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This study examined the effects of maternal stress on the response of the pig to acute restraint stress and in vitro measures of immune function. Pregnant sows were assigned by parity to one of two treatments and managed per current industry standards (Control; n=2) or subjected to a daily 5 min acute restraint stress from d 85 to 110 of gestation (Stressed; n=2). After farrowing, pigs (n= 12 from control sows; MC; and n=15 from stressed sows; MS) were weighed and tattooed for permanent identification and managed similarly throughout the remainder of the study. At 35 d of age, pigs were restrained and blood collected initially (t = 1.5 ± 0.1 min), and at 3 and 6 min. Plasma was collected and analyzed for cortisol (C), epinephrine (E), norepinephrine (NE) and dopamine (D). To assess immune function, lymphocytes were isolated using density gradient centrifugation. Cells were plated in DME/F12 media containing Concanavalin A (ConA; 0 to 10 ug/mL) and cultures incubated for 96 hours (37C and 5% CO2). Following incubation, IgM production and the extent of proliferation were determined. Plasma C did not differ (P > 0.05) between MS and MC pigs, and increased (P < 0.01) with duration of restraint (40±5 vs. 75±5 ng/mL for 1.5 vs. 6 min). Plasma E and NE increased with duration of restraint, (P < 0.05) and MS pigs had lower (P < 0.05) E and NE than MC pigs. In MC pigs, D increased (P < 0.05) with duration of restraint. In contrast, in MS pigs D was not affected (P > 0.05) by restraint, and D was lower in MS relative to MC (1.6 ± 0.2 vs. 2.9 ± 0.3, respectively). ConA induced dose-dependent increases (P < 0.01) in lymphocyte proliferation and IgM production. The extent of proliferation was not affected (P > 0.05) by duration of restraint. In contrast, IgM production by cultures decreased (P < 0.05) with increasing time of restraint. Regardless of duration of restraint, cultures established from MS pigs had a reduced (P < 0.05) proliferative and IgM response to ConA than MC pigs. These results indicate that maternal stress affects the stress response of the progeny which may have a negative impact on immune function. [ABSTRACT FROM AUTHOR]

This study examined the effects of maternal stress on offspring behavior in relationship to changes in the stress response. Pregnant sows were assigned by parity to one of two treatments and managed either per current industry standards (Control; n=2) or subjected to a daily 5 min acute restraint stress from d 85 to 110 of gestation (Stressed; n=2). After farrowing, pigs (n= 12 from control sows; MC; and n=17 from stressed sows; MS) were weighed, tattooed for identification and managed similarly throughout the study. On d 18 of age, pigs were subjected to a social confrontation test by placing 3 MC and 3 MS pigs in a 1.5 x 1.5 m open field. Each pig was numbered and the test was videotaped. The behavioral elements measured per pig included: (1) sniffing; (2) threat; (3) biting; (4) fighting; (5) chasing; (6) fleeing; and (7) withdrawal. An aggression score (AS) was calculated as the sum of elements 2 through 5. To assess pig stress response, pigs were subjected to an acute restraint test and blood samples collected at 1.5, 3 and 6 min. Plasma was analyzed for cortisol (C), epinephrine (E), norepinephrine (NE), and dopamine (D). All data was subjected to ANOVA using split-plot design. Sources of variation included treatment, time of bleed, and individual interactions. MS pigs displayed more (P < 0.05) sniffing than MC pigs. MS pigs had decreased (P < 0.05) incidents of biting and fighting, and increased (P < 0.05) incidents of fleeing. The AS score for MS pigs was lower (P = 0.03) than MC (10.9 ± 2.3 vs. 23.8 ± 6.2, respectively). The MS pigs had similar (P > 0.05) plasma concentrations of C, but had lower (P < 0.05) E, NE, D than MC pigs. For both MC and MS pigs there was a positive correlation between AS and E (r=0.76; P < 0.01), but no (P > 0.05) correlation between AS and NE and D. MC pigs showed a positive correlation between AS and C (r=0.78; P < 0.01). In contrast, in MS pigs there was a negative relationship between AS and C (r=-0.61; P < 0.01). Collectively, these data indicate that maternal stress reduces the normal aggressive behavior of pigs. In addition, the results suggest that the role of C in normal aggression in the pig is dependent upon concentrations of the E. [ABSTRACT FROM AUTHOR]

