A diet containing mango peel silage impacts upon feed intake, energy supply and growth performances of male dairy calves

Abstract

The major challenges for disposal of waste from fruit processing factories are high transportation costs, limited landfill availability and environmental pollution. Therefore, developing efficient waste management techniques to reduce transportation costs and environment pollution is important. In 2021, global mango production was estimated to be at 57 million tons and mango peel (MP) represents 7–24% of the whole fruit weight. MP has been considered for use as ruminant feed in the form of fresh, dried, or silage. Fresh MP was abundant during the mango season and high in fermentable carbohydrate, which can easily breakdown and pollute the environment if a proper waste management method is not implemented. Thus, in this study, fresh MP was ensiled after sun-drying for one day and then fed to male dairy calves as a roughage source to evaluate its effect on feed intake, digestibility, energy balance, BW gain, feed efficiency and blood metabolites. Eight growing crossbred weaned male dairy calves (Holstein Friesians × Zebu) were allocated into two groups [Control (n = 4) and mango peel silage (MPS, n = 4)]. This experiment lasted for 12 weeks and calves were housed in 3.0 × 1.5 meters individual pen with concrete floor. Before feeding times, the weights of feed ingredients were weighed and mixed for 15 min. Calves were then given their respective diets ad libitum twice a day, at 0800 and 1600 h. Daily feed offered and refusals were recorded to determine the daily feed intake. A digestion trial was performed over the last five days of the experiment. BW and measurements were recorded every two weeks to determine the weight gain and body physical changes. Blood was collected at the end of experiment to analyze serum biochemical parameters. Ensiling improved the energy and protein content and decreased fiber content of MP, thereby improving the forage quality. Feeding a diet containing MPS at 30% of DM weight, compared to an isonitrogenous Control diet increased (P < 0.05) feed intake, energy supply and energy balance, changes in body measurements, weight gain, feed efficiency, and glucose concentration, as well as lowered (P < 0.05) the blood urea nitrogen concentration of male dairy calves. Ensiling fresh MP after sun-drying for one day led to stable, high-DM silage. Therefore, ensiling fresh MP could improve the feed supply for ruminant production and be an effective waste management strategy for fruit processing businesses.