Modelos para estimar as exigências de energia metabolizável para poedeiras

Abstract

Objetivou-se, com este trabalho, elaborar um modelo para estimar as exigências de energia metabolizável (EM) para poedeiras leves da linhagem Lohmann LSL, utilizando-se o método fatorial. Para determinar o efeito da temperatura sobre as exigências de EM para mantença, foram conduzidos experimentos em câmaras climáticas com temperaturas constantes de 12, 22 e 31ºC, utilizando a técnica do abate comparativo. A exigência de energia líquida para o ganho de peso foi determinada por meio da regressão do conteúdo de energia da carcaça em função do peso corporal, enquanto a exigência de EM para o ganho de peso foi estimada considerando-se a eficiência de utilização da energia da dieta. Com base no teor de energia nos ovos, determinou-se a exigência de energia para produção de ovos e a eficiência de deposição de energia no ovo. A partir dos valores das exigências para manutenção, para ganho e produção, foram elaborados modelos para predizer as exigências diárias de EM (kcal/ave/dia): EM1=P0,75(165,74 - 2,37 .T)+6,68.G+2,4.O e EM2=P0,75 (163,67-2,09.T)+6,68.G+2,4.O, em que P é o peso corporal (kg), T, a temperatura ambiente (ºC), G, o ganho de peso (g/dia) e O, a massa de ovos (g/dia).

Prediction equations to estimate the demand of energy and crude protein for maintenance, gain and egg production for laying Japanese quails

“…From consumption and energy retention in the empty body and eggs of quails (Table 3), the regression equation estimate 92.34 kcal/kg 0.75 /day maintenance requirement (Figure 1) and the net requirement for 62.07 kcal/kg 0.75 /day energy maintenance (Figure 2) were elaborated. This estimate on maintenance energy requirement for Japanese quails on the egg laying peak was slightly higher than the 91.48 kcal/kg 0.5 /day estimated by Silva et al (2004b) for Japanese quails and lower than the 111.98 kcal/kg 0.75 /day found by Sakomura et al (2005) for laying hens. On the other hand, energy for maintenance was above 87.76 kcal/kg 0.75 /day determined with breeders by Spratt et al (1990) using the calorimetry technique.…”

“…The demand for energy and protein for egg production was obtained by the ratio between the average level of energy and/or protein in eggs and use efficiency Sakomura et al, 2005). The average levels of energy and/or crude protein of eggs were determined by proximal analysis of these components in all eggs collected in the plots and analyzed every five days.…”

“…The value of energy and/or crude protein of eggs (shell + contents) were determined by the product of egg mass vs. average content of energy and/or protein in eggs. The use efficiency of metabolizable energy and crude protein for egg production was calculated based on formulas presented in previous studies (Sakomura et al 2005;Rabello et al, 2002): use efficiency (%) = energy/protein retained in the egg ÷ [energy/protein consumption -(energy demand/protein for maintenance + energy requirement/ protein to gain)].…”

“…Feed formulation for quails is still made based on foreign tables for nutritional specifications, with estimated levels for quite some time and some adaptations of bird species, or studies on dose-response methodology. There are a number of recommendations for energy determined by prediction models for pullets (Albino et al, 1994), layers (Sakomura et al, 2005), breeders at growth (Sakomura et al, 2003) and laying (Rabello et al, 2004) phases, broilers (Longo et al, 2006) and quails (Silva et al, 2004ab) during growth. Similarly, there are several recommendations for protein determined by prediction models for pullets (Basaglia et al, 1998), breeders , broilers (Longo et al, 2001) and even quails (Silva et al 2004ab) during growth; however, there are no reports of experiments with quail on egg production.…”

Crude protein and metabolizable energy levels for layers reared in hot climates

“…Metabolizable energy requirements of commercial layers depend on environmental temperature (Rostagno et al, 2005;Sakomura et al 2005); it increases when the environment is cold or hot (Sakomura et al, 2005). Therefore, under heat stress situations, increasing energy levels in the diet of commercial layers by the inclusion of oil may compensate the low feed intake and supply the higher energy requirements.…”