Mathematical models to describe the growth curves of Vietnamese Ri chicken

Abstract

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike’s information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Gut Microbiota Composition and Diversity in Different Commercial Swine Breeds in Early and Finishing Growth Stages

“…Four mathematical models were used in the present study to determine growth curves for predicting pig production performance. All models showed good fit, although other functions might be suitable for growth curve fitting [29]. Fit accuracy was different based on different models for the three pig breeds evaluated in the study.…”

Estimation of genetic parameters for production, reproduction, and growth curve of Fars indigenous chicken

“…According to previous studies looking at the growth curve of birds, the predicted parameter A in the optimal model (Gompertz) was lower than the results of Zhao et al (2015), Selvaggi et al (2015), Yang et al (2006), and Kucukonder et al (2020). Although it was higher than values reported in naturalized chickens (Neto et al, 2020), in female Vietnamese indigenous Mia chickens (Nguyen Hoang et al, 2021), in both male and female Vietnamese Ri chickens (Nguyen et al, 2021), in native Khazak chickens (Faraji‐Arough et al, 2019), and in local chickens from Ghana (Osei‐Amponsah et al, 2014). The differences between predicted values reported by different researchers may be related to the implementation of specific growth functions, species, breed, size of the dataset, and different sampling times.…”

“…Indigenous breeds frequently show greater disease resistance and environmental adaption. These can therefore be utilized as important genetic resources (Nguyen et al, 2021). Harnessing these genetic resources is important for enabling increased production from native chickens and for boosting farmer income (Zhao et al, 2015).…”