The Inability to Screen Exhibition Swine for Influenza A Virus Using Body Temperature

Agricultural fairs create an unconventional animal–human interface that has been associated with swine‐to‐human transmission of influenza A virus (IAV) in recent years. Early detection of IAV‐infected pigs at agricultural fairs would allow veterinarians to better protect swine and human health during these swine exhibitions. This study assessed the use of swine body temperature measurement, recorded by infrared and rectal thermometers, as a practical method to detect IAV‐infected swine at agricultural fairs. In our first objective, infrared thermometers were used to record the body surface temperature of 1,092 pigs at the time of IAV nasal swab collection at the end of the exhibition period of 55 agricultural fairs. IAV was recovered from 212 (19.4%) pigs, and the difference in mean infrared body temperature measurement of IAV‐positive and IAV‐negative pigs was 0.83°C. In a second objective, snout wipes were collected from 1,948 pigs immediately prior to the unloading of the animals at a single large swine exhibition. Concurrent to the snout wipe collection, owners took the rectal temperatures of his/her pigs. In this case, 47 (2.4%) pigs tested positive for IAV before they entered the swine barn. The mean rectal temperatures differed by only 0.19°C between IAV‐positive and IAV‐negative pigs. The low prevalence of IAV among the pigs upon entry to the fair in the second objective provides evidence that limiting intraspecies spread of IAV during the fairs will likely have significant impacts on the zoonotic transmission. However, in both objectives, the high degree of similarity in the body temperature measurements between the IAV‐positive and IAV‐negative pigs made it impossible to set a diagnostically meaningful cut point to differentiate IAV status of the individual animals. Unfortunately, body temperature measurement cannot be used to accurately screen exhibition swine for IAV.     

Fecal shedding of Cryptosporidium oocysts in healthy alpaca crias and their dams

Objective-To determine the apparent prevalence of shedding of Cryptosporidium spp in healthy alpaca crias and their dams on 14 farms in New York and 1 farm in Pennsylvania. Design-Cross-sectional study. Animals-110 alpaca crias and their 110 dams. Procedures-Fecal samples were obtained from 220 alpacas at 14 alpaca farms in New York and 1 farm in Pennsylvania. For each animal, age, sex, and health condition were recorded. A fecal score (1 = normally formed; 2 = soft or loose; 3 = diarrhetic) was recorded for each cria. Cryptosporidium oocysts were identified in fecal samples by a direct immunofluorescence assay. Results-Apparent prevalence of fecal shedding of Cryptosporidium oocysts was 8% (95% confidence interval, 4% to 15%) in dams and was 7% (95% confidence interval, 3% to 13%) in crias. There was no significant difference in age between dams with positive fecal test results for Cryptosporidium oocysts (median age, 4 years; range, 3 to 8 years) and dams with negative results (median age, 4 years; range, 2.5 to 19 years). No significant difference was found in age between crias with positive fecal test results (median age, 20 days; range, 7 to 53 days) and those with negative results (median, 36 days; range, 2 to 111 days). No significant difference in fecal scores was found between crias with positive versus negative fecal test results. Conclusions and Clinical Relevance-A higher than previously reported apparent prevalence of fecal shedding of Cryptosporidium oocysts in healthy alpacas was found. A zoonotic risk should be considered, especially for Cryptosporidium parvum.     

Regulation of plasma oestrogen by dietary fats in the laying hen: Relationships with egg weight

1. Feeding a diet supplemented with maize oil was found to elevate plasma oestradiol concentration in laying hens.

2. In a larger‐scale experiment, isoenergetic and isonitrogenous diets containing 10, 20, 40 or 60 g/kg supplemental maize oil, tallow, coconut oil or fish oil were fed for 5 weeks.

3. Egg weights showed very different responses to the different fats. The responses could be described by quadratic functions that all gave optimum responses with supplemental dietary fat concentrations of about 40 g/kg. Egg weight increased the most with maize oil and was decreased with fish oil at the highest inclusion rate.

4. Measurements of egg components showed a relatively larger increase in albumen weights with maize oil than with other fats.

5. Across treatments, mean plasma oestradiol concentrations were very highly correlated (r = 0.96) with the changes in egg weights over the experimental period.

6. It is concluded that oestrogen is important in controlling egg weight and that the effect of dietary fats in influencing egg weight is mediated by an effect of the fats on oestrogen metabolism.     

The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses: Ireland

Spheroidal carbonaceous particles (SCPs) from the sediments of 48 Irish lakes were enumerated and characterised according to fuel type. The concentration of metals was determined in the surface sediments and in selected mosses from the catchments of these lakes. Generally the metal concentrations in both the surface sediments and mosses were consistent with background levels found in the remote parts of Europe. Where higher metal concentrations occurred these could often be accounted for by local geochemical sources. SCP levels in the sediments of the selected lakes along the east coast were of sufficient magnitude to suggest a transboundary influence notwithstanding local sources. SCP characterisation also suggests the influence of emissions in Northern Ireland on deposition, particularly in the north-west of Ireland. There was reasonable correlation between the concentration of oil particles in the surface sediments and vanadium, but not with nickel, in mosses. SCP concentrations were not correlated with measured physical characteristics of the lakes. The level of deposition indicated is not likely to have a significant impact on human health over and above the damaging effects of urban dwelling but the adverse impact of this deposition on acid-sensitive surface waters in Ireland has been recorded.     

A SHORT METHOD FOR THE PREPARATION OF ANIMAL TISSUES FOR STAINING

Increase of the blood sugar which invariably follows administration of cortico-adrenal extract to adrenalectomized cats with symptoms of insufficiency is a reliable index of potency and affords a means of bio-assay of the material.     

Forecasting lucerne productivity under dryland farming conditions in central-western and western New South Wales

Possibilities for growing dryland lucerne (Medicago sativa L.) productively in drier parts of central-western and western New South Wales (NSW) were investigated by consideration of meteorological records. Annual rainfall data and estimated evapotranspiration data for 1995-1999 were compiled to calculate lucerne growing days and N₂-fixing days at Condobolin, Trangie, Cobar and Wentworth. This information was used in conjunction with seasonal indices of dry matter production and nitrogen fixation derived from the work of Bowman et al. [Aust J Exp Agric 42 (2002) 439] at Trangie to estimate yearly biomass production and N₂ fixation for the four locations. It was concluded that (i) there are good prospects for growing lucerne productively on suitable soils located in that extensive region of central-western and western NSW between the 450 and 300 mm isohyets if it is feasible to develop techniques for establishment and management to maintain stands at an acceptable density—not less than eight plants/m², (ii) there are only poor prospects for growing lucerne in those western parts of the state where annual rainfall averages less 300 mm, and (iii) annual rainfall, irrespective of other factors such as erratic distribution, is a rough guide to potential lucerne production. In addition, there were indications that, were the threshold for cessation of lucerne N₂ fixation reduced by 2 °C (say from 10 to 8 °C), annual N₂ fixation would be enhanced by more than 20%.