CAGE HOUSING

23 LOHMANN › MANAGEMENT GUIDE 23 should be used in which the nutrient con- tent meets the birds changing needs. The di- ets are matched to the nutrient requirement and weight development at each stage of growth. The use of chick starter is recom- mended if the standard body weight is not reached by feeding grower feed or if the daily feed intake is expected to be low. The switch to developer should only be made when the standard body weight has been reached. A reduced nutrient density and an increased content of crude fibre (5–6 %) during this phase is beneficial for improving eating capacity. The pre-layer diet has about twice the calcium content of developer as well as higher levels of protein and amino acids. Feeding such a diet for about 10 days prior to the planned start of lay is therefore beneficial. This diet improves flock uniform- ity by providing a better nutrient supply to late maturing birds and by enabling early maturing birds to obtain sufficient calcium for eggshell production of the first eggs. Table 7: Ideal amino acid ratios (Digestible Lysine as 100 – others as ratios to 100) Starter Grower Develop er P re-lay Layer Feed Lysine 100 100 100 100 100 Methionine 44 45 47 50 50 Met. + Cyst. 75 80 85 90 90 Threonine 66 70 70 70 70 Tryptophane 19 21 24 21 22 Isoleucine 69 76 76 80 80 Valine 78 78 80 88 88 Arginine 105 105 106 104 104 The feed should be based / calculated on the level of digestible amino acids according to an ideal amino acid profile, above table shows the ratios of the most important amino acids as ratios to Lysine on digestible level. Pre-layer feed should be used for a short pe- riod of time before a flock starts being sup- plied with phase 1 layer feed. This leads to a smooth transition from the developer feed (low calcium and low nutrient density) to a diet with high calcium and nutrient levels. It helps to avoid the often reduced appe- tite/daily feed intake during early produc- tion. Typically, pre-layer feed contains about 2.0–2.5% calcium. This is too much for a typical feed for rearing but not enough for a Correct Use of Pre-Layer Feed