Effects of feeding the seeds of Prosopis laevigata, Acacia schaffneri and Ceratonia siliqua on the performance of broiler chicks

________________________________________________________________________________ Abstract The aim of the present study was to assess the nutrient contents and potential feeding value in the diet of broiler chicks of the seed of three tree species, mesquite (Prosopis laevigata), Schaffneri ́s wattle (Acacia schaffneri) and the carob tree (Ceratonia siliqua). The dry matter (DM), ash, crude protein (CP), amino acid and fatty acid concentrations of the seeds were determined. Growth performance was measured in terms of weight gain, feed intake and feed conversion ratio. Sixty-four day-old Cobb broiler chicks were randomly assigned to the following treatments: control diet; control + P. laevigata; control + A. schaffneri and control + C. siliqua. The diets were formulated to contain 200 210 g CP/kg and 13.39 MJ ME/kg, with approximately 60 g CP/kg diet originating from the respective seeds. Prosopis laevigata contained the highest protein level (394 g/kg DM), followed by A. schaffneri (229 g/kg DM) and C. siliqua (183 g/kg DM). The concentration of linoleic acid in the fat was found to be the highest in all three species, followed by oleic acid. The methionine concentration in the seed of the three species was low compared with that in soybean meal. Weight gain and feed intake of the chicks were significantly higher in the control diet and there were no significant differences between P. laevigata and A. schaffneri. Chicks receiving C. siliqua had the lowest weight gain. Feed conversion ratio was the lowest in the control diet, with no significant differences between the P. laevigata and A. schaffneri treatments, while C. siliqua had the highest feed conversion ratio. It is concluded that the seeds of the two species, P. laevigata and A. schaffneri, could partially replace commercial feed ingredients as protein and energy sources in diets of poultry kept under subsistence farming conditions in rural areas of Mexico. ________________________________________________________________________________