A growth pattern study in crosses and pure Indian breeds of goats

Abstract

The non-linear statistical models are tried to study the growth pattern of 4 Indian breeds of goats viz., Jamunapari (A). Beetal (B). Barbri (C), Black Bengal (D) and their crosses. The corrected data for body weight of male animals from birth to 12 month of age was used to fit the different non-linear models such as monomolecular. Gompertz and logistic curves. The data were corrected for 3 nongenetic fixed effects i.e. type of birth, season and period. On comparing the values of R2 and error mean square; it is found that monomolecular gave the best fit which is closely following by Compertz curve. Since, the monomolecular curve has the drawback that it does not provide the point of inflexion, the second best Gompertz curve is used to obtain the age, body weight and maximum growth rate at point of inflexion. The optimum age at point on inflexion for male anilnals in Jamunapari, Beetal, Barbari and Black Sengal are 11 5,3 9. 8.3 and 5.9 months respectively. The optimum age in crosses is around 6 months except for Jamunapari x Sabari and Beetal  Black Bengal far which these are 8.5 and 7.6 months respectively The grdwtll rate is maximum at the optimum age and it starts declining,thereafter at a slow. pace. There is considerable improvemtnt in body weight at the point of inflexion/optimum age in crosses as cOmpared to pure breed parent with lower body weight.