Effects of an evaporative cooling system on plasma cortisol, IGF-I, and milk production in dairy cows in a tropical environment

Abstract

Access to an evaporative cooling system can increase production in dairy cows because of improved thermal comfort. This study aimed to evaluate the impact of ambient temperature on thermoregulation, plasma cortisol, insulin--like growth factor 1 (IGF--I), and productive status, and to determine the efficiency of an evaporative cooling system on physiological responses under different weather patterns. A total of 28 Holstein cows were divided into two groups, one with and the other without access to a cooling system with fans and mist in the free stall. The parameters were analyzed during morning (0700 hours) and afternoon milking (1430 hours) under five different weather patterns throughout the year (fall, winter, spring, dry summer, and rainy summer). Rectal temperature (RT), body surface temperature (BS), base of tail temperature (TT), and respiratory frequency (RF) were lower in the morning (P < 0.01). The cooling system did not affect RT, and both the groups had values below 38.56 over the year (P = 0.11). Cortisol and IGF--I may have been influenced by the seasons, in opposite ways. Cortisol concentrations were higher in winter (P < 0.05) and IGF--I was higher during spring--summer (P < 0.05). The air temperature and the temperature humidity index showed positive moderate correlations to RT, BS, TT, and RF (P < 0.001). The ambient temperature was found to have a positive correlation with the physiological variables, independent of the cooling system, but cooled animals exhibited higher milk production during spring and summer (P < 0.01).

Accessing drop in milk production in cattle due to cold climate and subsequent nutrient amelioration in temperate Kashmir

“…The difference in cortisol (Table 3) was significantly (p<0.05) lower in treatment group (24.33±1.84 ng/ml) in comparison to control (33.04±0.27 ng/ml) during winter while the difference was nonsignificant in spring in both control (15.63±0.48 ng/ml) and treatment (13.90±0.38 ng/ ml) group of animals. The present study found the highest cortisol concentrations in winter, in agreement with the findings of other authors (Titto et al, 2013). Frank et al (2003) observed increased baseline concentrations of the stress-related hormones ACTH and cortisol in response to brief exposure (i.e., 5 d) of pigs to cold.…”

Heat stress and ACTH administration on cortisol and insulin-like growth factor I (IGF-I) levels in lactating Holstein cows

“…The inter-assay coefficient of variances (CVs) were 9.25% and 11.4% for CORT and IGF-I, respectively, and the intra-assay CVs were 12.1% and 12.9% for CORT and IGF-I, respectively. The kits were validated for cattle by demonstrating parallelism between standard concentrations and serially diluted samples curves (Pauletti et al 2005;Titto et al 2013).…”

Corrélation des taux de cortisol dans le sérum, les poils et les fèces chez le dromadaire (Camelus dromedarius)

“…La même différence a été rapportée chez la vache (Titto et al, 2013), la chèvre (Alila-Johansson et al, 2003) et l'homme (Hadlow et al, 2014). Le dromadaire possède une activité sexuelle saisonnière stimulée par les jours décroissants de la saison d'hiver (El Khasmi et al, 2011).…”