Browsing by Author "DiRienzo, Douglas B."

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    Compositions and methods for the treatment of dietary deficiencies
    (United States Patent and Trademark Office, 1992-12-01)
    Compositions containing peptides which are capable of absorption in the stomach are supplied to animals, such as but not limited to ruminants, in order to supply nutrients and treat dietary deficiencies. In a preferred embodiment, peptides containing at least one other amino acid which animals are deficient in are supplied to animals to treat specific amino acids deficiencies. Preferably, the peptides contain glycine, phenylalanine, or proline, and the peptides are formed from a total of four or less amino acid residues. An alternative embodiment involves formulation of peptide derivatives through the attachment of mineral compounds or medicaments to peptides, and the peptide derivatives are then supplied to the diet to treat mineral deficiencies or illnesses. The compositions and methods are particularly useful in treating amino acid deficiencies, such as but not limited to methionine deficiencies in ruminants.
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    Free and peptide amino acid fluxes across the mesenteric and non-mesenteric viscera of sheep and calves
    DiRienzo, Douglas B. (Virginia Tech, 1992-09-05)
    The flux of free and peptide amino acids across the stomach and intestinal tissues was quantified using sheep and calves maintained in "steady state” conditions by feeding at hourly intervals. Crossbred wethers and Holstein steers were surgically cannulated in the abdominal aorta, mesenteric vein and portal vein. All animals were fed an orchardgrass, corn, SBM-based diet. The steers received three abomasal infusions; a control solution, and an amino acid mixture simulating casein and casein each at a rate equivalent to 25% of daily crude protein intake. Nutrient fluxes from the mesenteric and portal-drained viscera were measured; non-mesenteric flux was calculated as the difference between portal flux and mesenteric flux. Results of this study support the concept that free amino acids are absorbed by the small intestine and not by the stomach. The flux of peptide amino acids across the portal-drained-viscera indicate that a major portion of the amino acids which are absorbed by cattle and sheep are absorbed in the form of peptides from the stomach. The observation that large quantities of peptide amino acids are absorbed from the stomach is unique and it is expected that this most important discovery will revolutionize the feeding of ruminants.
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    Intensive spring nitrogen management of winter barley: silage and grain yield and composition
    DiRienzo, Douglas B. (Virginia Polytechnic Institute and State University, 1987)
    The impact of rate and timing of spring nitrogen application on yield and composition of barley forage and grain and the fermentation and utilization of barley silage was investigated in a 3-yr study. The use of a growth regulator, ethephon, was also investigated. Nitrogen application at a rate of 135 kg/ha increased forage yields in 1984 and tended to increase yields in 1985 and 1986 though dry conditions existed. Crude protein yield was increased with application of 135 kg N/ha all three years. Major impact of N. fertilization appeared to be associated with an application at Feekes stage 5. Nitrogen treatments had little impact on nitrate, NDF or ADF concentration but higher rates generally lowered forage dry matter. Use of N resulted in increased dry matter intake and increased dry matter, crude protein, NDF, and ADF digestibility of silage when fed to lambs. In 2 of 3 yr grain yield appeared to be lowered as forage yield increased due to N treatment. Grain crude protein and crude protein yields were increased with the use of N. Increases in grain crude protein content were associated with applications of N at Feekes stage 5. Generally, test weight and 1000 kernel weight decreased and the number of tillers increased at rates of N application were increased. Use of Ethephon tended to increase yields in 1984 and increased yields in 1985.