Short communication: Effects of mesh leggings on fly pressure and fly avoidance behaviors of pastured dairy cows

Abstract

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.

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

“…Before the initiation of the study, fly counts and fly avoidance behaviors, respiration, and hygiene scoring were agreed upon on site by 5 observers (an experienced animal scientist and the 4 observers that were conducting the visual observations for the study). These definitions were based on previous research studies and the training of the animal scientist (Sjostrom et al, 2019;Perttu et al, 2020). Fly counts on cows were recorded twice during the morning (1000 h) and twice during the evening (1600 h) observations.…”

“…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.…”

Stable fly activity is associated with dairy management practices and seasonal weather conditions

“…Instead, modeling pen level average leg counts can identify to actionable factors that producers can manage. Previous studies modeled leg counts as an average based on several cows or over time [5,23,24,26,[39][40][41][42] as well as modeled fly counts for both leg counts and trap counts after log transformation [24,26,43].…”

A Historical Review of Management Options Used against the Stable Fly (Diptera: Muscidae)

“…Horse owners often put protective rugs, fly boots and face masks on their horses to reduce the numbers of stable flies being able to blood feed from their animals. The use of mesh leggings and leg bands as a physical barrier (non-insecticidal) to stable flies reduced foot stomps behavior in both horses [308] and dairy cows (only leggings tested) [309]. A recent and novel approach has seen the painting of black and white stripes on livestock such as cattle, which can reduce biting fly attacks (mostly stable flies) and associated fly-avoidance behaviors [310].…”