Egg production curves of Kadakanath and its crosses with CARI Red

D.P. Singh and Shiv Prasad*
Central Avian Research Institute; *LES & IT Division, IVRI
Izatnagar - 243 122

The number of eggs produced by Kadakanath (Kn) and its crosses with CARI Red (CR) viz. Kn x CR and CR x Kn from 20 th week to 72 nd week of age were arranged in 13 equal periods of four week each. The average number of eggs produced during first period (20-24 wk) were 0.03 + 0.07, 2.80 ± 0.57 and 4.00 ± 0.58 for Kn, Kn x CR and CR x Kn respectively. The maximum egg production of 17.05 ± 0.54 eggs was noted during 37- 40 weeks for Kn whereas maximum production of 21.79 ± 0.40 and 19.72 ± 0.47 eggs were observed during 41- 44 weeks for Kn x CR and CR x Kn crosses, respectively. During last period (69-72 wk) these groups produced 3.26 ± 0.42, 11.40 ± 1.02 and 12.51 ± 1.16 eggs respectively. The average numbers of eggs produced at each period by crosses were significantly higher than Kn. Annual egg production of these genotypes was 93.6, 205.9 and 195.7 eggs respectively.

To investigate the appropriate mathematical model to describe the egg production curves of these genotypes 21 models were fitted by using non-linear optimization technique (Levenberg-Marquardt) with SPSS-7.5 version. Curvilinear logistic, Monomolecular minus linear term and logistic minus linear term were found best models to describe the egg production curves of Kn, Kn x CR and CR x Kn genotypes with R 2 values of 91.60, 98.44 and 97.35 % respectively. The trend of egg production per unit time was observed to be similar to lactation curve having increasing, peak and decreasing phases of production.

Source : IPSACON-2005

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