Moderate summer heat stress does not modify immunological parameters of Holstein dairy cows

Abstract

The study was undertaken during spring and summer months in a territory representative of the Mediterranean climate to assess the effects of season on some immunological parameters of dairy cows. Twenty Holstein cows were used. Eleven of those cows gave birth during spring; the remaining nine cows gave birth in summer. The two groups of cows were homogeneous for parity. Values of air temperatures and relative humidity were recorded both during spring and summer, and were utilized to calculate the temperature humidity index (THI). One week before the expected calving, rectal temperatures and respiratory rates of the cows were recorded (1500 hours), and cell-mediated immunity was assessed by measuring the proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMC). Within 3 h of calving, one colostrum sample was taken from each cow and analysed to determine content of immunoglobulin (Ig) G1, IgG2, IgM and IgA. At 48 h after birth, passive immunization of the calves was assessed by measuring total serum IgG. During summer, daytime (0900-2000 hours) THI values were above the upper critical value of 72 [75.2, (SD 2.6)] indicating conditions that could represent moderate heat stress. That THI values were able to predict heat stress was confirmed by the values of rectal temperatures and respiratory rates, which were higher (P < 0.05 and P < 0.001 respectively) during summer. Proliferation of PBMC, the colostral concentration of Ig fractions and serum levels of IgG in their respective off-spring did not differ between spring and summer cows. Results indicated that moderate heat stress due to the hot Mediterranean summer does not modify cell-mediated immunity, the protective value of colostrum and passive immunization of the offspring in dairy cows.

The Hsp72 response in peri-parturient dairy cows: relationships with metabolic and immunological parameters

“…Analogously, other studies demonstrated that mild hot does not affect immunological parameters and Hsp expression or synthesis in cattle. In two previous studies on Holstein cows, we reported that moderate summer heat stress did not modify mitogen-driven proliferation of PBMC, immunoglobulin concentrations in colostrum, and passive immunization of newborn calves (Lacetera et al 2002), and that incubation temperatures simulating conditions of mild hyperthermia did not affect Hsp72 gene expression in lymphocytes (Lacetera et al 2006). Likewise, Yániz et al (2009) reported that conditions of mild hot did not affect Hsp72 concentrations in PBMC from early or mid-pregnant cows.…”

Peripheral blood mononuclear cells: a potential cellular system to understand differential heat shock response across native cattle (Bos indicus), exotic cattle (Bos taurus), and riverine buffaloes (Bubalus bubalis) of India

“…The utility of PBMCs as cellular model to understand stress response in livestock is attributed to its amenability to culturing and responsiveness to heat stress (Guerriero and 1990; Elvinger et al 1991;Malayer et al 1990;Kamwanja et al 1994;Lacetera et al 2002). Several in vitro studies in bovine have shown reduction in cell viability and responsiveness of lymphocytes to mitogens during short and severe heat shock challenge (Elvinger et al 1991;Kamwanja et al 1994);Lacetera et al 2002). However, no comparative study for cattle types and buffalo has been made to understand the cellular response to thermal stress.…”

Lymphocyte functions in dairy cows in hot environment

“…Several studies (Soper et al 1978;Kelley et al 1982a, b;Elvinger et al 1991;Kamwanja et al 1994;Lacetera et al 2002) have also been carried out to assess the relationships between heat stress and immune cell function in bovines. However, the results of these studies are conflicting.…”