Success in backgrounding calves for feedlots depends on far more than just good feeding once they are bought. Many of the health problems and deaths seen in feedlots originate earlier in a calf’s life, often linked to poor immunity, lung damage and the stress of weaning and transport. In this Q&A, Dr François de Villiers outlines the key management, vaccination and nutritional steps producers should take to prepare calves properly for feedlots and minimise losses later on.
Question: I want to buy and fatten calves (also called backgrounding) for feedlots. What should I consider in order to restrict later deaths?
Answer: Certain important factors determine whether a weaned calf will cope well in a feedlot. Many calves already have lesions on their lungs when they arrive at the feedlot. These calves wean lighter than their companions, they grow more slowly than the others and they contract pneumonia more easily and die sooner. For these reasons, make sure your weaner calves have healthy lungs.
Good passive immunity is needed to protect the calf during the first few months. Inoculate the dams of all the calves a month before calving with a killed vaccine that contains the four most important viruses that cause pneumonia in cattle – bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), parainfluenza type 3 (PI3) and bovine respiratory syncytial virus (BRSV). Doing so will ensure the presence of corresponding antibodies in the colostrum, which will then be available to the calf.
Ensure that the calf develops a good immunity early in its life, by following these steps:
- Ensure that his dam is immunized.
- Make sure he ingests the colostrum within eight hours of birth.
- Repeat the administration of the killed vaccine to the calves when they are three to four months old.
- Deworm the calves before they are weaned, because internal parasites can compromise the immune system.
Bovine viral diarrhoea plays an extremely important role in reducing the effectiveness of the immune system. A good inoculation programme for the herd is therefore vitally important. Vitamins and trace elements are extremely important in the development of a good immune system. It is essential to administer the supplements that are needed, especially vitamins A and E, selenium, zinc and cobalt.
A calf placed in an unfamiliar environment just after weaning will not eat or drink. It will also react poorly to vaccines and medicines. The weaning shock is not as great if a calf is taught to eat from a crib before being weaned. Calves then react much better to vaccines.
A seranol ear implant will not only stimulate the growth of a calf’s bones and muscles but also increase the benefit gained from the investment in creep feed. It will make a big difference if calves are weaned in sufficient time to learn to drink water from a crib before they are transported. It takes two to three weeks after the inoculation of a vaccine for calves to develop a good immunity to it. So it would be a good idea to wait before mixing groups of calves from different sources.
Internal and external parasites play an important role in preventing the development of an efficient immune system. They should, therefore, be well-controlled in calves. Apart from the viruses that make calves ill and can influence their growth, there are the bacteria that can cause sudden deaths, and this could lead to great losses.
Clostridial bacteria may be divided into three groups, based on their effects in animals:
- Members of the group that release neuro toxins and cause lamsiekte (botulism) and tetanus (lockjaw).
- Members of the gas-forming and gangrenous group cause blackquarter (quarter evil), gas gangrene of the uterus and pluck and swelled head (dikkop).
- Members of the group responsible for haemorrhagic syndromes cause lamb dysentery, redgut in cattle, bloodgut in sheep and pulpy kidney.
Vaccination against these diseases is essential because it induces good protection against diseases that can rapidly kill animals, without warning. Another bacterium, which causes the rapid death of an animal from pneumonia is Mannhaemia haemolytica. Inoculation against this disease, commonly known as pasteurellosis, is essential.
Anthrax, lumpy skin disease and ephemeral fever (three-day stiff sickness) are diseases that are responsible for sporadic outbreaks in feedlots, with disastrous results. The cost of vaccines to counter these diseases is very small compared to the financial losses that they can cause. For this reason, inoculation of calves is strongly recommended when preparing them for the feedlot.
Source: Agricultural Research Council (ARC)
Also read:
The cattle farmer’s manual | Why protein is the key to winter grazing success
The cattle farmer’s manual | Plenty of grass, thin cows: What’s going wrong?
The cattle farmer’s manual | Why winter feeding is critical for pregnant cows
