Auteur: Tremblay G.F., Bélanger G., Simili Da Silva M., Lajeunesse J., Papadopoulos Y.A., Fillmore S.A.E. and Jobim C.C.
Jaar van uitgifte: 2015
Herbage with a greater ratio of energy availability to protein degradability increases dairy cow N-use efficiency. We determined the variation in this ratio among 18 binary legume-grass mixtures and 8 complex mixtures combining three or four grass species with one of two legume species. Species included in those two experiments were birdsfoot trefoil (Lotus corniculatus L.), lucerne (Medicago sativa L.), white clover (Trifolium repens L.), cocksfoot (Dactylis glomerata L.), Kentucky bluegrass (Poa pratensis L.), meadow bromegrass (Bromus biebersteinii Roemer & J.A. Schultes), meadow fescue (Festuca pratensis L.), reed canarygrass (Phalaris arundinacea L.), tall fescue (Schedonorus phoenix (Scop.) Holub), and timothy (Phleum pratense L.). Carbohydrate and protein fractions of the Cornell Net Carbohydrate and protein system were measured in herbage from two clippings of the first post-seeding year at two sites in eastern Canada. The water soluble carbohydrate to crude protein ratio ranged from 0.39 to 0.70 among binary mixtures and from 0.64 to 1.04 among complex mixtures, while the ratio of non-structural carbohydrates to non-protein N and rapidly degradable proteins ranged from 3.62 to 5.28 and from 4.33 to 5.64, respectively. Our results confirm the possibility of improving the balance between energy and proteins through the choice of species in legume-grass mixtures.