The correct posture
When drinking from a teat, the calf holds its nose up and its head back. This is comparable to the natural drinking position. This position activates the oesophageal groove reflex in the calf, maximising the chance that the milk will enter the abomasum and not the rumen. Rule of thumb: the ideal teat height is the height of the withers.
Produce saliva
When drinking from the teat, the calf must actively suck. This way the milk is absorbed more slowly, which increases the chance that the milk will end up in the right place, in the abomasum. In addition, the calf produces saliva and thus sodium bicarbonate when sucking. This helps in the digestion of the milk.
More certainty
Using a teat means that things are less likely to go wrong, Johan has noticed. ‘If the temperature or concentration is not quite right, thanks to the posture and sucking behaviour, things are much less likely to go wrong than when drinking from a bucket or trough.’