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.

Calcium and available phosphorus requirements of Japanese quails in early egg-laying stage.

An experiment was conducted to estimate the nutritional requirements of calcium (Ca) and available phosphorus (aP) for Japanese quails (Coturnix coturnix japonica) in the egg-laying stage (64-168 D). The experiment was an entirely randomized design, in a factorial scheme (Ca = 1.70, 2.40, 3.10, and 3.80% and aP = 0.15, 0.30, 0.45, and 0.60%), with 3 replicates and 10 quails per experimental unit. No interactions were found for quail body weight and daily feed intake (DFI) (P > 0.05). However, body weight decreased linearly (P < 0.05) as the levels of Ca increased, whereas DFI exhibited a quadratic effect (P < 0.05) for both Ca and aP. The lowest values of DFI were estimated in 2.79 and 0.36% for Ca and aP, respectively. Egg production, egg mass, and feed conversion ratio per egg dozen presented significant interaction in which all of them had a quadratic effect (P < 0.05), with estimations for maximum yield in feed containing 2.74, 2.71, 2.75, and 2.74% Ca and 0.40, 0.39, 0.39, and 0.40% aP. The concentration of Ca in the eggshell increased linearly as per the levels of Ca studied, having a quadratic effect for aP levels, with a maximum point of 0.44%. In relation to the bone parameters, there was a linear interaction for Ca and aP in bone density and bone resistance (BR) of the femur, with a quadratic effect in BD estimating 2.84 and 0.50% for Ca and aP, respectively. In BR, the estimation was 3.27% Ca, with linear increase for aP. The BR of the tibiotarso increased linearly as per the Ca levels, obtaining the same Ca concentration response in this bone. As conclusion, when considering the estimations obtained through overlapped contour plots, the best responses to the effects of Ca and aP on productive characteristics were estimated at 2.68% Ca and 0.38% aP to produce feed for egg-laying Japanese quails.