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Responses of Dairy Heifers to Crownvetch, Sericea Lespedeza, and Alfalfa Forages 1
Author(s) -
Burns J. C.,
Mochrie R. D.,
Cope W. A.
Publication year - 1972
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1972.00021962006400020020x
Subject(s) - lespedeza , neutral detergent fiber , condensed tannin , dry matter , rumen , agronomy , tannin , forage , medicago sativa , chemistry , lignin , zoology , proanthocyanidin , palatability , digestion (alchemy) , biology , food science , botany , polyphenol , antioxidant , biochemistry , chromatography , fermentation
Early reports, indicating lack of palatability and also the presence of toxic substances in crownvetch ( Coronilla varia L.), have discouraged its use as a livestock feed. Crownvetch and sericea lespedeza [ Lespedeza cuneata (Dumont) G. Don] were compared with alfalfa ( Medicago sativa L.) for dry mater intake and daily gains by dairy heifers and for concentrations of volatile fatty acids, tannins, and total phenols in rumen fluid and blood. Experimental forages of crownvetch and alfalfa differed significantly in neutral detergent fiber, acid detergent fiber, lignin, and cellulose (structural constituents), but not in tannin or total phenol concentration. Sericea and alfalfa were similar in structural constituents, whereas tannin and total phenol concentrations in sericea were approximately three times those in alfalfa. When comparing crownvetch and sericea with alfalfa, in vitro dry dry matter disappearance (IVDMD) appeared depressed about equally by structural differences (crownvetch vs alfalfa, 15.8% units) and by tannin and phenol differences (sericea vs alfalfa, 14.2% units). Heifers consumed 7.5 kg/head/day of crownvetch, compared with 6.1 of alfalfa and 5.6 of sericea. The resulting daily gains were 0.98, 0.65, and 0.49 kg, respectively. The gains from crownvetch were good, and in agreement with expectations based on both intake and plant composition. The intake and gain data did not reflect the large depression in IVDMD obtained for sericea compared with alfalfa. This suggests that heifers adjusted more easily to changes in chemical inhibitors of digestion than they did to increases in the fibrous fraction. Volatile fatty acid (VFA) concentrations in the rumen fluid appeared to be a reflection of structural differences of the forages. Blood acetate levels were unaltered as a result of the hay fed. Tannin and total phenol levels were present in all rumen fluid samples, but tannins were not detectable in the blood. Crownvetch, which was readily consumed during this study, can be a desirable, nutritious forage for heifers.