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dc.contributor.advisorSánchez-Rodríguez, Héctor L.
dc.contributor.authorGarcia-Peña, Juan C.
dc.date.accessioned2018-11-14T13:22:20Z
dc.date.available2018-11-14T13:22:20Z
dc.date.issued2015
dc.identifier.urihttps://hdl.handle.net/20.500.11801/1217
dc.description.abstractThe Criollo cattle from the Caribbean have been suggested as an alternative highly adapted to difficult environmental conditions. However, to our knowledge, there has not been extensive research about its thermoregulatory capacity. The present study aimed to evaluate the effect exerted by the air temperature, relative humidity, thermal humidity index, solar radiation, wind speed, and gust speed over the vaginal temperature of 13 lactating Criollo dairy cows from the Dominican Republic. The environmental conditions and the vaginal temperature were recorded every 5 minutes for 6 consecutive days. The GLIMMIX and CORR procedures of SAS were used to analyze the data (averaged by hour). Because the environmental conditions were greater during the last three days of the study (P<0.0001), the study was separated in two periods: COOL (days 1, 2, and 3) and HOT (days 4, 5, and 6). Period and time (hour of the day) interacted to affect the environmental temperature (P<0.0001), the relative humidity (P=0.0334), the thermal humidity index (P=0.0002), the solar radiation (P<0.0001), the wind speed (P<0.0001), and the gust speed (P=0.0003). These interactions were the result differences mostly observed during the afternoon time with air temperature, thermal humidity index, solar radiation, wind speed, and gust speed presenting 4.72°C, 5.17, 284.68W/m2 , 0.89 m/s y 2.37 m/s greater during the HOT than during the COOL period, respectively. Also during the afternoon hours the relative humidity was 14.83% lower during the HOT than during the COOL period. Similarly, cows presented greater vaginal temperatures during the HOT than during the COOL period (P<0.0001) from 1400-1800h (38.96±0.03 vs. 38.75±0.02°C, respectively). However, this trend was inverted during the morning hours. Greater vaginal temperature values (P<0.0001) were observed during the COOL than during the HOT period from 0200-0400h (38.37±0.02 vs. 38.21±0.02°C) and 0800-1100h (38.60±0.02 vs. 38.44±0.01°C). On average, daily vaginal temperature ranges of 38.38 - 38.79°C and 38.19 - 39.09°C were observed during the COOL and HOT periods, respectively. There was also a smaller asociation between vaginal temperature and air temperature (r=0.46; P<0.0001 vs. r=0.65; P<0.0001), thermal humidity index (r=0.47; P<0.0001 vs. r=0.60; P< 0.0001), solar radiation (r=0.34; P<0.0001 vs. r=0.50; P<0.0001), wind speed (r=0.35; P<0.0001 vs. r=0.54; P<0.0001), and gust speed (r=0.38; P<0.0001 vs. r=0.51; P<0.0001) during the COOL than during the HOT periods, respectively. Otherwise, the association between the relative humidity and the vaginal temperature was greater during the HOT than during the COOL period (r=-0.56; P<0.0001 vs. r=-0.46; P<0.0001). Even with the difficult environmental conditions present in this study, the observed daily vaginal temperature range and the inversion in the vaginal temperature trends suggested that these Criollo cows were highly adapted to these conditions. Future studies should be directed to compare this genotype with the european breeds comonly used for milk production in the tropics.
