The growth of domestic goats and sheep: a meta study with Bertalanffy-Putter models

Brunner, N. and Kuhleitner, M.

Veterinary and Animal Science (2020) 10:

DOI: 10.1016/j.vas.2020.100135

Abstract

Growth literature often uses the Brody, Gompertz, Verhulst, and von Bertalanffy models. Is there a rationale for the preference of these classical named models? The versatile five-parameter Bertalanffy-Putter (BP) model generalizes these models. We revisited peer-reviewed publications from the years 1970-2019 that fitted growth models to together 122 mass-at-age data of sheep and goats from 19 countries and studied the best-fit BP-models using the least-squares method. None of the named models was ever best-fitting. However, for 70% of the data a single non-sigmoidal model had an acceptable fit (normalized root mean squared error \textless 5% and F-ratio test \textgreater 5% in comparison to the best-fit): the Brody model. The inherently non-sigmoidal character was further underlined, as there were only 39% of the data, where the best-fitting BP-model had a discernible inflection point. For these data, conclusions of biological interest could be drawn from the sigmoidal best-fit BP-models: the maximal weight gain per day was about 55% higher than the natal weight gain per day.

Citation

Brunner, N., & Kuhleitner, M. (2020). The growth of domestic goats and sheep: a meta study with Bertalanffy-Putter models. Veterinary and Animal Science, 10. https://doi.org/10.1016/j.vas.2020.100135 Animal Physiology and Biochemistry (Excluding Nutrition) [LL600], meta-analysis, liveweight gain, liveweight gains, mathematical models, Mathematics and Statistics [ZZ100], growth, models, sheep, goats, growth models

Keywords

• Animal Physiology and Biochemistry (Excluding Nutrition) [LL600]
• meta-analysis
• liveweight gain
• liveweight gains
• mathematical models
• Mathematics and Statistics [ZZ100]
• growth
• models
• sheep
• goats
• growth models