Are your calves turnout ready?

As days lengthen and temperatures increase conditions become more favourable for turnout of spring-born calves. For all the benefits that turning calves out to grass brings, it isn’t as simple as opening the shed door and leaving them off into the sunshine. There are a few essential areas that require forward planning in order to make the transition from indoor to outdoor life as smooth and stress free as possible. Three key considerations in preparation for turnout to grass surround minimising stressors, good nutrition, and promoting a high health status for calves.

Stressors

For young calves, any sudden change can be a stressor and management decisions can help reduce the impact. Stressors are like ‘gateways’ to poor animal health with priority areas to manage being weather, groupings and stocking levels. This time of year can bring thundery downpours along with the cool chill of hailstones which highlights the importance of choosing well sheltered fields to reduce weather shocks. Grouping calves of the one age together is another way to reduce the stressors of bullying by bigger stock as well as avoiding the disease risk from mixing old and young. High stocking levels and competition for resources like creep feeders can be a source of stress along with creating field areas with a significant level of dung build up which can increase susceptibility to disease. 

Nutrition

Rumen development can begin in the first week of life as soon as solid food is introduced to the calf. This means that a lot of the groundwork is already done by the time the calf reaches the paddock. Once calves are consuming at least 1kg of concentrate and hitting target weights of 85-100kg they are fit to be weaned off milk. A coarse ration that is highly palatable with a crude protein of ~18 per cent is an ideal choice for calves and continued provision of 1-2kg of concentrate after turnout for four to six weeks is essential. Grassland management can be altered to ensure the lowest risk paddocks are kept for calves with targeted grass covers of <1,000kg DM/ha. Low-risk paddocks are those that haven’t had stock grazing the previous year or have only been grazed by adult cattle – these scenarios create the lowest parasite burden pressure for young, naïve stock. As calves are selective grazers, preferentially choosing the leafier tops of the plants, they shouldn’t be forced to graze tight and a fresh break should be offered every three to four days. Ensure high levels of fibre in the diet by choosing older swards over new lush reseeds reducing risk associated with summer scour syndrome. Finally, water is one of the most critical nutrients but can be overlooked on farms. Clean, well-plumbed tanks, with a good water flow are essential for calf health. 

Health

Promoting a high health status for young stock equates to improving immune defences through vaccination. For calf health, vaccinations against infectious bovine rhinotracheitis (IBR) and clostridial diseases should be part of most young stock vaccination programmes around turnout. Approximately 70 per cent of Irish herds have been exposed to IBR and the risks posed to herds from outbreaks are considerable in terms of animal health and production losses. Upper respiratory signs such as nasal discharge, runny eyes, rapid breathing with animals being very off form are most commonly seen with IBR. The main issue is that once an animal is infected with the virus, even after symptoms have disappeared, it becomes a latently-infected carrier of the virus for the rest of its life. These latently-infected carrier animals can reactivate and shed the virus during times of stress infecting other animals within the herd and continuing the cycle of lifelong infection. Once farmers determine the herd prevalence of IBR through bulk-milk screening, a control plan can be implemented. Vaccination makes it less likely that a latent carrier will reactivate and shed the virus, reducing the impact across the herd. For the majority of Irish herds with medium/high prevalence of IBR antibodies, vaccination combined with steps to reduce the risk of bringing infection onto the farm is the most practical and appropriate control option. Calves from three months of age can receive a 2ml shot of Bovilis IBR Live into the muscle in May/June and integrate into the whole herd IBR vaccination programme with their booster shot six months later in November/December. 

Animals can be boosted every 12 months thereafter with either Bovilis IBR Live or Inactivated. In a high-prevalence herd vaccine needs to be given every six months, so animals boosted every six to 12 months. Clostridial diseases are more commonly known by names such as blackleg, botulism or tetanus. Clostridia are a family of robust bacteria found throughout the soil as well as within the digestive tracts of animals. They lie dormant for much of the time until they are activated to produce toxins, causing death within hours. The response to antibiotic therapy is very poor and vaccination should be considered in any area where risk factors exist. Vaccination with Tribovax 10 gives the broadest protection against clostridial bacteria with two shots given under the skin four to six weeks apart to calves as a primary course.