Growth performance and nutrition-related serum metabolites in growing pigs fed on Acacia Tortilis leaf meal
Animal and Poultry Science, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg, South Africa; Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada
The objective of the study was to determine the response in metabolites and growth performance in growing pigs fed on Acacia tortilis leaf meal-based diets using a dose-response trial. Forty-eight male hybrid pigs (28.5±2.18. kg BW) were individually penned and assigned in a complete randomized design to six experimental diets containing 0, 30, 60, 90, 120, and 150. g/kg DM of A. tortilis leaf meal. Pigs were bled once after three weeks for biochemical analyses. An increase in A. tortilis resulted in quadratic reductions in ADFI (P<0.0001) and ADG (P<0.05), and linear decreases in G:F (P<0.001). Serum iron, cholesterol and total protein initially increased, and then started decreasing with incremental levels of A. tortilis. There was a quadratic increase in alanine aminotransferase (ALT) (P<0.001) and aspartate aminotransferase (AST) (P<0.01) and a linear increase (P<0.001) in alkaline phosphatases (ALP) observed as A. tortilis inclusion increased. Using the broken-stick model, the optimum levels of leaf meals marking break points at which threshold values of ADG, serum iron, serum cholesterol and total protein occurred when A. tortilis was included at 64.8, 60.0, 87.1 and 63.2. g/kg DM, respectively. In conclusion, growth performance, serum iron and total proteins are reliable indicators of optimum inclusion levels of leaf meals in pigs. © 2015 Published by Elsevier B.V.