Effects of dietary antioxidant supplementation on metabolism and inflammatory biomarkers in heat-stressed dairy cows

ABSTRACT: Heat-stress-induced inflammation may be ameliorated by antioxidant supplementation due to the purported effects of increased production of reactive oxygen species or oxidative stress on the gastrointestinal tract barrier. Thus, study objectives were to evaluate whether antioxidant supplementation [AGRADO Plus 2.0 (AP); EW Nutrition] affects metabolism and inflammatory biomarkers in heat-stressed lactating dairy cows. Thirty-two mid-lactation multiparous Holstein cows were assigned to 1 of 4 dietary-environmental treatments: (1) thermoneutral (TN) conditions and fed a control diet (TN-CON; n = 8), (2) TN and fed a diet with AP (10 g antioxidant; n = 8), (3) heat stress (HS) and fed a control diet (HS-CON; n = 8), or (4) HS and fed a diet with AP (HS-AP; n = 8). The trial consisted of a 23-d prefeeding phase and 2 experimental periods (P). Respective dietary treatments were top-dressed starting on d 1 of the prefeeding period and continued daily throughout the duration of the experiment. During P1 (4 d), baseline data were collected. During P2 (7 d), HS was artificially induced using an electric heat blanket (Thermotex Therapy Systems Ltd.). During P2, the effects of treatment, day, and treatment-by-day interaction were assessed using PROC MIXED of SAS (SAS Institute Inc.). Heat stress (treatments 3 and 4) increased rectal, vaginal, and skin temperatures (1.2°C, 1.1°C, and 2.0°C, respectively) and respiration rate (33 breaths per minute) relative to TN cows. As expected, HS decreased dry matter intake, milk yield, and energy-corrected milk yield (32%, 28%, and 28% from d 4 to 7, respectively) relative to TN. There were no effects of AP on body temperature indices or production. Milk fat, protein, and lactose concentrations remained unaltered by HS or AP; however, milk urea nitrogen was increased during HS regardless of AP supplementation (26% relative to TN). Circulating glucose remained unchanged by HS, AP, or time. Additionally, HS decreased circulating glucagon (29% from d 3 to 7 relative to TN), but there was no additional effect of AP. There was a tendency for nonesterified fatty acid concentrations to be increased in HS-AP cows throughout P2 (60% relative to TN-CON), whereas it remained similar in all other treatments. Blood urea nitrogen increased for both HS treatments from d 1 to 3 before steadily decreasing from d 5 to 7, with the overall increase being most pronounced in HS-CON cows (27% relative to TN-CON). Further, supplementing AP decreased blood urea nitrogen in HS-AP on d 3 relative to HS-CON (15%). Circulating serum amyloid A tended to be and lipopolysaccharide binding protein was increased by HS, but neither acute-phase protein was affected by AP. Overall, AP supplementation appeared to marginally alter metabolism but did not meaningfully alter inflammation during HS

Effects of hindgut acidosis on metabolism, inflammation, and production in dairy cows consuming a standard lactation diet

ABSTRACT: Postruminal intestinal barrier dysfunction caused by excessive hindgut fermentation may be a source of peripheral inflammation in dairy cattle. Therefore, the study objectives were to evaluate the effects of isolated hindgut acidosis on metabolism, inflammation, and production in lactating dairy cows. Five rumen-cannulated lactating Holstein cows (32.6 ± 7.2 kg/d of milk yield, 242 ± 108 d in milk; 642 ± 99 kg of body weight; 1.8 ± 1.0 parity) were enrolled in a study with 2 experimental periods (P). During P1 (4 d), cows were fed ad libitum a standard lactating cow diet (26% starch dry matter) and baseline data were collected. During P2 (7 d), all cows were fed the same diet ad libitum and abomasally infused with 4 kg/d of pure corn starch (1 kg of corn starch + 1.25 L of H2O/infusion at 0600, 1200, 1800, and 0000 h). Effects of time (hour relative to the first infusion or day) relative to P1 were evaluated using PROC MIXED in SAS (version 9.4; SAS Institute Inc.). Infusing starch markedly reduced fecal pH (5.84 vs. 6.76) and increased fecal starch (2.2 to 9.6% of dry matter) relative to baseline. During P2, milk yield, milk components, energy-corrected milk yield, and voluntary dry matter intake remained unchanged. At 14 h, plasma insulin and β-hydroxybutyrate increased (2.4-fold and 53%, respectively), whereas circulating glucose concentrations remained unaltered. Furthermore, blood urea nitrogen increased at 2 h (23%) before promptly decreasing below baseline at 14 h (13%). Nonesterified fatty acids tended to decrease from 2 to 26 h (40%). Circulating white blood cells and neutrophils increased on d 4 (36 and 73%, respectively) and somatic cell count increased on d 5 (4.8-fold). However, circulating serum amyloid A and lipopolysaccharide-binding protein concentrations were unaffected by starch infusions. Despite minor changes in postabsorptive energetics and leukocyte dynamics, abomasal starch infusions and the subsequent hindgut acidosis had little or no meaningful effects on biomarkers of immune activation or production variables

