The Effects of Dietary Fat and Energy Levels on the Performance of Caged Laying Birds

Abstract

THE FOLLOWING experiment was conducted to study the effects of introducing fat into the ration of mature laying birds previously fed starting, growing and laying diets not supplemented with fat. Data on body weight, mortality, egg production rate, egg size, albumen quality, egg shell thickness and feed consumption are presented. EXPERIMENTALThe birds used were 300 White Leghorn pullets which were already in lay (11 months old) when they were fed the rations supplemented with different levels of fat. Five and 10 percent of tallow† were fed to the birds in the rations shown in Table 1. The control ration and rations 2 and 3 were formulated to supply 1270 Cal. metabolizable energy per lb. (based on average energy values given by Potter et al., 1961). Ration 4 contained 10 percent tallow, but no attempt was made to have the ration isocaloric with the other rations, and its calculated metabolizable …