International Journal of Agriculture and Agricultural Sciences ISSN 1712-3496 Vol. 2 (2), pp. 021-024, November, 2015. © Advanced Scholars Journals

 Full length Research paper

Estimation of growth curve of Horro (Zebu) and their crosses calves using Gompertz model

Habtamu Abera

Oromia Agriculture Research Institute, Bako Agricultural Research Center P.O. Box 03, Bako, Ethiopia

Email: [email protected]

Accepted 9 November, 2015

Abstract 

The estimate growth curve of birth weight, weaning and one year weight of Horro and their crosses with Holstein Friesian-Horro (FH) and Jersey-Horro (JH) calves were investigated by using gompertz model on data collected from Bako Agricultural Research center during the year 1980-2008.  Least squares means and growth curves were analysed using General Linear Model (GLM) of Statistical Analyses System (SAS). Environmental factors were the effects on mature weight (A), proportion body weight gained after birth (B) and maturing rate (k) parameters of the growth curve. The overall means of growth curve parameters were 83.7±0.93 kg, 1.4±0.012 and 0.015±0.00 for mature weight (A), proportion body weight gained after birth (B) and maturing rate (k), respectively. Coefficient of variations (CV) of A, B and K parameters were 24%, 18% and 221%, which implies there is much more variation in maturing rate (K), followed by mature weight. Degree of maturity at birth, weaning and one year were 0.25, 0.69 and 0.99, respectively, for Horro and their crossbred cattle. Therefore, development of a growth model that describes the growth pattern of a herd within a particular environment and management system may be useful to determine the relative importance of factors affecting production efficiency.

Keywords:  Crosses, Gompertz model, growth curve, Horro, maturity rate