alimentar. Os resultados mostram que codornas com peso corporal inferior a 140 gramas aos 42 dias de vida, ou inferior a 120 gramas aos 35 dias de vida, pioram significativamente os resultados produtivos durante o período de postura.Palavras-chave: peso corporal, produção de ovos, coturnicultura, maturidade sexual.

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Age, body weight and body composition requirements for the onset of sexual maturity of dwarf and normal chickens

Cited by 72 publications

References 11 publications

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

Curvas de crescimento e de deposição dos componentes corporais em aves de postura de diferentes linhagens

Anorexia and sexual maturity in female white rock chickens. I. Increasing the feed intake

<b>Productivity of japanese quails in relation to body weight at the end of the rearing phase

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