Bull, cow management impacts profitable herd

HANOVER, Ill. — Optimal cow and bull management will produce a uniform calf crop that is born in a 60-day window or less for most commercial herds.

“The most economical thing a veterinarian can provide for you is a breeding soundness exam for your bulls,” said Preston Cernek, associate veterinarian at Northern Illinois Veterinary Services, which has clinics located in Stockton and Milledgeville.

“It is more impactful than preg checking,” said Cernek during a presentation at the Cattlemen Connect Education Series organized by the Illinois Beef Association and held at Wildberry Farms.

Bulls have to be able to breed cows, the veterinarian said.

“A passing examination includes 70% or higher normal morphology, 30% or higher motility and an adequate physical exam,” he said. “If all three of these are not met, the bull does not pass.”

There is a difference between infertility and subfertility, Cernek said.

“A subfertile bull will get cows pregnant, but he will not get cows pregnant in an appropriate time window, the way you need him to,” he said. “The standards are set to help maximize the calving window and get the most calves as quickly as you can.”

Cernek advises checking bulls 60 to 90 days before turnout.

“If the bull is bad, that gives you enough time to wait the 60 days to recheck him,” he said. “Or, you have two to three months to find another bull.”

It is not a bad idea to have a spare bull, Cernek said.

“If you have extra bulls, then I’m OK with doing the exam on the day of turnout,” he said. “Then you know your bull is good for at least one day because a bull can go bad at any time.”

Bulls need to be interested in breeding cows.

“The only way this can be analyzed is if the farmer is watching the bulls,” Cernek said. “Most commonly, I’d say a bull that is not interested in cows is usually too young.”

The first step for a cow to have a calf is she must be bred.

“A key part of breeding is nutrition,” Cernek said. “And one body condition score can make a significant difference to your operation.”

Studies have shown, the veterinarian said, if cows have a body condition score of 6 at calving, 98% of them with show heat by day 40 after calving.

“And of those 98%, 90% of the cows will be confirmed pregnant if they have bull exposure at that heat,” Cernek said.

“If cows have a body condition score of 5, only 80% will show heat by day 40,” he said. “And more importantly, only 65% will be pregnant.”

Pregnancy checking is the second most economical service a veterinarian can provide, Cernek said.

“I generally say keeping open cows is unprofitable, but there are exceptions to every rule,” he said. “But it’s important to know exactly what the cost is.”

Milk production of the cow is important, as well as her feet and legs.

“And she needs to be tame enough so that you can handle her,” Cernek said. “I feel this one is overlooked.”

Most cows are evaluated on the calves they raise.

“So, keeping good records of calf growth can help find unprofitable cows,” Cernek said.

“The calf is the product that commercial producers sell, so everything is centered around the calf,” he said. “The cow and the bull are very important, but you have to have calves to sell.”

The most common reasons for a C-section, Cernek said, are either the calf is too big or the cow is too small.

“Less common reasons are the calf is deformed or the cow is dying,” he said.

Typically, a C-section requires two veterinarians.

“For our clinic, we have the farmer haul the cow to one of our facilities because we have found that the clinic is the great equalizer,” Cernek said.

“Everybody’s facilities are different, so we have a lot better success when the animal comes into our clinic even though it means taking a 20-minute ride in a trailer.”

Colostrum is the most important thing for a newborn calf.

“I cannot overemphasize the importance of colostrum for the calf,” Cernek said. “Generally, the calf needs four quarts of colostrum or colostrum replacer within four hours.”

Immune transfer occurs 12 to 24 hours after birth.

“So, when it doubt, give the calf colostrum replacer,” Cernek said.

“Calf scours is probably the biggest disease we deal with for newborns and young calves,” the veterinarian said.

“When young calves develop diarrhea, they become dehydrated,” he said. “Dehydration is what kills the calf — not the infection, but the lack of fluids.”

The No. 1 cause of scours is poor nutrition, Cernek said.

“If a calf doesn’t get enough energy from milk, that will cause scours,” he said.

Cold stress is another cause of scours.

“If you have a newborn calf that’s wet and it’s 45 degrees, that calf is going to be cold stressed and its nutrient requirements increase,” Cernek said.

Infectious agents can cause scours.

“But typically it’s poor nutrition and/or inadequate colostrum combined with a dirty environment,” Cernek said.

“Ninety-five percent of the infectious agents that are isolated in scour cases are rotavirus, coronavirus or cryptosporidium,” he said. “There are no antibiotics that cover these three pathogens, so when we are giving antibiotics to calf we’re worried about secondary infections.”

The best scour treatment is prevention, Cernek said.

“You can’t get out of scours with a needle — you have to rehydrate the calf,” he said. “Make sure the calf has enough colostrum and a clean environment, that will minimize disease problems.”