Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2018 May;101(5):4667-4675. doi: 10.3168/jds.2017-13367. Epub 2018 Mar 1.
The objective of this study was to evaluate the efficacy of a commercial vacuum fly trap (CowVac, Spalding Laboratories, Reno, NV) in on-farm organic dairy production systems to control horn flies, stable flies, and face flies. As cows walk through the trap, flies are brushed off the face, flank, and back with hanging flaps and blown off the belly, udder, and legs from one side, and then vacuumed from the air into a chamber from vacuum inlets opposite the blower and above the cow. The study included 8 organic dairy farms during the summer of 2015 in Minnesota, and herds ranged from 30 to 350 cows in size. The farms were divided into pairs by location; during the first period of the summer (June to July), the trap was set up on 1 farm, whereas during the second period of the summer (August to September) the trap was sent to its paired farm. Farms were visited once per week to collect and count flies from the trap as well as count and record flies on cows. Bulk tank milk, fat, and protein production and somatic cell count were collected on farms during the entire study period. Data were analyzed using the GLM procedure of SAS (version 9.3, SAS Institute Inc., Cary, NC). Independent variables for analyses were the fixed effects of farm, trap presence, housing scenario, and summer period. Horn fly numbers on cows were lower by 44% on farm in the presence of a trap (11.4 vs. 20.5 flies/cow-side) compared with the absence of a trap. Stable fly (5.4 vs. 7.1 flies/leg) and face fly (1.0 vs. 1.0 flies/cow) numbers were similar on farm whether the trap was present or absent on farms, respectively. Milk production was similar for farms with the trap (15.5 kg/d) compared to without (15.3 kg/d) the trap. Bulk tank milk, milk components, and somatic cell count were statistically similar in the presence and absence of the trap, so potential benefits of the trap for those measures were not evident at low fly populations observed during the study. The presence of a trap on farm reduced horn fly population growth rates (-1.01 vs. 1.00 flies/d) compared with the absence of a trap. Cows on farms with no housing (100% pasture) tended to have reduced horn fly numbers (11.7 vs. 28.3 flies/cow-side) in the presence of a trap compared with the absence of a trap on farm. Cows on farms with housing had similar horn fly numbers (11.2 vs. 14.8 flies/cow-side) in the presence of a trap compared with the absence of a trap on farm. In summary, these results indicate the trap was effective in reducing horn fly numbers on cows and reduced horn fly growth rates during the pasture season in organic dairy production systems, but benefits in improved milk production were not evident likely because of relatively low fly populations.
本研究的目的是评估商用真空捕蝇器（CowVac，斯伯丁实验室，里诺，NV）在有机奶牛场生产系统中的功效，以控制牛虻、厩蝇和家蝇。当奶牛走过陷阱时，苍蝇会被悬挂的襟翼从脸部、侧腹和背部刷下来，并从一侧吹到腹部、乳房和腿部，然后从空气真空入口对面的吹气口和奶牛上方被吸进室内。该研究于 2015 年夏天在明尼苏达州的 8 个有机奶牛场进行，牛群规模从 30 到 350 头不等。农场按位置分为两组；在夏季的第一阶段（6 月至 7 月），在一个农场设置了捕蝇器，而在夏季的第二阶段（8 月至 9 月），捕蝇器被送到其配对的农场。每周访问一次农场，从陷阱中收集和计数苍蝇，并对奶牛上的苍蝇进行计数和记录。在整个研究期间，在农场收集牛奶产量、脂肪和蛋白质以及体细胞计数。使用 SAS（版本 9.3，SAS 研究所，卡里，NC）的 GLM 过程分析数据。分析的独立变量是农场、捕蝇器存在、住房情况和夏季时期的固定效应。与没有捕蝇器相比，有捕蝇器时牛身上的牛虻数量减少了 44%（每侧 11.4 只苍蝇对 20.5 只苍蝇）。稳定苍蝇（每腿 5.4 只苍蝇对 7.1 只苍蝇）和家蝇（每头奶牛 1.0 只苍蝇对 1.0 只苍蝇）的数量在有或没有捕蝇器的情况下在农场相似。有捕蝇器的农场的牛奶产量与没有捕蝇器的农场相似（15.5 千克/天）。在有或没有捕蝇器的情况下，牛奶产量、牛奶成分和体细胞计数在统计学上相似，因此在研究期间观察到的低苍蝇种群中，该捕蝇器对这些措施的潜在益处并不明显。与没有捕蝇器相比，有捕蝇器时农场的牛虻种群增长率降低（-1.01 对 1.00 只苍蝇/天）。与没有捕蝇器的农场相比，没有住房（100%牧场）的奶牛身上的牛虻数量减少（每侧 11.7 只苍蝇对 28.3 只苍蝇）。有住房的农场的奶牛身上的牛虻数量相似（每侧 11.2 只苍蝇对 14.8 只苍蝇），与没有捕蝇器的农场相比。综上所述，这些结果表明，该捕蝇器在减少有机奶牛生产系统中牛身上的牛虻数量和减少牛虻生长速度方面是有效的，但由于苍蝇数量相对较低，改善牛奶产量的益处并不明显。
