As we faced a bleak spring last year, the message about the need for adequate amounts of quality silage was an easy one to drive home. The good weather that followed through the summer of 2013 may have made some farmers complacent in terms of their silage-making management systems. It was easy in the end, and now we need to re-adjust to what may be more typical conditions for the baled silage harvest of 2014.

The motto of planning for the worst to achieve the best must be in focus. That means cutting the grass in the best conditions available and then trying some form of wilting to give quality and manage the numbers of bales per hectare to control costs.

The arrival of new net replacement film technology has its benefits. The bale should be more secure in terms of plastic layers, giving almost a six-layer covering with a four-layer system coupled with the net replacement film.

Don’t be complacent; remember to handle these bales with great care. The fact that they have the equivalent of an additional two layers doesn’t mean that they are any more robust in terms of handling.

Keep that focus on attention to detail. That starts with the mowing and ends with the handling care at storage. The aim should be quality bale silage. Then protect those bales from birds and vermin. And don’t forget the damage that the cats will do, so invest in a net cover as the final protection.

Reduce mould levels on baled silage

Mould is often seen growing on the surface of baled silage. Mould on any feedstuff represents a loss of feed and feed value, and a potential health challenge to the livestock consuming it and the people handling it. Consequently, all baled silage should be free of visible mould growth.

Mould requires a continuous supply of oxygen to grow and proliferate. So, the prevention of mould growth on baled silage requires that bales are uniformly wrapped in adequate plastic stretch-film and that the integrity of both the stretch-film and the adhesion between the layers of film are maintained throughout bale storage. Thus, there should be no damage to the film, no looseness between the layers and no patches with inadequate film.

As part of an experiment at Grange, grass was baled after 0, 24 or 48 hours wilting (dry matter contents of 145, 296 and 530 g/kg) and in each case wrapped in different amounts of conventional black stretch-film. Wrapped bales were stored for seven or 18 months, and were protected from damage by wildlife, livestock, etc. The extent of mould growth on bale surfaces is summarised in Table 1.

These results confirm that when using conventional stretch-film that undergoes no direct physical damage during bale transport or storage:

  • No part of a bale should be wrapped in less than four layers of film
  • Four layers of such film are sufficient provided no aspect of the seal is breached

    • If bales are to be stored for a second season then six layers of film are justified with ‘wet’ bales. However, four layers of film should be adequate with wilted bales that won’t lose shape.