Page 220 - The Welfare of Cattle

ranGe beef CoW and CaLf heaLth and WeLfare 197

investment is typically in the low single digits, and where revenue comes from selling animals,
producers have additional compelling reasons beyond emotions and moral commitment to assure
that every animal is as healthy and robust as possible.

BeeF COW PrODUCtION CYCLe

Cattle have a long generation time compared with poultry or pigs. The gestational period of a
beef cow is approximately 280–285 days. After a cow conceives, she will carry the calf for about 9
and a half months. After delivering the calf she needs approximately 60 days until her reproductive
tract has recovered from the pregnancy and she returns to fertile reproductive status. Therefore, a
full cycle of reproduction is approximately a year.
Cows are capable of becoming pregnant at any time of year—they are not seasonal breeders
like sheep and goats. If bulls are left commingled with the breeding herd throughout the year, then
heifers can conceive as they reach puberty and cows will be bred whenever they come into heat
(ovulate), and calves can be born at any time of year. There are some producers who allow such
year-round access of cows to bulls, but the overwhelming majority of cow/calf producers in the
Western US focus on managing a breeding season of their choice. Managing a breeding season
establishes a “production cycle” that can improve herd productivity.
Having a breeding season allows a producer to control the birth time of calves, which in turn
helps focus labor efforts and forage availability, and develops a calf crop of relatively similar age
and size for marketing. Smaller scale producers and producers in the Southeastern US are more
prone (approximately 50% of producers) to not have a defined breeding season, probably because of
more year-round forage availability, or the desire to not manage the herd very much. Larger scale
producers and especially producers in the Western states mostly manage for a single calving season
(approximately 80% of producers), and most of these calve in the Spring, between February and
May (approximately 65%–70% of producers).
A spring calving season provides cows green grass with more nutrient density during lactation,
the time of most intense nutrient demand. Calving at other times of year means that cows need
more supplemental feed, which is very costly, if they are to maintain good milk production for their
calves, and still remain in good body condition so they can breed back again.
Having a successful defined calving season requires the producer to manage bulls and cows
fairly closely. But this effort can be rewarded by having most of the calves born in a short period
of time. This means that problems during the calving season can be more closely monitored, and it
produces a good crop of calves with very similar ages and sizes, which usually leads to better prices
for the calves when they are sold.

aNIMaLS ON a COW/CaLF raNCh

The cattle on a cow/calf operation represent both genders and a wide variety of ages and life
circumstances. The cows range in age from 2-year-old primiparous heifers (first calf heifers) to
very old dams. Typically around 15% of cows will be sold each year. Some may be sold to another
ranch as breeding animals, especially in circumstances where a ranch has too little feed to maintain
current herd size (e.g., during drought). More commonly cows are sold as slaughter animals (culled
from the herd) because they are no longer productive.
The two most common reasons for culling cows are that they do not produce calves (fail to
conceive, abort, or produce an unthrifty calf), or that they wear their teeth down as they get old and
cannot chew food well and maintain good body condition. This says a lot about cow health in the
cow/calf production system. The majority of cows are healthy and productive throughout their lives