Hyperlipemia and Ketonuria in an Alpaca and a Llama

An alpaca and a llama in late stages of gestation were evaluated for lethargy, anorexia, and recumbency. Both camelids had cloudy, white, turbid serum, elevated serum triglyceride (1564, 5658 mg/dL, respectively) and cholesterol (158, 297 mg/dL, respectively) concentrations, and ketonuria. Signs of fetal stress were evident ultrasonographically in the alpaca, and a live cria was delivered by Cesarean section performed under general anesthesia. The alpaca developed severe metabolic acidosis, hepatic lipidosis, and acute renal failure secondary to renal lipidosis and died 36 hours after admission despite medical therapy. Histopathology revealed renal and hepatic lipidosis and neutrophilic pancreatitis. The cria died 72 hours after birth. The llama responded to IV electrolyte, dextrose, and regular crystalline insulin therapy. The pregnancy was maintained, and the llama was discharged from the hospital 20 days after admission. Two months after discharge, the llama gave birth to a live, 5 kg cria. Findings of hypertriglyceridemia, hypercholesterolemia, elevated sorbitol dehydrogenase activity, metabolic acidosis, azotemia, and ketonuria occurred in these two camelids. Based on this report, camelids appear to be similar to both horses and cattle in their response to severe energy imbalances in late gestation.     

Theoretical and Empirical Relationships Between Oat Test Weight and Groat Proportion

Test weight and groat proportion are two very important quality characteristics of oat grain. In this study, we pose the hypothesis that these two characteristics are related through characteristics of grain density. Test weight is defined as the product of kernel density and packing proportion. Groat proportion, in theory, is the ratio of the groat mass to the kernel mass. We present two theoretical constructions expressing test weight in terms of groat proportion, packing proportion and kernel density components. To test these, we have applied measurements of test weight, groat proportion, kernel density components, and packing proportion of 18 oat cultivars grown at six environments. Whereas the groat proportion alone accounted for only 34% of the variation in test weight, our theoretical constructions that included groat proportion could account for ≤82% of variation in test weight. Also, we present previously undescribed variation in oat kernel density components across genotypes and environments. Although the kernel density alone could account for most of the variation in test weight across genotypes, packing proportion appeared to be more important in describing variation in test weight of a genotype across different environments. We observed significant variation in both groat and hull density which, together with groat proportion, described most of the variation in kernel density.     

Heterogeneity of Staphylococcus pseudintermedius isolates from atopic and healthy dogs

Staphylococcus pseudintermedius is part of the normal canine flora but frequently causes pyoderma in canine atopic dermatitis (AD). This study aimed to determine whether particular S. pseudintermedius strains were associated with AD and/or pyoderma. Ninety‐six S. pseudintermedius isolates from the ear, nares, perineum and lesions of 21 atopic and 16 healthy dogs were lysed with proteinase K and digested with 40 U SmaI. Restriction products were separated using pulsed‐field gel electrophoresis (PFGE) with an Oxford S. aureus control and lambda‐ladder DNA concatomer markers. A dendrogram was constructed by the unweighted pair group method. All isolates showed a ≥56% similarity coefficient. Nine distinct PFGE clusters were identified, as follows: five from both atopic and healthy dogs; three from atopic dogs only; and one from healthy dogs only. Nine clusters were isolated from the nares, eight from the perineum, five from the ears and six from pyoderma lesions. There were no significant differences in the frequency of isolation from atopic or healthy skin, body sites or infected lesions for any of the clusters. Two of six healthy dogs and 18 of 20 atopic dogs with multiple isolates had closely related isolates (less than three band differences) at more than one sampling site. Isolates from pyoderma lesions were closely related to at least one mucosal isolate in 11 of 16 dogs. Staphylococcus pseudintermedius isolates appear to be heterogeneous, and colonization or infection of atopic skin was not associated with any particular strain or cluster of strains.     

<Emphasis Type="Italic">Streptococcus uberis</Emphasis>-specific T cells are present in mammary gland secretions of cows and can be activated to kill <Emphasis Type="Italic">S. uberis</Emphasis>

The presence, phenotype and function of Streptococcus uberis-specific T cells in the mammary gland secretion (MGS) and blood of cows exposed to S. uberis were assessed. MGS T cells in the udder were purified and incubated with autologous blood monocytes as antigen-presenting cells (APC). Most cows, irrespective of prior S. uberis infection status and lactation status, were shown to have S. uberis-specific T cells both in MGS and in the blood. When cells from a subgroup of cows were studied, it was found that the S. uberis-specific T cells produced high levels of interferon-gamma (IFN-γ), but low levels of interleukin-10 (IL-10). A high percentage of responding T cells were of the CD8 ⁺ memory (CD45RO) subset. T cells from the MGS specific for S. uberis were propagated from animals during the drying off period and expanded in vitro using interleukin-2 (IL-2) and S. uberis antigens. This led to the accumulation of T cells of the CD8 ⁺ subset bearing memory cell markers (CD45A ⁻ , CD45RO ⁺ ), which released high levels of IFN-γ. Four of the five T cell lines derived from the MGS of three animals had substantial direct killing activity towards S. uberis in vitro. It is concluded that there is an emergence of S. uberis-specific bactericidal T cells in the MGS of cows after infection or environmental exposure to S. uberis. Vaccines aimed at activating and expanding this T cell population in the mammary glands of cattle may offer an avenue for the prevention of mastitis caused by S. uberis.     

