Effects of Dietary Calcium, Protein and Energy on Feed Intake, Egg Shell Quality and Hen Performance

Abstract

twenty-week experiment was conducted to determine if dietary levels of calcium, protein and energy act or interact to influence feed intake, egg shell quality and hen performance. The design was a 5 replicate, 3 × 3 × 3 factorial arrangement of 27 treatments composed of three levels each of calcium (1.8, 3.6 and 54. g.), protein (13, 16 and 19 g.), and metabolizable energy (200, 250, 300 kcal. M.E.) in 120 g. of feed. Hy-Line W-36 hens, 31 weeks old, were used. Egg production level was significantly influenced by dietary protein, energy and calcium, under the winter-time conditions of this experiment (October 18 to March 6). According to the overall treatment means, average egg production was best with diets containing 19 g. protein, 200 kcal. M.E. and 5.4 g. calcium. Voluntary feed intake was significantly influenced by dietary energy and protein (as protein level was increased egg production increased and consequently feed intake increased) but not by calcium. However, the hens fed diets containing 1.8 g. of calcium consumed as much feed as hens fed the 5.4 g. diets even though they produced 7.9 percent fewer eggs. This may indicate that hens fed rations low in calcium consumed more feed in an attempt to take in more calcium. Breaking strength of the egg shells increased significantly as dietary calcium was increased.