Comparison of non-linear models to describe the growth in the Andalusian turkey breed

Abstract

Seven non-linear growth models were compared in the Andalusian turkey, an endangered native breed. To this aim, turkeys were weekly weighted until they reached 35 weeks. The goodness-of-fit and flexibility criteria of Brody, Von Bertalanffy, Verhulst, Logistic, Gompertz, Richards, and Sinusoidal growth models were evaluated to quantify their ability to describe the biological growth curve. Goodness-of-fit criteria were assessed comparing the mean squared error (MSE) and adjusted determination coefficient (Pseudo-R 2 ), while the flexibility criteria of Akaike (AIC) and Bayesian information criteria (BIC) were evaluated to quantify the explanatory and predictive ability of the models tested. Afterward, all criteria were considered in a combined index to determine the most efficient model to describe and predict growth patterns. The best-fitting model for males growth was Logistic (MSE: 250,349.87; Pseudo-R 2 : 0.97) which also reported the best explanatory and predictive properties (AIC: 18,949.25; BIC: 18,963.24), while best goodnessof-fit criteria, explanatory and predictive capacity in females were reported for the Richards model (MSE: 144,432.45; Pseudo-R 2 : 0.95; AIC: 17,529.83; BIC: 17,549.02, respectively). Von Bertalanffy and Richards models underestimated the weight at early age stages, contrary to Logistic and Verhulst models. The asymptotic weight was higher in males than in females at all evaluated models, being 11,085.37 g for Logistic and 5,706.38 g for Richards, respectively. In conclusion, a marked sexual dimorphism is evident, with females reaching maturity earlier than males. The higher inflection point in males may enable their relatively easier commercial standardisation than in turkey hens. HIGHLIGHTSLogistic was the best fitting model for males' growth and Richards for females. Females reach maturity earlier than males with higher rates of maturity. Andalusian turkey breed shows an intense sexual dimorphism.

Genetic Effect and Growth Curve Parameter Estimation under Heat Stress in Slow-Growing Thai Native Chickens

“…The growth parameters were analyzed by using the Marquardt method NLIN procedure of SAS. The fit of the growth models (which is suitable for the non-linear regression model) was assessed by evaluating the mean squared error (MSE), the pseudo-coefficient of determination (Pseudo-R 2 ) and Akaike information criterion (AIC) [24,25]. After that, parameters α, β, and γ were used to estimate the age at inflection point (IPA), the weight at inflection point (IPW), and the maximum growth rate (MGR) [26].…”

Traditional sexing methods and external egg characteristics combination allow highly accurate early sex determination in an endangered native turkey breed

“…The Andalusian turkey breed is a very rudimentary population that has barely been submitted to selection or improvement. This population has often been described as a living representation of the first turkeys that arrived in Europe in the 16th century, and before that, these birds had only accomplished 1,300 years of domestication ( 10 ), while comparatively, the chicken species may have probably been domesticated for 4,700 years by that time ( 95 , 96 ). Therefore, black-feathered Andalusian turkeys could present a greater degree of relatedness to wild ancestors than the individuals presenting one of the remaining plumage patterns.…”

“…The implementation of a standardized accurate method for the sex determination of 1-day-old poults could mean a crucial improvement for breeders, making it possible to take proper management decisions at hatching instead of waiting for 4–5 months, when animals start to display sexual dimorphism characters ( 9 ). As a consequence, Andalusian turkey males may be aimed toward the maximization of their meat production while letting hen for the laying aptitude ( 10 ). These sexing methods can also be a beneficial tool when management strategies to preserve genetic diversity are designed, since sex distribution across the population is possibly biased ( 5 ).…”

Data Mining as a Tool to Infer Chicken Carcass and Meat Cut Quality from Autochthonous Genotypes

“…The importance of such local genotypes relies on the fact that they thrive on elements of organic and free-range farming due to the suitability of their nature to adapt to their origin area [ 13 ]. This has been confirmed by the international experience of several countries, where slow-growing native chicken breeds have been able to provide good-quality meat, at a reasonable price, which is the main rationale behind the increasing demand for distinctive products [ 14 ].…”