Article
METABOLIZABLE ENERGY REQUITEMENTS FOR BROILER BREEDER IN DIFFERENT ENVIRONMENTAL TEMPERATURES
INTERNATIONAL JOURNAL OF POULTRY SCIENCE 11(7): 453-461
Autor
REYES CORONEL, MARTHA ESTHER
Institución
Resumen
A 10 wk feeding experiment was conducted to develop a model for predicting the ME requirement
for broiler breeder hens housed in different environmental temperatures. Three groups of 50 Cobb 500
broiler breeder hens were individually housed in breeder cages located in environmentally controlled rooms
set at 15.5, 23 and 30°C. Each breeder was given an intramuscular injection of Tamoxifen (TAM) (5 mg/kg
BW) in corn oil at days 1 and 4 to stop egg production. Ten breeders from each environmental temperature
were sacrificed for carcass composition analysis at the beginning of the study. Breeders, during the nonlaying
period, housed at 15.5°C were fed 100 g providing 285 kcal MEn/b/d (2851 kcal/kg; 16%CP) and
breeders housed at 23°C and 30°C were fed 93 g providing 265 kcal MEn/b/d of same diet. Five breeders
were sacrificed from each environmental room after the breeders resumed egg production. The ME
requirement for maintenance (MEm) determined during the non-laying period was 104.3, 98.1 and 99.4
kcal/kg0.75 for birds housed in 15.5, 23 and 30°C, respectively. At first egg, 136, 130 and 128 g/bird/d of same
diet previously fed during the non-laying period provided 388, 371 and 365 kcal MEn/b/d to broiler breeder
hens housed at 15.5, 23 and 30°C, respectively. The egg number, egg weight and BW change for each
breeder during egg production was evaluated through the remainder of the 10 wk period. At the end of the
trial, all birds were sacrificed and frozen at -4°C for carcass composition analysis. Body weight data collected
during the non-laying period was used to construct a single equation by plotting Metabolizable Energy (ME)
against body weight change (BW)) for each individual hen to calculate the MEm. Egg production and egg
weights were recorded daily after egg production resumed. The MEg and MEe requirement for BW gain and
egg production were determined for breeders in each of the environmental temperatures based on the
energy content of carcass and egg mass and the respective efficiency of energy utilization. The average MEg
and MEe for the three environmental temperatures was 5.8 kcal/g and 2.3 kcal/g, respectively. Three
equations were developed from the feeding experiment to predict ME needs for breeders: Eq. 1: (ME = BW0.75
[111.9 - 0.46 T] + 5.8G + 2.3EM); Eq. 2: (ME = BW0.75 [110.3 - 0.47 T + 0.055 (T - 22.5)2] + 5.8G + 2.3EM);
Eq. 3: (ME = BW0.75 [111.02 - 0.49 T + 0.049 (T - 22.07)2] + BW) (1/0.77 x ERf + 1/0.37 x ERp) + ECE/0.73 x
EM), where ME = Metabolizable Energy (kcal), BW = Body Weight (kg0.75), T = Temperature (°C), BW) = Body
Weight change (g/d), ERf = Energy Retained as fat (kcal), ERp = Energy Retained as protein (kcal); ECE =
Energy Content of Eggs (kcal/g) and EM = Egg Mass (g).