Evaluation of a commercial vacuum fly trap for controlling flies on organic dairy farms

Abstract

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.

Activity and rumination of Holstein and crossbred cows in an organic grazing and low-input conventional dairy herd

“…In grazing herds, few to no studies have evaluated increases in activity; however, the low correlations in Sjostrom et al (2016) demonstrated a trend ( P = 0.10) for higher activity due to stable flies and fly avoidance behaviors. Kienitz et al (2018) reported that flies on cows may be challenging for organic dairy farms, and that farms similar to the experimental herd in the current study, would benefit from fly control methods to improve milk production and animal welfare.…”

Evaluation of solar photovoltaic systems to shade cows in a pasture-based dairy herd

“…Stable flies on front and back legs were recorded as the mean number of stable flies per leg, horn flies per a cow's side, and face flies per a cow's face. Fly counts were made from a distance of 4 m (Kienitz et al, 2018;Perttu et al, 2020). Ten behavior observations were conducted twice per day on every cow: once in the morning and once in the afternoon.…”

Determining the electromagnetic field parameters to kill flies at livestock facilities

“…At certain parameters, EMFs are widely used to enable suppressing action on insects [11]. Paper [11] shows that the cells of insects are able to absorb the electromagnetic energy from a millimeter range of wavelengths. All changes that are significant for larvae start and finish at the cellular level.…”

“…Expressions (11) to (13) allow us to derive from (9) the electric and magnetic components of the internal field for the first approximation. In this case, one can see that the main difficulty in determining the internal fields is associated with the calculation of elliptic integrals.…”

“…In this case, one can see that the main difficulty in determining the internal fields is associated with the calculation of elliptic integrals. The obtained expressions (11) to (13) define internal fields of the larva without taking into account their layered nature. Next, let an electromagnetic wave fall on the body of the insect of ellipsoidal shape, having two layers with the above-specified electrophysical characteristics.…”