Why is my newborn yellow?

“Everything that is yellow is not gold .” - Welsh proverb

If you're new to farming, there is a lot to learn, not least the weird and wonderful things that happen around birth. One thing that can be a surprise is when your newborn calves or lambs are born covered in a yellow fluid at birth. This is not the usual birth fluids which can also be yellowish. This is a definite yellow or green that stains the coat of the newborn. The colour can be quite shocking when you’re not expecting it.

The reason for the colour is due to meconium. Meconium is a newborn's first feces, which in most animals is not passed until after birth. If passed before birth it will colour the birthing fluids. It can vary in colour from greenish to yellow-brown. If a newborn is heavily stained with meconium, it can suggest that the animal has experienced stress during the birthing process.

Stress can occur due to a prolonged or difficult birth, known as dystocia. While the meconium is not usually a problem there is a danger that if the animal inhales meconium-stained fluid it can cause a condition known as meconium aspiration syndrome, which can lead to breathing difficulties and infection.

If the newborn behaves normally then there’s nothing to do. However, if it seems lethargic, struggles to breathe, or shows other signs of distress, contact a vet immediately.

While the sight of a bright yellow newborn calf or lamb can be disconcerting if you haven’t seen it before, it doesn't necessarily mean anything is wrong, only that they've had a rough time. Of course if the newborn had a rough birth then so did the mother so keep an eye on her to make sure she's bounced back after the difficult labour, and then keep an eye on both of them for the first couple of days.