Relación de temperatura rectal y frecuencia respiratoria con temperaturas de pelo obtenidas por termografía en ovejas gestantes estresadas por calor

Abstract

Relación de temperatura rectal y frecuencia respiratoria con temperaturas de pelo obtenidas por termografía en ovejas gestantes estresadas por calor Resumen El estudio tuvo como objetivo establecer la relación de temperatura rectal y frecuencia respiratoria con temperaturas de superficie del pelo (cabeza, espalda, ijar, cadera y vientre) obtenidas a través de imágenes termográficas en ovejas de pelo gestantes y estresadas por calor. Las variables se obtuvieron de 24 ovejas gestantes multíparas Katahdin x Pelibuey cada 15 días, dos veces por día (07:00 y 16:00 h), entre el día 100 de gestación y el parto. El análisis estadístico consideró correlación de Pearson y regresión lineal simple. La temperatura rectal (r = 0,66 a 0,74) y la frecuencia respiratoria (r = 0,60 a 0,66) correlacionaron positivamente (P < 0,0001) con las diferentes temperaturas de capa de pelo. Las ecuaciones desarrolladas con cada temperatura del pelo explicaron (P < 0,0001) entre 36 y 55% de la variación observada en la temperatura rectal y la frecuencia respiratoria. La temperatura de cabeza explicó la mayor variación (R 2 = 0,48 a 0,55) en ambas variables fisiológicas. Se concluye que las temperaturas de superficie del pelo tienen una relación moderadas con la temperatura rectal y la frecuencia respiratoria en ovejas de pelo gestantes mantenidas en hipertermia, asimismo, la temperatura de cabeza puede ser usada en el desarrollo de ecuaciones de predicción para ambas variables fisiológicas.Palabras clave: Hipertermia, ovinos de pelo, temperatura de cabeza, capa de pelo. AbstractRelationship of rectal temperature and respiratory frequency with hair coat temperatures obtained by thermography in heat-stressed pregnant ewes

Thermoregulatory Response of Blackbelly Adult Ewes and Female Lambs during the Summer under Tropical Conditions in Southern Mexico

“…Animals in heat stress, transport heat from inside the body to the skin through blood flow [ 41 ]. The RT showed slightly higher values than those reported for animals in the comfort zone [ 46 , 47 ]. The mean HR was close to the ranges considered acceptable for ewes under tropical environmental conditions (117.8 bpm) [ 48 ].…”

“…The RT values reported in this study are similar to those in the study by Gastelum-Delgado et al [ 43 ], changing only the THI (>80 U). In another investigation, pure-bred Blackbelly ewes and crosses with Dorset were more tolerant to heat than ewes of hair breeds such as Pelibuey, Dorper, Katahdin, or their crosses, as they presented lower RT values under heat stress in tropical environments [ 46 , 47 ].…”

“…Vicente-Pérez et al [ 46 ] reported an ST range of 24.4–32.7 °C in different body regions. In the present investigation, ewes exceeded this range, since temperatures of 42.01 ± 6.93 °C were recorded, as was the case in the anatomical area of the haunch.…”

Physiological response to thermal stress in hair-sheep ewes during subtropical summer

“…In females it directly affects the presence and duration of estrus, displaying low growth of the dominant follicle and reduced concentrations of gonadotropin-releasing and luteinizing hormones, reflected in a lower estrogen synthesis [9]. The corporal temperature observed by different methods such as rectal and thermographic infrared images and RF has been used as indicators of short-term thermic stress in different reproductive and growth stages in sheep [28], but not in early stage of pregnancy. In Pelibuey ewes, the available research indicate that this breed show more effective BT regulation under artificial conditions of environmental hyperthermia [20], less effects on progesterone levels [16] and their embryo percentage apparently is less influenced by artificial hyperthermia [27].…”

Relationship between rectal temperature measured with a conventional thermometer and the temperature of several body regions measured by infrared thermography in fattening rabbits. Influence of different environmental factors

“…Changes in body temperature can be measured correctly using RT (Marai et al, 2002), but this methodology is invasive and could negatively affect the animal's welfare, as it takes a long time to measure (Chung et al, 2010;Vicente-Pérez et al, 2019).…”