Breed differences in growth parameters of broiler chickens

Abstract

Broilers been essentially a meat type of chicken, coupled with its fast growth rate has been evaluated for factors that may affect its growth, which include but not limited to sex, breed and feeding. This study was carried out to evaluate breed differences in growth parameters of four different broiler breeds. The experimental units were derived from four commercial broiler breeds namely Arbor Acre®, Cobb®, Marshall® and Ross®. Each breed had 76 chicks totaling 304 across the four breeds. On arrival, each chick was tagged using a coloured leg tag, by breed and identification number, and the initial weight of the chicks were taken. Each of the breeds were thereafter randomly selected and assigned to four experimental plots as replicates of the same treatment, ensuring that each replicate had exact number of birds per breed. The broiler birds were reared for a period of 10 weeks and their weight taken and recorded at weekly intervals. All statistical analyses were conducted using boxplot, descriptive and general linear models of Minitab® 17. At the end of the experiment and after exploratory analysis to check for normality and outliers, a total of 217 birds were used in the final analyses. Except for the Marshall breed that had a highly significantly (P<0.01) lower initial weight, final weight, total weight gain and average daily gain, the other three breeds had fairly similar weight. However, there was no significant (P>0.05) difference in mean initial weight across the four replicates. While breed alone accounted for 37.81% of the total variation in initial weight, it only accounted for 30.31%, 30.07% and 30.07% respectively for final weight, total weight gain and average daily gain. The effect of breed on initial weight, total weight gain and average daily gain was only significant (P<0.01) in Marshall, while the other three breeds were not statistically different (P>0.05). It can be deduced from this study that performance in terms of growth parameters for most of the commercially available breeds studied are similar with the exception of Marshall breed which had significantly (P<0.05) lowest values.