Is there a difference between concentrate types i.e. standard beef mixes, “specials” (i.e. ingredient content specified) and home-mixed concentrates? asks Teagasc beef specialist, Aidan Murray.
Compound feed is best defined by its energy, (UFV), protein, mineral and fibre content. Once these criteria are being met in a concentrate feed, ingredient content is of little consequence.
The nutrient content of the compound feed is more critical than the individual ingredients that make up the compound feed, provided low-quality ingredients are not included at high levels.
Typically, concentrate feeds are purchased solely on the basis of crude protein content which is incorrect unless a protein balancer is required.
Energy is the most limiting nutrient when finishing cattle. Always ask for the energy content of the ration. Target energy density of concentrate mixes should be 0.94+ UFV / kg as fed, for finishing cattle.
Protein
The protein requirements of bulls are higher than steers, which, in turn, are higher than heifers. This is because of the greater lean meat deposition in bulls than steers and heifers.
For finishing steers and heifers,11% crude protein in the ration is adequate. For growing and finishing bulls, 14% and 12% crude protein in the concentrate mix, respectively, is adequate. It is important to specify the basis on which these nutrients are defined by your feed supplier i.e. fresh weight or DM basis.
Energy
Energy (UFV), expressed on a DM basis, is considerably higher but can be misleading. For example, a beef ration with a UFV of 1.07 / kg DM is actually 0.93 UFV / kg as fed.
A ration with a UFV of 0.93 has an energy value of 93% of the value of barley. In any given year, the price of cereals will fluctuate, some ingredients will be good value one year but will have to be substituted with a similar ingredient the following year so producers should shop around.
There will be variation in price between suppliers as some are well covered for raw materials while others are less well covered. If raw materials are traditionally purchased for home mixing, consider the cost of buying straights in comparison to buying a standard mix or a special.
Suitable rations
Sample rations are given below. Rations 1 and 2 are suitable for finishing steers and heifers as well as finishing bulls.
Ration 3 is suitable for growing bulls because of the higher crude protein content. If purchasing these rations, minerals and molasses will be added which will drop the energy content by approximately 0.02 UFL.
Table 1. Sample Rations
Ration 1 Ration 2 Ration 3
Barley 50 50 40
Citrus pulp 30 15 15
Maize meal 15 15
Distillers Grains 20 20 30
Energy (UFV / kg as fed) 0.97 0.99 0.99
Crude Protein % 12.0 12.4 14.0
Feed management
Ad lib feeding of concentrate requires a high level of feed management if cattle are to achieve high levels of performance.
Feed troughs should never be allowed to go below 5% of feed remaining. Cleaning out feed troughs regularly will ensure that fresh feed is available, along with a supply of clean fresh water.
Concentrate feed should be introduced gradually to cattle; aim for 21 to 25 days to adapt cattle to their new diet.
Starting with a daily 3 kg feeding rate and gradually increasing by 1.5kg every 4 days until the target level of feeding is achieved, is advised to minimise the risk of digestive upsets.
Avoid changing the concentrate formulation during the finishing period and consider including a rumen buffer to reduce the risk of acidosis.
Minerals
Cattle need minerals to maintain good health. It is recommended that minerals be fed to all finishing animals.
Feeding rate will vary from supplier to supplier but as a rule of thumb finishing animals should be offered 20g minerals per 100 kg LW i.e. 500 kg animal will need 20 * 5 = 100 grams of mineral per day.
Particular attention to minerals is needed in a number of areas:
- Feeding high levels of straights such as barley, which is low in calcium;
- Feeding alternative forages such as forage maize and whole crop cereal silage –mineral content is low;
- High concentrate feeding – It is important that a standard beef ration is not used for high concentrate feeding as the mineral specification will be in excess of requirements and may lead to poor performance and the risk of toxicity and severe diarrhoea;
- High moisture grains are low in vitamin E.
