Dairy calf-to-beef production systems can be profitable; however, many have found rearing dairy-bred beef calves to be challenging and key performance targets hard to achieve, particularly during the calf stage.
One of the main issues is that generally, the calves come from several different dairy farms and are then mixed on the rearer’s farm.
There isn’t a lot of social distancing, face masks or hand washing going on here, so as a result respiratory disease/pneumonia is common and has a detrimental impact on desired targets.
Calf pneumonia is a lifelong disease. Outwardly, calves may recover, but the internal damage to the lungs can be irreversible and affects lifelong health and productivity.
Calves with good respiratory health take fewer days to reach target weight, make more profit and create higher morale for the farmer and his/her team.
A herd health plan that includes measures for pneumonia control alongside correct management is therefore key to success and the following areas should be addressed.
1. Sourcing calves
Ideally, source directly from the herd of origin and not through a dealer or mart and ask the vendor about the animal’s history.
Aspects such as colostrum management and vaccination history can influence how well equipped an animal may be to fight off disease. Calves should be sourced from dairy farms that feed calves adequate levels of colostrum at birth and have a high herd health status.
2. Managing incoming stock
Calves will be tired and stressed after a journey. When calves are stressed, their cortisol levels are high and they are ready for fight or flight, not combatting disease or producing a good immune response to vaccination. Therefore, it is best to delay vaccination for 24 to 48 hours after calves have arrived.
Upon arrival the calves should be offered 2L of electrolytes each and be housed according to the groups in a well-bedded, well-ventilated and draught-free pen.
3. Vaccination protocols
Pneumonia is the number one cause of death in calves over four weeks of age, whilst respiratory syncytial virus (RSV), Parainfluenza Virus 3 (Pi3) and infectious bovine rhinotracheitis (IBR) are known to be the most common causes of viral pneumonia on Irish farms.
Rispoval RS+Pi3 IntraNasal protects calves from nine days of age against RSV and Pi3 for up to 12 weeks, whilst Rispoval IBR-Marker live can be given intranasally in calves from two weeks of age.
In general, intranasal vaccines have a quicker onset of immunity compared to injectable vaccines, meaning that calves will be protected for all three viruses 5-10 days after intranasal Rispoval vaccination.
Calves should not be disbudded or castrated until at least two weeks after intranasal vaccination to allow the development of an optimal immune response.
Clostridial (bacterial) diseases are another significant cause of mortality in Irish cattle. Clostridial organisms cause a variety of diseases and blackleg (Cl. Chauvoei) is one of the most common. Clostridial diseases generally affect calves once they go to grass.
However, they require two injections (four to six weeks apart) of the vaccine under the skin before they are protected. Ideally, the first injection is given two weeks after the calves have been disbudded and the second one shortly before going to grass.
Other commonly detected aetiological agents in cattle include Clostridium novyi, Cl. sordellii, Cl. perfringens and Cl. septicum. Covexin 10 protects cattle from 10 deadly causes of clostridial disease and provides cost-effective protection.
4. Nutrition: Correct feeding of a good quality calf milk replacer and creep ration
During the rearing phase calves should be allocated the correct amount of milk replacer as per manufacturer’s guidelines and be fed at the same times each day. Most milk replacers will specify the water temperature should not exceed 45-50°C for mixing. Any higher and you will start to damage the proteins in the milk formula that are so essential for optimum calf performance.
Both skim and whey-based milk powders can provide good quality feed but check the ingredients and nutrients they contain as they do vary. Coarse calf ‘starter’ ration, straw and fresh water should be freely available. The straw should be fed from a rack and not the bedding.
Calves should be weaned once they are eating 1.5 to 2kg of ration/day, rather than an age basis; target weaning weight is 85kg.
5. Calf housing
Incorrect housing provision can result in poor welfare and can predispose to disease outbreaks.
Firstly, there needs to be adequate lying space. Allow at least 1.5m2 of straw bedded space per calf. They will perform better if they each have 2m2. Housing facilities must be well-ventilated and draught free. Viruses and bacteria do not survive well in fresh air. Ensuring good air quality in cattle buildings reduces infectious burdens and promotes lung defences.
In order to get fresh air into your buildings you need:
- Inlet- somewhere for fresh air to get in;
- Outlet-somewhere for stale air to get out.
Whilst it is essential that fresh air is available in a building, all possible steps must be taken to avoid any draughts and ensure calves don’t suffer from cold stress.
Look for ways to reduce draughts and possibly create ‘micro-climate’ environments for young calves, and ensure pens are well bedded to enable them to ‘nest’. Calf jackets can be helpful in preventing calves from becoming chilled when temperatures drop, and they will lead to better growth rates.
High levels of moisture in a building increases the survival time of pathogens/bugs both in the air and in the bedding. Dampness reduces ambient temperature and increases the lower critical temperature (the temperature at which a calf starts utilising energy to keep warm) as well as requirements for fresh bedding.
Maintenance of gutters and downpipes, mending leaking water troughs and ensuring urine drains away from the bedding will reduce overall moisture levels.
Lastly, ensure the house is cleanable, without using water or a high-volume hose.
The weakest points in many calf facilities are the many thousands of tiny cracks that, even after cleaning, provide a resilient home for bugs outside the host. These tiny fissures in pens and walls and the joints between the walls and the floor are a predictable source of re-infection.
This could easily be improved upon, by for instance rendering and painting the walls to above animal height. By improving cleanability of pens, the time and money invested in the cleaning process is more likely to pay back.
In summary, for a successful dairy calf-to-beef operation attention to detail is crucial. This involves careful sourcing of the calves, followed by the correct feeding in a dry, well bedded and ventilated shed which is clean, warm and free from draughts. The right vaccines need to be administered carefully at the correct time.
For more information, contact your veterinary surgeon or Zoetis on: 01 256 9800; or visit www.zoetis.ie. Use medicines responsibly.
Rispoval RS+PI3 IntraNasal contains modified live Bovine PI3 virus and BRSV. Legal Category: POM (E). Rispoval IBR-Marker live contains Bovine Herpes Virus type 1 (BHV-1), strain Difivac (gE-negative), modified live (attenuated) virus.
Legal Category: POM (E). Covexin 10 Suspension for injection for sheep and cattle contains C. perfringens type A toxoid, C. perfringens type B & C (ß) toxoid, C. perfringens type D (ε) toxoid, C. chauvoei whole culture, C. novyi toxoid, C. septicum toxoid, C. tetani toxoid, C. sordellii toxoid, C. haemolyticum toxoid. Legal category: LM.
