Performance of Weaner and Grower Pigs Fed Diets Containing Graded Levels of Soybean Hull

Abstract

Twenty-four weaner pigs were used in a study to evaluate the response of weaner and grower pigs to diets containing graded levels of toasted soybean hull (SBH).In experiment 1(growing phase), twenty-four male hybrid (large white x landrace) weaner pigs, about 6 weeks old, weighing 5.92-6.85kg were randomly divided into four groups of six pigs each using a completely randomized design (CRD). Each group was randomly assigned to one of the four diets (1, 2, 3 and 4) containing 0% (control), 10, 15 and 20% SBH for 56 days. Each treatment was replicated 3 times with 2 pigs per replicate placed on a concrete-floored pen. The diets were formulated to be isocaloric and isonitrogenous supplying 2800kcal ME/kg and 18% crude protein. In experiment 2 (finishing phase), twenty-four male hybrid (large white x landrace ) grower pigs, about 14 weeks old, weighing 9.12-9.90kg were randomly divided into four groups of six pigs each using a completely randomized design (CRD). Each group was randomly assigned to one of the four diets (1, 2, 3 and 4) containing 0% (control), 10, 20 and 30% SBH for 56 days. Each treatment was replicated 3 times with 2 pigs per replicate placed on a concrete-floored pen. The diets were formulated to be isocaloric and isonitrogenous supplying 2900kcal ME/kg and 16% crude protein. Daily feed intake, body weight gain, feed conversion ratio, protein efficiency ratio and feed cost per kg weight gain were determined. At the end of each experiment, blood samples were collected from two pigs per treatment for haematological evaluation. Two pigs per treatment were also slaughtered for carcass evaluation at the end of the finishing experiment. In experiment 1, results showed that pigs fed the 10% SBH diet had higher(P<0.05) average final body weight, average weight gain and better efficiency of feed conversion than those fed 20% SBH diet. Increasing levels of SBH in the diets had no significant effect (P>0.05) on the PER values. Differences between the treatments in total digestible nutrients (TDN) were significant (P<0.05). Feed cost per kg weight gain was reduced at the 10% SBH inclusion level as compared to other SBH diets. Dietary treatments did not have adverse effect on the haematology of growing pigs. The overall performance of pigs fed the soybean hull based diets was not inferior to that of pigs fed the control diet (0% SBH). In experiment 2, the 20% and 30% SBH diets supported superior final body weight gain and growth rate, better feed conversion ratio, higher protein efficiency ratio, average daily protein intake and feed intake than the control diets(P<0.05). Inclusion of SBH in the diets reduced significantly (P<0.05) the cost of feed per kg weight gain, especially at the 30% SBH inclusion level. Pigs fed the control diets had comparable packed cell volume (PCV), haemoglobin concentration (Hb), red blood cell counts (RBC) ,white blood cell counts (WBC), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) values with the groups on SBH diets. While dietary levels of SBH did not exert significant(P>0.05) influence on body length, height at withers, lung weight, liver weight, spleen and pancreas weight; the heart girth circumference, heart weight, kidney weight, live body weight, and dressed carcass weight were all significantly (P<0.05) affected by the dietary levels of SBH. The dressing percentage, relative weights of lungs, liver and spleen were also influenced significantly (P<0.05) by the dietary levels of SBH, while the relative weights of heart and kidney were not significantly (P>0.05) affected. It was concluded that toasted soybean hull can be included in the diet of weaner pigs at 20% level and in the diet of grower pigs at 30% level without adverse effects on the performance, haematological values, carcass and organ weights of the animals.