In vivo determination of domestic quail (Coturnix japonica) muscle development by ultrasonography as a function of energy levels.

The aim was to evaluate the growth and meat production and some meat quality characteristics of domestic quail (Coturnix japonica) as a function of metabolizable energy (ME) levels in the diet and to adjust predicting equations in ratio to area pectoralis major muscle of the carcass through the ultrasound. Two hundred and seventy mixed sex quail from 7 to 49 days old were distributed in three treatments (7 to 21 days old, diets with 2700; 2900 and 3100 kcal ME/kg; from 21 to 49 days, diets with 2900, 3050 and 3200 kcal of ME/kg), with five replications per treatment. Ultrasonography was performed at 21; 35 and 49 days of age in the pectoralis major muscle to determine prediction equations through multiple linear regression. Feed intake (FI) and feed efficiency (FE) were linearly influenced (P < 0.05) by energy levels in both phases evaluated. Regarding sensory analysis, there was no interference of ME levels on sensory attributes. The equation for predicting breast area was Y = 0.00271*ME + 0.25411*Age-9.58002, R2 = 74.25%. It is concluded that increasing the energy level of the feed from 2700 to 3100 kcal ME/kg reduces FI and improves the FE of quail. The increase in carcass fat from 35 days of age does not harm the physical and sensory characteristics of the meat. The ultrasonography in vivo of the M. pectoralis major, considering the age and energy level of the diet, made it possible to predict the pectoral muscle are a with higher reliability.

Does the metabolizable energy influence the performance, carcass characteristics and biochemical parameters of European quails from 28 to 42 days of age?

This study was conducted to determine the metabolizable energy (ME) requirement for quails (Cortunix cortunix cortunix) from 28 to 42 days of age. Four hundred and twenty quails were distributed in a completely randomized design, with 5 treatments (2950, 3000, 3050, 3100 and 3150 kcal of ME/kg of feed), 7 replicates and 12 birds per experimental unit. Performance, relative weights of organs and viscera, carcass characteristics, meat quality, body composition and blood parameters of the birds were evaluated. There was a reduction in feed intake (ADFI) with the use of 3150 kcal ME/kg (p < 0.01), with a quadratic effect on feed efficiency (p < 0.01), estimating the energy requirement in the 3009.4 kcal ME/kg. The breast yield (BY) and the colour b* had an effect (p < 0.01), with better results for 2950 kcal ME/kg, while the meat texture reduced when the birds were fed with 3150 kcal ME/kg. HDL and LDL showed the quadratic effect (p < 0.01) when ME increased to 3111.6 and 3157.4 kcal/kg respectively. Very low density lipoprotein increased linearly (p < 0.01) in birds that received diets with 3000 kcal ME/kg. We conclude that the use of 3009.4 kcal of ME/kg for European quail meets the nutritional needs and provides an improvement in feed efficiency, without affecting the carcass parameters of the birds. Information regarding the nutritional requirements for European quails is still recent; therefore, it is essential to know the adequate levels of metabolizable energy, an important nutritional component for the maximum productive performance of birds.

Effect of prenatal ambient temperature on the performance physiological parameters, and oxidative metabolism of Japanese quail (Coturnix coturnix japonica) layers exposed to heat stress during growth.

A strategy to mitigate the negative effects of stress on animals is to enhance their ability to beneficially respond to stressful conditions. This study aimed to assess whether prenatal ambient temperature influences the response of Japanese quail (Coturnix coturnix japonica) chicks to environmental challenges during growth. The experiment was conducted in a 2 × 2 factorial arrangement: two temperature conditions for the mothers (thermoneutral and heat stress by continuous exposure to 32 °C) and two offspring ambient temperature conditions (thermoneutral and heat stress by intermittent exposure to 34 °C for 6 h/day from 15 to 35 days of age). Heat stress in mothers led to lower laying rate, egg mass, expression of methionine sulfoxide reductase A (MSRA) gene, and antioxidant capacity as well as higher chick mortality rate (1-15 days of age). Maternal heat stress led to lower weight gain and total antioxidant capacity and higher feed conversion ratio. Maternal temperature × Offspring temperature interaction effects were observed on carbonylated protein content and HSP70, GSS, and MSRA gene expression. It was observed that, for chicks hatched from heat-stressed mothers, exposure to heat stress led to higher carbonylated protein content and HSP70 expression than exposure to thermoneutral conditions. Maternal heat stress was also responsible for increasing GSS expression in chicks grown under thermoneutral conditions. Chicks hatched from non-stressed mothers and subjected to heat stress had higher MSRA expression compared to chicks maintained in a thermoneutral environment. Our results show that, although maternal heat stress had no negative effects on performance or oxidative metabolism of offspring grown under thermoneutral conditions, it was associated with lower performance and higher protein oxidation in offspring exposed to heat stress during growth. These results could be due in part to alterations in the expression of genes related to antioxidant capacity.

