20 LOHMANN TIERZUCHT › MANAGEMENT GUIDE 20 Laying Period Aiming at an optimal start of production with feed intake around 90–100 g/day, it is recommendable to use a phase 1 feed with 11.6 ME MJ/kg for a duration of 5–6 weeks. At around 26 weeks a normal phase- feeding programme with 11.4 ME MJ/kg should be introduced. The basis for the feed formulation in terms of nutrient and mineral content in each phase is the daily nutrient requirement and actual feed consumption. The diet for phase 1 is designed to cover the requirement for maximum egg mass. The recommended nutrient allowances shown in the tables 9–11 (phase 1–3) as- sume a dietary energy concentration of 11.4 MJ/kg (2725 kcal) metabolisable energy, a house temperature of 20 °C and good plumage. Under these conditions the daily feed con- sumption is expected to be 110–120g/day. The feed formulations for phases 2–3 cater for the reduced requirement for organic nutrients and the increasing requirement for calcium as the hens age. The time for switching diets is determined more by the level of production and the need for calcium rather than by age. Every 10 weeks throughout the laying pe- riod the composition of the diet should be adapted to the level of production and the hens’ nutrient requirement. Major changes in the raw material composition of the various phase diets or marked changes in feed consistency should be avoided. Nutrition and Egg Weight Within certain limits egg weight can be adapted to farm specific requirements by adjusting rations. The following nutritional factors should be noted: › Growing › Feeding for higher body weight/frame size increases the egg weight through- out the whole laying period. › Feed composition › crude protein and methionine › linoleic acid › Feeding technique › feed texture › feeding time › feed level in troughs › controlled feeding › frequency of feeding