A TWO-STAGE TECHNIQUE FOR THE IN VITRO DIGESTION OF FORAGE CROPS

A simple technique for the determination in vitro of the dry- or organic-matter digestibility of small (0·5 g) samples of dried forages is described. It involves incubation first with rumen liquor and then with acid pepsin. Using 146 samples of grass, clover and lucerne of known in vivo digestibility (Y), the regression equation Y= 0·99 X– 1·01 (S.E. ± 2·31) has been calculated, where X=in vitro dry-matter digestibility. This technique has been used for the study of the digestibilities of plant breeder's material, of the leaf and stem fractions of herbage and of herbage consumed by animals.

[1]  D. Minson.  THE EFFECT OF PELLETING AND WAFERING ON THE FEEDING VALUE OF ROUGHAGE—A REVIEW* , 1963 .

[2]  A. Warner.  Proteolysis by rumen micro-organisms. , 1956, Journal of general microbiology.

[3]  A. Kivimae.  Estimation of the digestibility of grassland crops from their chemical composition. , 1960 .

[4]  N. Dijkstra.  What has the State Agricultural Experiment Station at Hoorn contributed to research into the feeding value of roughage , 1954 .

[5]  W. F. Raymond,et al.  STUDIES ON THE DIGESTIBILITY OF HERBAGE. 1. Technique of Measurement of Digestibility and Some Observations on Factors Affecting the Accuracy of Digestibility Data , 1953 .

[6]  B. A. Dehority,et al.  Effect of Particle Size upon the in Vitro Cellulose Digestibility of Forages by Rumen Bacteria , 1961 .

[7]  Forbes Rm.  Protein as an indicator of pasture forage digestibility. , 1950 .

[8]  J. Tayler,et al.  The use of rumen-fistulated steers in the direct determination of nutritive value of ingested herbage in grazing experiments. , 1963 .

[9]  J. Scholl.  Research Techniques in use at the Grassland Research Institute , 1962 .

[10]  W. F. Raymond,et al.  STUDIES IN THE DIGESTIBILITY OF HERBAGE. VIII. The digestibility of S 37 cocksfoot, S 23 ryegrass and S 24 ryegrass , 1960 .

[11]  J. Pew.  Properties of Powdered Wood and Isolation of Lignin by Cellu[lo]lytic Enzymes , 1957 .

[12]  C. D. Kemp,et al.  Studies in the digestibility of herbage. 9. Herbage and faecal nitrogen as indicators of herbage organic matter digestibility. , 1961 .

[13]  E. Mcdougall.  Studies on ruminant saliva. 1. The composition and output of sheep's saliva. , 1948, The Biochemical journal.

[14]  H. L. Lucas,et al.  Significance of the differences in digestibility of feeds by cattle and sheep. , 1951, Journal of animal science.

[15]  C. N. Huhtanen,et al.  Fiber Digestion Using the Miniature Artificial Rumen , 1954 .

[16]  R. H. Alexander,et al.  ADVANCE NOTES ON RESEARCH , 1961 .

[17]  R. Weller,et al.  The conversion of plant nitrogen to microbial nitrogen in the rumen of the sheep , 1958, British Journal of Nutrition.

[18]  A. Virtanen.  Fermentation of Wood-dust by Cellulose Bacteria , 1946, Nature.

[19]  W. F. Raymond,et al.  Selection for Digestibility in Herbage Grasses , 1962, Nature.

[20]  R. E. Deriaz.  Routine analysis of carbohydrates and lignin in herbage , 1961 .