Performance and immune response of male broilers offered graded levels of safflower meal during the starter period -

Abstract

Two experiments were performed at the Agricultural Research and Education Center of the American University of Beirut to evaluate the performance of broiler chicks in response to a partial or total replacement of soybean meal (SBM) with de-hulled, pressed and extruded safflower meal (SFM) in practical starter rations. In the first experiment, 252 one week-old Ross 308 males were divided into 36 groups of seven birds each and maintained in Petersime battery brooder pens so that all pens had the same initial average body weight and range. The birds were offered for two weeks, isocaloric (3150 Kcal-Kg as metobolizable energy, ME) and isonitrogenous (23percent crude protein, CP) balanced rations containing either SBM (control) or SFM at 20, 40, 60, 80, and 100percent substitution rate of SBM. The diets were formulated on the basis of digestible amino acids. There were 6 treatments and 6 replicates per treatment with 7 birds per replicate in a complete randomized design. Feed intake, weight gain, and feed conversion were recorded at 3 weeks of age. In addition, 2 birds per pen representing the average body weight of each pen were slaughtered and their ready to cook carcass (RTC) and internal organs (liver, gizzard, heart and spleen) weight percentages were determined. Data were analyzed using one way ANOVA and means compared using Duncan’s multiple range test. SFM 40percent gave the greatest weight gain (788 g) which was significantly different (P0.05) only from both SBM and SFM100percent (754 and 731 g, respectively). The SFM100percent diet resulted in the greatest feed conversion ratio (1.49) in comparison to all treatments whereas the SBM-control diet had the smallest numerical feed conversion value (1.37) that was significantly different only from that of SFM80 (1.42) and SFM100percent. RTC carcass yield of birds fed the SFM40 and SFM80 was higher (P0.05) than that of SFM20 and control fed birds. However, weight percentages of internal organs were not affected by any of the dietary treatments. In the second experiment, the dietary SFM