Comparative evaluation of growth characteristics in commercial broilers, native chickens and a domestic pigeon (Columba livia) raised in Iran

The objective of this research was to compare the growth patterns of commercial broiler chickens, native chickens and domestic pigeon raised in Iran. The growth curves and their parameters were estimated by the Richards function. Body weight data of mixed-sex of commercial broiler chickens (n=326000), native chickens (n=244000) and pigeon (n=4000) were used. Birds were fed ad libitum and weighed in alternating periods on their life. The accuracy of the curve fit was high in all species (R2 = 0.996 to 0.970). The y+/A ratios (weight at the inflection point over mature weight), which determine the shape of the growth curve, were 0.358, 0.379 and 0.352 in chickens, native birds and pigeons, respectively. The age at the inflection point confirmed the high early growth of pigeons (t+ = 10.2 d) and chickens(t+ = 36.6 d). The phenotypic correlations between the inflection parameters t+ and y+ were higher in commercial broiler chicken than native and pigeon. The inflection parameter t+ and y+ were positively associated with the maturing index k in all birds, in this way, the evolutionary aspects are discussed. In practical view, these results could be used to develop the production strategies for native chicken breed and domestic pigeon to positively affect the growth parameters, efficiency as well as conservation of local genetic resources.