And yet, there was the speaker saying that this newborn HAD to receive its mother’s colostrum or it would have NO antibody. They even took a blood sample from the newborn to check it had antibodies AFTER it had had the colostrum.
“Why are you frowning?” asked the ECIC (AKA Wife).
“It doesn’t make sense” muttered the Microbiologist, “you get antibody in babies by transplacental transfer, not drinking milk.”
“So, you’re saying the experts are wrong and you’re right?”
“No, I’m just confused.”
“Well, that’s because you’re not a vet.” Continuing to mutter under her breathe “didn’t I say I’ll marry you ONLY if you NEVER act in a medical manner towards my cats…”
She had been “warned” about medical interference and the “know-it-all” attitude of medics by her vet!!!
Oh, sorry, did I not say? We were watching This Farming Life (one of our favourite TV shows) and they were talking about Clydesdale foals and whether they must be given the colostrum from the mare!
The placenta
The placenta is the organ formed during pregnancy that allows “most” mammals to give birth to live young (mammals excluded from this are rare egg laying mammals such as the duck-billed platypus and the echidna, a spiny anteater). The placenta allows a fetus which has half of its genetics from its father (and hence different to the mother) to be carried to term without it being attacked by the mothers immune system. It is also the place where the fetus is given oxygen and nutrition in exchange for carbon dioxide and waste products.
The placenta is amazing!
The other amazing thing about the placenta in humans is that it allows IgG antibody to be transferred to the developing fetus so that after the baby is born it has immunity against the different infections the mother has previously been exposed to. So if the mother has had chicken pox in the past, the baby is born immune to chicken pox, if the mother has had measles vaccine then the baby is born with vaccine induced immunity to measles, etc, etc. It’s a very clever evolutionary development that helps protect newborn babies BEFORE they come into contact with infectious diseases… and this immunity lasts about 3-6 months, hence the need for later vaccination in infancy. As I said, the placenta is amazing!
So, whilst watching This Farming Life this “human medicine-know-how” is what was going through my head. Horses are mammals, they have placentas, and so CLEARLY antibody crosses the placenta to protect the newborn foal… BUT actually NO it doesn’t, it’s one of those “human doctors stay away from animals, vets-know-better things” and here’s why….
Not all placentas are created equal
It turns out that there are different types of placentae… who knew?! …Vets probably!!
There are actually 4 main types of placentae:
- Haemochorial – humans, hares, rabbits and rodents
- Epitheliochorial – horses and pigs
- Synepitheliaochorial – ruminants e.g. cows, goats, sheep
- Endotheliochorial – carnivores
Only the haemochorial placenta is able to transfer antibody to the fetus. All of the other types of placentae have maternal tissue between the chorion part of the placenta (outermost membrane surrounding an embryo) and the maternal blood supply. This maternal tissue acts like a barrier to prevent antibody transferring. In the haemochorial placenta the chorion directly contacts the maternal blood supply, and the fetus is able to produce a specialist receptor (called a neonatal Fc receptor) that binds to IgG and then transports it to the fetus. That doesn’t happen with the other types of animals; they have to get their IgG some other way.
This is where colostrum comes in….
What is colostrum?
Colostrum is the first milk produced by a lactating mammal; it is full of proteins and has a yellow colour. Colostrum is also packed full of all sorts of goodies to help the newborn baby such as extra minerals and antibodies. This is why breast feeding is strongly encouraged; according to the WHO globally 3 in 5 babies are not breastfed in the first hour of life and only 40% of infants under six months of age are exclusively breastfed. Besides immunity and reduced newborn mortality, breast feeding is free, perfectly nutritious and clean which is particularly important if you live in a country where food is scarce and clean water tricky to come by. Despite the WHO concerns, for over four decades formula milk companies (most notably Nestle) continuing to use aggressive, clandestine and often illegal methods to target mothers in the poorest parts of the world to encourage them to choose powdered milk over breastfeeding, “formula is expensive … I only gave her half bottles”. OK, today’s ethical rant is over…
In humans the colostrum antibodies help protect the gut from mucosal and gastrointestinal acquired infections such as those that cause vomiting and diarrhoea, but they are not that important in terms of systemic infections. However, in other mammals the colostrum antibodies are ESSENTIAL for protecting the newborn.
For non-haemochorial placenta animals IgG in the colostrum milk is absorbed across their gut wall by passive transfer (due to differences in concentration between the gut and the surrounding tissue) rather than by binding to a specific active receptor (like the neonatal Fc receptor). If the newborn doesn’t get any colostrum into its gut, then it doesn’t get any antibodies and it is at high risk of acquiring a life-threatening infection after birth.
This is why farmers are obsessed with making sure newborn animals take an early milk feed from their mothers, and why if the mother isn’t producing milk, or the newborn isn’t able to feed for some reason, they will put a tube down through the mouth or nose into the stomach and pour colostrum directly into the newborns stomach. It may sound mean, but it’s so important for protecting them.
What does this mean in humans?
Human babies also benefit from getting colostrum, it helps provide some gut protection against infection, and gives the newborn baby a good healthy kick of protein and minerals. However, colostrum is not as essential for humans as it is for other animals because human mothers are able to give their antibodies (either from natural infection or from vaccines) to their babies. I guess we’re just lucky that way!
So, the farmer on This Farming Life was absolutely right to be worried about his Clydesdale foal (called Rocky) not getting colostrum, and whether it had enough maternally derived protection. Apparently, if the blood test didn’t show enough antibody in the foal, they would have had to give it a blood transfusion to give it antibody… GOSH! and doing that to a horse must be really difficult. And yes, ECIC is right, I’m not a vet and I should have nothing to do with looking after animals!
Fortunately for all concerned, Rocky had good antibody levels, and everything was okay in the end. This is good news as Clydesdales are “at risk” of becoming extinct with only about 5000 left in the World (800 in the UK). They are a magnificent breed of draught horse, originally from the valley of the River Clyde in Scotland. In the preindustrial era there were 10s of thousands working on the farms of Britain, but losses due to their use in World War I and the introduction of machinery onto farms has led to a serious decline in their numbers. So, you can understand why even one foal is important to those who are trying to keep this wonderful breed of horse alive… but then I’m biased… I think they are amazing!