Page 71 - The Welfare of Cattle

48 the WeLfare of CattLe

table 6.4 ectoparasite Impacts by Cattle Production System and Level of ectoparasite Management
extensive Systems Intensive Systems
active No active No
Cattle ectoparasites Management Management Management Management
Lice xx xxx xxx
scabies or “mange” mites xx xxx xxx
new World screwworm fly x xxx xxx
(Cochliomyia hominivorax)
Cattle grub (Hypoderma spp.) xxx xx
spinose ear tick (Otobius x xx x xxx
megnini)
Cattle fever ticks x xxx
(Rhipicephalus spp.)
3-host ticks (e.g. Dermacentor, x xx
Amblyomma ticks)
Pajaroello tick (Ornithodoros x x
coriaceus)
horn fly (Haematobia irritans) x xxx
stable fly (Stomoxys calcitrans) x xx x xxx
horse and deer flies x x
biting midges (Culicoides spp.) x x xx xx
black flies x x
Mosquitoes x x
face fly (Musca autumnalis) x xxx
house fly (Musca domestica) x x x xxx
x, xx, and xxx indicate an expected increasing abundance and impact of the ectoparasite(s).

(essentially a paintball gun firing insecticide loaded balls). However, the efficacy of treatment using
this method is still unclear given the low number of control trials performed to date.
Overall, the diversity of cattle ectoparasites will be greater in extensive, pasture-based systems
relative to intensive dry pen systems (Table 6.4). Most ticks, including 3-host ticks and the cattle
fever tick, will be more abundant in pasture systems than in intensive systems. However, the spinose
ear tick has proven to be an important pest in intensive systems where animal bedding provides
these ticks with refuge. For the most part, ticks are difficult to control in pasture settings and with
the exception of the cattle fever tick, herd managers do not put great effort into their control. Also
more abundant in pasture systems are horn fly and face fly which require undisturbed fecal pats
for development. These pests can be controlled on pasture using insecticide treated ear tags, feed-
through insecticides, or topical application of insecticidal dusts and sprays. They will not be present
in high numbers on intensive operations as manure pats do not remain intact. In contrast, the stable
fly and house fly develop in a wider range of fermenting organic materials, particularly in feces
and animal feed which are abundant in intensive systems. Control of these flies is difficult, with
manure management being the most important means to control them. Lice, mites, screwworm
fly (if reintroduced), and cattle grub could all be common in either extensive or intensive systems.
However for intensive systems, the high level of contact between herd managers and cattle along
with the ease of applying insecticides, acaricides, and parasiticides for control of these pests should
result in low abundance and low impacts from these pests. In extensive systems, while treatments
for these pests can be applied, the difficulty in quickly recognizing pest outbreaks and in applying
treatments to infested animals is likely to keep pest abundance and impacts higher than most herd
managers would like.