Unlike many other mammals, calves and lambs do not get any maternal antibodies through the placenta. This means they are born without any immune system, getting all of their antibodies through their mothers’ colostrum until they can create their own.
Antibodies bind to a specific pathogen, sending signals to white blood cells that then destroy them. In new-borns, antibodies are absorbed through the gut into the blood stream but there is a limited time before the gut ‘closes’ and these large molecules cannot pass through. This process is called passive transfer and if it fails, our new-born animals are left defenceless, meaning increased disease, increased death rates and longer term detrimental effects on growth rate and reproductive performance.
Therefore, it is important to get enough colostrum into our new-borns, and within the time frame mentioned. We can also ‘boost’ our animals’ colostrum by vaccinating the mother before calving or lambing.
They require 10-15% of their birthweight over the first 6-12 hours, which means a lamb requires over a litre (based on an average birthing weight of 5-6kg) of colostrum, and a calf needs 4-5 litres. Their stomachs cannot hold this much fluid at once so this has to be split into several feeds. Usually our lambs and calves are left to drink alone, but this is good to know if we have to hand rear them.
Vaccinations in the mother will increase the antibodies in the colostrum and so we recommend annual clostridial vaccines in sheep and cattle, and leptospirosis vaccines in cattle. In cattle we also have Rotavec and scour guard vaccines which help reduce the effects of rotavirus and our scour-causing pathogens.