Efficient beef production from spring-born bulls under 16 months
February 14, 2023
Many spring-born bulls in an under 16-month bull beef system are currently being moved onto their final finishing diet. Nigel Gould, CAFRE Beef and Sheep Adviser, looks at the key areas for efficient production.
Finishing male suckler bred cattle as young bulls under 16 months of age has been proven to be an efficient means of beef production, demonstrating superior feed conversion rates and lower total greenhouse gas emissions than their counterparts finished as steers. Spring-born bulls in particular can be finished at a time of higher demand for beef in May/June before the seasonal increase in cattle supply from grass-finished cattle commences.
This year in particular, with high concentrate costs and the high value of store cattle, it is important to do a beef budget before finishing any cattle to determine what beef price will be required to make a reasonable margin. Systems based on purchased ad-lib concentrates and straw will be most vulnerable to the current high costs of concentrates. It is also important to speak to your processor to make sure you have a market for these animals. High levels of management and attention to detail are required for this system to be successful. Calves selected should have good pre-weaning daily liveweight gains recorded of at least 1.25 kg. These should be from genetically superior sires showing high growth potential and easy fleshing ability to achieve appropriate levels of fat cover at slaughter.
As animals will be housed for 7-8 months in this system from weaning to finish, good housing facilities are required, providing adequate ventilation, feeding and lying space with a constant supply of clean water. Bulls consuming 10 kg of dry matter can drink 50 litres of water per day. A stringent herd health plan should be adhered to in order to eliminate or minimise any disease issues and maximise animal performance. To avoid animals getting hurt from fighting, animals should remain within their specific groups from weaning to slaughter, meaning that initial space allocation needs to be based on the target final finished weight of bulls in the pen or pens need to be split closer to finish.
Bulls need to average at least 500 kg by 12 months of age. An average daily live weight gain of 1.5 kg/day from 12 months to finish will give a final live weight of 680 kg. Assuming an average kill out of 58% this will give a carcass weight of 395 kg. Performance levels during this period can reach 1.7 kg per day or greater for certain bulls with strong terminal traits. Slaughter age can be reduced to 14-15 months in some cases.
Choosing the right type of concentrate feed is important. A crude protein content of 16% from weaning to 12 months of age will help grow frame. After this, crude protein can be reduced to 13% to focus on getting adequate carcass fat cover. Target a cereal content of 75-80%. Barley and maize are often the cereals of choice to achieve the desired starch levels for finishing bulls. At this stage, spring born bulls are likely to be eating at least 5-6 kg of concentrates and this should have been raised gradually. Gradually increasing concentrate intakes to ad-lib levels by approximately 1 kg every 4-5 days is recommended to avoid acidosis which can permanently reduce growth potential.
Where excellent quality silage is being fed to bulls in the finishing period, concentrate level could be limited to 8-9 kg. Again, excellent feeding management is required. Daily refusals of silage should be removed. Silage analysis is key to knowing your silage quality and if this is an option for your system. D-value of at least 70 is required.
Regularly monitor performance to ensure any possible problems are addressed as soon as possible. Any issues can quickly erode profit margins particularly for ad-lib concentrate systems.