Profile Analysis and Growth Curve for Body Mass Index of Broiler Chickens Reared Under Different Feed Restrictions in Early Age
Abstract. The purpose of this study is to investigate the effect of different feed restrictions which were applied in early period on change of Body Mass Index of Ross 308 broiler chickens. For this aim we used to two different statistical methods, namely Profile analysis and Growth curves. The daily body weight and weekly body length change of chickens was collected from 7 days of age to 42 days of age. Profile analysis was used to compare differences among the groups and the Gompertz growth function was regressed from these data to estimate the growth parameters. The group profiles were not found parallel in terms of Body Mass Index (P<0.001) as a result of the Profile analysis. Therefore once concludes that the difference in Body Mass Index (BMI) of the animals between weeks depends on feeding regime (profiles are not parallel). The value of A and b parameter values were 0.02368 and 0.83436 for ad libitum group (AD), 0.02216 and 0.75251 for 20 % feed restriction based on ad libitum group (YK), 0.02235 and 0.79656 for HG group, respectively. Inflection point (k) for HG group was fount smaller than that of the AD and YK groups. All parameter estimates and growth characteristics for chickens based on Gompertz growth model were significant (P<0.05).