Lazzarotto Eduardo Felipe Colerauz de Oliveira, Menezes Luís Fernando Glasenapp de, Paris Wagner, Molinete Marcos Luis, Schmitz Gean Rodrigo, Baraviera José Henrique Ignacio, Farenzena Roberta, Paula Adalberto Luiz de
Faculty of Animal Science, Universidade Tecnológica Federal do Paraná, Dois Vizinhos, PR 85660-000, Brazil.
Asian-Australas J Anim Sci. 2019 Jun;32(6):800-807. doi: 10.5713/ajas.18.0603. Epub 2018 Nov 27.
The aim was to evaluate backgrounding beef steers on oat + ryegrass pastures mixed with vetch and/or using energy supplementation.
A randomized block design with three treatments and three replications was used. The treatments were: grass + supplement (oat + ryegrass + supplementation), legume + supplement (oat + ryegrass + vetch + supplementation) and grass + legume (oat + ryegrass + vetch). A continuous grazing system with a variable stocking rate was used. Twenty-seven intact crossbred steers (1/4 Marchigiana, 1/4 Aberdeen Angus and 2/4 Nellore) aged 7 months old and average weight of 190 kg were used. Steers were supplemented at 1% of the body weight of ground corn. The experiment lasted 84 days, between May and August 2014. Behavioral assessments were performed two times per experimental period, for 24 hours.
The forage mass was different between treatments, being greater for steers fed without legume. The accumulation rate, forage allowance, and stocking rate did not differ between treatments due to the adequate adjustment of forage allowance. The final weight of animals, as well as the dry matter intake (kg/d), did not differ between treatments. However, forage intake was higher for non-supplemented animals in relation to supplemented steers. Supplement intake did not alter the total digestible nutrient intake due to pasture quality. Animals fed grass + supplement had higher live weight gain per area than those fed grass + legume. Animals without supplementation spent more time in grazing.
Feeding behavior was not altered by mixing with vetch or supplementation. Non-supplemented animals started the grazing peak earlier and spent more time in grazing than those supplemented; however, the average daily gain was similar between treatments. The live weight gain per hectare was 47% higher in pastures in which the animals received supplementation compared with those mixed with vetch, a consequence of the substitutive effect.
旨在评估在燕麦+黑麦草牧场上混播巢菜和/或使用能量补充剂对育肥牛的育肥效果。
采用随机区组设计，设3种处理，3次重复。处理分别为：草+补充剂（燕麦+黑麦草+补充剂）、豆科植物+补充剂（燕麦+黑麦草+巢菜+补充剂）和草+豆科植物（燕麦+黑麦草+巢菜）。采用可变载畜率的连续放牧系统。选用27头7月龄、平均体重190 kg的未阉割杂交育肥牛（1/4马尔凯牛、1/4阿伯丁安格斯牛和2/4 Nellore牛）。育肥牛按体重的1%补充磨碎的玉米。试验于2014年5月至8月进行，为期84天。每个试验期进行2次行为评估，每次24小时。
各处理间牧草量不同，未饲喂豆科植物的育肥牛的牧草量更大。由于牧草供应量调整得当，各处理间的累积率、牧草供应量和载畜率没有差异。各处理间动物的最终体重以及干物质摄入量（千克/天）没有差异。然而，未补充饲料的动物的牧草摄入量高于补充饲料的育肥牛。由于牧场质量，补充剂的摄入量并未改变总可消化养分摄入量。饲喂草+补充剂的动物每单位面积的活体重增加高于饲喂草+豆科植物的动物。未补充饲料的动物放牧时间更长。
与巢菜混播或补充饲料不会改变采食行为。未补充饲料的动物比补充饲料的动物更早开始放牧高峰期，且放牧时间更长；然而，各处理间的平均日增重相似。与混播巢菜的牧场相比，动物接受补充饲料的牧场每公顷活体重增加高出47%，这是替代效应的结果。
