Use of nonlinear models to evaluate the growth curve of lambs
DOI:
https://doi.org/10.35699/2447-6218.2023.45002Keywords:
Adult weight, Logistic model, Mean square error, Quality evaluatorsAbstract
The objective was to use non-linear regression models to evaluate the growth curve of lambs. For this, data regarding the weight and age of 70 crossbred Dorper x Santa Inês lambs born between the years 2016 to 2019 were used. The production system was intensive and semi-confined. The animal data were adjusted using non-linear Brody, Von Bertalanffy, logistic and Gompertz models. To compare the fit of the models, the adjustment quality evaluators were used: mean square error (MSE), coefficient of determination (R2) and percentage of convergence (%conv). The growth curves were made by individual adjustments. All analyzes were performed using the RStudio software, version R 4.1.2. The Logistic model was the one that best estimated the parameter a (adult weight) with 48.09 kg, while the others overestimated the biological reality of the parameter. Likewise, it presented the highest value for parameter k (maturity rate) with 0.0219. All models obtained a coefficient of determination (R²) greater than 96%. Von Bertalanffy's model had the lowest SMQ (1.61), followed by Gompetz (2.27), Logistic (2.76) and Brody (3.36). The Logistic model had the highest percentage of data convergence (87.14%), followed by Gompertz (71.43%), Von Bertalanffy (35.71%) and Brody (10%). Therefore, the logistic model showed the best fit compared to the others with adequate R², low MSE, high percentage of convergence and adequate asymptotic value, not tending to overestimate adult weight.
Downloads
References
Farhadian, M.; Rafat, S. A.; David, I. 2022. Determination of the best non-linear funcion and genetic parameters on early growth in Romane lambs. Journal of Science and Technologies, 10:1-9. doi: https://doi.org/10.22103/JLST.2022.16350.1327
Farrell, L. J.; Kenyon, P. R.; Tozer, P. R.; Ramilan, T.; Cranston, L. M. 2020. Quantifying sheep enterprise profitability with varying flock replacement rates, lambing rates, and breeding strategies in New Zealand. Agricultural Systems, 184:1-11. doi: https://doi.org/10.1016/j.agsy.2020.102888
Hossein-Zedh, N. G. 2015. Modeling the growth curve of Iranian Shall sheep using non-linear growth models. Small Ruminant Research, 130:60-66. doi: https://doi.org/10.1016/j.smallrumres.2015.07.014
Kucukonder, H.; Demirarelan, P. C.; Alkan, S.; Ozgur, B. B. 2020. Curve fitting with nonlinear regression and grey prediction model of broiler growth in chickens. Pakistan Journal of Zoology, 52:347-357. doi: https://doi.org/10.17582/journal.pjz/2020.52.1.347.354
National Research Council - NRC. 2007. Nutrient requirements of small ruminants. Washington, D. C.: National Academy Press., 362 p.
R Core Team. 2022. R: A language and environment for statistical computing. Disponível em: https://www.R-project.org/. Acesso em: 12 de abril de 2023.
Raineri, C,; Nunes, B. C. P.; Gameiro, A. H. 2015. Technological characterization of sheep production systems in Brazil. Animal Science jornal, 86:476-485. Doi: https://doi.org/10.1111/asj.12313
Selvaggi, M.; Laudadio, V.; D’Alessandro, A. G.; Dario, C.; Tufarelli, V. 2017. Comparison on accuracy on diferente nonlinear models in predicting growth of Podolica bulls. Journal of animal sciences, 66:1126-1133. doi: https://doi.org/10.1111/asj.12726
Sharif, N.; Ali, A.; Mohsin, I.; Ahmad, N. 2021. Evaluation of nonlinear models to define growth curve in Lohi sheep. Small Ruminant Research, 205:1-9. doi: https://doi.org/10.1016/j.smallrumres.2021.106564
Van der Merwe, D. A.; Brand, T.S.; Hoffman, L.C. 2019. Application of growth models to diferente sheep breed types in South Africa. Small Ruminant Research, 178:70-78. doi: https://doi.org/10.1016/j.smallrumres.2019.08.002
Varanis, L. F; Silva, N. A. M.; Teixeira, A. M. 2016. Seleção de modelos não lineares para estimação da curva de lactação de vacas mestiças pelo método de análise de agrupamento. Caderno de Ciências Agrárias, 8:28-37. doi:
Weber, S. H.; Santos, S. K.; Heizen, B. C.; Viana, N. P.; Sotomaior, C. S. 2021. Comparison of nonlinear mathematical models for lamb growth analysis. Tropical Animal Health and Production, 53:1-9. doi: https://doi.org/10.1007/s11250-021-02597-3
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 Agrarian Sciences Journal
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish in this journal agree to the following terms:
The Copyright for articles published in this journal follow authorship. The articles are open access, with their own attributions, in educational and non-commercial applications.
The journal reserves the right to make regulatory, orthographic and grammatical changes in the originals, with the aim of maintaining the standard language and the credibility of the vehicle. It will respect, however, the writing style of the authors.
Changes, corrections or suggestions of conceptual order will be forwarded to the authors, when necessary. In such cases, the articles, once appropriate, should be submitted for further consideration.
The opinions issued by the authors of the articles are their sole responsibility.
Agrarian Science Journal is licensed under a 