Dairy special: Silage buffer key to tackle shortages

Condition

“Given that there are plenty of cows still needing to regain condition lost last summer, limiting buffer feeding will only extend the problem, with knock-on effects for cow performance later in the year.”

Buffer feeding this spring therefore needs to support both body condition and provide the nutrients needed for yields above the 10-12 litres/cow typically produced from grazing. It also needs to maximise utilisation of the nutrients in the grass by correctly balancing them with complementary feeds.

“That means prioritising feeds which contain lower levels of the rumen degradable protein (RDP) and sugars highly prevalent in spring grass, and that are high in the fibre that is essential for good rumen function and help maintain milk fat production,” she adds.

She says feeds like brewer’s grains, draff and wheat-gluten moist feed contain high levels of digestible fibre energy, plus a good proportion of rumen-bypass protein to balance the RDP in spring grass.

Palatability

“Moist feeds also add palatability to buffer rations, which can help lift intakes if forage shortages mean that only lower quality silages are available, or additional straw is being fed,” she adds.

“To directly replace 4kg of 30 per cent DM grass silage would take around 2.5kg of wheat-gluten moist feed, 5.0kg of brewers’ grains or 6.0kg of draff (on a freshweight basis), depending on availability.

“In addition, all supply extra energy compared to a typical 10.5MJ ME/kg DM grass silage, so there is additional milk output to help offset costs (table 1).”

Other options for digestible fibre energy include sugar beet feed, which is low in protein and ideal for feeding alongside spring grass. Soya hulls are also worth considering, with prices having come down in recent months.

“A 50:50 mix of soya hulls and palm kernel expeller can work well as a dry silage replacer. As with the moist feed options already mentioned, there’s an additional payback in terms of extra milk production that will help cover some of the extra feed cost (table 1).

Other feeds to consider as part of the mix include sodawheat to provide additional starch energy in a form that minimises the risk of acidosis (particularly if maize silage volumes are tight).

Table 1 - Options to replace 4kg FW of grass silage¹ in buffer rations this spring

¹ Based on replacing 4.0kg FW of a 30% DM grass silage supplying 10.5MJ ME/kg DM.

²At 5.0MJ ME/litre milk, 28ppl

³ Prices correct at the time of writing and subject to change, based on 29t tipped bulk loads delivered on-farm within 50 miles of origin.

Source:KW