Butterfats and yields crash dive in summer drought

Buffer feeding dairy cows this summer is a must, with low grass quantity and quality triggering a plummet in butterfats and yields.

According to Frank Wright’s technical director John Allen, butterfats are falling and even crashing on many dairy farms this summer. “Data from our Milk Yield from Grazing system shows this month’s average milk yield is down by three litres per cow a day compared with the same time last year.

“The daily fibre intake from grazing is also lower by some 0.8 to 1.3kg a day in 2010, with only 4.7 and 5.5kg of NDF supplied a day in May and June, respectively, compared to a target of 6.6kg. And while butterfats can be diluted in herds that are milking extremely well or that have a high number of cows in early lactation, this data suggests it is likely nutrition is having the biggest influence on rumen health and digestion,” he says.

Protein is also lacking in grass, particularly in second-cut ­aftermaths, says Phil Clarke of P and L Agriconsulting. “However, we are in a position of change and while grass in many areas isn’t high in protein after weeks of little rain, if we were to get a downpour and fertiliser has been applied then there will be an uptake of nitrogen and protein levels will increase. All these factors need to be taken into account when rationing,” he says.

Protein levels from grazing will also depend on how much clover is in the sward, says independent grazing consultant Tom Philips. “The more clover the more protein, which is why it’s important to assess swards on an individual basis.”

A number of actions can be taken to alleviate the problems, says Dr Allen. “Although they are individual to each farm, solutions could include increased feeding of a forage buffer, which in light of forage stock shortages may be easier said than done. But whole-crop, straw and other fibrous feeds such as soya hulls, citrus pulp and sugar beet pulp could be considered.”

Haylage would also work well to increase fibre levels, says Mr Clarke. “Rather than opening up already depleted silage stocks, haylage would help increase fibre intakes. However, if we don’t get rain and protein levels remain low, farmers may be forced to feed silage. But, if you are going to do this then it may be worth supplementing forage stocks with a moist feed now rather than in the winter, when prices of moist feed will probably be higher.”

And what supplements farmers choose to feed can have an impact on sward recovery, says Mr Philips. “In most areas the grazing rotation now needs to be about 40 days and while silage will act as a substitute to grass, when feeding concentrates there is no substitution and they will continue to graze.”

Whatever farmers decide to do one things for sure, doing nothing is not an option, says Dr Allen. “When cows start losing condition because they are milking from reserves, it’s not just milk yields that are in danger, but fertility too.”