Winter calls for focus on gestating cows’ health
For many ranchers, calving season is just around the corner. This means that cows in their final trimester of gestation are also battling winter weather. As a result, their needs, as well as the needs of their unborn calves, increase during the colder months.
From increasing a cow’s energy intake to giving vaccinations in the final trimester, there are several considerations to keep in mind for caring for gestating cows to make sure the calves are healthy at birth and beyond.
“What we do for the calf in utero makes a big difference once the calf is on the ground,” said Daniel Scruggs, DVM, Zoetis managing veterinarian. “The fetus is without protection for most of the pregnancy, relying on the dam’s immune system. Disease prevention is crucial throughout gestation, especially since the fetus does not develop an immune system until later in gestation, so vaccination programs can help improve colostrum quality to help fight off early infection.”
The concept of fetal programming suggests that during development of the fetus, maternal nutrition impacts fetal, neonatal, and postnatal health and performance of the offspring. In other words, the care of gestating cows through the winter months will determine the quality of those cows’ daughters as replacement heifers or the gains of fat steers.
“How do we help the calf in utero?” asked Scruggs. “It all comes down to nutrition. There’s emerging information that shows how that cow is nourished helps that calf develop and helps it thrive and grow after birth. I’m always concerned about that calf’s ability to withstand cold temperatures within the first 48 hours of life. Calves that come from poorly nourished cows have a lot less ability to maintain a body temperature if they are unfortunate enough to be born during a cold rain in March or April.”
Simply put, “Cow nutrition is equal to calf vigor, which is equal to survivability,” said Scruggs. Therefore, the health of the gestating cow should be a top priority. Scruggs recommended sorting off thinner or older cows for more specialized care, if possible, during the cold winter months.
“Cows who have a lower body condition score are going to require more energy during the winter months, and this can be addressed through supplemental feed or sorting them off” he said. “Once they calve and go into lactation, it’s extremely hard to address issues of a low body condition score.”
For the rest of the herd, understanding how lower temperatures and increased moisture can impact the herd’s intake needs is crucial.
“For maintaining body temperature, it becomes an astonishing difference in energy needs when a cow is in 35°F weather with a wet hair coat and 50 mph wind,” he said. “It’s okay if it’s a few days of that at a time, but last winter, we had weeks and months of cold weather, and if the cattle weren’t getting enough groceries, they were shelled out. Not accounting for extremes in weather is a big mistake.”
To give an idea of energy needs, University of Nebraska-Lincoln (UNL) Extension Beef Team offered this example:
According to the UNL Beef Team, “Let’s say, for the next week temperature is going to be 5°F and the wind out of the North at 15 mph, then the wind chill index is -10° F. At those environmental conditions, energy needs of the herd increases by about 30 percent. If the total digestible nutrients (TDN) requirements of the cows are 12 pounds of TDN/head/day for this week, you would consider bumping the ration to 15.5 lb./head/day. This is an increase in 3.5 pounds of TDN/head/day. If grass hay is 57 percent TDN, that’s an increase of about 6 pounds per head per day on a dry matter basis. If the hay is 88 percent dry matter that would mean each cow receives an additional 7 pounds per head per day.”
To address cow needs in cold weather, watch body condition scores, allow access to shelter belts for wind protection, and be prepared to feed more energy to cows.
In addition to nutritional needs of the gestating cow herd, health issues are also a concern.
“In colder climates where ranchers calve cows in tighter areas, we see more diarrheal diseases,” said Scruggs. “Ranchers need to think about vaccinating cows to prevent against rotavirus, E. coli, and Coronavirus. It really comes down to planning ahead. Producers should be thinking about this 3-4 months before calving begins.”
He adds, “If you have treated 10-15 percent for scours in previous years, it would be worthwhile to run them through the chute to address the reoccurring problem in your operation.
Biologically, the best time to administer vaccines would be a month before the cow starts making colostrum, so the antibody levels peak at calving time.
“Realistically in a 90-day breeding season it’s difficult to get every cow within a month of calving, so within a reasonable time frame of calving is fine,” he said. “Because antibodies are concentrated in the colostrum, the most important part is getting the colostrum into the calf at birth. This means that calf has to get up and nurse aggressively, which goes back to cow gestation. The calf’s vigor and ability to control body temperature depends a lot on how that cow is fed from the fifth month of gestation on.”
The advantage of offering a little extra care is increased profits down the road.
“When we’re getting north of three dollars for a weaned calf, those people who put more money into those calves last winter, aren’t sad they did,” said Scruggs. “The new trend in the cattle business is better execution, and the market is rewarding ranchers for that. Ranchers who are offering better managed calves are getting paid for what they are doing.”
When it comes to cow and calf nutrition, Scruggs advised working with a veterinarian and nutritionist to figure out the best plan for the herd. Whether that’s testing feedstuffs to know how much supplementation is needed or selecting the appropriate vaccination program to address your herds needs seek the advice of a professional and know that going the extra mile will pay off in the long run.