Influence of dietary fat on economic returns of commercial leghorns

The beneficial effect of dietary fat and protein on improving egg weight (EW) is well-documented. However, many egg producers do not supplement fat in commercial hen diets because of inadequate storing and mixing facilities. To improve egg size without using fat, higher protein levels are fed. However, dietary protein has a greater heat increment than fat that could adversely affect hen performance during summer. The maximum dietary protein level that can be economically fed with no added fat without having an adverse effect on hen performance during summer or heat stress is not known. A study was conducted under summer conditions to determine the maximum dietary protein level that could be economically fed without using fat and if money is lost by not using dietary fat during summer. Supplementing fat increased EW and BW of hens in the study. Increasing dietary protein had a positive linear effect on EW. Neither fat nor protein had an effect on egg production, egg mass, or egg specific gravity. Fat increased FC and feed efficiency at the two higher protein levels (19.8 and 18.7%) but not at the lower level (17.4%). Economics of using fat indicated that egg producers feeding diets without fat are losing approximately 1.4 to 3.1 cents per dozen eggs depending upon fat cost and the spread in price between medium and large eggs.