1042 Associations between the environmental conditions and vaginal temperature in wild-type and slick-haired Puerto Rican Holstein cows

Body dimension comparisons between slick and wild type-haired Puerto Rican Holsteins

“…However, when cows are taken to the pasture paddocks (where solar radiation is a major environmental issue in the tropics) it is not uncommon to observe SLICK cows grazing under the sun during the hottest hours of the day; while all their WT relatives rest in the shade, lying in the mud in an attempt to alleviate the negative impacts of heat stress (Sánchez-Rodriquez, 2019). In fact, such differences in intake may help to explain the greater milk production reported in SLICK cows by Delgado et al (2014) and Contreras-Correa et al (2016). In order to eat greater amounts of tropical grasses, a larger ruminal capacity is required, since tropical grasses are high in fiber (Stobbs, 1995), including lignin, which is especially high during the dry season (Detmann et al, 2009).…”

“…It is well known that heat stress limits feed intake in dairy cattle (West, 2003). However, because SLICK cows have a superior thermoregulatory capacity (Castro et al, 2015;Contreras-Correa et al, 2016;Sánchez-Rodríguez et al, 2016;Contreras-Correa et al, 2017;Muñiz-Cruz et al, 2018), a smaller impact on feed intake may be reasonably expected in this group when exposed to tropical weather conditions. The diet of the evaluated cows consisted of limited access to concentrate feed immediately before milking and ad libitum access to tropical grasses the remaining daily period.…”

“…Due to the negative impact that heat stress exerts on the productivity of temperate Bos taurus cattle (West, 2003), SLICK cattle received considerable scientific attention in recent years because of its superior thermoregulatory capacity. Studies have determined that, when exposed to heat stress, mature SLICK cows maintain lower body temperatures (Sánchez-Rodríguez et al, 2016) and respiration rates (Castro et al, 2015), have larger sweat glands (Contreras-Correa et al, 2017;Muñiz-Cruz et al, 2018) and higher milk production values (Contreras-Correa et al, 2016).…”

Revisión histórica y científica sobre el desarrollo de la ganadería de leche en Puerto Rico con énfasis en el ganado pelón

“…Su borla (parte final del rabo) suele ser de menor tamaño que la observada en vacas de pelo normal, aunque existe variabilidad considerable entre individuos. Ejemplares de ambos tipos de pelo pueden observarse en varias razas en PR, incluyendo la Holstein (Figura 2; Sánchez et al, 2015;Sánchez-Rodríguez et al, 2016b) y la Jersey (Figura 3;Castro et al, 2015).…”

“…Se ha obtenido evidencia de que, en efecto, las vacas Holstein pelonas puertorriqueñas presentan una menor temperatura corporal bajo condiciones ambientales cálidas que las de pelo normal, la cual es dependiente del grado de estrés por calor del animal (Sánchez et al, 2015;Sánchez-Rodríguez et al, 2016b). Esto quiere decir, que las diferencias en temperatura corporal entre animales pelones y sus contemporáneos de pelo normal aumentan a medida que la temperatura del aire se incrementa.…”