Page 13 - MWC 2-3-2022s

The Midwest Cattleman · February 3, 2022 · P13
Cold Stress and Beef Cows

By Steve Boyles, OSU Extension Beef Specialist

Factors that create stress as scours. Animals in poor the current calf crop (milk
during the winter months condition before calving, pro- production) and next year’s
are cold, wind, snow, rain, vide inferior colostrum and calving date (rebreeding
and mud. The primary effect lower milk production. This date).
on animals is due to tem- can lead to lighter weaning In most years hay and
perature. All these factors weights or fewer pounds of stockpiled forage can ade-
alter the maintenance ener- calf to sell. Females that are quately provide the needed
gy requirement of livestock. in less than desirable body nutrients, but it can vary
Maintenance requirement condition at calving are slow- widely and should be tested
can be defined as the nutri- er to return to estrus. Body
ents required for keeping an condition at calving affects continued on page 31
animal in a state of balance
so that body substance is nei-
ther gained nor lost. An in-
teresting thing to note is that
while energy requirements
increase, protein require-
ments remain the same.
Some published sources
contain nutrient require-
ments for beef cattle that
include guidelines for ad-
justing rations during winter
weather. Even without pub-
lished sources, competent
livestock producers realize
the need for more feed during
cold weather. Make sure that
water is available. If water is
not supplied, cattle will re-
duce feed intake.

Daily dry matter intake of
beef cows with respect to
lower temperatures

Temp, F Intake, % Change
< 5 1.16
5-22 1.07
22-41 1.05
59-77 1.03

The metabolic response to
the stimulus of cold involves
practically all the systems of
the body. The striated mus-
cles shiver, the heart beats
faster, breathing becomes
deeper, urine flow is in-
creased, and the sympathetic
and pituitary controlled sys-
tems are activated to elevate
biological oxidations (energy
expenditure or heat produc-
tion) in all tissues. The result
is an increase in the cow’s re-
quirements for energy.
Spring calving cows, and
particularly heifers, in poor
body condition are at risk for
calving problems. The result
may be lighter, weaker calves
at birth, which can lead to a
higher death loss, and more
susceptibility to things such