3rd Degree Polynomial Model: Is It Best Non-Linear Model for the Estimation of Growth Curve in Anatolian Black Cattle?

Abstract

Abstract In this study, it was aimed to estimate the growth curve of live weights from birth to 24 months of age in Anatolian Black Cattle raised for conservation purposes. For this purpose, a total of 493 weight records of 113 animals at birth, 3, 6, 12, 18 and 24 months were examined in the study. Six different non-linear models were used to describe the growth curve of animals, these are 2nd degree polynomial, 3rd degreee polynomial, Logistic, Brody, Von Bertalanffy and Gompertz models. In the study, R2 values of these models determined 0.997, 0.999, 0.953, 0.979, 0.924 and 0.862; corel (correlation between the observed and estimated) were 0.994, 0.998, 0.989, 0.993, 0.961 and 0.703; Residual Standart Deviation were 3.216, 1.388, 11.533, 3.561, 14.736 and 27.141 respectively. According to these values, it was determined that the 3rd degree polynomial model was best described the growth curve of Anatolian Black. As a result of the analyses, it was determined that the values predicted by this model deviated by 1–3 kg from the observed values in all periods and in all environmental factors examined (sex, dam age, parity, birth year and birth season). It was determined that these differences increased up to 4–5 kg only in the 18-month period. The results also showed that Anatolian Black continued to grow after 24 months of age. As a result, activities such as sexual maturity age, breeding age and slaughter age can be easily predicted by determining the model that best describes growth and development in herds.