Thiamine and Riboflavin in Various Fractions of Rumen Contents of Young Calves1

TECHNICAL NOTES T H I A M I N E A N D R I B O F L A V I N IN V A R I O U S F R A C T I O N S OF R U M E N C O N T E N T S OF YOUNG C A L V E S 1 Recently, Usuelli and Pinna (4) have reported that thiamine is synthesized in the sheep rumen by bacteria but not by protozoa. Observations made in this laboratory on the B-complex vitamin content of various fractions of rumen contents indicate that this is also true in young calves fed high roughage rations. Rumen samples, which were obtained from rumen-inoeulated, high-roughage-fed calves (2) ranging m age from 4 to 6 months, were fraetionated by straining through two layers of cheesecloth, which yielded a residue of partially digested feedstuff and rumen juice. A portion of the strained rumen juice was then centrifuged at 1,000 r.p.m, for 5 minutes, which layered the protozoa in the bottom of the centrifuge tubes. The supernatant liquid was decanted and saved. The protozoa were washed in physiological saline and allowed to stand 4 to 6 hours. During this procedure they settled as a white mass at the bottom of the eontainers (3). The supernatant liquid remaining after removal of protozoa was then centrifuged at 3,000 r.p.m., which removed a large proportion of the remaining bacteria. The bacterial fraction was obtained after decanting the supernatant liquid. However, this decanted supernatant liquid still contained some bacterial cells; therefore, it was passed through a Seitz bacterial filter to obtain the bacteria-free filtrate fraction. Results of thiamine and riboflavin assays (1) of these various fractions of rumen col~tents are presented Approved by the director of the Ohio Agricultural Experiment Station as Journal Article No. 53 -54.

in Table 1 with similar assays of the feed given the calves at the time of sampling. These data show that rumen bacteria provide a relatively rich source of thiamine and riboflavin and that these vitamins are principally bound in the bacteria cells. Although tureen protozoa provided a relatively rich source of riboflavin, their thiamine content was not much higher than that found in the feed. These results suggest that thiamine is synthesized by bacteria and not by protozoa in the rumen. This is in agreement with the results reported by Usuelli and Pinna (4). H. R. CONRAD AND J. W. HIBBS Ohio Agrictdtural Experiment Station REFERENCES (1) ASSOCIATION Or VI~AMI~ CttE~ISTS, INC. Methods of Vitamin Assay. Interscienee Publ. Co., New York. 1951. (2) CO,-RAn, H. R., AN9 HIBBS, J. W. A High Roughage System for Raising Calves Based on the Early Development of Rumen Function. I. Effect of Variations in the Ration on Growth, Feed Consumption, and Utilization. J. Dairy Sei., 36: 717. 1953. (3) JOHNSON, B. C., HA~(ILTOI~, T. S., ROBINSON, W. B., AND GAREY, J. C. On the Mecha n i s m of Non-Protein Nitrogen Utilization by Ruminants. J. Animal Sci.~ 3: 287. 1944. (4) USUELLI, F., AND PIAI~A, G. B-Vitamins in Zooteehniques. Ann. fac. agrar., univ. Milano, 1: 173. 1953. (Abs. in Chem. Abstr., 48: 7722. 1954.)

TABLE 1 The content of thiamine and riboflavin in various fractions of ru~nen contents Thiamine No. of samples Rumen contents (7/g of D.M.) Residue after straining (~/g of D.M.) Strained rumen juice (7/100 ml.) Centrifuged rumen juice (~//100 ml.) Bacteria-free filtrate (~//100 ml.) Rumen bacteria (~¢/g of D.M.) Rumen protozoa (7/g of D.M.) Feed (~/g of D.M.)

548

Riboflavin

6

6

2.61 1.77 8.28 4.77 2.87 9.71 3.34 2.53

92.0 1O.1 112.8 54.9 21.1 39.2 59.0 6.9