Spring bull buying season is an exciting time as cattle producers select bulls that they hope will improve the genetic composition of the herd. However, what many producers may not realize is that they could be bringing home more than just good genetics. 

In order to reduce the disease risk in the herd, the experts at the Kansas State University Beef Cattle Institute joined with Kansas animal health commissioner Justin Smith to outline good biosecurity practices for bulls coming to the ranch. This was the topic of discussion of the BCI weekly podcast, CattleChat. 

“When you bring a new bull onto the ranch, it is important to put him in isolation both for biosecurity and animal nutrition reasons,” said Bob Weaber, beef cattle extension specialist. 

Regarding biosecurity, it is important to select a bull that comes from a herd that matches the buyers’ cattle health protocols.

Evaluating bull health

K-State veterinarian Bob Larson advised buyers to confirm the bull has completed a breeding soundness exam. 

“Even if the bull was examined several months ago, it is worth repeating that exam just prior to the start of the breeding season so you can be assured he is fertile and ready to breed,” Larson said. 

Another test that Smith recommends is for trichomoniasis, which is a venereal disease in beef cattle that can lead to infertility and early term abortions in pregnant heifers and cows.

“Trichomoniasis is a silent disease because you don’t see it until you have open cows or term abortions. It is easy to test for when you are handling the bulls,” Smith said.

He encouraged producers to test for this disease at least twice a year in non-virgin bulls. 

“Look at your state regulations because some states require that test on bulls at 18 months of age, while other states don’t require it until a bull is 24 months old,” said veterinarian Brad White. 

Another tip White offered related to parasite control. 

“It is important that those bulls are well vaccinated and treated for internal and external parasites,” he said.

Adjusting bull diets

In addition to a thorough review of a bull’s health status, Weaber also advised producers address the bull’s nutritional needs. 

“Sale bulls are likely coming from a high starch diet and need to be transitioned to a forage-based diet ahead of pasture turnout,” he said. “With mature bulls we need to make sure they are in appropriate body condition prior to breeding.” 

Weaber said research has shown a connection between body condition scores and semen quality. Ideally the bulls that can maintain body condition scores of 5 and 6 tend to score the highest for semen quality. 

“Bulls don’t typically gain weight during the breeding season, so before turnout is a good time to transition them to a high roughage ration,” Weaber said. Often these high roughage diets, consisting mostly of prairie hay or brome hay, are deficient in protein. He recommended supplementing with dry distillers grains and a 20% range cube as a protein supplement. 

“They really only need a pound or two of either those two products in addition to dry hay to meet their nutrient requirements,” Weaber said 

Larson added: “Producers have to make sure that the bulls are in just the right body condition going into the breeding season because they are going to be walking a long distance and they need to have the energy reserves to be in good condition, while not being over-conditioned.” 

To listen to this podcast, search for BCI Cattle Chat wherever podcasts are found.

Alicia Boor is the Agriculture and Natural Resources agent with K-State Research and Extension – Cottonwood District. Contact her by email at aboor@ksu.edu or call 620-793-1910.