School of Animal Sciences, Virginia Tech, Blacksburg, Virginia, United States of America.
Shenandoah Valley Agricultural Research and Extension Center, Virginia Tech, Raphine, Virginia, United States of America.
PLoS One. 2023 Mar 23;18(3):e0282923. doi: 10.1371/journal.pone.0282923. eCollection 2023.
A silvopasture system intentionally integrates trees, forages, and livestock, allowing dual land use. These systems can provide high-quality habitat for broiler chickens; however, such systems have not been widely adopted by the broiler industry in the United States. The objective of this study was to examine the effect of silvopasture versus open pasture access on fearfulness and leg health in fast-growing broiler chickens. A total of 886 mixed-sex Ross 708 chicks in Experiment 1 (Exp 1) and 648 chicks in Experiment 2 (Exp 2) were housed in coops and had access to 16 (Exp 1) or 12 (Exp 2) 125m2 silvopasture plots (x̄ = 32% canopy cover) or open pasture plots (no canopy cover) from day 24 of age. Fearfulness was measured using a tonic immobility test (tonic immobility duration), and leg health was assessed by quantifying footpad dermatitis, hock burns, gait, and performing a latency-to-lie test on days 37-39 of age. Birds in the silvopasture treatment were less fearful than birds in the open pasture treatment. Overall, birds in both silvopasture and open pasture systems had excellent leg health. Silvopasture birds had lower footpad dermatitis scores than open pasture birds. Silvopasture birds tended to have worse gait than open pasture birds in Exp 1, but not in Exp 2. Hock burn scores and latency-to-lie did not differ between treatments in Exp 1 or Exp 2. Raising birds in silvopasture reduced fear and improved footpad health compared to birds raised in open pastures, which indicates that silvopasture systems provide some benefits for affective state and leg health in fast-growing broilers.
一个林牧系统有意地整合了树木、饲料和牲畜，实现了双重土地利用。这些系统可为肉鸡提供高质量的栖息地；然而，此类系统并未在美国的肉鸡产业中得到广泛应用。本研究的目的是检验林牧与开放牧场对快速生长肉鸡的恐惧和腿部健康的影响。试验 1（Exp 1）中共有 886 只混性别罗斯 708 小鸡和试验 2（Exp 2）中共有 648 只小鸡，它们在 24 日龄时被安置在鸡舍中，可以进入 16 个（Exp 1）或 12 个（Exp 2）125m2 的林牧地（平均树冠覆盖率为 32%）或开放牧场地（无树冠覆盖）。从 24 日龄开始，通过测定刻板不动时间（刻板不动时间）来评估肉鸡的恐惧程度，通过量化脚垫皮炎、跗关节烧伤、步态和在 37-39 日龄时进行卧倒潜伏期试验来评估腿部健康状况。林牧处理组的肉鸡比开放牧场处理组的肉鸡更不易产生恐惧。总体而言，林牧和开放牧场系统中的肉鸡都具有良好的腿部健康状况。林牧组肉鸡的脚垫皮炎评分低于开放牧场组肉鸡。在 Exp 1 中，林牧组肉鸡的步态比开放牧场组肉鸡差，但在 Exp 2 中并非如此。在 Exp 1 或 Exp 2 中，跗关节烧伤评分和卧倒潜伏期在处理组之间没有差异。与在开放牧场上饲养的肉鸡相比，在林牧地上饲养的肉鸡恐惧程度降低，脚垫健康状况得到改善，这表明林牧系统为快速生长的肉鸡的情感状态和腿部健康提供了一些益处。
