What makes a healthy dairy herd?

A health dairy herd is a profitable dairy herd

Rhys Beynon-thomas BVSc MRCVS is a dairy farmer’s son from Hendy. He graduated from Bristol in 2012 and worked in a farm practice in Gloucestershire. His family have a pedigree Holstein Herd and Berrichon flock at home. He now works for Prostock Vets, who cover Carmarthenshire and Ceredigion. Here he gives his vet’s view on what makes a healthy dairy herd

Nutrition

Nutrition forms the basis of a heathy dairy herd. the variation in the farm systems and genetics of the national herd means that the diets fed from farm to farm may be completely different. the balance of the diet is the key to good health. Suitable, balanced feeding provides the cow will all the building blocks for a strong immune system.

Visible signs of an insufficient diet include poor/decreasing body condition scores, loose or hard faeces, dirty backends and swishing tails. Blood samples to test for ketone (BHBs) levels can be taken from fresh cow to give an idea of negative energy levels at calving.

Mineral imbalances, especially calcium also has an important role in the animals defence mechanism against bacteria, controlling sphincter closure in the teat end amongst other things.

Fertility

Good fertility is key for a healthy herd. Regular breeding results in increased efficiency of production, with better feed conversion ratios achieved in the first trimester of lactation. Poor fertility results in an extended lactation, and the inevitable fat deposition as yields drop. this results in less efficient organ function e.g liver, oversize calves, fat deposition in the pelvic canal, appetite suppression and ketosis.

tight calving patterns are especially important for batch calving herds in order for the cows to match the nutrition on offer by the farmer.

A historic indication of fertility performance is the calving index, while a more current and relative indicator of performance is the pregnancy rate. Do you know yours?!

Lameness

An incidence of lameness will have serious welfare and financial implications on each individual cow. A problem at a herd level must be identified, treated and future incidence prevented.

Mobility scoring is now a part of the herd health plan and allows the recording of the lameness data over time. this, along with foot trimming reports, can act as useful references when trying to identify the main causes of the lameness incidence.

Some of the most common effects seen would be sole ulcers, often linked to increased standing time, white line separation linked to tight turning points, and over crowding and digital dermatitis which can be linked to slurry management and poor foot- bathing protocols.

Infectious Disease

Prevention is better than cure when it comes to disease control in any population and the availability of a range of vaccinations against several disease allows this theory to be implemented.

A starting point to identify the disease status of your herd is through a bulk milk-tank sample. this test can be used to identify the presence of diseases such as IBR, Leptospirosis, and BVD (both antibody and antigen).

Fluke antibody levels and lungworm antibody levels can also be given although great care should be taken when interpreting these due to the persistence of antibody levels for months after treatment. Be sure to ask your vet about bulk milk sampling on the next visit.

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