Author

Karl F. Hoppe

Document Type

Dissertation - University Access Only

Award Date

1990

Degree Name

Doctor of Philosophy (PhD)

Department / School

Animal Science

Abstract

Quality of proteins after partial degradation and conversion into microbial protein was evaluated for lambs fed a corn cob based semipurified diet. Three animal experiments were conducted to measure nitrogen balance and plasma or blood free amino acids in lambs fed purified protein sources differing in rumen degradability. Before amino acid concentrations could be analyzed by gas chromatography as heptafluorobutyryl, isobutyl esters, methods for extracting free amino acids from plasma were evaluated. Either plasma dilution with 1 N acetic acid (1: 1 O, vol:vol) or deproteinization using 10% sulfosalicyclic acid (1: 1, vol:vol) prior to solid phase extraction was determined adequate. Experiment 1. Casein, soy protein isolates and zein included at 12% and urea included at 4.3% in the semipurified diet were fed at 2.2% body weight to lambs. Apparent biological value was greater (P<.05) lysine. An amino acid ratio was used to determine limiting amino acids. For urea diets, leucine and lysine were identified as first and second limiting, respectively. For zein diets, lysine was identified as first limiting.

Format

application/pdf

Number of Pages

84

Publisher

South Dakota State University

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