Effects of substituting roasted soybean (<em>Glycine max</em>) seeds by those of cowpea (<em>Vigna unguiculata</em>), and of the protein level in the diet, on growth performance and profitability of local-breed chickens (<em>Gallus gallus</em>) in Burkina

This study aimed to evaluate the effects of substituting roasted seeds of soya (Glycine max) by those of cowpea (Vigna unguiculata), and of the protein level in the diet, on growth performance and economic profitability of local-breed chickens (Gallus gallus) in Burkina Faso. Three hundred 12-day-old chicks were divided into 12 batches of 25 chicks each. Four diets incorporating seeds of cowpea or soya, with different protein levels for starting and growing/finishing, were prepared. Data on various parameters (body weight, weight gain, intake and feed conversion, mortality) were recorded once every two weeks from the 12th to the 138th day of age. At the 138th day, four chickens (two males and two females) from each batch were slaughtered to assess the characteristics of carcasses and selected organs. The comparative profitability of the different treatments was evaluated. Results indicate that the substitution of roasted seeds of soya by those of cowpea had no devaluing effect on growth performance nor on carcass characteristics of the local chicken. In addition, the use of these seeds did not decrease profitability. Lastly, increasing the protein level in the diets significantly (p ≤ 0.05) improved weight gains and reduced the duration of the breeding period by two weeks