Assessment Performance Across Generations of Iraqi Indigenous Brown Chickens Under Selection for High Egg Production

Abstract

A study was conducted to evaluate sexual and productive performance of Iraqi indigenous brown chickens. Data were descended from 2234 females across six-generation of selection for high egg production. Data of age at first egg [AFE], body weight at first egg [BWFE], first egg weight [FEWT], egg weight [EW], egg number [EN], and egg mass [EM] were recorded individually. The average of AFE, BWFE, FEWT, EW, EN and EM was 149.31d, 1489.59g, 35.7g, 44.44g, 110.39 egg\hen, and 4895.01g, respectively. Monthly gg number was 10.07, 20.35, 21.16, 20.12, 19.36, 18.13 egg\hen from moth 1 to 6 respectively. Monthly egg weights were 37.69, 41.51, 44.23, 45.78, 47.46, 48.72 g from moth 1 to 6 respectively. Monthly egg mass was 379.91, 849.78, 935.46, 921.31, 918.84, and 882.43 g from moth 1 to 6 respectively. The effect of generation, hatch and season showed highly significant effect on sexual and productive traits. The higher FEWT and BWFE shown in the second generation compared to other generations. The cumulative EN and EM from the onset of lay to 43 weeks of age varied between generations where the highest EN and EM was recorded in the six-generation compared to the first generation. EW achieved better values in the second generation [47.60g] while the lowest was recorded in the third to the sixth generations [ca 43.0g]. EW increased with age-progressive. The hatch effect had a significant effect on FEWT, BWFE, AFE, EN, EW, and EM. Hens hatched first achieved better performance compared to the second hatch. The effect of season was significant on FEWT, BWFE, AFE, EN, EW, and EM. Birds hatched in the spring season achieved higher FEWT, BWFE, EW, and greater days to reach maturity. The overall EN for the hens hatched in the spring season was significantly lower than their counterparts hatched in the other season times. Birds hatching in the winter season achieved higher EN than in other seasons. Results suggest that Iraqi brown local chickens shown in the current work have good potential for egg-productive traits and could be used as a gene pool for enhancing egg production through selection approaches.