Evaluation of the effects using diets with different nutrient levels and same metabolizable energy level on performance of laying hens in early laying period

This study was conducted to evaluate the effects of different nutrients level on performance of Hy-line W-36 laying hens in early laying period. This experiment was conducted with two hundred and forty laying hens from 37 to 47 weeks in a completely randomized design with 5 treatment and 4 replicate with 12 bird in each replicate. Experimental diets were isocaloric and included: diet with nutrients recommended by NRC 1994 for laying hens (control) and 4 other Experimental diets with 10% and 15% more and low nutrients than recommended by NRC 1994 with same metabolizable energy level for laying hens. The results of this experiment showed that the performance and egg quality in laying hens are affected by different experimental diets (P<0. 05). The highest percent of egg production (86. 66)، the highest amount of egg weight (62. 05 g)، the highest amount of egg mass (32. 4 g)، the highest value of daily feed intake (117 g)، the best feed conversion (2. 17) and the lowest value of feed price for production per kilogram of egg (8150 Rials) were observed in control group، whereas the lowest percent of egg production (56. 22)، the lowest amount of egg weight (57. 17 g)، the lowest value of egg mass (32. 4 g)، the lowest value of daily feed intake (106. 5 g)، the worst feed conversion (3. 30) and the highest amount of feed price for production per kilogram of egg (1130 Rials) were observed in treatment contain 15% lower level of nutrients than recommended by NRC 1994 with same metabolizable energy level for laying hens. Three were significantly difference between treatments in eggshell weight (P<0. 05). The highest value of eggshell weight (6. 35 g) was observed in control group and the lowest value of eggshell weight (5. 52 g) was observed in group with diet contain 15% lower level of nutrients than recommended by NRC 1994 with same metabolizable energy level for laying hens. Can be concluded that in Hy-line W-36 laying hens in early laying period increasing or reduction of nutrient recommended by NRC 1994 with same metabolizable energy level has adverse effects on performance and egg quality and causes the feed price for production per kilogram of egg be high and do not recommended.