Promote vaccination against lungworm

As turnout approaches immunisation against pasture-borne parasites such as lungworm should be a priority to help protect the growth and yield potential of replacement heifers.

Rearing replacement heifers can be costly but investment in good parasitic control can pay dividends in more ways than one.

Cheshire-based cheese-maker Joseph Heler’s Helton herd of 280 pedigree Holsteins knows this only too well. Mr Heler’s heifers not only help supply milk for processing, but his herd has established a strong reputation at dairy sales as quality, high-genetic merit replacements - often topping the price league tables at the Western Holstein Club sales at Beeston Castle in Cheshire.

Herd manager, Mark Thornton, knows that the success of a dairy cow is often rooted in establishing a strong, healthy calf. “The first grazing season can often be critical,” says Mr Thornton. “Heifers faced with a big challenge from parasites at grass can see growth suffer. For example, lungworm can literally stop a heifer in its tracks and in the very worst cases they never recover that lost ground.”

Conscious of the costs that rearing replacement heifers places on the delicate profits from dairying, the Helton herd has developed a thorough lungworm and gutworm control programme, aided by vet Mark Proctor of the Nantwich-based Willows Veterinary Group.

“There are several challeng­­­­­­­­es but lungworm is certainly a major concern. Having seen the consequences of the disease (poor growth and lost yield), we ensure youngstock are treated before turnout,” adds Mr Thornton.

Husk manifests as a mass infestation of lungworms, explains vet Mark Proctor. Having established themselves on pasture, the lungworm larvae complete their lifecycle in the calves’ lungs and upper airways. “This has a serious impact on the host animal’s breathing,” says Mr Proctor.

Common signs include a husky cough or laboured breathing due to a build-up of lungworm and fluid in the respiratory system. Death or incapacity may result, but at the very least, growth rates can be poor. The situation almost invariably worsens and lost growth and vigour can rarely be recovered.

The effects continue into adulthood. It is widely acknowledged among researchers, advisers, vets and farmers that milk yield can be cut by 10%, as an average, - in mature animals, thereby reducing their lifetime income potential. On top of this loss are the additional feed, medicine and labour costs for sick animals.

“To counter the parasitic challenge all calves within the Helton herd are treated with Bovilis® Huskvac prior to turnout. Two doses are needed with an interval of four weeks between them. These must be completed at least two weeks before turnout”, explains Mr Proctor.

Despite being on the market for nearly 30 years, Bovilis Huskvac (or Dictol as it was formerly known) still represents one of the best investments a stock-keeper can make for disease prevention, suggests Mr Proctor. “It is a unique product that has stood the test of time. Some worming regimes involve frequent dosing or use of long acting anthelmintics, but none cannot offer the level of husk protection afforded by vaccination.

“A few years ago, when season-long continuous treatment with Ivermectin wormers was common practice, many of our clients suffered outbreaks of Husk in young adult milking cattle. The consequences were severe and we concluded that their immunity to lungworm was poor, possibly due to rigorous and highly effective wormer regimes.

“The situation was rectified in when many clients reverted to using Bovilis Huskvac having previously abandoned vaccinating. We’ll continue to recommend Bovilis Huskvac as an integral and highly cost-effective vaccine for dairy heifer rearing. It can be used alongside a gutworm control regime as part of every farm’s herd health plan.”

Mr Thornton firmly believes that healthy calves lead to healthy heifers. “We have a herd average of approaching 8,800 litres at 4.1% butterfat and 3.35% protein. Heifers sold through the Western Holstein Breeders Club sales at Beeston Castle market have recently averaged 1750gns.

“Heifers have to do well and hold their own, since the commercial buyer is looking for something with a bit of power. With rearing costs of £850/head, there is little room for unnecessary expense, but investment in an effective parasite control programme is just that - a good investment,” Mr Thornton concludes.