10 July 1998

Question-mark over first-cut silage quality

By Simon Wragg

EARLY first cut silage analyses show a huge variation in quality and producers should graze grass and look at forward buying alternative winter feed rather than take excessive second cuts.

Midlands-based ADAS nutritionist Bruce Cotterill says the 125 samples he has seen so far present an encouraging, but misleading picture. "Theres a lot of variation – the average results must not be judged by producers to be representative of all silage."

ADAS analysis shows average dry matter of 29%, ME averaging 11MJ/kg DM, crude protein of 18.2% and D-value of 69.

"Dry matters are expected to fall as we sample more clamps reflecting the poor weather when first cut was taken. However, MEs are likely to go up – a lot of forward swards werent growing from the base, so were stemmy, which will have affected quality," explains Mr Cotterill.

Analysis by Axient of 73 samples from the south and west gives an almost identical picture, but crude proteins are significantly lower. Axients results give average dry matters of 29, an ME of 11%, but lower crude protein of 14.8% and D-value of 68.6.

Hereford-based Nigel Davies, Axient senior consultant, says the quality of early cuts, taken before the inclement weather of late May, bode well for improving stock performance this winter. "But later cuts will be poorer," he warns.

However, the main concern is low sugars, down to 16% compared to 30% for the same period last year, which will have affected fermentation and feeding quality, he says.

The variation in silage quality is endorsed by BOCM Pauls. Over 200 samples taken nationwide show MEs varying from 9.3 to 11.8MJ/kg DM and crude proteins from 8.7 to 18.9.

First cut analysis results for Scotland and Ireland are not expected until late July, says Jesse Patterson of SAC analytical services – reflecting the later season.

Staffs-based Ian Browne, of the Farm Consultancy Group, suggests there is little salvation for dairy producers in second cut silage to balance poorer first cuts as he believes theyre declining in quality already.

"Looking at silage analyses, there is likely to be a shortfall in energy – so now is the time to negotiate with your feed merchant for winter feed. Forward buying, whether in bulk or agreeing ingredient costs for smaller orders, should keep prices down," he says.

Basil Lowman, SAC beef specialist, warns against taking an excessive second cut as liveweight/ha of grazing stock is increasing.

"Remember the amount needed for grazing is increasing, with sward heights needing to be raised by 1-2cm to compensate for lower nutrient value as the season progresses," warns Mr Lowman.

Where silage swards are too long to graze efficiently, mowing daily allowances and fencing off uncut areas will allow 99% of grass to be utilised by stock at a fraction of the cost of making silage, adds Mr Lowman.

FIRSTCUTSILAGE

&#8226 Wide range of ME.

&#8226 Crude protein may be low.

&#8226 Sugars low.

&#8226 Ammonia N up to 33%.