Getting buffer feeding right will be critical this spring as the impact of last summer’s dry weather is still being felt on dairy units across the country. Farmers Guardian reports.
Silage shortages are likely to be a concern for many dairy producers, with remaining stocks already stretched thin to last until turnout.
Charlotte Ward, a nutritionist with KW, says the volume of additional feed needed this spring will depend on a number of factors, such as how reliant the herd is on buffer feeding through the grazing season, as well as the date when new crop silages will be ready to feed out.
She says: “The key is to work out requirements as accurately as you can now, and build a plan to counter any silage shortfall.”
Hoping for a plentiful supply of high quality grazing is not the answer, warns Ms Ward, as the risk of poor weather is just too great. And if grass growth is anything less than ideal, even those operating New Zealand-style grazing systems may well need to buffer through until the end of April to maintain production and start rebuilding cow condition.
“For many, it is going to be tempting to cut back and rely more heavily on grazing, but that is likely to be a false economy,” she continues. “Spring and summer feeding not only provides an opportunity for extra low-cost milk production, it is also the foundation for performance next winter.
“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.
“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
|
kg feed required1 (FW basis) |
Extra milk supported2 (litres/cow) |
Milk value2 (p/cow/day) |
Feed cost3 (p/cow/day) |
Net cost (p/cow/day) |
Wheat-gluten moist feed |
2.5 |
0.8 |
22.4 |
25.5 |
3.1 |
Brewers’ grains |
5.0 |
0.3 |
8.4 |
23.0 |
14.6 |
Draff |
6.0 |
0.2 |
5.6 |
27.6 |
22.0 |
Soya hulls |
0.7 |
0.5 |
14 |
19.2 |
5.2 |
Palm kernel expeller |
0.7 |
0.5 |
14.0 |
19.2 |
5.2 |
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