39 39 LOHMANN TIERZUCHT › MANAGEMENT GUIDE Production Vitamin & Mineral supplements Grit The main target of production is to adjust the nutrient requirements in order to optimise the egg output while maintaining body weight. Since egg output is influenced by energy, protein/amino acid levels and body weight, it’s advisable to monitor the birds’ weight on a regular basis as well as measuring parameters like feed and water intake, egg weight, and egg numbers. This allows you to detect if the hens are producing to their full potential and if the nutrient specifica-tions are appropriate. Once nutrient specifications are es- tablished, any further switch in diets should be made based on the param- eters mentioned above. To achieve the full productive poten- tial of LOHMANN hens, maximizing feed intake is a must. Feed intake capacity must be devel- oped through training, which starts in rear, and by using a feed with an appropriate nutrient density and an adequate supply of fibre alongside a homogenous feed format and feed distribution program. All LOHMANN breeds should be fed ad libitum. Any feed restriction will impact on productivity exacerbate any health issues and potentially lead to increased mortality. Recommendation for Nutrient Levels for Production – Brown Hens Recommendation for Nutrient Levels for Production – White Hens As raw materials alone are unable to meet the vitamin and mineral require- ments of the hen they should be added as supplements (premix) to the feed. These supplements are susceptible to oxidation and/or degradation, so inclusion of antioxidants may be ad- visable. When manufacturing feed, it’s also important to consider the inclusion rate of the supplements to guarantee an optimal distribution of all the in- gredients and nutrients. Adding thepremixat a rateno less than 2 kg per tonne of feed is advisable. Recommended Micro-Nutrient Specification for Hens and Pullets In nature, birds consume grit (insol- uble stones) that improve the grind- ing activity of the gizzard. Grit stimulates the development of the crop and the gizzard during the rearing pe- riod, which in turn has a positive effect on feed intake capacity. Amount and Granulation of Grit dependent on age Week Allowance Particle size 1 – 3 1 g/bird/week 1 – 2 mm 4 – 9 2 g/bird/week 3 – 4 mm 9 – 13 3 g/bird/week 3 – 4 mm >_ 14 4 g/bird/week 3 – 4 mm Lay 4 g/bird/month 3 – 4 mm situations where has not been pos- sible to get an adequate feed intake development. A pre-peak diet is pro- posed. Provide this diet for brown birds till hens achieve 105 g/day and 110 g / day of feed intake for brown and white birds respectively. If a correct feed intake development has been reached, then continue with > 59 grams /hen/ day egg mass diet for both. Recommendation for Nutrient Levels for Onset of Lay LOHMANN TOOLBOX