Influence of polyethylene glycol inclusion on growth performance and serum biochemistry of growing pigs fed on Acacia tortilis leaf meal.
The broad objective of the study was to determine the influence of polyethylene glycol (PEG) in leaf meal diets on growth performance and serum biochemistry of growing pigs. Forty eight clinically healthy male F1 hybrid (Landrace x Large White, IPC group) pigs were randomly allotted to individually pens, in a complete randomized design. There were eight pigs with an initial body weight of 15.8 (s. d. 0.032) kg per treatment. The Acacia tortilis leaf meal was treated with six incremental levels (0, 5, 10, 15, 20 and 25 g/kg) of PEG. Each of the six diets was offered ad libitum to pigs for four weeks. Clean water was available at all times. Average daily feed intake (ADFI) and average daily gain (ADG) were determined every week. Scaled feed intake (SFI) and gain: feed ratio (G: F) were also calculated. Blood was collected at the end of the experiment to determine total protein (TP), albumin, globulin, creatinine, cholesterol, uric acid and activities of alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). There was a quadratic increase in SFI (P < 0.01) and G: F ratio (P > 0.05) with PEG and ADF inclusion. There was a linear relationship between ADG and PEG inclusion (P < 0.01). There was linear relationship between PEG inclusion level and TP and globulin concentrations (P < 0.01). A quadratic increase on albumin with PEG inclusion was observed (P < 0.01). Cholesterol, creatinine and uric acid concentrations were not influenced by PEG inclusion (P > 0.05). There was a linear decrease in the activity of AST and ALT (P < 0.01). An increasing quadratic relationship on ALP enzyme to PEG inclusion was also observed (P > 0.05). In conclusion, PEG up to 25 g/kg increase most of the response variables quadratically. It can be concluded that the relationship between PEG inclusion and performance of growing pigs fed on A. tortilis is exponential, rather than linear.