Feed intake and growth performance of growing pigs fed on Acacia tortilis leaf meal treated with polyethylene glycol.

The objective of the study was to determine the response in feed intake and performance of pigs fed on incremental levels of polyethylene glycol (PEG). Forty-eighty male F1 hybrid pigs were randomly allotted to six diets containing 0, 5, 10, 15, 20, and 25 g/kg of PEG, respectively. Acacia tortilis leaf meal was included at a rate of 150 g/kg. Each diet was offered ad libitum to eight pigs in individual pens. Average daily feed intake (ADFI), scaled feed intake (SFI), average daily gain (ADG), and gain to feed ratio (G:F) were determined weekly. The ADG showed a linear response to PEG (p < 0.01). The linear regression equation was y = 0.0061x + 0.6052 (R(2) = 0.64). There was a quadratic response to PEG on ADFI, and SFI (p < 0.01) and G:F (p > 0.05). The regression equations and R(2) values were as follows: ADFI y = 0.0008x(2) - 00086x + 1.2339 (R(2) = 0.96), SFI y = 0.0147x(2) - 0.2349x + 40.096 (R(2) = 0.95), and G:F ratio y = 0.0002x(2) - 0.0017x + 0.5168 (R(2) = 0.56). The ADFI, SFI, and ADG increased as weeks of feeding progressed (p < 0.01), but the G:F ratio decreased as weeks increased. It can be concluded that the relationship between PEG inclusion and performance of growing pigs fed on A. tortilis is exponential, rather than linear. The economic benefit of using PEG depend on cost of labor, availability of Acacia, costs of harvesting together with processing, and acceptability of the pork.