<p class="SiMPLE">Background. The association of legumes with grasses improves the quality of the diet as well as the protein value, increases productivity, allows savings in nitrogen fertilizer and maintains the proportion of the botanical components of the meadow. The cutting date affects the productive behavior of the forages species in temperate, arid and semi-arid climate zones. Therefore, it is important to continue evaluating established grassland with legumes associated with grasses to generate information that will serve producers and increase the economic profitability of livestock activities. Objective. The objective of the present study was to evaluate the cutting date on dry matter production (PMD), growth rate (RG), botanical composition (BC), as well as relationships between RG and PMD and BC and PMD. Hypothesis. It is evident that the cutting date modifies the PMD, RG, as well as the relationship between RG and BC with PMD, but has no influence on BC. Methodology. Meadows irrigated with <em>Trifolium alexandrinum</em> L. associated <em>Lolium multiflorum</em> Lam. of a proportion of 40:60 sowing seeds, respectively subject to eight cutting dates (treatments): T₁ = 90 to 97 days elapsed between the sowing date and the first cut (DTS-PC), T₂: 97 to 104 DTS-PC, T₃: 104 to 111 DTS-PC, T₄: 111 to 118 DTS-PC, T₅: 118 to 125 DTS-PC, T₆: 125 to 132 DTS-PC, T₇: 132 to 139 DTS-PC and T₈: 139 to 146 DTS-PC, under a randomized complete blocks design with four replicates. The trend of the factor under study (cutoff date) on the response variables was determined using orthogonal polynomials. Results. The DTS-PC caused a linear positive effect (P &lt;0.001) of the evaluated species on the PMD and RG, observing that increasing the DTS-PC increased the PMD. (P = 0.0001). In contrast, no significant differences (P&gt; 0.05) were observed in the BC. Regardless of the DTS-PC, the legume as <em>T. alexandrinum </em>contributed 64 % of the biomass, these percentages were determined dividing the PMD of <em>T. alexandrinum </em>by the PMD of <em>L</em>. <em>multiflorum</em> added with that of dead material and weeds. There was an effect of the DTS-PC on the relationship of RG:PMD (linear effect, P &lt;0.01), while for the ratio relationships BC:PMD only a linear decrease was presented (P &lt;0.01) at increasing the DTS-PC.  Implications. The results of the present study contribute to knowing the productive parameters of a grass established with legume-grass in temperate, arid and semi-arid climate zones to improve the production of meat and milk. Conclusions. The elevation of the cutting date increased the PMD, but has an inverse effect for the relationships BC:PMD, as well as RG:PMD of each species.  The highest RG was found at 97-104 DTS-PC for the evaluated species and dead material.</p>

<p><strong>Background.</strong> The intensity and grazing interval are two very important factors in the management of grasslands that can affect the morphological and productive behavior of the forage species. Due to its productivity and persistence to grazing, ryegrass (<em>Lolium multiflorum</em> Lamb.) is the main source of pasture for backgrounding cattle during winter-spring in northwestern México. Therefore, it is important to generate knowledge of established pasture with grasses to generate information that will serve producers to improve the economic profitability of livestock activities. <strong>Objective.</strong> The objective of this study was to evaluate the influence of grazing intensity (GI) and grazing interval (GIv) on forage yield, elongation rate and botanical composition of ryegrass, under ambient conditions of this arid region. <strong>Hypothesis. </strong>It is evident to observe that GIv and GI modify the forage yield, elongation rate and botanical composition of <em>L. multiflorum</em> established in irrigated grassland in temperate climate zones.<strong> Methodology.</strong> The study involved 1008 crossed bull calves (<em>Bos indicus </em>ˣ<em> Bos taurus</em>) of 16 months of age. Calves were distributed in a 3 ˣ 2 factorial arrangement in an RCB design, with three repetitions. Three GIv (21, 28 and 35-d) and two GI (grazed to 4 to 6 cm vs 10 to 12 cm) were evaluated. This 105-d trial was initiated on January 16, 2019, 90 days post-planting and finished on May 01, 2019, using an intensive grazing system with stocking rate of 56 calves per ha. The main effects of grazing interval were evaluated by means of orthogonal polynomials. <strong>Results.</strong> Forage yield increased linearly (P&lt;0.01) with increasing GIv; whereas with GIv of 28 and 35 days, yield increased with increased GI (interaction, P&lt; 0.01). Stem contribution to yield increased linearly (P&lt;.01) with increasing GIv. Forage lef to stem ratio decreased with increasing GIv and GI; however, at 28-d GIv, GI did not affect this ratio. <strong>Implications.</strong> The results of the present study contribute to know the productive parameters of an established L.<em> multiflorum</em> meadow in zones of arid climates under two intensities and three grazing intervals. <strong>Conclusions.</strong> In conclusion, both grazing intensity and grazing interval are effective management tools to modify ryegrass performance during the hot ambient conditions of the Sonoran Desert region, associated with late-spring grazing period.</p>