اثر سطوح مختلف انرژی وپروتئین جیره بر عملکرد تخم‌گذاری مرغ‌های بومی استان فارس در مرحله اول تخم‌گذاری

An experiment was carried out to investigate the effects of different levels of energy (2700, 2900 and 3100 kcal/kg) and protein (13, 14.5 and 16 %) on laying performance of Fars native hens during the first phase of production. Two hundred and sixteen 25-week-old native pullets were put into fifty four groups of similar live weight (994 ± 169 gr) of four chickens, which were randomly allocated to nine experimental diets. Each treatment was replicated six times in factorial CRD design (3×3). At each level of energy, three diets were formulated to contain three levels of protein (16, 14.5 and 13%). The diets were fed ad libitum for a period of 20 weeks (week 25-45). The treatments 1 with 3100 kcal/kg ME and 16% protein and 3 with3100 kcal/kg ME and 13% protein had less daily feed consumption than treatment 7 with 2700 kcal/kg ME and 16% protein (90.50 and 87.30 vs 101.20 gr respectively, P<0.05). The effect of energy levels on daily feed and energy consumption and feed conversion ratio was significant (P< 0.05). Feed conversion ratio for energy level of 3100 kcal/kg was significantly different from 2700 kcal/kg (2.85 vs 3.08 respectively). The effect of protein levels on uric acid content of excreta and daily protein consumption was significant (P< 0.05) and protein level of 16% was significantly differed from protein level of 13% (11.40 vs 10.50 gr respectively). The results of this experiment showed that it is preferable to use the energy level of 2700 kcal/kg and protein level of 13% during the first phase of production of Fars native hens.