Demand for red meats: principles, research evidence, and issues.

Demand is not measured by per capita consumption. Demand is a schedule of the quantities consumers will take at alternative prices. The level of demand and demand changes over time are tied to consumer incomes, prices of substitutes, and consumer tastes and preferences. Critical to increasing meat demand is a greater understanding of consumer preferences for new meat products. Developing branded products such as "natural" or "guaranteed-tender" beef may not be the answer for all cattle producers, but research suggests that there are segments of the population willing to pay premiums for such products. Differentiating meat products through technology and branding provides a means of better meeting consumers' desires and increasing overall demand for meat and livestock.     

Soybean yields and soil water status in Argentina: Simulation analysis

Recent changes in management of soybean production in Argentina may have large impacts on the soil water balance and on crop yield response. Changes in this system have included widespread adoption of a no-till management leaving crop residue on the soil surface, intensive cropping rotations (e.g. double cropping of wheat and soybean) so that the soil may not be fully recharged with water at the time of soybean sowing, and the occurrence of high water tables in a number of areas. The objective of this analysis was to assess the need to account for these factors in simulating soybean yields in Argentina. The influence of no-till management was simulated by simply decreasing the soil evaporation estimated for a bare soil by 70%. However, this alteration resulted in an over prediction in yield in many cases when it was assumed that the soil water content had been fully recharged at the initiation of the simulations. The difficulty with assuming a full soil water profile was confirmed when simulated yields were found to match well with observed yields when measured soil water content was used as an input to the model at the beginning of the soybean season. Finally, even with decreased soil evaporation there were still a few cases where simulated yield was less than observed yield. In these cases, a hypothetical water table, which relieved any drought stress once roots reached a depth of 1 m, resulted in yields that more closely matched observations. Overall, these results highlighted the need to estimate well both the influence of crop residue on soil evaporation and the soil water profile at sowing in simulating soybean yields in Argentina.     

Changes in smooth muscle contractility of rainbow trout (Oncorhynchus mykiss Walbaum) intestine during acclimation to altered temperature

The effects of altered water temperature in vivo on in vitro smooth muscle contractility of rainbow trout intestine were investigated. Temperature has a significant effect on receptor-mediated intestinal smooth muscle contractility in the rainbow trout. The efficacy of 5-HT, carbachol, and transmural stimulation increased with temperatures above 10°C, with an optimal increase at 15°C. There was also a modest increase in the potency of 5-HT and carbachol within 2 days of establishing trout at 20°C. By day 8, most of these changes had either stabilized or were returning to control values, suggesting that acclimation changes in membranes and enzyme activities were taking effect. However, the contractile responses to carbachol and transmural stimulation were still increasing at this time. This may imply that the muscarinic receptors are more resistant to membrane acclimation changes and may take longer to adapt. Because these experiments were controlled for handling stress and seasonal changes that affect contractility, we have been able to demonstrate some early changes in smooth muscle contractility that occur during acclimation to altered temperature.     

The effects of acute temperature change on smooth muscle contractility of rainbow trout (Oncorhynchus mykiss Walbaum) intestine

The effects of altered temperature in vivo on in vitro smooth muscle contractility of rainbow trout intestine were investigated. Initial analysis of the data revealed a seasonal variation in the maximal tension of intestinal smooth muscle attainable with 5-hydroxytryptamine (serotonin), carbachol, KCl, and transmural stimulation in vitro. Peaks occurred in spring and troughs in autumn. There was no seasonal cycling of the potency of the stimulants. All data regarding the efficacy of the stimulants were subsequently corrected for seasonal variation. The response of smooth muscle depends on the temperature of the water in which the fish are placed (2°C−20°C). There was a marked linear increase in efficacy and a slight increase in potency of the stimulants with increasing temperature. Changes in responsiveness of the intestinal smooth muscle occurred within 30 min of moving the fish between tanks. Smooth muscle reactivity returned to pretreatment values by 48h. Any changes in responsiveness with regards to time were unlikely to be as a consequence of water temperature, but may have been a result of handling stress.     

Effect of leukoreduction on inflammation in critically ill dogs receiving red blood cell transfusions: A randomized blinded controlled clinical trial

BackgroundPrestorage leukoreduction of red blood cell (RBC) bags prevents accumulation of pro‐inflammatory mediators and experimentally attenuates post‐transfusion inflammation in healthy dogs. However, the effect of leukoreduction on post‐transfusion inflammation in critically ill dogs is unclear.HypothesisDogs transfused with leukoreduced (LR) RBC will have lower concentrations of leukocytes, interleukin (IL)‐6, IL‐8, monocyte chemoattractant protein‐1 (MCP‐1), and C‐reactive protein (CRP) within 24 hours of post‐transfusion compared to dogs transfused with nonleukoreduced (NLR) RBC.AnimalsSixty‐one RBC‐transfused dogs (LR = 34, NLR = 27).MethodsRandomized, blinded, controlled preliminary clinical trial. Blood bag processing was randomized to create identically appearing LR and NLR bags. Group allocation occurred with transfusion of the oldest compatible RBC bag. Blood samples were collected pretransfusion and at 8 and 24 hours post‐transfusion for leukocyte count, IL‐6, IL‐8, MCP‐1, and CRP. Data were analyzed on an intention‐to‐treat basis using linear mixed effects models. Significance was set at P < .05.ResultsNo significant differences were found between groups in concentrations of leukocytes (P = .93), IL‐6 (P = .99), IL‐8 (P = .75), MCP‐1 (P = .69), or CRP (P = .18) over time. Eleven LR dogs (32%) and 4 NLR dogs (15%) were euthanized in the hospital (P = .14). No natural deaths occurred.Conclusions and Clinical ImportanceNo differences in inflammation biomarker concentrations were detected over time between dogs transfused with LR or NLR RBC, but heterogeneity likely hampered the ability to detect a difference with this sample size. The novel randomization and enrollment protocol was successfully implemented across 2 participating institutions and will be easily scaled up for a future multicenter clinical trial.