Heat stress effects on the genetics of growth traits in Thai native chickens (Pradu Hang dum)

Abstract

Objective: The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens.Methods: A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters.Results: At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, –0.85, and –0.83 for BW, 0.17, –0.81, and –0.95 for ADG, 0.25, –0.61, and –0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to –9.30, –0.23, –15.21 (in males) and –6.04, –0.21, –10.10 (in females) gram per 1 level increase of THI from the THI of 76.Conclusion: The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

Modeling the growth curve in ducks: a sinusoidal model as an alternative to classical nonlinear models

“…Therefore, AGR records provide a more comprehensive and dynamic insight into poultry growth patterns than relying solely on body weight records. This information enables better knowledge of growth trajectories and patterns, such as periods of rapid growth, growth plateaus or possible growth anomalies ( Boonkum et al, 2024 ). Early detection of differences in growth performance can be facilitated by AGR values.…”

“…Keeping track of weight gain trends allows for early identification of any irregularities in growth patterns, which in turn facilitates timely interventions or modifications in management techniques. This can involve adjusting feeding schedules, addressing health concerns, or implementing specific strategies to enhance growth potential ( Boonkum et al, 2024 ). It is important to investigate this trait by giving ducks unrestricted access to food and by avoiding demanding schedules while they are growing more quickly.…”