Rick Rasby talks about having bulls in ideal condition is important for a successful breeding season
April 10, 2012
One of the most important considerations for beef producers as breeding season approaches is having the bull battery in tip-top shape, according to Rick Rasby, University of Nebraska beef extension specialist. ” A pregnant cow is worth more than an open cow,” Rasby said. “We need to give the bulls every opportunity to get the females pregnant. It is important that the bulls are in shape for the upcoming breeding season, so as many cows are bred as possible,” he explained.
“Many times, the bulls are pulled from the breeding pastures and left to fend for themselves,” he continued. “The impact of the bull on the herd is significant. A bull contributes half of the genetic material of the calves. It is important to make sure that bull is in the best shape possible. Eighty to 90 percent of the genetic change in a beef cowherd is based on the bull you select, in an operation where heifers are retained as replacements,” Rasby said.
Prior to breeding, Rasby recommends producers work closely with their veterinarians to ensure the bulls have all their vaccinations, and have passed a breeding soundness exam. “The Beef Improvement Federation (BIF) recommends bulls 15-18 months of age have a scrotal circumference of at least 31 centimeters,” Rasby said. “Scrotal circumference is a threshold trait. A larger scrotal circumference means the bull produces more sperm. In relation to puberty, a larger scrotum also means the bull’s heifer daughters will reach puberty at a younger age.”
Rasby recommends producers have a veterinarian perform a breeding soundness exam on any bulls that will be used during the breeding season. During this exam, the scrotum should be palpated for any damage from weather, or injury. Bulls should also be semen checked to ensure they are producing plenty of viable sperm. During the exam, the hooves, legs and eyes of the bulls should also be evaluated to make sure the bull has the ability to get around with good, clear sight.
Start monitoring body condition early
Producers should start monitoring the body condition score (BCS) of their bulls as early as January. Body condition scores can range from one to nine, with one being extremely thin and nine being extremely fat. Rasby said producers should aim for a BCS of 6 for their young bulls that are still growing. “Young bulls can lose at least 100 pounds during the breeding season,” he said. “What you don’t want to see them losing is muscle tissue. I recommend to producers that they try and keep young bulls in a BCS of 5 and a half to 6.
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When a producer purchases a new bull, Rasby recommends trying to get them home as soon as possible. “If they are over-conditioned or under-conditioned, you will need time to get them in to the right body condition prior to breeding,” he explained. “If a bull is carrying too much condition, reducing its energy intake will get them into the right body condition score at a slower rate,” he said.
For mature bulls, Rasby recommends putting condition on them by allowing them to graze native grass. “It will build their energy reserves or body condition gradually,” he said. The bulls can also be fed five to seven pounds of grain once a day, and some good quality hay to improve their body condition.
Rasby said he has fed bulls four to five pounds of distillers grain each day and allowed the bulls to graze on dormant native range. “Feeding a good quality grass hay also works well,” he added. “If the bulls are really thin, you may have to feed up to 20 pounds of concentrate per head per day,” he said.
Introducing the bull battery
It is important to introduce the bull battery well before the breeding season begins. “Bulls like to establish a pecking order, especially when you introduce a new bull,” he said. “It is important to allow them to do that prior to the breeding season.”
He recommends introducing new bulls to established bulls in a large pasture, rather than a smaller, confined pen, to reduce the chance of injury.
How many cows a bull can service can be impacted by the age of the bull, the terrain of the breeding area, and the size of the pasture. “Younger bulls can service less cows,” he said. Beef producers should limit yearlings to 15-month-old bulls to servicing about 15 cows, he said. Bulls that are 24-months can service around 24 cows, and mature bulls can service 25-35 cows.
During the first two weeks of the breeding season, Rasby recommends checking the bulls two to three times a week. “It is imperative to observe the bulls frequently. Check them for injuries, especially in mult-sire pastures,” he said. “In a multi-sire pasture, if a bull can’t breed cows, the others will cover up his mistakes so there is less chance of having open cows at the end of the breeding season,” he explained.
Single sire pastures should be monitored frequently throughout the breeding season to make sure the bull is getting the cows bred and is not injured. Producers may want to consider rotating bulls in case a bull goes bad. Rasby said producers should also write down ear tag numbers of cows they see being serviced, and check 21 days later to make sure that cow doesn’t come back into heat.
Maintenance after breeding
After the breeding season, Rasby recommends checking the bulls for physical problems, especially in their feet and legs. Producers should also take note of the bulls’ condition. “Mature bulls typically do well once they are back on pasture. Just put them where they can get plenty of exercise,” he said. “They shouldn’t need a supplement, other than the vitamins and minerals you are already feeding the cows. Make sure they have adequate salt,” he added. “Young bulls can lose 100-300 pounds during breeding, so I recommend putting them on a vegetative pasture where they can gain one and a half to one and a quarter pounds per day. They also need vitamins, minerals, and salt,” he said. “The goal for the younger bulls is to make sure they will reach their mature weight by the next breeding season.”
Although Rasby doesn’t recommend feeding a lot of grain, since it can affect the longevity of the bull in the herd, some situations may call for some concentrate in the diet. Rasby said bulls will typically eat 2.2-2.5 percent of their body weight each day. “The makeup of their diet is dependent on their weight and what they need to gain,” he said. Typically, a bull will need a diet with 9-11 percent crude protein and 56-64 percent TDN. Ranchers can feed distillers grain as a supplement, but Rasby warns ranchers to remember distillers grain is high in phosphorus, so they may need to add calcium to the diet. “It is important to keep calcium and phosphorus in check so the bull doesn’t develop urinary calculi problems,” he said.