29 August 1997

PNEUMONIA HIDDEN COSTS

Planning can help reduce pneumonia incidence and maintain cattle growth rates. Emma Penny reports

THE true cost of pneumonia in calves is far more than vet bills belie. The greatest loss is the hidden cost of reduced production -weight loss, longer finishing times and ill thrift all add to costs and reduce profit margins.

So warns Kelso-based vet Robert Anderson, of the Merlin Veterinary Group, who says that pneumonia cases have increased as herd size has risen over the last 10 years. "There are more cattle housed in the same area, which adds to risk, and the pathogens involved -viruses and bacteria -also seem to be increasing in virulence."

Although some calves may die of pneumonia, even greater losses accumulate through lost production, he warns. "Calves often make a full recovery, but that can take two to three months. That increases finishing time -which is a crucial consideration – as well as feed and labour costs."

In the current beef climate, impaired performance is unaffordable, he stresses. "That means pneumonia risk must be reduced. There are two areas to concentrate on – housing management and vaccination where appropriate."

Housing management is as important as vaccination, he says. "Theres a lot that can be done that will give good results. Stress at housing must be minimised -that means planning."

Traditionally, producers have combined weaning, housing and other management procedures such as de-horning, vaccinating and worming, often tackling them all on the same day.

"It may be difficult to avoid this when buying suckled calves. However, it is far less stressful to carry out these operations over the six weeks before housing. Less stress will reduce pneumonia incidence," says Mr Anderson.

Adjusting to a winter diet, weaning, transporting, housing and vaccination should all be tackled in stages to reduce stress.

"Calves should be introduced to their winter diet while at grass with their mothers. Creep feeding six weeks before housing will give the rumen time to adapt to the new ration.

"Where calves are housed and suddenly introduced to concentrate, the resulting rumenal acidosis will reduce dry matter intake, while the excess of carbon dioxide produced by the calf can only be dissipated by panting. Both increase pneumonia risk," warns Mr Anderson.

Weaning should occur about two weeks before housing. "Calves should always be turned out onto grass or stubbles after weaning. This allows them to continue adapting to the winter diet and develop a pecking order, so reducing bullying and the risk of calves not feeding.

"Most producers will have land available for calves, but where this is not an option an outdoor corral or loafing area will reduce disease incidence, particularly where older buildings with less than ideal ventilation are used."

About two weeks after weaning, producers should aim to house calves. This should be done on a dry day, and the calves left to settle. Small groups – a maximum of 25 – make management and spotting ill calves easier, he says.

"Once calves are housed increase feeding slowly. Its important to ensure each calf eats, so dont introduce ad-lib feeding until about a month after housing."

Vaccination also needs to be planned, he warns. "This should be tied in with planned housing date, particularly where producers chose to vaccinate against respiratory syncytial virus – RSV. It needs two shots, three weeks apart to give solid immunity; giving the first dose at housing is too late."

Producers with a past history of calf pneumonia should consider blood testing affected calves to ensure they target the correct strain (see table).

"Best results are obtained when first tests are carried out in the early stages of pneumonia, followed by a second blood test two to three weeks later. The results will be historical, but at least you will know what to target. Pharangeal – throat- swabs and lung washings can give more immediate results, and allow the most appropriate antibiotic to be chosen," says Mr Anderson.

AN outbreak of pneumonia on a Borders farm carrying 75 cows and calves and 25 weaned spring born calves in 1993 cost £936 in antibiotics, as well as the cost of loss of performance.

"The mix of six to nine month old animals and calves increases risk. The older calves may be resistant to pneumonia, but will carry the virus, spreading it to young calves," says Mr Anderson.

The following year, vaccination for IBR/Pi3 was carried out at housing, costing £325, but a pneumonia outbreak added a further £792 to costs.

The pneumonia prevention plan was reviewed in 1995, and vaccination against RSV introduced. The first RSV vaccine was given at grass, the second RSV, plus IBR/Pi3 given at grass three weeks later, and cattle housed 10 days later. The herd did not require any vet visits for pneumonia, and only five calves were treated. Vaccination cost £810, and antibiotics £58, but calf performance increased considerably.

The same programme was followed in 1996, giving equally good results. "This shows that it pays to persevere. Some of the autumn born calves were young for vaccination, but vets can tailor prescriptions according to farm needs," says Mr Anderson.

Farm 2

THE 300-cow commercial suckler herd, again in the Borders, with 150 spring- and 150 autumn-born calves, plus bought-in suckled calves, suffered persistent pneumonia.

In 1993, 300 calves were weaned, transported and housed over a two to three day period, with constant additions to the herd from bought-in calves. This resulted in a severe pneumonia outbreak, leaving eight calves dead, may which were severely affected and failed to recover, and substantial production losses. Antibiotic costs of £2222 added to IBR vaccine costs of £886.

The next year, vaccination and management were reviewed. A IBR/Pi3 vaccine was given three weeks before weaning, and calves weaned and transported to grass and stubbles. The winter ration was fed at grass for two weeks before housing, and feed levels slowly increased after housing. Although the calves again suffered from pneumonia, it was less severe; antibiotic costs were reduced to £578, with vaccination costs of £1208.

In 1995, a further review was carried out, and creep feed introduced before weaning, which contributed greatly to better health. Wind tunnels were also introduced to improve housing ventilation, and backs were clipped at housing. There were no vet visits, antibiotic costs were reduced to £38, while vaccination cost £1579.

"Calf performance increased dramatically, with animals finishing three months earlier. That meant cattle could be finished off grass rather than having to come back inside for a second winter housing period," he says.

The same programme was followed last autumn. Blood testing has shown that RSV is present in the herd, but Mr Anderson says that the results obtained in 1995 suggest that the herd could perform well without RSV vaccination.n

The hidden cost of pneumonia can add up to far more than vet bills, warns Robert Anderson.

Kelso vet Robert Anderson (left) and one of his clients, Farmer Focus contributor Ewan Brewis, discuss herd management in the run up to housing, aiming to reduce pneumonia and maintain calf performance.

REDUCING PNEUMONIA

&#8226 Plan vaccination.

&#8226 Feed winter ration before housing.

&#8226 Wean two weeks before housing.

&#8226 House and allow to settle.


ViralVaccineDosing regime

infection

IBRInbovac IBROne dose, intra-nasal route

or intramuscular

TracherineOne dose, intra-nasal route

Pi3ImurespOne dose, intra-nasal route

Pi3 Imuresp RPOne dose, intra-nasal route

and IBR

Inbovac IBR/Pi3One dose, intra-nasal route

RSVRispoval RSTwo doses, three weeks apart

by intramuscular injection

Torvac RSVTwo doses, three weeks apart

by subcutaneous injection

Source; Signet Sheep and Beef Notes