Politicians polarize and experts depolarize public support for COVID-19 management policies across countries

none15Political polarization impeded public support for policies to reduce the spread of COVID-19, much as polarization hinders responses to other contemporary challenges. Unlike previous theory and research that focused on the United States, the present research examined the effects of political elite cues and affective polarization on support for policies to manage the COVID-19 pandemic in seven countries (n = 12,955): Brazil, Israel, Italy, South Korea, Sweden, the United Kingdom, and the United States. Across countries, cues from political elites polarized public attitudes toward COVID-19 policies. Liberal and conservative respondents supported policies proposed by ingroup politicians and parties more than the same policies from outgroup politicians and parties. Respondents disliked, distrusted, and felt cold toward outgroup political elites, whereas they liked, trusted, and felt warm toward both ingroup political elites and nonpartisan experts. This affective polarization was correlated with policy support. These findings imply that policies from bipartisan coalitions and nonpartisan experts would be less polarizing, enjoying broader public support. Indeed, across countries, policies from bipartisan coalitions and experts were more widely supported. A follow-up experiment replicated these findings among US respondents considering international vaccine distribution policies. The polarizing effects of partisan elites and affective polarization emerged across nations that vary in cultures, ideologies, and political systems. Contrary to some propositions, the United States was not exceptionally polarized. Rather, these results suggest that polarizing processes emerged simply from categorizing people into political ingroups and outgroups. Political elites drive polarization globally, but nonpartisan experts can help resolve the conflicts that arise from it.mixedFlores A.; Cole J.C.; Dickert S.; Eom K.; Jiga-Boy G.M.; Kogut T.; Loria R.; Mayorga M.; Pedersen E.J.; Pereira B.; Rubaltelli E.; Sherman D.K.; Slovic P.; Vastfjall D.; Van Boven L.Flores, A.; Cole, J. C.; Dickert, S.; Eom, K.; Jiga-Boy, G. M.; Kogut, T.; Loria, R.; Mayorga, M.; Pedersen, E. J.; Pereira, B.; Rubaltelli, E.; Sherman, D. K.; Slovic, P.; Vastfjall, D.; Van Boven, L

The vesicular monoamine transporter (VMAT-2) inhibitor tetrabenazine induces tremulous jaw movements in rodents: Implications for pharmacological models of parkinsonian tremor

Tetrabenazine (TBZ) is a reversible inhibitor of vesicular monoamine storage that is used to treat Huntington’s disease. TBZ preferentially depletes striatal dopamine (DA), and patients being treated with TBZ often experience parkinsonian side effects. The present studies were conducted to investigate the ability of TBZ to induce tremulous jaw movements (TJMs), which are a rodent model of parkinsonian tremor, and to determine if interference with adenosine A2A receptor transmission can attenuate TJMs and other motor effects of TBZ. In rats, TBZ (0.25–2.0 mg/kg) significantly induced TJMs, which primarily occurred in the 3.0–7.5-Hz frequency range. The adenosine A2A antagonist MSX-3 (1.25–10.0 mg/kg) significantly attenuated the TJMs induced by 2.0 mg/kg TBZ in rats, and also significantly reduced the display of catalepsy and locomotor suppression induced by TBZ. In mice, TBZ (2.5–10.0 mg/kg) dose dependently induced TJMs, and adenosine A2A receptor knockout mice showed significantly fewer TJMs compared to wild-type controls. MSX-3 (2.5–10.0 mg/kg) also significantly reduced TBZ-induced TJMs in CD1 mice. To provide a cellular marker of these pharmacological conditions, we examined c-Fos expression in the ventrolateral neostriatum (VLS). TBZ (2.0 mg/kg) significantly increased the number of c-Fos-positive cells in the VLS, which is indicative of reduced DA D2 receptor transmission, and 10.0 mg/kg MSX-3 significantly attenuated the TBZ-induced c-Fos expression. These results indicate that TBZ induces tremor as measured by the TJM model, and that pharmacological antagonism and genetic deletion of adenosine A2A receptors are capable of attenuating this oral tremor