Keep your calves scour-free this spring

It is vital that farmers have a robust colostrum-management protocol in place during the spring-calving season.

This is paramount to improve hygiene, reduce stress, and reduce the incidence of disease, all to get calves off to the best start possible. When it comes to colostrum, there’s only one opportunity to get it right.
The first few hours of a calf’s life are probably the most critical, because what happens during this time has a lasting impact on the lifetime production and profitability of the animal. High-quality, clean colostrum, given at the right time and in the right amount, provides a foundation for success for any calf-rearing programme.

A calf’s immune system is not fully functional for the first few months, so the calf needs the antibodies from the colostrum to protect it against pathogens and disease. The calf’s ability to absorb these antibodies is at its highest in the first hour of life; the absorption rate declines rapidly thereafter and will completely cease at 24 hours, so time is of the essence.  Colostrum doesn’t only provide the newborn with antibodies; it is an immediate, easily metabolised energy source, vital for the calf immediately after birth. Thermoregulation, standing and feeding deplete a calf’s energy. Without a quickly available supply of colostrum, the calf’s natural activity will be hindered and development of organs and physiological systems delayed.

The quality of colostrum can vary widely between animals; it is affected by age, length of dry period, vaccinations, breed, and time collected post-calving. High-quality colostrum should contain at least 50g/L

of immunoglobulin G (IgG), but a study in Ireland revealed that 44 per cent of samples had an IgG concentration below target 50mg/ml. To ensure colostrum quality, always test it with a colostrometer or Brix refractometer.

The golden rule — or 3-2-1 rule — is to get at least three litres of colostrum into the calf within two hours of birth for the first feed (Holsteins require four litres, or 10 per cent of bodyweight).

By following the 3-2-1 rule, you will:

• Improve rate of daily gain and feed efficiency;
• Reduce morbidity and mortality pre- and post-weaning;
• Reduce age at first calving;
• Increase first and second lactation milk production; 
• Improve fertility; and
• Reduce culling rate.

The risk of disease development is lessened by good management of colostrum, vaccination of dams, and disinfection of calving pens. The figure overleaf shows a comparison of calves fed two litres in volume of colostrum at birth (blue line) to those fed four litres of colostrum at birth (red line). The latter group achieved a higher IgG status for up to 72 hours after birth and experienced less scour.

An InTouch survey identified scour as the most common disease within spring calving herds, found on 60 per cent of farms. However, 30 per cent of the farmers whose herds were affected were unable to identify the type of scour they had on-farm. This highlights the need to consider and implement a well-informed management protocol, designed to prevent disease exposure, prior to the beginning of calving. As you do this, keep in mind that calf mortality is caused by metabolic acidosis and dehydration rather than by scour itself. The survey showed that 52.6 per cent of mortality tends to occur within the first month after calving.  Therefore, the proactive application of successful strategies that effectively target these consequences is essential to a full recovery from scour. 

Key focus areas

Colostrum
The foundation of a successful calf-rearing system begins with successful, passive transfer of colostrum. Calves require a minimum of 150g of IgG from three to four litres of colostrum fed as soon after birth as possible (and definitely within six hours) to protect against early-life health issues and to support optimal growth and performance. 

Cleanliness
A clear, defined hygiene policy will ensure consistency throughout the calving season. Cleanliness begins in the calving pen, so check stocking rates and clean-out procedures regularly. Clean and disinfect calf pens after every use, making sure the disinfectant used is effective against common scour pathogens and that it’s applied at the appropriate concentration. Keep feeding equipment clean and change teats frequently.

Rehydration
From the first sign that something is not right with a calf, offer electrolytes. Dehydration is the primary cause of death when a calf has scour. Oral rehydration solutions provide:

• Sodium and glucose, essential to replenish lost fluids and facilitate water absorption;
• Sodium, potassium and chloride, required to correct the mineral imbalances caused; and
• Alkalising agents, to increase blood pH.

Water
You can never have enough clean water. Water is a vital and often overlooked component of calf nutrition. It should be available, offered separately from milk, at all times. Any milk that is consumed goes straight to the abomasum, bypassing the rumen, meaning that there is no water to aid the digestion of the calf concentrate in the rumen. Only 30 per cent of respondents from the calf-rearing survey reported that they provided water from birth, but this simple step can increase growth rates by 38 per cent and starter/concentrate intakes by 31 per cent.

Energy
Contrary to popular belief, milk should not be withheld in cases of scour. Not only do scouring calves require energy and nutrients to grow, but they lose a lot of water from the scour. Because milk is necessary to provide energy and nutrients, regular milk feeds should be continued during treatment.

Isolate, then identify the cause

Many scour-causing agents are highly contagious, so isolate sick calves quickly to prevent widespread contamination. 

Ask your vet to then help identify the cause of the scour; quick, pen-side scour kits are also readily available and can be helpful. After the initial assessment, additional testing can help identify underlying causes. An effective treatment plan can only be successful if you know the cause of the scour and have a customised treatment plan.

Many farms now use supplements and additives in their calf-rearing protocols for disease prevention or treatment; however, with the high incidence of scour and the mortality that can result, farmers should re-evaluate their colostrum protocols to assess whether the supplements and additives they are using are actually effective. 

A key highlight from the survey was that the majority of respondents believed housing/infrastructure/space to be the biggest contributor to scour. Sometimes this may be true, as on a block calving farm with a high throughput of calves in a small timeframe. However, simple tips such as testing colostrum quality, ensuring that calves have access to fresh, clean water, roughage and starter from birth, and employing effective supplements can greatly improve calf health and cost less than building new infrastructure.