Feeding High Concentrate Diets to Finishing Cattle

Francis Breen Beef and Sheep Development Adviser CAFRE

There are many potential advantages to high concentrate feeding systems.These include eliminating the effects of poor quality silage (and, indeed, any requirement for silage at all), achieving more predictable performance, higher kill-out percent, lower carcase fat, reduced labour and a higher turnover of animals. However this system requires a much greater level of management skill than traditional grass silage based systems.

Suitability of cattle and feeding period

Bulls should always be fed ad lib while the highest and most efficient rates of gain in steers and heifers will be achieved where concentrates are fed ad lib for 80 – 100 days. Animal performance in steers and heifers tends to deteriorate if ad lib feeding is prolonged due to the inefficiency of increased fat deposition.

The most suitable animals for this system are those of high genetic potential for growth which are in relatively lean condition and hence benefit from compensatory growth.

Intakes

If high intakes are not achieved it is impossible to get high performance. Dry matter intakes are typically two percent of animal body weight. It is useful to record feed intake to ensure that target performance is achieved.

Roughage

At least 10 percent of the diet should be a source of long roughage to maintain adequate rumen function. However this should not exceed 15 percent as performance may be reduced. Straw is the best option mainly due to its high fibre and dry matter content. The use of grass silage can depress concentrate intake therefore reducing performance potential and efficiency and may not provide adequate long fibre, particularly if it is finely precision chopped.

Feed quality

Energy - High-energy feeds should be used for maximum weight gains. A mixture of energy sources is preferable. For example maize meal is excellent for the finishing phase – assuming it is cost effective- but should not be included at levels above 30 percent of the ration whilst citrus and sugar beet pulps are good sources of digestible fibre making them very safe ingredients.

Protein – Finishing cattle require dietary protein levels of approximately 12-14 percent on a dry matter basis. Rapeseed meal, soyabean meal and cereal by products such as maize gluten and maize distillers’ grains are suitable protein sources. However, the inclusion of maize distillers’ should be capped at 25 percent as its high oil content can interfere with roughage digestion.

Minerals

It is important that minerals and vitamins are included to maintain health and animal performance. An inappropriate mineral mix may exceed requirements and increase the risk of toxicity, diarrhoea and reduce animal performance. A suitable mineral/vitamin mix with a calcium:phosphorus ratio of at least 2:1 should be used.

Water

Due to the high intake of dry feed fresh water should be available at all times to maintain feed intake and animal performance. It is recommended that water troughs are inspected daily and cleaned at least two to three times per week or more frequently if water is fouled.

Feeding management

Key elements include

Build up intakes gradually by feeding three times per day. Increase the amount offered per head at any feed by no more than 0.5 percent at a time. Animals will be established on ad lib feed when they are barely clearing up from the feed before.
Once established on ad lib feed never allow animals to run out of feed, straw or water.
Bird and vermin infestation can be a problem where ad lib feed is available. Ways to overcome this include the use of shorter troughs or covered hoppers.
Good trough management is critical. Even sub-clinical digestive upsets will affect growth rates and profitability well before an animal is visibly ill. Adjust feed level according to how much is left in the trough and avoid letting stale feed build up.
Never go below five percent feed remaining in the trough at each feeding time. Do not have animals waiting at empty troughs for the next feed.
Avoid sudden changes in diet type or brand. If a change is unavoidable ensure that nutrient levels are not altered substantially. Any new diet should be introduced by mixing it with the previous concentrate over a 7-10 day period until substitution is complete.

Table 1. Sample rations for high concentrate feeding

Maize Meal 25%

Distillers 25%

Citrus pulp 25%

Barley 20%

Molasses 2.5%

Min& Vits 2.5%.CP 13.0%

Barley 20%

Maize Meal 30%

Maize gluten 20%

Distillers 15%

Citrus pulp 10%

Molasses 2.5%

Min& Vits 2.5%.CP 15.7%

Barley 47.5%

Maize meal 20%

Rapeseed meal (EC origin double zero varieties) 15%