Evaluation of the Chemical Composition and Feeding Value of Sweet Orange Pulp and Pineapple Peel Meals as Fibre Sources in Pigs’ Rations

Abstract

The piggery industry in Nigeria is on the verge of collapsing due to the high cost of conventional feed resources including wheat offal and palm kernel cake that usually form bulk in the diets of pigs. This study was, therefore, designed to compare the chemical composition of orange pulp meal, pineapple peel meal, and wheat offal and evaluate their feeding value in pig rations. The orange pulp and pineapple peels were dried on a concrete floor and analyzed for chemical composition. Three experimental diets were formulated with orange pulp and pineapple peel meals replacing wheat offal as a fibre source. Thirty crossbred (Chester white x Landrace) growing pigs with an average initial weight of 8.20 -- 8.75kg were distributed into three groups, with ten animals per group, and assigned to the three experimental diets. The average daily feed intake and weight gain were monitored throughout the 56-day duration of the experiment. Seven days to the end of the experiment, three pigs randomly selected for the digestibility trial were individually housed in metabolism crates and allowed 5 days of adaptation to the crates and feed before faecal collection commenced. Animals were fed the experimental diets at approximately 4% of their body weight, and the faeces of the animals were collected for 5 days. The determination of the nutrient composition of feed and faecal samples was performed. Data collected were subjected to analysis of variance using a completely randomized design. The result indicated that samples were significantly (P<0.05) different in crude protein composition, with the wheat offal having the highest value corresponding to 9.21 ± 0.12%. Orange pulp had the highest content of ash (6.72 ± 0.12%). The gross energy values were 15.23MJ/kg, 15.31MJ/kg and 16.15MJ/kg for pineapple peel, orange pulp and wheat offal, respectively. The highest manganese concentration was observed in wheat offal (5.19± 0.11mg/l), while orange pulp and wheat offal were higher in sodium and phosphorus concentrations. The pigs fed an orange pulp meal diet recorded the highest average daily weight gain (0.31 kg) and a superior feed conversion ratio (4.19) relative to others. Digestibility values were similar across the three treatment groups. It was, therefore, concluded that orange pulp and pineapple peal meal could serve as alternative fibre sources in growing pigs' rations. Key words: Wheat offal, pineapple peel, orange pulp, growing pigs, digestibility