بررسی تعیین سطح تغذیه در پرواربندی بره های نر عربی

It is very important that underestood how much energy and protein in diets of native fattening lambs, However in order to finding of the best component of energy and protein of diets in this research in comparison to standard requirments from N.R.C, 135 male Arabic lambs in 9 treatments and 3 blocks (weight) in Randomized Complet Block Disign (R.C.B.D) and with a 3 2 factorial experiment that is evaluated of the effect of different diets in daily weight gain and their carcass characteristics.The different treatments take diets with different energy and protein levels. These diets provide from 3 energy levels less than standard (c1), standard (c2), over than standard (c3) and 3 protein levels less than standard (P1) standard (P2) and over than standard (P3) give to lambs. Duration of experiment has been 105 days, adaptation period 15 days and main period experiment is durated 90 days. In this study was recognized that high daily wieght gain has been from the treatment number 9 (e3P3) (0.235 0.002 kg) and low daily weight gain has been from the treiltment number 1 (e1P1) (0.183 0.020 kg) (P<0.01).But there is non significant difference betwecn the treatment number 3 (e1 P3)(0.200 0.278 kg),number 5 (e2P2) (0.249 0.0333 kg), number 6 (e2P3) (0.226 0.217kg), number 9 (e3P3) (0.235 0.002kg) (P<0.01). To consider the expense of feed consumption per one kg alive weight gain is prefered the diets number 5 (e2P2), 6 (e2p3) and 4 (e2P1) in response. The high dressing percentage has been from the treatment number 4 (e2P1)(%51.8 1.126) and the low dressing percentage is from the treatment number 1(e1p1)(%48.81 0.709) (p<0.05) There is non significant difference between different treatments for meet percentage to carcass wieght and fat percentage to carcass wieght, (P<0.01), but there is the significant difference between different treatment for bone percentage to carcass weight so that the high bone percentage to carcass weight is from the treatment number 1 (e1p1) (%17.48 1.483) and the low is related to the number 9(e3P3) (%14.99 1.071) (P<0.05).