Calf Immunity: Weaning In Cattle
Weaning a calf consists of separating it from the mother so that it stops feeding with milk and starts feeding as an adult. As we all know, for mammals, the consumption of breast milk during the first months of life is essential for their development, as this greatly increases the effectiveness of their immune system.
Do you know why many breeders want to wean some farm animals early? What are the effects of early weaning on the immunity of calves? We’ll show you the answer to these and many more questions.
Factors involved in weaning and influencing the calf’s subsequent immunity
When a breeder plans weaning, he takes into account two other factors in addition to the calf’s characteristics: the cow and post-weaning feed. Based on these parameters, the professional decides which is the best strategy to be applied.
The calf and its first months of life
Any mammal, at birth, depends on breast milk for food. In the case of calves, this relationship is even more complex, especially when taking into account the development of the digestive system of ruminants.
This is because, during the first weeks of life, the “stomachs” of the bovine species undergo important changes :
- Once born, the calf still does not use the first three gastric compartments – rumen, reticulum and omasum. Milk passes directly to the fourth compartment, known as the abomasum, and from there to the intestine. This means that a newborn calf behaves like a non-ruminant animal.
- As the weeks go by, the calf’s other “stomachs” begin to develop, while its nutritional needs increase. By the age of 100 days, these needs already exceed what breast milk can provide.
- From the age of five months onwards, the nutritional support provided by the pasture becomes greater, mainly because the mother’s milk production also begins to run out. It is at this point that weaning begins.
Prolonging lactation beyond these ages can deplete the cow, thus limiting its chances of postpartum recovery. This would represent a great cost without any benefit, as it would not bring anything positive to the calf.
The cow, responsible for the calf’s immunity during its first days of life
The period of greatest nutritional requirements for a cow occurs in the two months after calving. During this period, milk production gradually increases, at the same time that the estrous cycles of the female in question are restarted.
From then on, production begins to decrease, until it ends with weaning. As a result, the cow’s nutritional needs are also reduced, as she no longer needs to produce this fat and energy-rich liquid for her offspring.
Strange as it may seem, a cow’s nutritional needs are much higher throughout lactation than during gestation. Controlling these periods allows you to optimize the use of resources in exploration. In the end, the sooner the calf is weaned, the better for the cow and the breeder.
Feeding after weaning
Weaning allows you to make the most of the pastures to which the cattle have access. When it becomes dry – when it stops producing milk – the cow can stay healthy with a poor quality pasture. Thus, the best quality pasture can be used to feed the calf so that it grows strong and healthy.
What are the advantages of early weaning?
As we have seen, the peculiarities of weaning in cattle are not few. The fact of opting for the early weaning of the calf can bring advantages to the breeder. Let’s show some of them:
- A quick and effective resumption of the cow’s reproductive cycles.
- Greater number of calves at each reproductive period, due to the concentration of estrus in females.
- Shortening the interval between birth and conception.
- Rapid recovery of mothers’ body condition.
- Better management of pastures.
Is calf immunity not affected?
Simply explained, immunity is the body’s ability to deal with bacteria and viruses. When a pathogenic organism enters an animal’s body, an army of white blood cells – lymphocytes – rushes to enter the scene. These cell bodies are responsible for dealing with the disease.
The problem is that, once born, mammals do not have white blood cells. Also, when they start to produce them, it takes a while for them to be able to generate antibodies. So how does an animal defend itself once it’s born?
Very easy: thanks to the passive immunity provided by the mother through colostrum. This fraction of breast milk transfers to the calf the antibodies necessary to defend itself against infections, at least until its own body is able to do this on its own.
The problem of immunodeficient calves
Immunodeficient calves are those that do not have adequate maternal antibodies. Unfortunately, these animals will be more exposed to succumbing to the infectious diseases that threaten them during the first few weeks after giving birth.
The main cause of immunodeficiency is inadequate absorption of antibodies through colostrum. So anything that can improve this absorption will be very helpful: for example, helping the calves while they get their first colostrum feeds as soon as they are born.
It must be concluded by saying that, although weaning appears to be a miraculous technique in animal husbandry, it should be treated with caution, especially from the point of view of the calf, for whom milk is its first defense barrier. Thus, it is recommended that an in-depth study of all variables be carried out before the animal is weaned.
