Page 336 - The Welfare of Cattle

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denying the needed care to minimize further damage and to increase chances of recovery jeopar-
dizes animal welfare and all of the five freedoms as described by the Farm Animal Welfare Council
(2009). Preventive strategies and proper management of the downer cow with the goal of preserving
her welfare will be the focus of the remainder of this chapter.

rISK FaCtOrS aND PreVeNtION StrateGIeS

Ideally, efforts of livestock producers and workers should focus on preventing new cases of
nonambulatory cattle. In order to prevent this condition, it is necessary to be aware of risk factors
associated with it. Again, it is important to understand that while the issue of nonambulatory cattle
has been highly publicized at slaughter facilities, most downers originate and are managed on the
farm. If we are to focus on the prevention of downers, we must focus on best farm management
practices that result in fewer occurrences of disease and injury. It is essential to understand that a
downer cow can be the result of a multifactorial process and that in many cases determining the
contributing factors and managing the affected cow can be a complex task.
Causes of downers can be classified into four general categories: injuries, metabolic imbalances,
infectious or toxic diseases (Green et al., 2008). For several decades, cases of prolonged recumbency
on dairy farms have been associated with milk fever (hypocalcemia), and other problems around the
time of parturition such as dystocia, retained placenta and stillbirths (Correa et al., 1993; Fenwick,
1969). Over-conditioned dairy cows with a variety of metabolic or infectious diseases at the time of
parturition have been linked to greater morbidity and mortality in early lactation (Littledike et al.,
1981). Dairy owners recognize the challenges of the periparturient period in dairy cows. When
surveyed about risks associated with downer cows, producers reported that most cases occur within
one day of calving and are associated with dystocia (Cox, 1986). The fact is that after parturition,
dairy cows can be compromised with a variety of metabolic conditions, infectious diseases, and
lameness and become recumbent (Stojkov et al., 2016).
Greater milk production has also been linked to the occurrence of downer cows on dairy opera-
tions. Dairy producers perceive high or average milk-producing cows as the great majority of down-
ers (Cox et al., 1986), and a national survey identified high milk production as a risk factor for
downers (Green et al., 2008). Greater milk production per cow brings about challenges that must
be met with excellent management practices, including but not limited to nutrition, cow comfort,
reproductive management, and disease identification and treatment protocols. Injuries related to
facilities design, maintenance, and animal handling are associated with lameness and downers.
Concrete flooring has been associated with more lame cows (Adams et al., 2017), and with downer
cows (Green et al., 2008). When paired with improper maintenance and incorrect animal handling,
concrete flooring can cause injuries that lead to lameness and downers.
Herds with greater number of animals inherently have more opportunity for disease or injury
events that can lead to downers. A recent survey identified larger herd size as a risk factor for
the occurrence of downer cows (Green et al., 2008). It is worth mentioning that recent studies
have also associated larger herds with fewer lame cows (Adams et al., 2017). Lager herds can
be managed in such a way as to prevent those disease events that could lead to downers. For
example, having sand bedding and having cows on pasture has been associated with fewer lame
cows (Adams et al., 2017). Additionally, providing heat abatement and feeding rations formu-
lated by a nutritionist was recently associated with fewer thin cows on dairy farms (Adams et
al., 2017). These practices are not exclusive of a specific herd size and can therefore be used to
reduce the prevalence of lameness and low body condition, two factors that have been associ-
ated with downers. Careful management and closer observations of animals at risk, especially
during the periparturient period are key factors in the prevention of downers (Cox et al., 1986;
Stull et al., 2007).