Comparison of several models to fit the growth curves of Kivircik and Daglic male lambs


AKBAS Y., Taskin T. , DEMIROREN E.

TURKISH JOURNAL OF VETERINARY & ANIMAL SCIENCES, vol.23, pp.537-544, 1999 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 23
  • Publication Date: 1999
  • Title of Journal : TURKISH JOURNAL OF VETERINARY & ANIMAL SCIENCES
  • Page Numbers: pp.537-544
  • Keywords: growth curve, lambs, Daglic and Kivircik breeds, linear models, non-linear models

Abstract

This research was carried out to estimate the growth curves of Kivircik and Daglic male lambs using monthly body weight data from birth to 420 days of age. Fifteen models were compared in terms of growth curve parameters and for the best fit to the data of Kivircik and Daglic male lambs. Among the linear models simple linear model gave the best fit for Daglic and quadratic model for Kivircik. However heterogenity was found in terms of regressions equations within each breed and between genotypes. These results say that common regression equation can not be used for all individual in a breed having different growth pattern, not only regression coeffiecient but also mean levels of dependent variable. Among the non-linear models Brody, Negative Exponential, Gompertz, Logistic and Bertalanffy gave quite good fit for the male lambs data. Brody had the highest coefficient of determination.