Centro de Recursos Naturales Renovables de la Zona Semiárida, Centro Científico Tecnológico CONICET Bahía Blanca, and Departamento de Agronomía, Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina.
J Anim Sci. 2012 Aug;90(8):2763-73. doi: 10.2527/jas.2011-4703. Epub 2012 Mar 5.
This study determined whether early experiences by sheep with monotonous or diverse diets influence intake of unfamiliar flavors and feeds later in life. Thirty 2-mo-old lambs were randomly assigned to 3 treatment diets (n = 10): diverse (DIV), diverse with plant toxins (DIV+T), and monotonous (MON). Lambs in DIV received in 9 successive periods of exposure 4-way choice combinations of 2 foods high in energy and 2 foods high in protein from an array of 6 foods: 3 high in energy [beet pulp, oat grain, and a mix of milo:grape pomace (60:40)] and 3 high in digestible protein (DP) (soybean meal, alfalfa, corn gluten meal). Lambs in DIV+T received the same exposure as DIV, but 2 plant toxins, oxalic acid (1.5%) and quebracho tannins (10%), were randomly added to 2 of the feeds in each of the choice combinations. Lambs in MON received a monotonous balanced diet, made with a mixture of all 6 feeds detailed before. All treatments received their feed in 4 separate buckets. During exposure, treatments did not differ in total daily DMI (P = 0.31), but daily intake of ME was less (P < 0.02) and daily intake of DP was greater (P < 0.03) for lambs in DIV and DIV+T than for lambs in MON. Treatments did not differ in ADG or G:F (P > 0.05). After exposure, lambs were offered a familiar feed (wheat bran) containing novel flavors (maple, garlic, or bitter) and 2-way choices of novel feeds (fescue hay vs. corn distillers grains, rice vs. calf manna, and green peas vs. rolled oats). Intake of maple-flavored wheat bran tended (P = 0.08) to be greater for lambs in DIV than for lambs in DIV+T and MON. Intake of bitter-flavored and garlic-flavored wheat bran were greater (P = 0.03 and P = 0.04, respectively) for lambs in DIV and DIV+T than for lambs in MON. During 2-way choice trials, lambs in DIV, but not in DIV+T, showed greater intakes of fescue hay (P = 0.05) and rice (P = 0.04) than lambs in MON. Intake of green peas was greater (P = 0.03) for lambs in DIV and DIV+T than for lambs in MON. At the end of testing, lambs in DIV but not in DIV+T showed greater ADG than lambs in MON (P = 0.05). Thus, early exposure to diverse foods enhanced acceptance of novel flavors relative to early exposure to a monotonous ration. Early experience with diverse feeds plus plant toxins led to a less diverse diet than early experience with diverse feeds. Early exposure to diverse feeds may be beneficial in production systems that require rapid acceptance and high intake of unfamiliar feeds.
本研究旨在确定绵羊在早期经历单调或多样化的饮食后，是否会影响其在以后的生活中对不熟悉味道和饲料的摄入。30 只 2 月龄的羔羊被随机分为 3 种处理日粮（n = 10）：多样化（DIV）、多样化加植物毒素（DIV+T）和单调（MON）。DIV 组羔羊在 9 个连续周期内接受 4 种选择组合的 2 种高能量食物和 2 种高蛋白质食物的 4 路选择，这些食物来自 6 种食物的组合：3 种高能量食物[甜菜浆、燕麦粒和混合的甜高粱：葡萄渣（60:40）]和 3 种高可消化蛋白质（DP）食物（豆粕、紫花苜蓿、玉米蛋白粉）。DIV+T 组羔羊接受与 DIV 组相同的暴露，但在每个选择组合中的 2 种饲料中随机添加 2 种植物毒素，草酸（1.5%）和奎拉乔单宁（10%）。MON 组羔羊接受单调平衡日粮，由之前详细描述的所有 6 种饲料的混合物制成。所有处理组均在 4 个单独的桶中喂食。在暴露期间，处理组的总日采食量（DMI）没有差异（P = 0.31），但 DIV 和 DIV+T 组羔羊的每日 ME 摄入量较少（P < 0.02），每日 DP 摄入量较大（P < 0.03），而 MON 组羔羊的每日 ME 摄入量较少（P < 0.02），每日 DP 摄入量较大（P < 0.03）。处理组的 ADG 或 G:F 没有差异（P > 0.05）。暴露后，羔羊被提供一种含有新口味（枫糖、大蒜、或苦味）的熟悉饲料（小麦麸皮），以及 2 种新饲料的选择（雀稗干草与玉米酒糟，大米与小牛甘露，和青豆与燕麦片）。与 DIV+T 和 MON 组羔羊相比，DIV 组羔羊对枫糖味小麦麸皮的摄入量有增加的趋势（P = 0.08）。与 MON 组羔羊相比，DIV 和 DIV+T 组羔羊对苦味和大蒜味小麦麸皮的摄入量增加（P = 0.03 和 P = 0.04）。在 2 种选择试验中，与 MON 组羔羊相比，DIV 组羔羊对雀稗干草（P = 0.05）和大米（P = 0.04）的摄入量增加。与 MON 组羔羊相比，DIV 和 DIV+T 组羔羊对青豆的摄入量增加（P = 0.03）。在测试结束时，与 MON 组羔羊相比，DIV 组羔羊的 ADG 增加（P = 0.05）。因此，早期接触多样化的食物会增强对新口味的接受度，相对于早期接触单调的饲料。早期接触多样化的饲料加植物毒素会导致比早期接触多样化的饲料更不多样化的饮食。早期接触多样化的饲料可能对需要快速接受和大量摄入不熟悉饲料的生产系统有益。
