Oats for intensively finished bulls

Results Summary:

Bulls recorded the fastest growth rates when fed the barley and oats/barley mix, with bulls on a diet with just oats as the cereal component tending to grow more slowly. Slaughter and carcase weight of the oats fed bulls was lower than the other two diets. The poorer performance of the oat based ration may have been due to the lower starch and energy density of the ration. Oats contain more fibre than other cereals but less starch hence they may be best included in diets where acidosis is a high risk or in growing cattle diets where energy density is less important.

There were no differences between diets in terms of killing-out percentage, conformation and fat score.  Liver scores for all the cattle were low, indicating that none of the diets in the trial had caused acidosis problems.

Dry matter intake of both diets containing oats was recorded to be 7% higher than the barley fed bulls yet the animals did not show any associated increase in growth rate. Hence, oat fed cattle tended to have poorer feed conversion efficiency than barley fed cattle, requiring more feed to gain a kg of liveweight.

Based on a price of barley at £152/tonne and oats at £170/tonne, the barley diet tended to have a higher margin over feed, and lower feed cost per liveweight gain than the diets containing oats. Replacing 50% of barley with oats resulted in a reduction in margin of some £61 per bull. The margin was £126 per bull lower with 100% oats.

At these prices it was calculated that oats would have to cost £49/t less than barley to justify a 50% inclusion in the finishing ration and £51/t less to justify the complete replacement of barley with oats.

Planned activity:

The results of this study will be presented to industry in the form of a briefing and press articles.  It will be incorporated into presentations made EBLEX staff at farmer meetings and in other publications where relevant. It will also be communicated by Simon Marsh at HAUC and at the next farmer meeting that EBLEX holds at Harper Adams.

The Problem:

Oats have a number of benefits for feeding to cattle such as low growing costs, reduced starch content and higher fibre content which may reduce the incidence of rumen acidosis and higher oil content than wheat or barley. Consequently there has been interest in investigating the use of oats more in cattle rations and how animals perform compared to more commonly fed cereals.

Project Aims:

The aim of this project is to determine the effect of feeding oats to intensively finished bulls through to slaughter.

Approach:

The cattle used in this study will be 48 Sept/Oct 2010 born Holstein and Continental cross Holstein bulls weighing approximately 290kg at 7 months old.

The three treatments are a traditional rolled barley based finishing ration, barley: oats (50:50), and an oats based ration.  All rations will be isonitrogenous at 14% CP in DM, balanced with a protein blend.  Straw will be offered ad libitum from racks.

Live weight at slaughter is predicted to be approximately 550kg at 13 months old.  The target fat class will be 3. Feed samples including the straw will be analysed using wet chemistry and liveweight and carcase measurements will be taken as well as group feed intakes and straw use recorded.