ABSTRACT Master Thesis
A research on the Effects of Body Weight and Uniformity at 18th Weeks of Age in Layer Pullets on Some Performance Criteria in Laying Period.
Ali ÇOLAK Selcuk University
Department of Animal Science Supervisor: Prof. Dr. Ramazan YETİŞİR
2006, …..
Jury: Prof. Dr. Ramazan YETİŞİR Doç. Dr. İskender YILDIRIM Yrd. Doç. Dr. Abdurrahman TOZLUCA
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, peak egg production level and age at peak level, mortality and egg production (Hen-Day, HD; Hen-Housed, HH) 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 operation 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 higher (P<0,01) than white genotypes almost 270 g at 18th weeks of age. Egg production (HH) at 43rd weeks of age for Nick Chick, Brown Nick, Isa Brown and Hisex strains were 152,9 (%84,0), 149,35 (82,06), 139,19 (%76,5) and 145,0 (%79,7), respectively. The differences between brown and white egg layers were not statistically significant but the differences between operations were important (P<0,01). This result implies that brown and white layers should be judged for egg-production efficiency.
On the other side, between age at 50% egg production and egg production properties (HD, HH; for % and number) statistically significant (P<0,01, r < -0,75) negative correlation coefficients were determined.
For HH egg production, the below linear regression prediction equation, 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. It is also stressed that, egg producers must keep records on egg weight and others economically important production traits.
