Genetic evaluation and genetic curve for egg production in Thai native chickens (Pradu Hang Dam) using a random regression test-day model

Abstract

The objective of this research was to investigate an appropriate random regression test-day model from various egg production functions for genetic evaluation and genetic curve construction for egg production in the first generation (G1) of Thai native chickens (Pradu Hang Dam). Data included 1,669 monthly egg production records of 203 Thai native chickens between September, 2007 and June, 2009. Data were obtained from the Research and Development Network Center for Animal Breeding (Native Chicken), Faculty of Agriculture, Khon Kaen University. An average (+SD) of yearly egg production was 140+36 eggs and average (+SD) age at first egg was 187+22 days. Considering to -2logL, AIC, and MSE, random regression test-day model with egg function of Koops and Grossman (RRTDM(KD)) had the best fit for genetic evaluation and genetic curve for egg production in this population. The estimated monthly heritability ranged from 0.220 to 0.289, and highest heritability found in month 2 and 3 of egg production periods. Genetic correlations among monthly egg production were higher than 0.880. Genetic curves for egg production were different in both cocks and hens. Therefore, selection plan for individual genetic potential can be efficiently performed.