American-Eurasian Journal of Scientific Research 6 (4): 201-204, 2011 ISSN 1818-6785 © IDOSI Publications, 2011 Corresponding Author: Sandip Banerjee, Department of Animal and Range Sciences, Hawassa University. Tel: +913325827092, +251916011747. 201 Estimatation of Body Weight at Different Ages Using Linear and Some non Linear Regression Equations in a Duck Breed Reared in Hot and Humid Climate of Eastern India Sandip Banerjee Department of Animal and Range Sciences, Hawassa University Abstract: The present study pertains to estimation of body weight of Vigova Super M, broiler ducks using linear and some non linear (log, inverse, quadratic, cubic, power, S, compound, logistic, growth and exponential) regression equations. Breast angle was considered as a predictor for estimation of the body weight. The results indicate that quadratic regression equation provided the most accurate estimator. The coefficient of determination values being highest at seven weeks of age and thereafter the values decreased as redistribution of muscles occurred and the growth of the birds decreased. Key words: Vigova Super M %Curve fit equations %Body weight and breast angle. growth INTRODUCTION ducklings were procured from Central Poultry Ducks are reared both for their eggs and meat. Hessarghatta. The ducklings were reared according to the The state of West Bengal in India has the highest recommendations of the organization. They were reared duck population in the country, Muthukumar and on commercial broiler ration and rice bran mixed in a ratio Dev Roy [1]. Vigova Super M is a meat type duck of 2: 1. The body weight of the ducklings was taken on a which is imported from Vietnam and is ideally digital balance with an error margin of 10 grams. The suited for hot and humid climate of India. The breast ducklings were weighed early in the morning without angle (m. pectoralis. superficialis and m. pectoralis being provided their daily ration. The breast angle of the profundus), of avian can be used predictors for estimating ducklings was estimated using a modified caliper and body weight, Siegel [2]. Usually in most of the livestock according to the method suggested by Macjowski and experiments the growth is estimated using linear Zieba [5]. The body weight and the breast angle of the equations, ducklings were taken every week from 3 weeks till they Wolf and Kn¥æ etová [3], Raji [4]. However, as the attained 8 weeks of age. The regression values (linear, log, growth of an individual varies with time and age, the inverse, quadratic, cubic, power, S, compound, logistic, estimation of body weight at different ages are mostly non growth and exponential) were estimated using SPSS V.12. linear. The present study was carried out to compare some for Windows. Descriptive statistics too was calculated non linear regression equations with respect to linear using the same software. regression equations to estimate the body weight of the Linear model equation is the most popular Vigova Super M ducks at various ages using breast angle regression equation used in predicting various as a predictor. biological parameters. The values are modeled as a MATERIALS AND METHODS systems never follow linearity and hence is of limited The study was conducted at Livestock Instructional above in mind the comparison between some curve fit Farm at Bidhan Chandra Krishi Viswavidyalaya, West equations was carried out to predict growth in broiler Bengal India. The ducklings of the Vigova Super M ducks. Development Organization, Southern Region linear function of time. Where as the biological importance towards prediction. Therefore, keeping the