ABSTRACT

This study was conducted to evaluate the performance of broiler chickens to soyabean diet partially replaced with Smart Choice (SCC). A total number of 150 Marshall broilers were used for the experiment which lasted for 56 days (8 weeks). The experiment was carried out at the Poultry Unit of the Teaching and Research farm of Michael Okpara University of Agriculture, Umudike. The experimental birds were divided into five treatment groups denoted as T1, T2, T3, T4and T5containing 0%, 25%, 50%, 75% and 100% SCC respectively. Each treatment group was replicated thrice and each replicate contained at least 10 birds arranged in a Completely Randomized Design. Data were collected on proximate composition of experimental diet, growth performance (initial weight, final weight, daily feed intake, daily weight gain, Feed Conversion Ratio), carcass characteristics and internal organ proportions. All data collected were analyzed statistically using SPSS Software Package. The result of the proximate composition shows that crude protein, ether extract, Nitrogen Free Extract and metabolizable energy decreased whereas the crude ash increased as the level of SCC increased in the diets. The 25% SCC (T2) recorded the most acceptable nutritional content which compared to the Control diet especially in crude protein both in the starter and finisher phases. The 25% SCC recorded the most significant (P<0.05) FCR values 1.68 and 2.47 as well as daily weight gain (79.8 Ig/bird/day and 43.72g/birdlday) and final weight values (2281.55g and 228 1.55g) in the starter and finisher phases. The 50% SCC (T3) recorded comparable performance to the control in body weight and daily feed intake in 14-56 days and the 14-35 days periods and in FCR at 14-56 days. T3also recorded superior performance to the Control diet in daily weight gain in the two periods and better FCR (3.04) in the finisher period compared to the value (4.46) obtained for the Control diet. Levels higher than the 50%SCC depressed performance as observed in T4and T5. Replacement of soybean with CC significantly (P<0.05) affected the live weight, defeathered weight, dressed weight, dressed percent; wings, breast and thigh expressed as percentage of dressed weight but did not affect (P>0.05) the back muscle and drumstick of the broiler chickens T2recorded the most significant (P<0.05) values in live weight (2016.67g), defeathered weight (1950.oOg), dressed weight (1391 .67g), dressed percent (68.96%), breast (31.89%) and thigh (19.02%) but least (P<0.05) in relative wing weight (12.08%). 1'3similarly compared to the control diets whereas higher levels depressed performance. The SCC affected (P<0.05) the heart, gizzard and proventriculus but did not affect the spleen and liver. Similarly, T2 followed by T3, obtained the best values for internal organs: heart, spleen, gizzard and liver, which compared best to the Control diet. Levels higher than the 50%SCC tended to cause inflammation of the heart, gizzard and proventriculus as observed in T4 and T. From the foregoing, it can be concluded that optimum replacement is possible at the 50% level of SCC (T3) based on its comparable as well as superior performance to the control in growth performance, carcass characteristics and internal organ proportions. Based on the superior performance of T2 in proximate compositions, growth performance, carcass characteristics and internal organ proportions, the 25%SCC is recommended as the best level to replace soybean.