8 December 2000

Avoiding a third silage cut can improve margins

Lowering feed costs and

improving consumer

perception of meat were key

topics at the British Grassland

Society beef conference.

Simon Wragg continues his

report from last week

DOING without third cut silage and concentrating on two better quality grass cuts could help improve margins for beef farmers, suggest researchers from the Agricultural Research Institute of Northern Ireland.

UK producers make 20mt of silage each year, but the comparative value of each cut is falling in relation to the availability of cheaper cereals, ARINIs Raymond Steen told delegates attending the BGS meeting.

If grass has a base price of 1, silage costs would be 2.4, and concentrated between 3.2-4.8. "But the value of silage is dependant on its quality judged by digestibility, dry matter, fermentation and type of concentrate supplement," he said.

Trials at the Hillsborough research centre had shown that higher quality silage with a D-value of 74 – which resulted from a lighter cut of grass wilted quickly – supported greater production in Continental-bred steers than a later cut medium quality silage with a D-value of 64 (see table).

"The higher quality silage is able to support 85% of the potential weight gain at the lowest level of supplementation compared with less than 50% on the medium silage. Taking into account the difference in silage DM and costing concentrate at £100/t, total feed costs for the high DM silage worked out at £75/animal compared with £115. This offers a significant opportunity to reduce costs."

Output from silage-based rations also depend on the type of supplement, he warned. Trials supplementing steers with either 3kg of barley, a mix of barley and soya or barley and fishmeal saw little variation in weight gains or carcass yield. But results suggest concentrates with high oil, ash and fibre values can restrict stock from making the greatest use of nutrient in the silage.

Medium quality silage may only support half a beef animals potential liveweight gain, says Raymond Steen.

Effect of silage quality and supplementation on weight gain

Concentrate 20% 40% 60% 80%

Concentrate (kg/head/day) 2.2 4.7 7.3 9.5

High DM silage intake (kg/day) 9.4 10.2 10.4 10.2

Med DM silage intake (kg/day) 8.2 9.3 10.1 10.1

Liveweight gain (kg/day)

High DM silage 1.01 1.09 1.04 1.12

Liveweight gain (kg/day)

Med DM silage 0.60 0.78 0.77 0.79

Carcass gain (kg/day)

High DM silage 0.67 0.78 0.77 0.79

Carcass gain (kg/day)

Med DM silage 0.38 0.48 0.64 0.77

Source: R Steen, ARINI.