Artificial feeding systems for calves in tropical conditions

ABSTRACT The objective of this study was to evaluate the bioeconomic performance of calves in the first 60 days of life submitted to three feeding systems. Twenty-four calves (Dutch x Guzerá) were used, 12 males and 12 females, with initial weight of 32.25±4.8kg for females and 36.92±6.8kg for males. The animals were distributed in a completely randomized design, in a factorial scheme (3 x 2). The calves received water at will and six liters of milk replacer a day for 60 days in three different strategies, called the suckling system (SA-30: 3 liters of milk replacer, twice a day until 30 days of age; SA-45: 3 liters of milk replacer, twice a day until 45 days of age; SA-49: 3 liters of milk replacer, twice daily up to 49 days old). The lactation systems studied did not present statistical difference (P>0.05) for the consumption and digestibility of nutrients, except for organic matter (OM) and ethereal extract (EE). There was an interaction (P<0.05) between the suckling system and sexual class for the OM and EE intakes, as well as for the average daily gain, in which HS 49 males presented higher averages in relation to SA 30. The bioeconomic performance of male calves from the lactation system 49 was superior and presented the best cost-benefit ratio among the systems studied.

摘要 本研究旨在评估接受三种饲喂体系的犊牛在出生后前60天的生物经济性能。试验共使用24头荷兰牛与古泽拉牛的杂交犊牛，其中公犊、母犊各12头；母犊初始体重为32.25±4.8kg，公犊初始体重为36.92±6.8kg。试验采用完全随机设计，设置3×2因子试验方案。试验为期60天，犊牛可自由饮水，每日饲喂6升代乳粉，共设置三种不同饲喂策略，分别命名为哺乳体系SA-30：每日饲喂2次，每次3升代乳粉，直至犊牛30日龄；SA-45：每日饲喂2次，每次3升代乳粉，直至犊牛45日龄；SA-49：每日饲喂2次，每次3升代乳粉，直至犊牛49日龄。本研究涉及的三种哺乳饲喂体系对犊牛的养分消耗与养分消化率均无统计学差异（P>0.05），仅有机物（organic matter, OM）与乙醚浸出物（ethereal extract, EE）例外。哺乳饲喂体系与性别对有机物、乙醚浸出物采食量以及平均日增重均存在显著交互效应（P<0.05）；其中SA-49组公犊的各项指标均值均高于SA-30组公犊。在所有试验饲喂体系中，SA-49组公犊的生物经济性能最优，且成本效益比最高。