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Protein nutrition in ruminants
Animal Feed Science and Technology, 9 (1983) 149--153 Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands
149
Book Reviews
PROTEIN NUTRITIONIN RUMINANTS Protein N u t r i t i o n in R u m i n a n t s . E.R. 0rskov, Academic Press (London),
1982, x + 160 pp., £ 11.80 (U.K. only) / $ 24.50, ISBN 0.12.528480.2. New knowledge on protein, particularly nitrogen metabolism in the rumen, has given rise to important changes in the way of thinking about protein nutrition in ruminants. Improved systems for expressing protein requirements and for protein evaluation have been adopted recently. This book offers in five chapters a well documented, comprehensive review of the recent developments in the field of protein nutrition of ruminants. In the first chapters the anatomical and physiological peculiarities of the digestive system of ruminants are discussed. The development of a functioning rumen, which depends mainly on different nutritional factors, is of primary importance for feeding growing ruminants. In Chapter 2 the occurrence, biochemical significance and growth of tureen micro-organisms (bacteria, protozoa and fungi) are discussed. Information on the composition of microbial protein and on the stoichiometry of tureen fermentation is given. Chapter 3 is devoted to the dynamics of nitrogen in the rumen, that is degradation, recycling and deposition of nitrogen in microbes. Methods for measuring degradability of feed protein and of estimating microbial yield are quoted, and the consequences of deficiencies in covering microbial requirements on food utilization shown. Finally, some remarks are made on microbial fermentation in the large intestine and on the composition of faecal nitrogen-containing substances. In Chapter 4 protein requirement and protein utilization are considered from the viewpoint of the host animal. Requirements for maintenance, tissue growth, lactation and pregnancy are discussed in detail and the factors which influence the rate of protein deposition reviewed. For calculating protein need the utilization of microbial protein by the host animal and the degradability of the protein in the rumen are of primary importance. Therefore, treatments for reducing degradability, that is for producing so-called protected protein, are described. Also, methods for testing the effectiveness of the protection are mentioned. In Chapter 5 old and new systems of protein evaluation for ruminants are compared and areas for further research suggested. This up-to
149
Book Reviews
PROTEIN NUTRITIONIN RUMINANTS Protein N u t r i t i o n in R u m i n a n t s . E.R. 0rskov, Academic Press (London),
1982, x + 160 pp., £ 11.80 (U.K. only) / $ 24.50, ISBN 0.12.528480.2. New knowledge on protein, particularly nitrogen metabolism in the rumen, has given rise to important changes in the way of thinking about protein nutrition in ruminants. Improved systems for expressing protein requirements and for protein evaluation have been adopted recently. This book offers in five chapters a well documented, comprehensive review of the recent developments in the field of protein nutrition of ruminants. In the first chapters the anatomical and physiological peculiarities of the digestive system of ruminants are discussed. The development of a functioning rumen, which depends mainly on different nutritional factors, is of primary importance for feeding growing ruminants. In Chapter 2 the occurrence, biochemical significance and growth of tureen micro-organisms (bacteria, protozoa and fungi) are discussed. Information on the composition of microbial protein and on the stoichiometry of tureen fermentation is given. Chapter 3 is devoted to the dynamics of nitrogen in the rumen, that is degradation, recycling and deposition of nitrogen in microbes. Methods for measuring degradability of feed protein and of estimating microbial yield are quoted, and the consequences of deficiencies in covering microbial requirements on food utilization shown. Finally, some remarks are made on microbial fermentation in the large intestine and on the composition of faecal nitrogen-containing substances. In Chapter 4 protein requirement and protein utilization are considered from the viewpoint of the host animal. Requirements for maintenance, tissue growth, lactation and pregnancy are discussed in detail and the factors which influence the rate of protein deposition reviewed. For calculating protein need the utilization of microbial protein by the host animal and the degradability of the protein in the rumen are of primary importance. Therefore, treatments for reducing degradability, that is for producing so-called protected protein, are described. Also, methods for testing the effectiveness of the protection are mentioned. In Chapter 5 old and new systems of protein evaluation for ruminants are compared and areas for further research suggested. This up-to