Further Evidence for an Unidentified Nutrient in Fish Solubles Which Improves Hatchability and Progeny Growth of Turkeys and Japanese Quail

In a continuation of earlier work (Touchburn et al., 1972), six experiments were conducted to improve the assay for the unidentified dietary factor found in a dried fish solubles supplement. Japanese quail were shown to serve as excellent pilot animals for turkeys. Both species generally showed significantly improved hatchability or improved early growth of their progeny in response to dried fish solubles supplementation of semi-purified and purified-type diets. Growth responses to dietary addition of dried fish solubles were observed in poults and quail chicks from depleted parents. Although housing the breeder hens in cages in a controlled environment and feeding purified diets helped standardize the conditions it tended to minimize reproductive performance and hence limit the response to the fish factor. This suggested that the factor, like several other essential nutrients, is synthesized by the bird but at a rate insufficient to meet requirements under optimum conditions of performance. Results suggest that the activity cannot be accounted for by dietary selenium or sulfate. In the course of fractionating the dried fish solubles its activity was enhanced by acid treatment and by pepsin digestion, possibly by release of the active principle from a bound form or by otherwise altering its configuration.