Effect of summer heat environment on body temperature, estrous cycles and blood antioxidant levels in Japanese Black cow

Abstract

This study investigated the effect of summer heat environment on estrous cycles and blood antioxidant levels in Japanese Black cows. A total of 13 non-lactating Japanese Black cows (summer: 9, winter: 4) were examined. Body temperature was measured rectally and intravaginally using a thermometer and data logger, respectively. Estrous behavior was monitored using a radiotelemetric pedometer that recorded walking activity. Rectal temperatures were higher during summer than winter (P<0.001). There was an acute increase in vaginal temperature at the onset of estrus during winter but such an increase was not observed during summer. Walking activity during estrus decreased dramatically in the summer compared to the winter. Duration of estrous cycle was longer in summer (23.4 days, P<0.05) than winter (21.5 days), and the subsequent rise in progesterone concentrations following estrus tended to be delayed in summer. The level of thiobarbituric acid reactive substances (TBARS) in peripheral blood cells was higher during summer (P<0.05), while the levels of superoixde dismutase (SOD), glutathione peroxidase (GPx) and glutathione were lower (P<0.05). These results indicate that high ambient temperature during summer increases both body temperature and oxidative stress, and also reduces signs of estrus in Japanese Black cows.

Characterization of genes and pathways that respond to heat stress in Holstein calves through transcriptome analysis

“…pathways they are involved in HS response in animals Sakatani et al 2012). Study of genetic factors for HS in dairy cattle should be valuable to evaluate the availability of genetically superior animals that can respond better to changing temperatures without any significant drop in production rate and also for identifying target genes and genomic region for breeding genetically superior animal with increased tolerance to HS.…”

Evaluation of the relationship between milk glutathione peroxidase activity, milk composition and various parameters of subclinical mastitis under seasonal variations

“…BERNABUCCI et al (2002) also defined a decrease in blood GSH-Px activity during the summer months. Levels of blood SOD, GSH-Px and glutathione decreased in high ambient temperature during the summer (SAKATANI et al, 2012). However, no information regarding the relationship between milk GSH-Px and heat stress is present in the literature.…”

“…However, high ambient temperature has been found to induce free radical production. Decreased antioxidant enzyme activity during the summer months has been reported in several studies, while levels of antioxidant and oxidant enzymes in blood have been used to analyze the relationship between heat stress and oxidant levels (BERNABUCCI et al, 2002;SAKATANI et al, 2012;TURK et al, 2015), but studies based on milk samples are missing.…”

El estrés calórico afecta el comportamiento reproductivo y el desarrollo embrionario temprano en bovinos

“…Con el estrés calórico, no sólo disminuye la intensidad sino también la duración del estro, aumentan las ovulaciones silenciosas y la incidencia de anestro (Wakayo et al, 2015). La intensidad del estro, medida como actividad (pasos) fue 2,34 veces menor en verano que cuando se midió durante el invierno (Sakatani et al, 2012b). La tasa de no retorno a celo (NRR) durante 90 días para el primer servicio, es decir, vacas que quedaron preñadas después del servicio, varió entre 15,8 y 23,6% entre animales expuestos a estrés calórico y animales en ambiente termoneutral, donde los animales expuestos al estrés calórico tuvieron menores NRR que aquellos animales servidos en ambiente termoneutral (Al-Katanani et al, 1999).…”