Inadequate feeding of early and mid-lactation cows through late summer and early autumn can have serious knock-on effects for winter milk production.
Dr Anna Sutcliffe, a nutritionist with KW, says as milk yield potential from grazed grass drops towards zero around mid-September, it is easy for cows to lose an extra 0.5 body condition score (BCS) if buffer feeding does not adequately make up the shortfall.
She says: “Not only will summer milk production potential be compromised, but cows will also prioritise replacing lost condition over milk production once fully housed.”
According to figures from Trouw Nutrition, the energy needed to replace 0.5 BCS equates to a daily milk yield loss of 1.9 litres/cow for the first three months of winter. That is worth about £9,000 for a 200-cow herd, even at 26ppl.
Dr Sutcliffe says offering a buffer feed will help avoid many knock-on effects of losing excess BCS during early lactation. These include poor fertility and greater risk of lameness.
She says: “It has been shown that as much as 50 per cent of the lameness risk in early lactation is due to BCS loss, for example.
“This is likely due to a thinning of the fat pad in the foot, the digital cushion, that protects against pressure injuries, such as those that lead to sole ulcers.”
According to Dr Sutcliffe, the priority for buffer feeding should be cows that will provide a good return over additional costs of feeding.
Focus on cows that have calved since the start of June and minimise costs per litre by choosing feeds that provide the best value, rather than price per tonne.
She says: “Maintaining nutrient intake is key and that comes down to a combination of dry matter intake [DMI] and ration nutrient density.
“The best value feeds tend to be those that are nutrient dense, which has the added advantage of requiring a lower DMI for a given nutrient supply.”
Moist feeds such as wheat-gluten moist feed, brewers’ grains and draff will add considerable palatability and intake potential to high fibre buffer feeds.
The same is true of the various distillery syrups and molasses-based liquid feeds. Many of the alternative starch feeds are also worth considering, despite the falling price of cereals.
Dr Sutcliffe says as an example, processed bread for less than 25p/kg starch costs about 7 per cent less than rolled wheat at 27p/kg starch, plus has a higher energy density (14MJ ME/kg DM vs. 13.6MJ ME/kg DM) and contains more protein (14 per cent crude protein vs. 12 per cent crude protein).
She says: “This means that in many cases, changing to better value feeds and reformulating the diet to match can provide extra nutrients needed for little extra outlay.
“However, there are also situations where additional investment is justified, such as choosing more rumen-friendly starch feeds like sodawheat when acidosis risk is already high.
“In the end, it comes down to being realistic about expectations for milk from grazing as autumn progresses, and it is not just current production at stake. Winter production depends heavily on appropriate feeding now.”