Evaluation of 12% and 14% crude protein rations for 300kg intensively finished Continental dairy-bred bulls
Simon P. Marsh, Principal Lecturer, Harper Adams University
Animal Science Research Centre - Beef Unit Trial Results – 2015 (a)
Introduction and Objective:
There is increasing concern that the stated energy and protein requirements for beef cattle (AFRC, 1993) are now underestimated for today’s modern high genetic merit beef cattle, especially for young fast growing intensively fed bulls.
The current recommendation for the crude protein (CP) content of cereal based rations for young bulls from 3 to 7 months old is 140g CP/kg (14%) which can then be reduced to 12% through to slaughter for Holstein bulls (EBLEX, 2012, Marsh et al., 2009).
In the study by Marsh et al., (2009) 285kg Holstein bulls were intensively finished on cereal based rations containing 12%, 14% or 16% CP. There was no response to feeding elevated levels of CP. However genetic improvement and sire selection for higher productivity and lean tissue deposition may have substantially increased the protein requirement with Continental bred cattle.
With the increased costs of protein feedstuffs relative to cereals and the requirement to determine the optimum protein content of finishing rations for continental bred beef cattle the objective of this experiment was to evaluate different protein levels for intensively finished Continental cross Holstein bulls from 7 months old to slaughter.
Animals & Timing:
36 Sept-Oct 2014 born British Blue x Holstein bulls weighing approximately 320kg at 7 months old randomized according to live weight to the following treatments:
Straw was offered ad lib to both groups of bulls from racks. The 12% and 14% rations were analysed to contain 35.8 and 37.6% starch (as fed).
Discussion & Conclusions: