Getting out of negative energy quick
Many cow health problems in early lactation are avoidable with good dry cow management. This ensures fresh cows spend little time in negative energy balance (NEB), return to ovulation within 50 days and hit a calving index of 390 days, putting 2p/litre into producers’ pockets.
It sounds simple, but not getting the dry period right sees everything thereafter fall apart, Bryn Davies of Advanced Nutrition told delegates. “NEB is the gateway to all disasters,” he warned. “But it’s not all about feed – it is also about the dry cow environment.”
Cows should be dried off 50-60 days before calving, allowing time to adjust ration to achieve a target body condition score of 2.75 when fresh calved. “The cow needs a low-energy, high-fibre ration in the dry or transition period. The problem is we don’t have one fixed ration that works.”
Aiming for 14-15kg DM intake to supply just 110-115 MJ of energy a day for maintenance and the developing calf can be a challenge, but is possible, he said. “Anything over ends up as body fat.
“I plan for a 14% crude protein ration, 12% starch, 1,000g of a quality metabolisable protein and a quality mineral. Bottom line is we want intake without too much energy,” he said.
Producers should aim to make a dedicated dry cow forage, he suggested. “Second cut grass, left longer to head before cutting, should make an ideal forage at ME 8.5. A dry cow needs 10kg DM a head a day of this, so over a 50-day dry cow period that’s 0.5t/cow.
“She should also be getting about 3kg chopped straw a head a day to sit on top of the rumen, which helps avoid displaced abomasums in the first few days of lactation.”
Accommodation was also key. It should be clean, airy and social, with dry cows able to see fresh cows from within the same group, he recommended. Allow 75sq ft a cow, feed a single short-chop ration to avoid “sorting”, but with a small amount of longer scratch fibre, and provide clean water. “Water is the most understated nutrient we have,” he said.
“Those on bore holes should have supplies tested for pH,” he advised. All water should be clean enough for the farmer to consider drinking it. “A dry cow drinks 50-60 litres daily and milkers up to 100 litres, so it’s important.”
Post calving, 10% of cows die in the first 60 days of lactation in the UK. “Watch those giving more than 5% butterfat in particular, as they tend to mobilise more body fat.”
Cows losing less body condition in early lactation will return to heat quicker, with first ovulation within 50 days versus 70 days.
Producers should end lactations to achieve a 390-day calving index, he recommended. Nationally it is nearer 430 days. The 40-day difference can yield 22 litres/day (880 litres total) extra milk and at 25p/litre – even after 7p/litre feed costs – added £150/cow to producers’ pockets. For a 7,000-litre cow that’s 2p/litre extra, he said.
“We need to be getting the basics right,” he warned.