Trial by fire: some claim forage-fed bull tests are a better indicator of on-the-job breeding performance

摘要

Gain tests of 120-150 days on high-energy feeds have long been a seedstock producer's barometer of bull quality. Such tests grow young bulls fast, make them look better for sale, and illustrate the bulls' genetic ability as feed converters and to sire calves that do well in the feedlot. In the past decade, however, some stockmen have begun to find fault with this system. The reasons: 1. Overfat young bulls that are infertile (too much fat deposited in the scrotum interferes with sperm production and viability); 2. Unsoundness (feet and leg problems from too much weight too soon on immature bones and joints, and founder due to high grain diets); 3. A lack of stamina during breeding season. Many young bulls coming off feed tests "fall apart" when they're forced to rough it in the real world. 4. Some question the wisdom of striving for genetics that create larger animals with fastest gain on grain. This runs counter, they say, to the focus of building economical and profitable cow herds that raise good calves and breed back quickly on the forages available without expensive grain supplements.