While 60 can mean a lot of things, it is also an important number in the cow-calf world that can have repercussions all the way down the supply chain. More specifically, 60 is the number of days a calf has to reach its full genetic potential.

Woolsey cassidy
Managing Editor / Ag Proud – Idaho
Cassidy is a contributing editor to Progressive Cattle and Progressive Forage magazines.

“A calf’s highest genomic potential is the day they are born, and then we start to screw it up,” said Vic Cortese, a veterinarian and director of cattle and equine immunology for Zoetis. “It starts with you at the cow-calf.”

Speaking to producers at the Cattlemen’s College during the 2017 National Cattlemen’s Beef Association (NCBA) Cattle Industry Convention in February, Cortese highlighted research in the area of “perinatal programming” and the impact it has long-term.

He explained the term “prenatal” is referred to everything done before the calf is born to help it express its genomic potential, whereas “perinatal” is everything that is done after the calf is born to help it express its genetic potential – and it’s set by 60 days of age.

One such factor is colostrum. The benefits of colostrum in immediate health and immunity aren’t new to the cow-calf producer, but studies over the last decade suggest that the biggest impact may actually be in long-term performance.


Cortese said, “As cow-calf operators, we always thought, ‘Well, if we don’t have early pneumonia or scours, we are getting good colostrum transfer and everything is good.’” But that’s only half of the story.

Researchers are finding there is a whole series of hormones concentrated in colostrum at higher levels than in the bloodstream of the cow. Some of the hormones include insulin, leptin and relaxin – which influence feed and reproductive efficiency, gain, appetite and how the animal perceives stress long-term.

Bringing the point closer to home, Cortese asked seedstock attendees if they had ever had a bull with exceptional genomics that didn’t pass his breeding soundness exam (BSE). He explained that might have occurred because he didn’t get good colostrum transfer; the same goes for heifer reproductive failures.

“Colostrum transfer is one of the best predictors on how your calves are going to do,” Cortese emphasized. The challenge for cow-calf producers is to know how good their colostrum transfer really is.

Other constituents

Looking at another area of research, Cortese went on to explain the implications of early respiratory disease in perinatal programming.

He said when calves are treated for early respiratory disease before 3 months of age, they are 2.5 times more likely to die after 3 months of age. They are also 2.4 times more likely to die all the way up to 2 ½ years of age, and heifers are 2.4 times more likely to have calving problems.

“That calf with mild pneumonia when it is young never catches up,” he said. “That one-time respiratory instance will follow a heifer forever.”

But that’s not all. Cortese also told attendees that using an antibiotic to treat scours could have a long-term impact. Using an antibiotic will change the animal’s feed efficiency and weight gain for the rest of its life, he said. Producers need to know what is causing scours in their facility and whether they need to use an antibiotic or not.

Introducing the concept of “prime boost,” Cortese explained that it’s a lifetime vaccination strategy, or in other words, “a look at how to start the baby, maintain it as a teenager and then build on to that as an adult.”

Different from what producers have traditionally been taught, the research on prime boost shows that by combining intranasals with injectables, better vaccine response can be achieved. Essentially, it’s better to start with the intranasal and build it with the injectable, Cortese said.

In addition to that, Cortese cautioned producers about administering multiple vaccines on the same day. He said the first time a calf is vaccinated (regardless of age) and given an injectable IBR-vaccine (modified-live or killed) it will down-regulate its immune response to other vaccines given to the calf.

Only one out of three calves will have a normal response to pasteurella, and only one out of three calves will have a normal response to clostridial. But the good news, he said, is that when IBR goes intranasally, that interference goes away.

“This research explains why you may vaccinate calves perfectly and still have a bad outbreak of pneumonia,” he said. “It may have occurred because of your colostrum or the vaccinations you gave pre-wean weren’t working.”

Coming full circle

The last piece of perinatal programming Cortese touched on was early growth. As previously stated, perinatal programming is done by 60 days of age. Research shows that if the genomic potential is hit just right, producers can swing weaning weight by 60 to 90 pounds. “That’s free money for those of you in cow-calf,” he said.

When looked at in those terms, what would have another 60 to 90 pounds done for producers last year? There is a limited window of opportunity for producers to help their calves reach their full potential. Whether it’s kept as a replacement heifer or breeding bull, or whether it goes to the feeding industry, the number 60 has never been more crucial.  end mark

Cassidy Woolsey

PHOTO: Calves have a 60-day window to reach their full genetic potential. Staff photo.