A RESEARCH ON THE EFFECTS OF BODY WEIGHT AT 18TH WEEKS OF AGE AND FLOCK UNIFORMITY IN LAYER PULLETS ON SOME PERFORMANCE CRITERIA IN LAYING PERIOD

This research was carried out to determine the statistical relations (r, b) between live weight (LW) and flock uniformity at the18th weeks of age with age at point of lay (POL), age at 50% egg production, age at peak level, peak egg production level and percistency, mortality and egg production (HH:Hen-Housed; HD:Hen-Day) at the end of the 43rd weeks of age of hybrid genotypes (Nick Chick, Brown Nick, Isa Brown and Hisex) rising in the integrated layer operations in Konya province. The mean values of selected traits of totally 25 flocks were evaluated. According to the results obtained; LW of brown genotypes were almost 270 g higher (P 0.01) than white genotypes at 18th weeks of age. Egg production (HH) at 43rd weeks of age for Nick Chick, Brown Nick, Isa Brown and Hisex strains were found as 152.9 (%84.0), 149.35 (82.06), 139.19 (%76.5) and 145.0 (%79.7), respectively. This results implies that brown and white egg layers should be judged for egg production efficiency. Differences between brown and white egg layers for egg production in same operation were not statistically significant but the differences between the operations were important (P 0.01). There were no significant relationship between flock uniformity and the other production traits. On the other side, between age at 50% egg production and egg production properties (HD, HH; % and number) statistically significant (P 0.01) negative correlation coefficients (r =- 0.75) were determined. For HH egg production, the linear regression prediction equation below which has all parameters statistically significant (P 0.01) were determined. Egg production number (HH) = 290-1.25 Age at 50% Egg Production + 0.114 Age at Peak Level + 0.0624 Percistency. With same properties, for %HH and HD (number and %) egg production, statistically significant (P 0.01) regression equations were determined, too.