Evaluating bulls’ BCS prior to breeding season is critical
Published on March 21, 2020
Although breeding season for many operations is still a few months away, University of Nebraska-Lincoln (UNL) Extension Cow/Calf Specialist Karla Wilke says producers need to start evaluating the body condition of their bulls and preparing them for the breeding season.
“Body condition score (BCS) is just as important in bulls as it is in cows,” says Wilke. “Many times when producers are disappointed with the results of their preg check, they assume the cows were thin and/or not cycling well at breeding time.”
Wilke continues, “While this may be a part of the issue, seldom the condition of the bulls prior to breeding time is evaluated to see if BCS of the bulls could be a potential issue.”
BCS of bulls
Wilke notes research has shown bulls with a BCS of five or six have better semen quality than those with a four and below or a seven and above.
“Much like evaluating a cow’s BCS, producers need to evaluate the cover over the front ribs, in the brisket and over the tailhead,” explains Wilke. “It is also important not to let gut fill or hair cover impact their evaluation.”
According to a UNL publication titled Body Condition Scoring Beef Cows, “In a moderate BCS of five the 12thand 13th ribs are not visible to the eye unless the animal has been shrunk. The transverse spinous processes can only be felt with firm pressure and may feel rounded but are not noticeable to the eye. Spaces between the process are not visible and are only distinguishable with firm pressure. Areas on each side of the tailhead are starting to fill.”
The report notes in a moderate BCS of six, the ribs are fully covered and are not noticeable to the eye, the hindquarters are plump and full and there is noticeable “springiness” over the foreribs and on each side of the tailhead. It states firm pressure is required to feel the transverse processes and the brisket contains some fat.
Preparing bulls for breeding
“It is not uncommon for a bull to lose 100 to 200 pounds during the breeding season which can translate to one or two scores,” states Wilke. “Therefore, it is critical to have bulls with a BCS of 5.5 to 6.5 before the breeding season.”
Wilke recommends evaluating bulls at least 90 days before the breeding season.
“This will allow producers time to add the necessary weight to bulls before the busy season,” she says.
“Typically, prior to breeding season, bulls are fed hay throughout the winter,” Wilke adds. “If a 1,300 pound yearling bull was fed 35 pounds grass hay with 56 percent total digestible nutrient (TDN) and 10 percent crude protein, he would likely maintain his weight but not gain any.”
Wilke goes on to explain if a producer wanted this bull to gain weight, 100 pounds for example, they would need to feed 35 pounds of grass hay with an additional protein source. Wilke recommends one pound of distillers’ based cube.
“It is important to evaluate bulls 90 days prior to the breeding season,” she states. “If they wait until 60 days before the breeding season, and they need a bull to gain 100 pounds, they will have to decrease hay to 31 pounds and increase their protein supplement to 3.5 pounds. Of course, this is more costly.”
Wilke also notes mature bulls often weigh more, between 1,500 and 2,000 pounds, so feed intake would need to be increased accordingly.
“A few additional ways to maintain wellness and put weight on bulls is to use windbreaks and bedding to reduce body weight loss and prevent frostbite on testicles,” says Wilke.
“On top of evaluating bulls beforehand, producers also need to continue monitoring their bulls condition throughout the breeding season as well,” says Wilke.
She continues, “Lastly, I want to remind producers Extension personnel are always available to help with ration development when producers are trying to maintain or increase the BCS of their bulls.”
Hannah Bugas is the assistant editor for the Wyoming Livestock Roundup. Send comments on this article to email@example.com.