Clamp stocks need careful assessment
By Jessica Buss
ASSESS forage stocks in clamp accurately, analyse for quality, and plan winter requirements before deciding to take subsequent silage cuts or whole-crop cereals.
So advises SAC researcher and MGA whole-crop consultant John Bax. Producers with cereals intended for whole-crop silage and those planning further silage cuts are advised to work out the dry matter of forage clamped from the volume of the clamp and estimated dry matter %.
Where there is sufficient grass silage, it is possible to cut less whole-crop – or none at all – and take it as grain or crimp it to feed as a moist concentrate. But before doing so, consider the quality and intake characteristics of silage in the clamp, he says. "Have a core sample analysed. Silage quality has been variable this year and its intake potential will be related to its dry matter and fermentation. Also check the energy content.
"When silage quality is good and stocks are adequate, whole-crop could still offer higher cow dry matter intakes. But to see this benefit about a third of the forage should be whole-crop. One option is to cut the cereal crop higher, increasing the proportion of grain and boosting energy intakes."
Producers who have the option of making second or third cut grass silage or whole-crop should consider the costs of making each crop. It may be more economic to make whole-crop than silage where grass yields are low and quality can be poor, and Mr Bax advises against making silage when grass can be grazed by stock.
When wetter grass silage has been made, it can be more acidic. To reduce the acid load on cows, Mr Bax suggests making some alkali treated whole-crop, while fermented whole-crop also helps buffer acidic silage.
Whole-crop is drier than silage, so is good for buffer feeding cows in spring, but for a summer buffer, alkali treated whole-crop may be more stable in the clamp.
When grass silage quality is good, he advises taking fermented whole-crop at 35-40% dry matter, with grain at the soft-cheddar stage, to avoid having grain which passes through the cow. But be aware that in hot dry weather the DM can increase by 2% a day, so prompt harvesting is vital, he warns.
Alkali treated whole-crop should be taken when grain is at the hard cheddar stage and 55-60% dry matter. But before committing to alkali whole-crop check whether your contractor will do this, as some will only make fermented, he adds. *
• Graze grass where possible.
• Analyse silage stocks.
• Is whole-crop necessary?