Density-Dependent Ecohydrological Effects of Piñon–Juniper Woody Canopy Cover on Soil Microclimate and Potential Soil Evaporation

Many rangeland processes are driven by microclimate and associated ecohydrological dynamics. Most rangelands occur in drylands where evapotranspiration normally dominates the water budget. In these water-limited environments plants can influence abiotic and biotic processes by modifying microclimate factors such as soil temperature and potential soil evaporation. Previous studies have assessed spatial variation in microclimate and associated ecohydrological attributes within an ecosystem (e.g., under vs. between woody canopies) or across ecosystems (e.g., with differing amounts of woody canopy cover), but generally lacking are assessments accounting systematically for both, particularly for evergreen woody plants. Building on recently quantified trends in near-ground solar radiation associated with a piñon–juniper gradient spanning 5% to 65% woody canopy cover, we evaluated trends in soil temperature and associated estimates of potential soil evaporation as a function of amount of woody canopy cover for sites overall and for associated canopy vs. intercanopy locations. Quantified soil temperature trends decreased linearly with increasing woody canopy cover for intercanopy as well as canopy patches, indicating the coalescing influence of individual canopies on their neighboring areas. Notably, intercanopy locations within high-density (65%) woody canopy cover could be as much as ～10°C cooler than intercanopy locations within low-density (5%) cover. Corresponding potential soil evaporation rates in intercanopies within high-density woody canopy cover was less than half that for intercanopies within low density. Our results highlight ecohydrological consequences of density-dependent shading by evergreen woody plants on soil temperature and potential soil evaporation and enable managers to rapidly estimate and compare approximate site microclimates after assessing amounts of woody canopy cover. Such predictions of microclimate have general utility for improving management of rangelands because they are a fundamental driver of many key processes, whether related to understory forage and herbaceous species or to wildlife habitat quality for game or nongame species.     

Differential effects of the endocrine-disrupting compounds bisphenol-A and octylphenol on gonadotropin secretion, in prepubertal ewe lambs

This study examined the effects of long-term exposure to the endocrine-disrupting compounds (EDCs) Bisphenol-A (BPA) and Octylphenol (OP) on gonadotrophin secretion in pre-pubertal female sheep. Four-week-old, female lambs were randomly allocated to four groups (n=6), and twice each week treated with i.m. injections of either corn oil (vehicle controls), diethylstilbestrol (DES; 0.175mg/kg), BPA (3.5mg/kg) or OP (3.5mg/kg). After 5 weeks of treatment, animals were ovariectomized (ovx) and ovary weights recorded. Two weeks later, blood samples were collected from lambs every 15min for 6h, for LH pulse analysis. Animals were then euthanased and adrenal and kidney weight recorded. An age-related increase in tonic LH secretion was noted in Control, BPA- and OP-treated lambs, but was absent in DES-treated lambs. Following ovx, LH secretion increased in all except DES-treated lambs; FSH concentrations increased in all groups. BPA and DES significantly suppressed LH pulse frequency (C: 6.7+/-0.3pulses/6h, DES: 1.5+/-0.8pulses/6h, BPA: 2.3+/-0.8pulses/6h) and amplitude (C: 7.1+/-1.0ng/ml, DES: 1.9+/-0.6ng/ml, BPA: 1.6+/-0.4ng/ml). OP had no effect on LH secretion (Frequency: 5.8+/-0.5pulses/6h, amplitude: 8.0+/-2.0ng/ml). Ovary weight was similar among all groups. Results show that chronic in vivo exposure of prepubertal female lambs to BPA, at levels lower than those reported previously, can have significant effects on LH secretion that are comparable to those seen following exposure to the known xenoestrogen, DES. Exposure to an equal dose of the EDC OP, over the equivalent period of time was without effect on gonadotropin secretion in the prepubertal ewe lamb. These results indicate that exposure of prepubertal female lambs to the EDC BPA can induce significant effects on gonadotropin secretion, the potential long-term effects of exposure and the effects of these changes on reproductive performance and efficacy, therefore, merit further study.     

Characterization of age- and location-associated variations in the composition of articular cartilage from the equine metacarpophalangeal joint

Objective: To characterize the impact of age, gender, location and individual animal variation on the composition of articular cartilage from the metacarpophalangeal joint of horses. Design: Cartilage specimens were obtained from the metacarpophalangeal joints of 28 male, female and castrated male horses ranging in age from one day to 27 years of age. Cartilage samples from the distal metacarpus, proximal first phalanx and proximal sesamoids were analyzed separately. Chondrocyte number, DNA content, proteoglycan concentration and total collagen content were determined for each animal and joint location. Results: Age and joint location had a significant effect on chondrocyte number and DNA content with higher cell counts and DNA content detected in cartilage from the youngest age groups and in cartilage from the metacarpus and proximal sesamoids. The influence of age on chondrocyte numbers was not significant in horses over two years of age. Both age and joint location also influenced total proteoglycan and collagen content. Lower proteoglycan and collagen concentrations were detected in younger horses, and cartilage from the metacarpus had lower proteoglycan and collagen concentrations than that from other joint locations. Gender did not appear to influence chondrocyte number or matrix content of equine articular cartilage. However, there was significant residual variation in cellularity, proteoglycan levels and collagen content between individual animals that could not be explained by the signalment factors considered in this study. Conclusions: Future studies examining equine articular cartilage should avoid direct morphologic comparisons between animals of different ages, and any comparisons made between individuals should be interpreted cautiously. In addition, in vitro tissue culture models should avoid the use of cartilage pooled from different animals or from different locations within the same joint.