Soya hulls for intensively finished bulls

Results:

Animal performance (kg per bull)

Within row, means with the same superscript are not significantly different (P>0.05)

NS = not significant, * = P<0.05, ** = P<0.01, *** = P<0.001

Carcase characteristics

¹ EUROP carcase classification: Conformation: P+=1 and E=7, Fat class: 1=1 and 5H=7.

² See appendix 5 for Liver Assessment Scores

Ration formulation and costs

Overall bull performance was satisfactory with the Holsteins recording slaughter weights of 566kg at 14.0 months old.

The High starch fed bulls recorded significantly higher (P<0.05) slaughter weights (574 v 561 v 564kg) compared to the Standard and Medium starch fed bulls. The High starch fed bulls also recorded numerically higher daily live weight gains and carcase weights however they were not statistically significantly different. There were no differences in carcase characteristics or liver scores.

The High starch fed bulls recorded the best FCR (6.93, 7.29 and 7.37:1 kg feed: kg gain respectively for the High, Standard and Medium starch treatments). The FCR of 6.93:1 (fresh weight) for the High starch fed bulls appears relatively high but it must be taken into consideration that the trial did not include the period of growth from 110kg to 300kg. During this rearing phase dairy-bred bulls at Harper Adams University typically record DLWGs of 1.52kg with an intake of 625kg of feed with an FCR of 3.3:1.

The highest margin over feed was recorded with the High starch fed bulls which was £17 (2.9%) and £13 (2.2%) more than the Standard and Medium starch mixes respectively.

The replacement of some barley with soya hulls increased the feed costs per kg carcase gain by 3.6% (9p).

Farmer Recommendation:

• From this study optimum performance with barley based rations with intensively finished dairy-bred bulls was recorded with rations containing 42% starch in the DM (36% as fed).

Planned activity:

• Aim for coverage in major trade publications
• Summary paper for BSAS
• Harper Adams 2 page summary
• EBLEX producer bulletin

The Problem:

Intensive finishing rations can predispose the cattle fed on them to acidosis due to their high starch and low fibre content. Work with lower starch co-products have shown that they can be used to substitute for cereals in these types of rations without compromising cattle performance and at the same time reducing the incidence of liver abscesses of the finishing cattle. Soya hulls have a lower starch and higher NDF content than barley and maybe another feed which offers similar benefits.

Project Aims:

• To evaluate the partial substitution of rolled barley with soya hulls in a cereal based intensive finishing ration fed to dairy-bred bulls

Approach:

Forty-eight dairy-bred bulls (42 Holstein and 6 Beef cross Holstein) weighing 300kg were reared through to slaughter and fed ad libitum cereal based rations with either a high (42% in DM, 36% as fed), standard (37% in DM, 32% as fed) or medium (30% in DM, 26% as fed) starch content. The rations were based on rolled barley, with either 10% or 20% of barley replaced with soya hulls. The rations were formulated to contain 165g crude protein/kg DM (14%CP as fed) with the inclusion of soyabean meal, rapeseed meal, molasses and minerals.