TY - JOUR AU - Sánchez-Rodríguez, Héctor L. AU - Domenech-Pérez, Katherine PY - 2021/01/01 Y2 - 2024/03/28 TI - Light sensors assess solar radiation vs. shade exposure of slick- and wild-type Puerto Rican Holstein cows JF - The Journal of Agriculture of the University of Puerto Rico JA - JAUPR VL - 105 IS - 1 SE - Articles DO - 10.46429/jaupr.v105i1.19634 UR - https://revistas.upr.edu/index.php/jaupr/article/view/19634 SP - 39-48 AB - <p>Anecdotal data suggest that slick-haired cows (SLICK) graze under&nbsp;solar radiation longer than their wild type-haired (WT) counterparts.&nbsp;However, to the authors’ knowledge, empirical data regarding the&nbsp;suggestion is scarce. This study aimed to use light sensors (HOBO&nbsp;Pendant MX) to study solar radiation exposure. Sensors (attached to&nbsp;a collar) were validated in 20 Holstein cows rotated from shade (0837&nbsp;to 0906h) to sunlight (0907 to 0932h) and then back to shade (0933 to&nbsp;1005h). After validation, sensors were used to compare the differences&nbsp;in solar radiation exposure between 10 SLICK and 10 WT Holstein cows.&nbsp;Data were analyzed by the GLIMMIX and FREQ procedures (SAS). Light&nbsp;intensity was greater under solar radiation than during the first (P&lt;0.01)&nbsp;and second (P&lt;0.01) shade periods (51,026.00±682.25; 2,282.40±647.64&nbsp;and 1,907.27±626.28 lx, respectively). No differences were observed&nbsp;between shade periods (P=0.62). The SLICK cows spent more time under&nbsp;solar radiation than the WT cows (52.67 vs. 47.33%, respectively; P&lt;0.01).&nbsp;Hair coat type and period interacted (P&lt;0.01), with greater light intensities&nbsp;in SLICK than in WT cows under solar radiation (24,702±106.65 vs.&nbsp;20,518±98.43 lx, respectively); but no differences were observed under&nbsp;shade (1,856±7.03 and 1,793.2±6.53 lx, respectively). The SLICK cows&nbsp;showed greater exposure time to direct solar radiation than their WT&nbsp;counterparts.</p> ER -