OMAHA (DTN) -- Bull buying season is in full swing. Purchase prices in most cases are on the expensive side.

Taking care of that bull investment from the time of purchase until he is turned out on pasture for the breeding season is critical. They must be in proper body condition score (BCS) before breeding season and they need the correct nutrition.

Forage plays a vital role in this transition period, according to an extension specialist.

BULLS CAN BE OVERCONDITIONED

Bulls from weaning to yearling age are often managed to measure their genetic growth potential, according to James Rogers, North Dakota State University Extension (NDSU) forage crops production specialist. The type of feed ration they are developed on during this time can contain a high percentage of concentrates and a low percentage of forage to maximize growth rate.

At the end of this feeding period, some bulls may be "overconditioned," which can affect their fertility and also their ability to settle cows, he said in a NDSU press release.

Rogers said overconditioned bulls will have a BCS of 7 or higher on a scale of 1 to 9. Young bulls should have a body condition score of 6 to 6.5 at the start of the breeding season to compensate for weight loss during the breeding season.

Bulls that are actively breeding can lose up to 200 pounds during the breeding period. Bulls at a BCS of 7 or higher can have fat deposits in the scrotum that interfere with temperature regulation, which can affect semen quality.

"Evaluation of overconditioned bulls at the University of Georgia found that only 41% passed a breeding soundness examination compared to an 81% passage rate of bulls in adequate condition," Rogers said. "Bulls that are overconditioned may also lack the stamina required to work through an entire breeding season."

STRATEGIES TO EASE THE TRANSITION

There are several management practices which can ease the transition of bulls from being overconditioned to breeding-season condition, Rogers said.

When new bulls are brought to your operation, consider biosecurity. Ideally, bulls should be quarantined for 30 days or at least two weeks before being introduced to other animals. This reduces the risk of introducing disease into your herd.

Provide an area where bulls can exercise with fresh water available, he said.

Give bulls some time to get adjusted to their new surroundings with a 90-day transition period being the best plan. This gives them time to adjust to different feeds and new routines.

Another benefit of a 90-day transition period is that it fits the spermatogenesis cycle, which lasts approximately 60 days. If there are any problems with the bull's semen quality, 90 days is enough time for a new cycle to be complete and resolve any issues.

FOCUS ON BULL NUTRITION

Buyers of bulls should know what feed ration the bull was developed on prior to purchase. Initially, after purchase, if bulls can continue to be fed a similar ration to what they had been used to, this will reduce stress and help keep them healthy.

Rogers said producers should avoid rapid and dramatic changes in diet. If bulls have been developed on high-concentrate diets, the change to a forage-based diet should be gradual. Replace concentrate with forage at a rate of 10% a week over several weeks.

"While we don't want young bulls to put on excessive condition, we still want them to grow," he said.

A daily weight gain target should be about 1.5 to 2.0 pounds per day. To do this, bulls will need access to a good supply of quality forage. Forage quality should be 10% crude protein and 60% to 70% total digestible nutrients (TDN).

Rogers said good grass hay or a grass legume blend will work well to stimulate rumen microbial development.

Producers should avoid feeding pure alfalfa hay as this might cause bloat or other digestive issues. Aim to have the bull transitioned to a forage-based diet two to three weeks before the start of the breeding season.

The goal is for the bulls to be ready to consume and digest pasture and range forages, Rogers said.

Once out on pasture, bulls should be monitored for excessive weight loss or physical problems that can prevent them from breeding. If possible, provide bulls with the supplementation to keep them growing and in good breeding condition.

"If you buy bulls that are overconditioned and turn them straight out into the pastures for breeding, you may not recognize them at the end of the breeding season," Rogers said. "Time spent getting bulls into breeding-season shape is time well spent, just like an athlete training for a sporting event."

Russ Quinn can be reached at Russ.Quinn@dtn.com

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