Horn Meal Research Articles

Sulfide liberation from raw soybean protein.

Numerous reports have been concerned with the factors or properties that cause an inferior nutritive value of raw soybean meal as compared to properly cooked meal. These reports have been reviewed recently(1). Among such factors have been anti-enzymes, pancreatic hypertrophy, amino acid deficiency or unavailability, toxic proteins, and indigestible protein fractions, but the effects or even the existence of some are still matters of disagreement. Proteins which are known to be highly indigestible, i.e., the keratins, have been shown to be improved in digestibility by steam cooking under pressure. A comprehensive report (2) has reviewed the literature in this field and presented specific data in respect to feather protein. It was shown that the principal changes on treatment with steam were loss of cystine, corresponding appearance of lanthionine and increased susceptibility to enzymatic hydrolysis. The conversion of cystine in part to lanthionine, which involves breakage of disulfide cross links between amino acid chains and loss of one-half the sulfur, was most rapid during the first 30 minutes of processing at 30 1b steam pressure. At the same time, amino nitrogen liberated by rupture of peptide bonds increased very slightly, if at all. Some data (3) obtained during steam processing of hoof and horn meal are in agreement with the later studies on feather protein. Volatile sulfur, particularly H2S, was detected in the exhaust gases. Neartly two-thirds of the original cystine was lost, while the apparent digestibility to pepsin and HCI improved from an original 13 to 73%. The loss of sulfur from proteins during cooking has been known for a long time. Recently, the cooking of cod muscle has been shown to result in a loss of cystine(4). We investigated the possibility that such changes could take place in other protein sources such as the soybean.

Disponibilidade de nitrogênio em diversos fertilizantes nitrogenados

Neste trabalho são apresentados os resultados preliminares obtidos com a aplicação de diferentes fertilizantes nitrogenados, a fim de se determinar a forma de nitrogênio preferida pelo arroz durante os dois primeiros meses do ciclo vegetativo. Para isso instalou-se uma experiência em vasos contendo terra-roxa misturada e empregando-se os seguintes materiais nitrogenados : salitre do Chile, sulfato de amónio, calciocianamida, uréia, torta de algodão, farinha de chifre e casco, e solução de amoníaco. Os resultados apontaram a uréia como o fertilizante que propiciou maior produção de matéria sêca. Seguiram-se-lhe o sulfato de amônio, solução de amoníaco, farinha de chifre e casco, calciocianamida, torta de algodão e, finalmente, o salitre.

A Method for Separating Coarse Hoof and Horn Meal From Meat and Bone Scrap

A Method for Separating Coarse Hoof and Horn Meal From Meat and Bone Scrap

The nitrogen status of soils Part I. The nitrification of some nitrogenous fertilizers

The rates of nitrification and the extent to which a number of nitrogenous materials are nitrified in soil have been studied. Of the substances used ammonium sulphate was most rapidly and most completely nitrified under these conditions. A reputedly genuine sample of Peruvian guano was almost as rapid as ammonium sulphate. At the other end of the scale was horn meal, which was nitrified most slowly and in which the percentage of nitrogen converted was lowest. On a basis of nitrification alone there appears to be no justification for the traditional view that hoof and horn is slow- and that dried blood is quick-acting. Two samples of bone meal showed very different rates of decomposition. This, and the anomalous behaviour of hoof and horn separately as compared with mixed hoof and horn, suggest that differences occur in the behaviour of different samples of what are nominally the same materials. Some of the commercial implications of these findings are discussed.

The Use of a Hoof and Horn Meal to Replace Animal and Vegetable Protein in Rations for Growing Chicks

IT HAS recently been demonstrated (Wagner and Elvehjem, 1942) that chicks and rats can make use of the protein in powdered swine hoofs and, furthermore, that this material is more adequate for the nutrition of the chick than is purified casein. In a later report (1943), these same authors indicated that powdered swine hoofs was a satisfactory substitute for meat meal and fish scraps in practical starting rations for chicks.The present experiments were made in an attempt to establish the practical feeding value of a product represented as containing 5 to 10 percent horn, 65 to 70 percent cattle hooves and 20 to 30 percent calf and hog hooves.* The calf and hog hooves mixture was predominantly hog hooves. All these ingredients were ground in a ball mill to a very fine powder and, subsequently, were thoroughly mixed. Seventy-five percent of the resultant material would pass through a 100 .

Decomposition of Keratin by Soil Micro-Organisms (With One Text-figure.)

Keratin, prepared from horn meal, was added to moist field and garden soil and allowed to decompose in the laboratory. The keratin was found to undergo a decomposition resulting in a slow, but steady accumulation of ammonia and nitrate. 35–40 per cent, of its nitrogen was transformed into nitrate after 120 days. The addition of keratin produced little or no increase in the number of bacterial colonies on agar platings, but markedly increased the number of actinomycete colonies, especially in garden soil. Two strains of actinomycetes were isolated and found capable of thriving on keratin in pure culture, decomposing the keratin with the formation of ammonia. One of the strains could be recognised asActinomyces citreusKrainsky, as described by Waksman. The other strain could not be named, but corresponded closely to the description of Waksman'sActinomyces145.