Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2020 Jan;103(1):846-851. doi: 10.3168/jds.2019-17267. Epub 2019 Nov 14.
Ectoparasitic stable flies (Stomoxys calcitrans [L.]), horn flies (Haematobia irritans [L.]), and face flies (Musca autumnalis De Geer) negatively affect dry matter intake, milk production, and health of pastured dairy cows. These flies cause fly avoidance behaviors and are a major welfare concern for dairy producers. The objective of this study was to evaluate the effects of mesh Shoofly Leggins (Stone Manufacturing & Supply, Kansas City, MO) on fly avoidance behaviors and numbers of flies attacking pastured dairy cows. In a crossover design, lactating dairy cows (n = 80) were randomly assigned to groups with and without leggings (Shoofly Leggins worn on all legs). All cows were managed in one group. Cows were observed for 2-wk periods, and then treatments were reversed in the next 2-wk interval. Counts of stable flies, horn flies, and face flies on all cows were recorded twice daily (once in morning per cow: 0930 to 1230 h; and once in the afternoon per cow: 1330 to 1630 h), 3 times per wk on Tuesday, Wednesday, and Thursday of each week during the study period. The total number of flies per cow was greater on cows with leggings than cows without leggings. The number of horn flies per cow was greater on cows in with leggings (26.4 flies/side) compared with cows without leggings (24.1 flies/side). Stable fly numbers were similar for cows with and without leggings (12.8 flies/leg). A random subset of 20 focal cows per group was observed during 5-min intervals to record frequencies of 4 behaviors: leg stomps, head tosses, skin twitches, and tail swishes. Counts of head tosses (2.6 vs. 3.1), skin twitches (20.9 vs. 19.6), and tail swishes (21.3 vs. 19.3) were similar for cows without leggings versus cows with leggings, respectively. However, foot stomps were 39% lower for cows with leggings compared with cows without leggings, and leg stomps were 26% higher in the afternoon than in the morning (2.9 vs. 2.4, respectively). A positive correlation was observed between stable and horn flies and all insect avoidance behaviors. Numbers of stable flies were 1.5 times greater in the afternoon than in the morning. The results of this study indicated that flies were associated with cow fly avoidance behaviors regardless of the use of leggings, but leggings effectively reduced foot stomps by 39%, so their use may provide some relief from stable fly injury to pastured dairy cows.
体外寄生性厩螫蝇（Stomoxys calcitrans [L.]）、牛虻（Haematobia irritans [L.]）和厩蝇（Musca autumnalis De Geer）会降低干物质摄入量、产奶量并影响牧场奶牛的健康。这些苍蝇会引起奶牛回避行为，是奶牛养殖户主要关注的福利问题。本研究的目的是评估网眼 Shoofly 裤（Stone Manufacturing & Supply，堪萨斯城，密苏里州）对牧场奶牛回避苍蝇行为和苍蝇叮咬数量的影响。采用交叉设计，将 80 头泌乳奶牛随机分为有裤组和无裤组（所有腿均穿 Shoofly 裤）。所有奶牛均在一组中进行管理。在两周的观察期内，每天两次（每头奶牛一次在上午：0930 至 1230 h；每头奶牛一次在下午：1330 至 1630 h）记录所有奶牛的厩螫蝇、牛虻和厩蝇的数量，每周二、三、四每天记录 3 次。与无裤组相比，有裤组奶牛每头的苍蝇总数更多。有裤组奶牛的每侧牛虻数量（26.4 只/侧）多于无裤组（24.1 只/侧）。有裤组和无裤组奶牛的厩螫蝇数量相似（每腿 12.8 只）。每组随机选择 20 头焦点奶牛，在 5 分钟的间隔内记录 4 种行为的频率：腿踩踏、头部摆动、皮肤抽搐和尾巴摆动。与无裤组相比，有裤组奶牛的头部摆动次数（2.6 次对 3.1 次）、皮肤抽搐次数（20.9 次对 19.6 次）和尾巴摆动次数（21.3 次对 19.3 次）相似。然而，有裤组奶牛的腿部踩踏次数比无裤组低 39%，下午的腿部踩踏次数比上午高 26%（分别为 2.9 次和 2.4 次）。稳定和牛虻苍蝇与所有昆虫回避行为之间存在正相关关系。下午的厩螫蝇数量是上午的 1.5 倍。本研究结果表明，苍蝇与奶牛的回避苍蝇行为有关，无论是否使用裤腿，但裤腿能有效减少 39%的腿部踩踏行为，因此，对于牧场奶牛来说，使用裤腿可能有助于减轻厩螫蝇的伤害。
