Livestock in the northern highlands of Peru is fed on the association of ryegrass (Lolium multiflorum L.) ecotype cajamarquino - white clover (Trifolium repens L.) Ladino variety constantly varies in its agronomic characteristics and nutritional value due to management considerations and its association with the soil and the animal. The objective was to evaluate yield, plant height, growth rate, number of tillers, spikelets, basal diameter in ryegrass, elongation rate, internode length, and decrease points in clover over one year. Nutritional value was represented by crude protein (CP), neutral detergent fibre (NDF), in vitro digestibility of dry matter (IVDDM) and metabolisable energy (ME) at three cutting frequencies. Better yield (5588 kg DM ha) and plant height (47.1 cm) showed the 60-day cutting frequency; however, there was no difference (p>0.05) among the three cutting frequencies in annual yield. There was no difference between number of tillers and basal diameter. Clover height, elongation rate and internode length were higher at 60 days. The highest CP concentration and lowest NDF value (p<0.05) were achieved by clover at 30 and 45 days. The producers should consider the findings obtained to decide the time of use of this association in dairy cattle feeding.

Livestock production in the Cajamarca, La Libertad and Amazonas basins is based on pasture-based feeding with "Cajamarquino ecotype" ryegrass under monoculture or in association with white clover. The objective of this research work was the morphological characterization and evaluation of the productive yield and cutting time of annual ryegrass - Lolium multiflorum L. Six local genotypes of Lolium multiflorum in six locations were characterised, using the multiplicative interaction effect model and additive main effects for the analysis of interaction and variability of the genotypes and locations. Ryegrass “Cajamarquino ecotype” is semi-erect with intermediate growth, with a dark green colouring, 0.8 cm broadleaf, and can reach an average stem length of 46 cm, up to 1.6 cm.day, achieving the growth of the fourth leaf after 28 days under adequate management conditions. Despite the differentiated characteristics, according to the BLASTn evaluation, the ITS1 sequences showed an identification greater than 99.9% similar to Lolium multiflorum L. It was determined that the Cajamarquino ecotype produces from 3.52 to 4.98 Mg.ha.biomass cutting. Likewise, the pasture's quality is better when used at 30 days with 14.84% protein and at 45 days, it achieves 12.75% protein with a biomass of 4.05 Mg.ha.cut. With these morphological and yield characteristics, the "Cajamarca ecotype" ryegrass is a well-adapted species for local livestock farming. These species are adapted to the Sierra Norte area of Peru.