Genetic evaluation of egg production curve in Thai native chickens by random regression and spline models

Abstract

The objective of this research is to investigate appropriate random regression models with various covariance functions, for the genetic evaluation of test-day egg production. Data included 7,884 monthly egg production records from 657 Thai native chickens (Pradu Hang Dam) that were obtained during the first to sixth generation and were born during 2007 to 2014 at the Research and Development Network Center for Animal Breeding (Native Chickens), Khon Kaen University. Average annual and monthly egg productions were 117 ± 41 and 10.20 ± 6.40 eggs, respectively. Nine random regression models were analyzed using the Wilmink function (WM), Koops and Grossman function (KG), Legendre polynomials functions with second, third, and fourth orders (LG2, LG3, LG4), and spline functions with 4, 5, 6, and 8 knots (SP4, SP5, SP6, and SP8). All covariance functions were nested within the same additive genetic and permanent environmental random effects, and the variance components were estimated by Restricted Maximum Likelihood (REML). In model comparisons, mean square error (MSE) and the coefficient of detemination (R) calculated the goodness of fit; and the correlation between observed and predicted values [Formula: see text] was used to calculate the cross-validated predictive abilities. We found that the covariance functions of SP5, SP6, and SP8 proved appropriate for the genetic evaluation of the egg production curves for Thai native chickens. The estimated heritability of monthly egg production ranged from 0.07 to 0.39, and the highest heritability was found during the first to third months of egg production. In conclusion, the spline functions within monthly egg production can be applied to breeding programs for the improvement of both egg number and persistence of egg production.

Genetic analysis of egg production traits in turkeys (Meleagris gallopavo) using a single-step genomic random regression model

“…Previously reported heritability estimates for monthly egg production using random regression models in turkeys ranged from 0.08 to 0.12 [ 24 ]. In our study, estimates of heritability for weekly egg production were lower, ranging from 0.09 to 0.22, which is consistent with estimates obtained with spline models in laying hens [ 25 ]. For the first four weeks, our estimates of heritability for egg production were lower than those reported for White Leghorn hens and native chickens for the early weeks of production [ 22 ].…”

Simple recycling of biowaste eggshells to various calcium phosphates for specific industries

“…In the case of agro industry, the farming of different types of animal species has a number of waste eggshells after eggs are hatched. In Thailand, egg consumption has used significant amounts of egg that account for more than 15,000 million eggs a year 8 . From previous research, average weight of an egg is about 60 g, generating shell about 11%; thus, the produced wastes can be estimated as being around 90,000 tons per year 1 .…”

Characterization of Oviduct Lining, with Emphasis on the Sperm Storage Tubule Region (Uterovaginal Junction), Correlated with Fertility in Mature and Old Thai Native Hens

“…Flock production rises sharply and reaches a peak 6–8 weeks later, followed by a gradual decline to about 65% after 12 months [ 1 ]. In Thai native chickens, our previous studies reported that the production peak occurred in the third month of the egg production period, after which, the monthly number of eggs decreased until the end of the production period [ 28 , 29 ]. Therefore, we inferred that the egg production performance was related not only to feeding management and environmental control [ 30 , 31 ] but also to follicular development.…”