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

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. Mango peels (MP) are 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 were ensiled after sun-dried for one day and then fed to dairy male calves as the roughage source to evaluate its effect on feed intake, digestibility, energy balance, body weight gain, feed efficiency and blood metabolites. Eight growing crossbred dairy male 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 daily feed offered and refusal were recorded to determine the daily feed intake. Digestion trial was performed at the last five days of experiment. Body weight and measurement were recorded every two weeks interval to determine the weight gain and body physical improvement. Blood was collected at the end of experiment to analyze the serum biochemical parameters. Ensiling improved the energy and protein contents and decreased fibre content of MP, thereby improving the forage quality.  Feeding MPS to calves 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 urea nitrogen concentration. Ensiling fresh MP after sun-drying for one day improved silage quality, and feeding MPS to dairy male calves as a roughage source improved feed intake, energy supply and growth performances. Therefore, ensiling fresh MP could improve the feed supply for ruminant production and be an effective waste management strategy for fruit processing businesses.

果品加工厂废弃物处置面临的主要难题包括高昂的运输成本、有限的填埋场可用量以及环境污染问题。因此，研发高效的废弃物管理技术以降低运输成本与环境污染至关重要。芒果皮（Mango Peels, MP）在芒果丰产季产量充足，且富含可发酵碳水化合物，若未采取恰当的废弃物管理措施，极易发生降解并造成环境污染。据此，本研究将新鲜芒果皮经1天日晒干燥后进行青贮处理，随后作为粗饲料来源饲喂给生长发育期杂交乳用公犊牛，以评估其对采食量、消化率、能量平衡、体重增长、饲料转化率以及血液代谢物的影响。本试验选取8头生长发育期杂交乳用公犊牛（荷斯坦弗里生牛×瘤牛），将其分为两组：对照组（n=4）与芒果皮青贮料组（Mango Peel Silage, MPS, n=4）。本试验周期为12周，每日记录饲喂饲料量与剩余饲料量，以计算日均采食量。试验最后5天开展消化试验。每两周记录一次犊牛的体重与体尺数据，以计算体重增长量并评估其体格发育情况。试验结束时采集血液样本以分析血清生化参数。青贮处理可提升芒果皮的能量与蛋白质含量，降低其纤维含量，从而改善其饲用品质。向犊牛饲喂芒果皮青贮料可显著提升采食量、能量供给与能量平衡状态，改善体尺指标变化、体重增长、饲料转化率以及血糖浓度（P<0.05）；同时可显著降低血清尿素氮浓度（P<0.05）。将新鲜芒果皮经1天日晒干燥后进行青贮处理，可优化青贮料品质；以芒果皮青贮料作为粗饲料饲喂乳用公犊牛，可提升采食量、能量供给与生长性能。因此，对新鲜芒果皮进行1天日晒干燥后再行青贮处理，既可提升反刍动物生产的饲料供给量，也可为果品加工企业提供一种高效的废弃物管理策略。