Comparison of nonlinear models for predicting live weight growth curves in lamb production of Kıvırcık and Karacabey Merino


Kader Esen V., Karadağ O., Elmacı C., Esen S.

TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES, vol.48, no.3, pp.126-137, 2024 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 48 Issue: 3
  • Publication Date: 2024
  • Doi Number: 10.55730/1300-0128.4346
  • Journal Name: TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, CAB Abstracts, Veterinary Science Database, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.126-137
  • Bursa Uludag University Affiliated: Yes

Abstract

Abstract: To achieve sustainable lamb production, it is crucial to determine the optimal slaughter age for maximum economic efficiency and have a comprehensive understanding of breed characteristics. This study focuses on evaluating different nonlinear models to determine the optimal slaughter age for Karacabey Merino and Kıvırcık lambs, renowned for their early development and superior meat quality, respectively. The dataset comprised age-related live weight data from 98 lambs, including 36 female and 15 male Kıvırcık lambs, as well as 33 female and 14 male Karacabey Merino lambs. Six models, namely, negative exponential, Brody, Gompertz, logistic, Bertalanffy, and Richards were utilized to analyze the data. The model parameters were estimated through an iterative process, and their goodness of fit was evaluated using various metrics. The adjusted coefficient of determination for male Kıvırcık lambs was 0.9755, while female Kıvırcık lambs exhibited a lower value of 0.8912. For Karacabey Merino lambs, males had an adjusted coefficient of determination of 0.9534, while females had a slightly lower value of 0.9044. The study concluded that the Brody model provided more accurate predictions for the growth curve of these sheep breeds compared to the other models.

Key words: Nonlinear models, growth curve, lamb, Kıvırcık, Karacabey Merino