Important to focus on cow nutrition during the dry period

Shortening the dry period to 42 days and meeting a cow’s specific nutritional needs with a balanced diet is having a big impact on herd health and post-calving vigour in a Cheshire Jersey herd.

Independent nutritionist Tony Blackburn, who formulated the herd’s dry-cow feeding programme, says it’s important not to underestimate a cow’s nutritional needs at this critical stage of her production cycle.

“Cows don’t need to be dry for 60 days. Herds would see a difference in production and health if they concentrated on their needs during the last six weeks of pregnancy. Feeding high levels of straw and expecting cows to get back on song in the last three weeks before calving is reckless management,” says Mr Blackburn.

The 42-day regime is under way at Red Hall Farm, Leighton, Cheshire, where James Charlesworth runs a herd of 200 Danish Jerseys. The original approach to dry-cow management was based on the typical two-group system of “far-offs” and “close-ups”, but the ability to chop straw through a Keenan feeder prompted a rethink.

Dry-cow management

“Jerseys can be prone to milk fever and I felt a new approach to dry-cow management would reduce that. As the herd is block-calved from late June, it was easy enough to run dry cows as one group and to feed them a properly formulated mixed ration,” says Mr Blackburn.

Various diets have been created depending on the availability of maize. The no-maize inclusion ration is mixed every three days and cows have ad-lib access. The ration comprises 12kg (freshweight) third-cut grass silage, 4kg brewers’ grains, 3kg straw, 2kg big-bale silage and a daily feed of 2.5kg dry cow nuts. That constitutes a daily DM intake per cow of 10.42kg with an ME of 10.11 and CP of 14.87. It’s a moderately energy dense diet that quickly takes the milk off cows.

The mineral inclusion needs care, particularly over the potassium content, because high levels affect magnesium uptake. Mr Blackburn says potassium is often the root cause of milk fever, rather than the magnesium itself.

“Potassium affects magnesium uptake and that has an impact on calcium uptake. Dry cows left outside in late summer and eating grass that’s high in potassium and low magnesium are at a higher risk from milk fever.

“Trying to put in enough minerals in the last 21 days before calving is too little too late. Mineral supplements are essential and must provide protected copper and zinc as well as high levels of Vitamin E – say, 1500iu a day.”

Immune system

He believes the 42-day regime gives greater control over a cow’s immune system, which can be built up during this period.

“It takes the guess work out of dry cow management where far-offs can often be neglected in terms of their dietary needs – and it enables chopped straw to be fed properly as part of a mix all through the dry-cow period.

“You can’t build-up a cow’s immune system in the last 21 days of the pregnancy. The dry-cow period isn’t just about avoiding milk fever it’s about avoiding problems with retained cleansings, whites and mastitis.

“By feeding the correct diet you are building up the rumen function to help the cow perform once she starts milking.”

Improving health

James Charlesworth says the 42-day period has worked well. “We moved from Holsteins to Jerseys seven years ago and since we introduced the 42-day dry period we’ve seen a big improvement in the health, condition and performance of the cows after calving.”

“Feeding the mix for 42 days cost £28 a cow compared with £13.20 a cow if it was fed for just 21 days. But the extra 18 days of milk at 30p/litre generated £54 in milk sales,” he says.

Mr Blackburn warns producers to be wary of feeding high straw inclusions in the diets of dry cows. “Cows seem to eat it OK, but suffer a higher incidence of whites post-calving. Many cows on high-straw diets lose excessive body condition during the first 30 days of their lactation – and that leads to problems with fertility, ketosis and lower yields. The cause could be the low levels of calcium being fed to these cows, possibly as low as 35g a day,” he says.