dc.description.abstractEl ganado Criollo de los países tropicales caribeños ha sido sugerido como una alternativa altamente adaptada a producir bajo condiciones ambientales estresantes. Sin embargo, según nuestro conocimiento, poco se sabe sobre su capacidad termoreguladora. El presente estudio evaluó el efecto que ejercen la temperatura del aire (TA), la humedad relativa (HR), el índice de temperatura y humedad (ITH), la radiación solar (RS), la velocidad del viento (VV) y la velocidad de ráfaga (VR) sobre la temperatura vaginal (TV) en 13 vacas Criollas lecheras maduras lactantes de la República Dominicana. Para esto se determinaron las condiciones ambientales y la TV cada 5 minutos por 6 días consecutivos. Los datos promediados por hora fueron analizados mediante los procedimientos GLIMMIX y CORR de SAS. Debido a que se observaron condiciones ambientales menos cálidas durante los primeros tres días del estudio (P<0.0001), el mismo fue separado en dos periodos: FRESCO (días 1, 2 y 3) y CALIENTE (días 4, 5 y 6). En el presente estudio periodo y hora del día interactuaron para afectar la TA (P<0.0001), la HR (P=0.0334), el ITH (P=0.0002), la RS (P<0.0001), la VV (P<0.0001) y la VR (P=0.0003). Estas interacciones fueron el resultado de diferencias observadas principalmente durante las horas de la tarde con la TA, el ITH, la RS, la VV y la VR presentando en promedio 4.72°C, 5.17, 284.68W/m2 , 0.89 m/s y 2.37 m/s mayores durante el periodo CALIENTE que durante el FRESCO, respectivamente. También durante las horas de la tarde se observó en promedio un 14.83% menor de HR durante el periodo CALIENTE que durante el FRESCO. Similarmente a las condiciones ambientales, las vacas presentaron mayores valores de TV (P<0.0001) durante el periodo CALIENTE que en el FRESCO de 1400-1800h (38.96±0.03 vs. 38.75±0.02°C, respectivamente). Sin embargo, este patrón se invirtió en las horas de mañana. Se observaron mayores valores de TV (P<0.0001) durante el periodo FRESCO que durante el CALIENTE en los periodos de 0200-0400h (38.37±0.02 vs. 38.21±0.02°C) y 0800-1100h (38.60±0.02 vs. 38.44±0.01°C). En promedio se observaron rangos en TV diaria de 38.38 - 38.79°C y de 38.19 - 39.09°C durante los periodos FRESCO y CALIENTE, respectivamente. Se observó también un menor impacto de la TA (r=0.46; P<0.0001 vs. r=0.65; P<0.0001), el ITH (r=0.47; P<0.0001 vs. r=0.60; P< 0.0001), la RS (r=0.34; P<0.0001 vs. r=0.50; P<0.0001), la VV (r=0.35; P<0.0001 vs. r=0.54; P<0.0001) y la VR (r=0.38; P<0.0001 vs. r=0.51; P<0.0001) sobre la TV durante el periodo FRESCO que durante el CALIENTE. Por el contrario, la HR tuvo mayor relación con la TV durante el periodo CALIENTE que durante el FRESCO (r=-0.56; P<0.0001 vs. r=-0.46; P<0.0001). A pesar del considerable impacto ejercido por las condiciones ambientales sobre las vacas, la amplitud de valores y la inversión observadas en los patrones de TV sugieren gran aclimatación a condiciones climáticas adversas. Futuros estudios deben ir dirigidos a comparar este genotipo con las razas europeas comúnmente utilizadas en esta parte del mundo.
dc.language.isoesen_US
dc.subjectVacaen_US
dc.subjectCriollaen_US
dc.subjectLecheraen_US
dc.subjectRepública Dominicanaen_US
dc.titleEvaluación de la capacidad termoregulatoria de la vaca criolla lechera de la República Dominicanaen_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2015 Juan Carlos Garcia Peña.en_US
dc.contributor.committeeSantana Nieves, Carmen
dc.contributor.committeeCabrera Cabrera, Carlos J.
dc.contributor.committeePagán Morales, Melvin
dc.contributor.committeeLatorre, José R.
dc.contributor.representativeGélica, Jocelyn A.
thesis.degree.levelM.A.en_US
thesis.degree.disciplineAnimal Industryen_US
dc.contributor.collegeCollege of Agricultural Sciencesen_US
dc.contributor.departmentDepartment of Animal Scienceen_US
dc.description.graduationSemesterFallen_US
dc.description.graduationYear2015en_US


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