The rumen check (also called hunger groove) is a way of checking food intake and the speed at which it is moving in an individual cow. Stand behind the cow to look at the cow’s left flank, to assess the rumen fill. The fill indicates the feed intake, the fermentation speed and the rate at which the feed is passing through the cow’s digestive system. The fermentation and passage speed depends on the content and properties of the feed. The latter includes fast or slowly fermentable feed, the particle size and the balance between the different feed components in the rumen.
A deep dip in the left flank. The skin under the lumbar vertebrae curves inwards. The skin fold from the hook bone goes vertically downwards. The paralumbar fossa behind the last rib is more than one hand-width deep. Viewed from the side, this part of the flank has a rectangular appearance. The cow has eaten little or nothing, which could be due to sudden illness, insufficient or unpalatable food.
The skin under the lumbar vertebrae curves inwards. The skin fold from the hook bone runs diagonally forward towards the last rib. The paralumbar fossa behind the last rib is one hand-width deep. Viewed from the side, this part of the flank has a triangular appearance. This score is often seen in cows in the first week after calving. Later in lactation, this is a sign of insufficient food intake, or a rate of passage that is too high.
The skin under the lumbar vertebrae goes vertically down for one hand-width and then curves outward. The skin fold from the hook bone is not visible. The paralumbar fossa behind the last rib is still just visible. This is the right score for milking cows who have a good food intake and when the food is in the rumen for the correct amount of time.
The skin under the lumbar vertebrae curves outwards. No paralumbar fossa is visible behind the last rib.
This is the correct score for cows nearing the end of lactation, and for dry cows.
The lumbar vertebrae are not visible as the rumen is very well filled. The skin over the whole belly is quite tight.
There is no visible transition between the flank and ribs. This is the correct score for dry cows.
Source: D. Zaaijer, W.D.J.Kremer, J.P.T.M. Noordhuizen (2001), in J. Hulsen, Cow Signals. first published on delaval milkproduction.com