Although livestock experience many stressors throughout their life, one of the most commonly experienced, and most difficult to control, is stress caused by fluctuations in environmental temperatures that extend beyond the thermoneutral (TN) zone for an animal. In swine, cold stress has long been recognized as a main cause of neonatal morbidity and mortality. A possible explanation for this increased morbidity and mortality may be related to their inability to generate a febrile response. Previously, we reported that the acute phase immune response, including the generation of fever, after exposure to lipopolysaccharide (LPS; Escherichia coli O111: B4; Sigma-Aldrich, St Louis, MO, USA) is substantially altered in neonatal pigs maintained in a cold environment (ie, 18°C). Neonatal pigs that were maintained in a cold environment and administered LPS experienced a period of hypothermia coupled with altered endocrine and proinflammatory cytokine responses that could prove detrimental. In cattle, we previously reported differences in the acute phase immune response of two diverse breeds of Bos taurus cattle (Angus and Romosinuano) when maintained under TN conditions and exposed to LPS. More recently we have reported that differences in the stress and immune responses of Angus and Romosinuano heifers varies, depending on whether the cattle were housed at either TN or heat stress air temperatures. Our data clearly show that even intermittent periods of heat stress similar to that experienced in production environments can have significant effects on the stress and innate immune responses of cattle. Understanding the effect of thermal stress on livestock is critical to developing and implementing alternative management practices to improve their overall health and well-being., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Our primary objective of this experiment was to evaluate potential genetic differences between two diverse Bos taurus breeds [Angus (AG) and Romosinuano (RO)] in response to an endotoxin challenge. Eighteen steers (n = 9 steers/breed; 299.4 ± 5.2 kg BW) were acclimated to environmentally controlled chambers maintained at thermoneutrality (19.7 °C) and then fitted with indwelling jugular catheters and rectal temperature (RT) recording devices 1 d before the endotoxin challenge. The next day, blood samples were collected at 30-min intervals from -2 to 8 h, and RT was measured continuously at 1-min intervals throughout the study. At time 0, all steers received an intravenous bolus injection of lipopolysaccharide (LPS; 2.5 μg/kg BW). Serum samples were stored at -80 °C until analyzed for cortisol, proinflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and interferon gamma (IFN-γ)], and acute phase proteins (serum amyloid A, acid soluble protein, ceruloplasmin, and α-acid glycoprotein). Rectal temperatures increased in both breeds within 1 h after LPS, with RO producing a greater increase in RT than AG steers (P < 0.001). Serum cortisol and TNF-α increased (P < 0.01) in both breeds within 1 h after the LPS challenge. For cortisol, an overall breed effect (P < 0.02) was detected, such that AG steers had a higher cortisol response than RO steers. A breed × time interaction (P < 0.01) was observed for TNF-α, such that the response was delayed and extended in the RO steers compared with the AG steers. At 2 and 2.5 h after LPS, TNF-α concentrations were greater (P < 0.03) in RO steers than in AG steers. For IL-1β, a breed × time interaction (P < 0.04) was also observed. At 3 h after LPS, IL-1β concentrations were greater (P < 0.01) in RO steers than in AG steers. Serum IL-6 and IFN-γ increased (P < 0.01) in a similar manner in both groups after the LPS challenge. These data show differences in the innate immune response between two diverse Bos taurus breeds which may provide insight about differences observed in productivity, heat tolerance, disease resistance, and longevity among cattle breeds., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The present study tested the hypothesis that the oral administration of DHEAS enhances the in vitro and the in vivo immune response of young pigs. Crossbred, female pigs (80 days of age; 49+/-2 kg) were separated into two treatment groups (n=4/treatment) receiving either 0mg/kg (control) or 1mg/kg DHEAS twice daily (DHEAS) for 5 weeks. On day 7 pigs were immunized against KLH and ovalbumin. Body weight increased weekly throughout the study but did not differ between treatment groups. While white blood cell counts increased in response to immunization but did not differ between treatments, the neutrophil:lymphocyte ratio was enhanced (P<0.05) in DHEAS-supplemented pigs. Concanavalin A (ConA) induced an in vitro dose-dependent increase (P<0.05) in lymphocyte proliferation, but treatment did not affect proliferation prior to immunization. However, lymphocytes isolated from DHEAS-supplemented pigs displayed a greater increase in proliferation following immunization relative to control pigs (P<0.05). Dexamethasone (DEX) attenuated ConA-induced lymphocyte proliferation, with DHEAS-supplemented pigs retaining a greater proliferative response relative to control pigs (P<0.05). Serum IgG concentrations and relative concentrations of antigen-specific IgG increased after immunization with maximum values attained at 21 and 28 days for control and DHEAS-supplemented pigs, respectively. The DHEAS-supplemented pigs had greater (P<0.05) concentrations of IgG and relative concentrations of antigen-specific IgG compared to control pigs. Collectively these data suggest DHEAS supplementation increases the responsiveness of young pigs to antigenic challenge, and may be beneficial for improving their immune function.