Choice of non-linear models to determine the growth curve of meat-type quail / Escolha de modelos não-linearespara determinar a curva de crescimento de codornas de corte

ABSTRACT: The objective of this study was to compare non-linear models fitted to the growth curves of quail to determine which model best describes their growth and check the similarity between models by analyzing parameter estimates.Weight and age data of meat-type European quail (Coturnix coturnix coturnix) of three lines were used, from an experiment in a 2 × 4 factorial arrangement in a completely randomized design, consisting of two metabolizable energy levels, four crude protein levels and six replicates. The non-linear Brody, Von Bertalanffy, Richards, Logistic and Gompertz models were used. To choose the best model, the Adjusted Coefficient of Determination, Convergence Rate, Residual Mean Square, Durbin-Watson Test, Akaike Information Criterion and Bayesian Information Criterion were applied as goodness-of-fit indicators. Cluster analysis was performed to check the similarity between models based on the mean parameter estimates. Among the studied models, Richards' was the most suitable to describe the growth curves. The Logistic and Richards models were considered similar in the analysis with no distinction of lines as well as in the analyses of Lines 1, 2 and 3.

RESUMO: Objetivou-se, neste estudo, comparar modelos não lineares ajustados às curvas de crescimento de codornas para determinar qual modelo que melhor descreve o crescimento de codornas e verificar a similaridade dos modelos analisando as estimativas dos parâmetros. Para as análises foram utilizados os dados peso e idade de codornas européias de corte (Coturnix coturnix coturnix) proveniente de três linhagens, em um esquema fatorial 2x4, instalado em um delineamento inteiramente casualizado, com dois níveis de energia metabolizável e quatro níveis de proteína bruta, com seis repetições. Os modelos não lineares utilizados foram: Brody, Von Bertalanffy, Richards, Logístico e Gompertz. Para a escolha do melhor modelo utilizou-se o Coeficiente de Determinação Ajustado, o Percentual de Convergência, o Quadrado Médio do Resíduo, o Teste de Durbin-Watson, o Critério de informação Akaike e o Critério de informação Bayesiano como avaliadores da qualidade do ajuste. Utilizou-se a análise de agrupamento para verificar, baseado nas estimativas médias dos parâmetros, a similaridades entre os modelos. Entre os modelos estudados, o Richard foi o mais adequado para descrever as curvas de crescimento. Os modelos Logístico e Richards foram considerados similares nas análises sem distinção de linhagem, bem como nas análises das Linhagem 1, 2 e 3.

Estudo bioclimático das regiões litorânea, agreste e semiárida do estado de Sergipe para a avicultura de corte e postura / Bioclimatic study for broiler production and posture in the of coastal, agreste and semi arid regions of Sergipe state, Brazil

Objetivou-se com o presente trabalho realizar o estudo bioclimático do estado de Sergipe para a avicultura, como forma de definir os limites de aceitabilidade da espécie às condições ambientais prevalecentes nas regiões litorânea, agreste e semiárida do estado. Para isso, foi realizado o levantamento histórico dos valores médios mensais de temperatura e umidade relativa do ar e o cálculo mensal do índice de temperatura e umidade (ITU) das três regiões do estado de Sergipe. Verificou-se que, apesar de suas particularidades climáticas, as regiões litorânea, agreste e semiárida do estado de Sergipe apresentam as melhores condições de conforto térmico para a avicultura de corte e postura apenas durante os meses de junho a setembro; no período seco, nenhuma das regiões apresenta condições de conforto térmico para a atividade avícola; no período chuvoso, apenas a região agreste apresenta condições de conforto para a avicultura de corte; para a avicultura de postura, apenas a região litorânea não apresenta condições de conforto térmico.

This research aimed to carry out a bioclimatic study of Sergipe state to poultry farming, as a way to define the limits of acceptability of the species to the prevailing environmental conditions in coastal, agreste and semi arid regions of the state. For this survey it was conducted a history of the monthly mean values of temperature and relative humidity of the air and the calculation of the monthly index of temperature and humidity (ITU) of the three regions of the state of Sergipe. It was found that despite its special climate, coastal, agreste and semi arid region of Sergipe present the best thermal comfort conditions for the poultry industry and posture only during the months from June to September. In the dry season, no region presents thermal comfort conditions for the poultry activity. Only in the rainy season the region has rugged comfort conditions for the poultry industry. For laying poultry only the coastal region not provides thermal comfort.