It is well known that disease in early life will affect the thrive and growth of calves but results of AFBI research  indicate that it can also affect milk yield and fat and protein content when these calves reach the milking parlour.

Calf scour

The survey indicated that calf scour remains a major issue on farms, with 38% of producers in Northern Ireland indicating it is a significant problem within their calf rearing system.  To minimise the risk of nutritional scour it is important that feeding times each day do not vary and that recommendations regarding the mixing of milk replacers are followed rigidly.

Non nutritional calf scours can be caused by a number of pathogens.  The results of tests on calf faecal samples sent to the AFBI Veterinary Sciences Division in the last few months indicate that the main pathogens linked with severe calf scour in calves are cryptosporidia and rotavirus.  Neither of these are treatable with antibiotics, but the antibodies present within colostrum do control their effects.

Pathogens are often picked up from the surrounding environment, thus lack of cleanliness in the calving area and in the calf rearing accommodation are major risk factors.  Dry bedding, disinfecting utensils after each use and minimising the time period the calf is in the calving pen, all reduce the risk of infection.

Pneumonia

AFBI Hillsborough data indicates that calves with a case of pneumonia in early life experienced a significant reduction in growth right through to weaning (-0.57 kg perweek compared with calves with no cases).  In addition, there was some evidence that a case of pneumonia in early life had significant long-term effects. Calves that had suffered from pneumonia in the pre-weaning stage tended to have lower milk fat production in first lactation compared with calves clear of pneumonia.  Pneumonia at a later stage in development, from post-weaning to 1 year of age, also had detrimental long-term effects (Table 1).

Outbreaks of pneumonia occur more frequently when calves are housed in poorly designed, poorly ventilated houses, with high stocking rates and where young calves are housed in the same airspace as older cattle.

Table 1.  Milk production of first lactation heifers with or without pneumonia during the rearing stage (AFBI Hillsborough)

Effective colostrum management is the key tool in preventing many calf diseases.  However, vaccination of cows in order to boost colostrum quality, coupled with early life vaccination of the calf against a number of pathogens, can help when required.  Vaccinating cows prior to calving can help protect the calf against a number of common pathogens such as Rotavirus, Coronavirus, E Coli K99 and Salmonella.  Unfortunately there is no vaccine currently available for Cryptosporidia.

Vaccinations that are given early in the calf’s life can help protect the calf against pneumonia related pathogens such as Bovine Respiratory Syncytial Virus (BRSV), Parainfluenza type 3 (PI3), Infectious Bovine Rhinotracheitis (IBR) and Bovine Viral Diarrhoea (BVD).  A vaccination programme should be designed in consultation with your veterinary surgeon.

Survey data from farms across Northern Ireland indicates that 15% of producers currently vaccinate their cows to provide better immunity to calves against scours (only effective where calves receive adequate colostrum). Twenty-one percent of producers vaccinate their calves against pneumonia agents.  The survey also indicated there is some uncertainty amongst producers on the specific details of their current vaccination programmes.

Main messages

Emphasis on colostrum management during the first 6-hours of life is crucial.  Wherever possible, stomach tube or bottle feed calves with colostrum (10% of calf weight) within 6 hours of birth and continue feeding colostrum for 3-4 days.

Vaccinations can be an effective method of boosting a calf’s ability to combat many disease causing pathogens.  In designing the most appropriate vaccination programme, seek advice from your local veterinary practitioner.