Nutritional availability of spray dried lard water protein

Four growth trials were conducted with rats and chicks to investigate the nutritional value of Spray Dried Lard Water (SDLW--a by-product from the rendering process of animal lard) as a source of protein in a semipurified diet. Weanling rats lost weight when fed a diet containing 10% of SDLW as sole source of protein. Responses of rats to amino acid(s) supplementation indicated tryptophan as the first-limiting amino acid, then threonine, methionine and lysine. One-week-old chicks fed diets containing SDLW to provide 20% crude protein responded to dietary amino acid supplementation. The results suggested that the limiting amino acid sequence of spray dried lard water for chicks was methionine, tryptophan, threonine and lysine, respectively. Results from this study also showed that biological availability of the amino acids in SDLW protein was rather low.