Yellow grease in sheep diets: intake and digestibility

ABSTRACT This study aimed to assess the effects of yellow grease supplementation on the intake, digestibility, and nitrogen balance in sheep. Twenty Santa Inês lambs with a mean age of 95 ± 10 d and body weight of 19.29 ± 3.17kg were evaluated in a completely randomized design. The diets were supplemented with oil at concentrations of 0, 20, 40, 60, and 80 gkg-1 of dry matter (DM) of the concentrate. The diets were based on roughage and concentrate (50:50). The experimental period lasted 19 d and included 14 adaptation days and five collection days for the total supplied diet, orts, feces, and urine. Supplementation with yellow grease had no significant effect on the intake of DM, crude protein (CP), neutral detergent fiber (NDF), or non-fiber carbohydrates (NFC). However, the ether extract (EE) intake increased linearly with supplementation of yellow grease. Moreover, no effect was observed for DM, CP, NDF, and NFC digestibility and nitrogen balance. EE digestibility increased linearly with the yellow grease dietary supplementation. Thus, sheep dietary supplementation with yellow grease may be used at a level of up to 80 gkg-1 of DM of concentrate without impairing nutrient intake and digestibility.

摘要 本研究旨在评估添加黄色油脂对绵羊采食量、消化率及氮平衡的影响。本试验采用完全随机设计，对20只平均日龄为95±10 d、平均体重为19.29±3.17 kg的圣塔伊内斯（Santa Inês）羔羊开展研究。试验日粮以精混合料的干物质（dry matter, DM）为基准，分别添加0、20、40、60、80 g·kg⁻¹的黄色油脂，日粮粗料与精料配比为50:50。试验周期共计19 d，包含14 d适应期与5 d样本收集期，用于采集总投喂日粮、剩料、粪便及尿液样本。结果显示，黄色油脂添加对干物质（DM）、粗蛋白质（crude protein, CP）、中性洗涤纤维（neutral detergent fiber, NDF）及非纤维碳水化合物（non-fiber carbohydrates, NFC）的采食量无显著影响，但随着黄色油脂添加量提升，乙醚浸出物（ether extract, EE）采食量呈线性升高。此外，黄色油脂添加对DM、CP、NDF、NFC的消化率及氮平衡均无显著影响，而乙醚浸出物消化率随日粮中黄色油脂添加量提升呈线性升高。综上，绵羊日粮中黄色油脂的添加量最高可达精混合料干物质的80 g·kg⁻¹，且不会损害营养物质采食量与消化率。