Turning young bulls into productive herd sires

All beef cattle producers want their young bulls to develop into productive sires, but for this to happen, they need to manage these animals carefully. Annelie Coleman spoke to livestock nutrition specialist Dr Francois van de Vyver about how to achieve this.

- Annelie Coleman

FAST FACTS

• As bulls mature, their nutritional requirements change from those for growth and development to those primarily for maintenance.
• Young bulls need rations with a high level of crude protein to ensure optimal muscle development.
• Environmental factors such as temperature and terrain affect the nutritional requirements of livestock, young bulls included.

Environmental factors, of which herd management forms an integral part, exert a 70% influence on the performance of an adult bull, whereas genetics account for only 30%. This means that the nutrition of young bulls is crucial to ensuring a top-performing adult animal, according to Dr Francois van de Vyver, national technical manager at Voermol Feeds. He warns, however, that putting young bulls on high-concentrate rations can be detrimental to their future fertility and soundness.

FEED FOR MUSCLE GROWTH

As bulls grow, their nutritional requirements change. Mature bulls use nutrients primarily for maintenance, whereas younger animals require nutrients to support growth, development and maintenance. Nutritional requirements must be met in full to develop growing bulls from weaning onwards, but feeding a young bull a high-energy diet after weaning will result in rapid weight gain, which can create a host of problems such as a reduction in semen quality. In addition, an excessively fat bull will be lazy and unhealthy.

Animals go through different phases of growth on the road to adulthood. “It’s therefore vital that animals are fed according to their nutritional demands at the different stages of tissue development,” explains Van de Vyver.