Monday, 28 November 2016
Preventing Digital Dermatitis (DD) infection pre-calving and minimising body condition score loss post-calving are a must to ensure optimum foot health in an animal’s first lactation and beyond.
Speaking at a recent AHDB Dairy Calf to Calving (C2C) meeting at Blackmarsh Farm, Sherborne, AHDB Dairy’s dairy senior scientist, Jenny Gibbons said now was a good time to think about controlling DD over the winter housing period.
She explained: “Digital Dermatitis is a painful condition and if you’ve got it in your heifers, you’ve got to control it. The stress of calving means that it will get worse and the heifers can be an infection pressure for the rest of the milking herd.
A University of Wisconsin study found that heifers that calved in with DD were also 55% less likely to conceive to first service and produced 334kg less milk in the first 305 days of lactation.”
To control DD, Dr Gibbons recommended implementing a control program for in-calf heifers, which focused on picking up the early signs of the disease.
“Before a control program can be implemented, a reliable method of detecting DD in heifers is needed. Heifers affected with DD can easily be spotted by the way they behave. For example, they walk “on their toes” to take weight of their heel,” she added.
Dr Gibbons advised walking through in-calf heifers and visually assessing for heel lesions. Feet with early signs of the disease should then be cleaned, dried and treated with a topical spray. Infection pressure should also be reduced by minimising contact with slurry, by making sure stocking rates are correct to prevent slurry pooling.
“If you’ve got signs of Digital Dermatitis in the heifer, the most effective way to prevent new lesions is to run the heifers through a footbath. But make sure it’s deep enough to cover the whole hoof and clean enough so that the disinfectant is effective,” she explained.
As part of the Calf to Calving initiative, farmer meeting are being run on various host farms across the country with the aim of bringing the latest research and best practice to farmers, improving calf survival and increasing the number of heifers making it into first lactation. The growth, health and nutrition of 10 heifers on each of 13 host farms are also being monitored every three months.
At the recent event in Dorset, Dr Gibbons also emphasised the importance of minimising body condition score loss in both cows and heifers post-calving.
This is essential, as a Nottingham University study found that animals that lost back fat post-calving or had low back fat thickness, were more likely to develop sole ulcers or sole haemorrhages. This was due to the fact these cows also lost fat in the ‘fat pad’ or digital cushion in the foot, which acts as a protective layer under the pedal bone.
Dr Gibbons explained: “At calving, ligaments in the foot relax so there is potential for the pedal bone to sink and cause pinching or bruising, which can later develop into sole ulcers or bruising. At the same time, when a heifer calves, she is only 90% of mature body weight so the fat pad is not fully formed anyway, so there is increased risk.”
To limit the risk of lameness, focus should be placed on minimising body condition loss and social stress around calving.
Where a separate heifer group is not being used, this could involve moving heifers in groups of twos or threes at the end of the day when things are quieter. This will give her time to find a place to eat and lie. Plenty of feed space is also vital to drive feed intakes.