Genetic analysis of residual feed intake and growth parameters in indigenously developed coloured broiler chicken

The present study estimated residual feed intake (RFI) and feed conversion ratio (FCR) over two juvenile growth periods i.e. 21–28 days and 28–35 days to find out various genetic factors influencing these traits and their correlations with other growth traits. The birds were maintained in individual cages and provided standard management during 35 day experimental period. The heritability (h²) estimate of RFI (28–35 days) was 0.49 which was higher that of RFI during 21–28 days (0.29). The h² estimate of FCR during 28–35 days was 0.38 which was less than that of FCR during 21–28 days (0.44). Higher genetic correlation (0.60) between RFI and feed intake (FI) for period 21–28 days than that of 28–35 days (0.49) indicates that selection for RFI at 21–28 days will be more effective in decreasing the feed intake. Simultaneously, the genetic correlation between RFI and body weight gain (BWG) for the period 28–35 days was higher than that of 21–28 days thereby making selection for RFI at this period is more useful. The correlation between feed intake and RFI justify the age of selection as 28 days; however, the correlations with BWG indicate that 28–35 day is suitable for selection. Finally, based on the mean body weight (BW) of 987.97g achieved at 35 d indicates that for achieving better market weight with reduced feed intake, the selection may be based on RFI 28–35 days.