Page 238 - The Welfare of Cattle

WeLfare Issues In feedLot CattLe 215

Weaning

Weaning in beef calves typically occurs between 6 and 8 months of age (United States
Department of Agriculture [USDA], 2008a). The combined effect of the abrupt separation
( physically and visually from the cow) and loss of milk is well known to be stressful for the calf
(Haley et al., 2005; Hötzel et al., 2010). Alternative methods of weaning include fence-line weaning
where auditory and visual contact is retained between the cow and calf or two-stage weaning where
a nose-flap first stops the calf from suckling and is removed when the cow and calf are separated
(Haley et al., 2005). Weaning is typically done with one or more of the procedures discussed earlier
including castration, dehorning, branding, ear tagging, and vaccination. Newly weaned calves are
at an increased risk for greater morbidity especially when other stressors such as transportation and
commingling with unfamiliar calves are added (Wilson et al., 2017).

Preconditioning

It is well documented that routine management procedures (castration, dehorning, branding, and
weaning), on their own, cause stress and or pain in calves to some degree. However, it is common
for several or all of the procedures listed above to be conducted at the same time to reduce animal
handling. It should be noted that handling itself is a known stressor for cattle (Woiwode et al., 2016),
particularly if rough (Grandin, 1997). The welfare implications of handling cattle numerous times
to conduct one routine management procedure must be weighed against the effects of conducting
multiple routine procedures at one time. Research studies assessing this are currently lacking in the
literature.
The most important and relevant point regarding ranch processing and the welfare of feedlot
cattle is that the effects of multiple acute and/or chronic stressors are additive. A study conducted
assessing the effects of castration and branding done at the same time compared to each procedure
alone confirmed that calves receiving both procedures had greater physiological and behavioral
indicators of pain than those that only received one of the procedures (Meléndez et al., 2017b
unpublished data). This was also confirmed in another studies assessing the combined versus sin-
gle effects of castration and dehorning (Sutherland et al., 2013). Ultimately, the greater the stress
response the more substantial the immunosuppressive effect resulting in increased calf morbidity
and mortality (Dhabhar et al., 1997; Duff and Galyean, 2007; Wilson et al., 2017).
Preconditioning is a management strategy used to reduce welfare issues associated with
bovine respiratory disease (BRD) in highly stressed, weaned and transported beef calves
(Radostits, 2000). Although there is no standard protocol for what constitutes preconditioning,
the most common recommendations are that calves be weaned for a minimum of 35–45 days, be
familiar with eating from a feed bunk, be castrated and dehorned at least 3 weeks prior to being
transported off the ranch and be vaccinated (no earlier than 4 months of age) and provided para-
site control (Radostits, 2000). If only some of these preconditioning criteria are done the term
“conditioned” is used instead of preconditioned. The welfare benefits of preconditioning are well
known and include improved rate of gain (Karren et al., 1987) as well as the reduced incidence of
BRD in the first 28 days in the feedlot (Macartney et al., 2003). It is assumed that conditioned and
preconditioned cattle would experience similar health and welfare benefits but this has not been
well studied. One of the few studies assessing the effect of conditioning (or not) combined with
long and short haul transport on calf welfare, reported that conditioning calves prior to transport
allowed them to better tolerate the stressors of transport and handling (Schwartzkopf-Genswein
et al., 2006). This was concluded based on the fact that conditioned calves had reduced stress hor-
mone (cortisol) concentrations pre- and post-loading and spent greater proportions of their time
feeding and less time standing and walking after transport compared to nonconditioned calves
(Schwartzkopf-Genswein et al., 2006).