SELECTION FOR SOME PRODUCTIVE TRAITS IN NORFA LAYING HENS .

Abstract

The present experiment has been carried out at the Poultry Experimental Farm, Faculty of Agriculture, Menoufia University, Shebin El-Kom, Egypt, during the period from 2013 to 2017 on Norfa chickens. Total number of 475 dams were used in the present experiment in the base population, first and second generations. Independent culling levels (ICL) method of selection has been applied on the selected flock (+0.5sd). The criterion of ICL method of selection was to select hens having at least average EN90d + 0.5 sd on condition that egg size and body weight should be around the average flock. Results obtained and conclusions can be summarized as follows: The heritability estimates (h2) showed that AgeSM had low h2 estimates, both of BWSM and BWM showed moderate h2 estimates, EWSM showed moderate to high h2 estimates while EWM had moderate h2 estimates and the heritability estimates for EN90d and EN42wk were moderate to high. The expected genetic changes for AgeSM, BWSM, BWM, EWSM, EWM, EN90d and EN42WK in the base population were -1.12 d. ، 41.82 g، 22.28 g ، 1.19 g ،0.46g ، 3.57egg and 1.70 eggs respectively. While the actual   genetic gains were7.79، 17.9، -0.093، -1.60، -1.60، 5.18 egg and 8 eggs respectively. The expected genetic changes for AgeSM, BWSM, BWM, EWSM, EWM, EN90d and EN42WK) in the first generation of Norfa chicken were 1.69 d ، 22.43 g،31.01 g ، .89 g ،.32g ، 1.8 egg and 1.27 eggs respectively. While the actual   genetic gains were -13، -29.9،-38، -1، -1.180،5.8 egg and 5.24eggs, in the same order. The expected genetic changes for AgeSM, BWSM, BWM, EWSM, EWM, EN90d and EN42WK in the first generation of Norfa chicken were 1.31 d., 26.14 g, .27 .73 g ,0 .87 g ,0.26 g , 2.95 egg and 2.91 eggs respectively. While the actual   genetic gains were -10، -30، -22،-1.4، 1، 14.05 egg and 19.72 eggs respectively. The actual genetic gains for EN90d and EN42WK were high than the expected genetic changes through the base population, first and second generations by applied the Independent culling levels. The selected line was better than the control line for productive traits in Norfa laying hens.