I am often asked why we advise giving hens grit on a regular basis. Grit is a vital part of your hen’s digestive process, however it is important to remember that there are different grades of grit and they perform two different functions in your hen.
Fine or soluble grit is the sort that dissolves in the hens’ digestive system. This is mostly calcium-based and can be in the form of limestone (calcium carbonate) either as small chips or ground flour in commercial poultry feeds, or as crushed oyster or mussel shells. These different forms of the ‘grit’ are essential for egg shell formation.
Insoluble grit is comprised of things like small pea-sized gravel chips or small stones which birds pick up if they are allowed to forage around outside. These stones do not dissolve, nor do they provide calcium, but they do provide a mechanical aid to break down food.
Did you know that hens don’t have any teeth (remember the expression ‘as rare as hen’s teeth’)?
When your hen tucks in to her pellets or corn, the food passes into her crop (imagine that this is the hen’s shopping basket)
Feed is stored for up to six hours where it softens and swells and starts the process of digestion. During the course of the day the food leaves the crops and enters the Proventriculus (basically her stomach). At this stage the feed is mixed with enzymes which break down protein and peptides and assist with absorption.
Having left the Proventriculus the feed enters a tough muscular structure called the Gizzard. This is the grinding mill of the gut. Here the insoluble grit helps to grind up the fibres in vegetation and breaks down the hard husks of grains and seeds that your hen might eat. This grinding processes the food into a form which allows the nutrients to be worked on by digestive enzymes and absorbed into the bloodstream.
Ideally your hen should be fed a mixture of soluble and insoluble grit to maintain good health.