If they haven’t done so already, cattle producers should inventory the amount and quality of forages they will have available during winter. They should also evaluate each cow’s body condition and hair coat condition, and provide herds with shelters or windbreaks, suggests Kansas State University’s Dale Blasi, beef cattle Extension specialist.
Forage test to determine forage quality; higher-quality feeds should be used to increase the herd’s caloric intake during several days with sub-freezing temperatures. But, he adds, depending on the harshness of winter, increased animal requirements might need to be continued well into spring.
“Especially with those spring-calving cows, they are starting to enter into their third phase of gestation,” Blasi says. “We have to make sure we keep those pregnancies as healthy as possible.”
If feeding co-products such as distillers dried grains, producers should provide additional protein and fat to cows. Adding corn is fine – to a certain level.
“You get too much corn into the diet, you start to impact the rumen’s ecosystem, and you start to hurt the fiber-digesting capability of the lower-quality forages being consumed.” He recommends not more than a half of a percent of the animal’s weight. A 1,000-lb cow would not feed more than 5 lbs of additional corn.
“Make sure there is adequate protein coming elsewhere, so you’re not driving a protein-limiting ecosystem,” the beef specialist advises.
Assessing body and hair coat condition for each cow in a herd can help producers determine what energy requirements are needed in winter.
Cows with body condition scores of less than 5 might be at a health risk moving into winter, and that could compromise the health of the calves they carry. A hard winter’s affects could last into spring, and cows might lack in the quality of their first milk for calves and the ability to breed back in a timely manner.
Separate cattle by body condition scores, so thin cows can be supplemented with more nutrients. And watch younger and smaller females closely, Blasi recommends.
Be aware that, when cows are wet from snow or cold rain, their coats become matted and their insulation breaks down.
Kansas State research has shown that the critical temperature for a cow with a summer coat or wet coat is 60 degrees F. For cows with fall coats, it’s 45 F; for those with winter coats, 32 degrees; for those with heavy winter coats, it’s 19 degrees.
Increase forage requirements as the wind chill lowers, Blasi says. At freezing temperatures and winds at more than 10 mph, cows could need 15-20% more forage.
“The amount of hair will help those females combat the impact of wind chill.” As they start to shiver, however, they need more fuel, he says.
Many producers put cows out on grazing sorghum and corn fields. But they should also provide windbreaks to keep cows out of cold winds. A windbreak can provide up to a 70% reduction in wind velocity and change wind chill from -5 F to 7 F, a 12-degree swing, Blasi says.
“Any kind of shelter is a tremendous step forward for helping them withstand and coast over these inclement weather events.”
Producers may also consider providing cows grazing stocks with supplements on extremely cold days, and at certain times of day.
“A well-known phenomenon with feeding pregnant beef cows is that feeding them in the afternoon and evening hours has a corresponding effect on calving in daylight hours,” Blasi says. “Obviously, when we’re expecting babies coming, it’s nice to be there if the cows should need help. Feeding in the evening also increases the heat of fermentation for the cow as we see these nighttime lows.”
K-State Research and Extension’s Beef Cow Nutrition Guide offers more information on winter cow diets and supplements.