“…Earlier reports have indicated that the decline in hatchability can be delayed by supplementing the diet with sources of unidentified factors. Some of the supplements reported to increase hatchability are pork liver meal, desiccated meat meal, fish meal, dried buttermilk, dried skimmilk, meat scraps, dehydrated alfalfa meal, distillers dried solubles, dried whey, and liver "L" (Nestler et al, 1936;Dickens et al, 1941;Atkinson et al, 1951Atkinson et al, , 1953Atkinson et al, , 1955bCouch et al, 1954;and Ferguson et al, 1956). The fat soluble vitamins E and D, as well as pantothenic acid, have been shown to be necessary in the maintenance of hatchability (Stadelman et al, 1950;Jensen et al, 1953;Jensen, 1953;Jensen et al, 1956;Atkinson and Couch, 1954;Atkinson et al, 1955a, b;Scott and Nelson, 1955;Kratzer etal., 1955;and Ferguson et al, 1956).…”