Available space in feeders for housed sheep: social behavior and performance

ABSTRACT This study was designed to assess the effects of feeding space availability on social behavior and performance of housed crossbreed sheep through the use of three different types of feeders. Thirty-six crossbreed ewes (Santa Inês × Dorper; 2-3 years old) with initial body weight of 34.99±4.28 kg were randomly assigned to a 3 × 3 (feeder type × available space at the feeder) factorial arrangement among nine pens. Pens had one of three feeder types (concrete bunk, plastic, or wood barrel) and one of three amounts of available space in the feeder (0.33, 0.25, or 0.20 m animal−1). Total dry matter intake/pen, dry matter intake per animal, total weight gain/pen, daily weight gain/animal, and food waste were evaluated. Percentage of time spent at feeding and frequency of aggressive behaviors/12 h were recorded. We observed a higher total daily weight gain in ewes with a feeding space of 0.33 and 0.25 m animal−1. The wastes were essentially insignificant for wood feeders in all feeding space treatments. The average number of aggressive behaviors was lower (P<0.05) for animals kept in pens with feeding space of 0.33 m animal−1 than for those maintained in pens with feeding space of 0.20 and 0.25 m animal−1. Ewes with feeding space of 0.33 m animal−1 fed simultaneously 54% of the time, while among pens with feeding spaces of 0.25 or 0.20 m animal−1, this period was reduced to 41 and 30%, respectively. An available feeding space of 0.33 m animal−1 is recommended for adult housed ewes, once it favors simultaneous access, lower competitive interactions at the feeder, and less variation in terms of individual weight gain among ewes.

摘要 本研究旨在通过三种不同类型的饲喂器，探究采食空间可用量对圈养杂交绵羊社交行为与生产性能的影响。选取36只圣塔伊内斯×杜泊（Santa Inês × Dorper）杂交母羊，年龄2~3岁，初始体重为34.99±4.28 kg，将其随机分配至9个圈舍中，采用3×3（饲喂器类型×饲喂器可用空间）因子试验设计。每个圈舍配备三种饲喂器类型之一（混凝土料槽、塑料饲喂器或木质料桶），以及三种饲喂空间可用量之一（0.33、0.25或0.20 m·只⁻¹）。测定指标包括圈舍总干物质采食量、单只羊干物质采食量、圈舍总增重、单只羊日增重以及饲料浪费量；同时记录采食时长占比与每12小时内攻击行为发生频次。结果显示，采食空间为0.33和0.25 m·只⁻¹的母羊总日增重更高。在所有采食空间处理组中，木质饲喂器的饲料浪费量基本可忽略不计。采食空间为0.33 m·只⁻¹的圈舍中，母羊的平均攻击行为频次显著低于采食空间为0.20和0.25 m·只⁻¹的组（P<0.05）。采食空间为0.33 m·只⁻¹的母羊同时采食的时长占比达54%，而采食空间为0.25或0.20 m·只⁻¹的圈舍中，该占比分别降至41%和30%。综上，建议成年圈养母羊的采食空间设置为0.33 m·只⁻¹，该配置有利于母羊同时采食、降低饲喂台的竞争互动，并减小个体增重的差异。