34 LOHMANN TIERZUCHT › MANAGEMENT GUIDE 34 Check the water quality regularly, especially if you use your own water supply like well water. For example excessive salt levels in drinking water can cause persistent damage to shell quality and hard water with high TDS* levels may cause kidney damage. *TDS: Total Dissolved Solids Grit Feeding of grit is not a must – and quite dif- ficult to apply via the automatic feeding sys- tem – but recommended when rations are supplemented by whole grains. Grit stimu- lates the development of the crop and the gizzard during the rearing period, which in turn has a positive effect on daily feed in- take capacity. Furthermore it helps the bird to get rid of or handle straw, hay or litter as such throughout the digestive tract which the birds might eat in non-cage systems. Via this effect and sometimes as a supporter of healthy digestion at all grit has an overall positive effect (increased nutrient absorp- tion) and as reported from practice – grit even can have a positive effect on birds’ be- haviour. These will be highly appreciated by farmers in all kind of alternative housing sys- tem, especially if any kind of beak treatment is prohibited as already in some countries and under rules of organic farming. These ideas are mostly highly accepted but still quite confusion exists about the mean- ing of ‘grit’! In our LTZ understanding grit are small insoluble particles/stones which As example pictures from grit in different particle sizes – in LTZ understanding Source: LTZ