ABSTRACT The objective of this study was to estimate the growth parameters of body weight and body nutrient deposition in males and females of one meat- (Coturnix coturnix coturnix) and two laying-type quail strains (Coturnix coturnix japonica), designated either yellow or red, using the Gompertz model. A total of 1350 quail from 1 to 42 days of age were used and they were distributed in a completely randomized design, with five replications for each strain. The parameters of body weight and body composition of the quail were analyzed weekly and evaluated using the Gompertz equation; growth rates and body nutrient deposition were evaluated through derivative equations. The three strains evaluated showed differences in their potential, growth rates, and body chemical composition. The composition up to 42 days of age was not sufficient to adjust the fat deposition data using Gompertz. Due to the period evaluated, the Gompertz model allowed to verify that females have higher body growth rates when compared with males of the same strains, with accelerated growth up to 14 and 21 days of age for males and females, respectively. Regarding the laying strain, the red has greater growth, with similar potential in depositing protein and water in the carcass, but they are more precocious in the deposition of these nutrients.

Desempeño y rendimiento en carcasa y piezas de tres diferentes líneas de codornices

The objective of this study was to evaluate the performance and yield of the carcass and parts (wing, thigh and drumstick, back and chest) of males and females of a meat-type quail strain (Coturnix coturnix sp.) and two strains of laying quails (Coturnix coturnix japonica) called yellow and red. 1350 birds were used, one to 42 days of age, distributed in a completely randomized design, with five repetitions for each line. The birds were fed ad libitum with diets formulated to meet its nutritional requirements. The performance was evaluated weekly and the parts and carcass yield at 35 and 42 days of age. The meat-type strain showed higher body weight, average weight gain, feed conversion, biomass accumulated body of a 14 day of age carcass yield at 35 days and chest at 35 and 42 days. Among the laying quails, red obtained better results for weight gain, feed conversion and yield wing after 42 days of age. The gender effect was observed for yield wing and back to 35 days of age to 42 days and breast. It is verifi ed that the three evaluated quail strains showed higher body accumulated biomass and better feed conversion within one to 14 days of age demonstrating higher growth effi ciency during this period. Higher if there meat-type strain development capability, with better carcass yield at 35 days of age.

O objetivo deste trabalho foi avaliar o desempenho e o rendimento da carcaça e partes (asa, coxa e sobrecoxa, dorso e peito) de machos e fêmeas de uma linhagem de codornas de corte (Coturnix coturnix sp.) e duas linhagens de codornas de postura (Coturnix coturnix japonica) denominadas amarela e vermelha. Foram utilizadas 1.350 aves, de um a 42 dias de idade, distribuídas em delineamento inteiramente ao acaso, com cinco repetições para cada linhagem. As aves foram alimentadas ad libitum com dietas formuladas para atender as suas exigências nutricionais. O desempenho foi avaliado semanalmente e o rendimento da carcaça e partes aos 35 e 42 dias de idade. A linhagem de corte apresentou maior peso vivo, ganho médio de peso, conversão alimentar, biomassa corporal acumulada de um a 14 dias de idade, rendimento de carcaça aos 35 dias e de peito aos 35 e 42 dias de idade. Dentre as codornas de postura, a vermelha obteve melhores resultados para ganho de peso, conversão alimentar e rendimento de asa aos 42 dias de idade. O efeito do sexo foi observado para o rendimento de asa e dorso aos 35 dias de idade e peito aos 42 dias. Foi verificado que as três linhagens de codornas avaliadas apresentaram maior biomassa corporal acumulada e melhor conversão alimentar no período de um a 14 dias de idade demonstrando maior eficiência de crescimento durante este período. Verificou-se maior capacidade de desenvolvimento da linhagem de corte, com melhor rendimento de carcaça aos 35 dias de idade.

The objective of this study was to estimate the nutrient requirements of digestible threonine for meat-type quails (Coturnix coturnix sp) in the growth phase. A total of 1350 not sexed meat-type quails were distributed in a completely randomized design with six threonine levels (10.80, 11.50, 12.20, 12.90, 13.60 and 14.30 g/kg as fed), five replications and 45 quails per experimental unit, from 1 to 14 days of age. The threonine levels in the diet had a quadratic effect on body weight, feed intake and weight gain. Estimates for highest body weight (79.41 g), feed intake (128.96 g/bird) and weight gain (70.73 g) were observed with diets containing 12.60 g/kg of digestible threonine. According to the LRP model, the threonine intake was estimated at 13.40 g/kg of digestible threonine. Protein deposition rate and energy retained in the carcass showed quadratic effect, with estimated digestible threonine levels of 11.80 and 12.00 g/kg in the diet for maximum protein deposition rate (2.00 g/bird) and retained energy in the carcass (15.88 kcal/g), respectively. There was a linear effect on feed cost per kg of live weight gain as threonine levels were increased. Nutritional requirement of digestible threonine for meat-type quails for maximum growth is 12.60 g/kg, corresponding to a digestible threonine:digestible lysine ratio of 67.02.

The objective of this experiment was to estimate the digestible tryptophan (DTrp) requirements for growing meat quails. In the first experiment (1-14 days of age), 1,950 quails were distributed in a completely randomized design, with six levels of DTrp (0.27; 0.30; 0.33; 0.36; 0.39 and 0.42% of diet), five replications and 65 quails per experimental unit. There was a linear increase of feed intake, tryptophan intake, weight gain and body weight with the DTrp levels increase. In the second experiment (15-35 days of age), 1,350 quails were distributed in a completely randomized design, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replications and 45 quails per experimental unit. There was a linear increase for tryptophan intake, carcass yield, ash levels and protein deposition rate with the DTrp levels increase. In the third experiment (28-35 days of age), conducted to determine the nitrogen balance, 150 males were housed in galvanized wire cages featuring drinker, feeder and individual metal tray lined with plastic to collect the excreta. The design was completely randomized, with six levels of DTrp (0.22; 0.25; 0.28; 0.31; 0.34 and 0.37% of diet), five replicates and five quails per experimental unit. Linear decrease was observed on the nitrogen balance and metabolization coefficient with the DTrp levels increase. The nutritional requirement of digestible tryptophan for maximum growing of meat quail, in the period from 1 to 14 days of age, is higher or equal to 0.42%; in the period from 15 to 35 days, it is 0.22%.