Bovine sire effects on daughters' in vitro blood neutrophil functions, lymphocyte blastogenesis, serum complement and conglutinin levels

Blood neutrophil functions, lymphocyte blastogenic responses, serum complement, and serum conglutinin activity of 98 lactating Holstein cows from two genetic lines were evaluated. The genetic lines were produced in a selection experiment that created and perpetuated genetic differences in milk production for up to seven generations. No significant differences between the two genetic lines of cows were found for neutrophil function, lymphocyte blastogenic responses, serum complement levels, or serum conglutinin levels. Significant differences between sire progeny groups within lines were found for unstimulated and mitogen-stimulated lymphocyte blastogenesis (P less than 0.0001), and almost all neutrophil functions (antibody independent neutrophil cytotoxicity, antibody dependent neutrophil cytotoxicity, ingestion of bacteria, iodination, chemiluminescence, chemokinesis, and chemotaxis (P less than or equal to 0.05)). Sire progeny group differences (P less than or equal to 0.0001) within lines for serum complement and conglutinin activity were also found. Neutrophil chemiluminescence activity (positive relationship; P less than or equal to 0.001), concanavalin A-stimulated lymphocyte blastogenesis (positive relationship; P less than or equal to 0.004), and serum conglutinin activity levels (negative relationship; P less than or equal to 0.01) each had small but significant associations with the total milk somatic cell count. Cows seropositive for bovine leukosis virus had increased resting and mitogen-stimulated lymphocyte blastogenic activity and were associated with increased in vitro neutrophil random migration and production of superoxide anion. Estimates of genetic parameters of various immune cell functions, of serum complement and of conglutinin levels for daughters of 11 sires with 4-6 daughters in the data set were determined. In this report, genetic variation was demonstrated for nonspecific humoral and cellular immunity.     

A novel approach to studying the effects of temperature on soil biogeochemistry using a thermal gradient bar

The temperature dependence of chemical reaction rates and microbial metabolism mean that temperature is a key factor regulating soil trace gas emissions and hydrochemistry. Here we evaluated a novel approach for studying the thermal response of soils, by examining the effects of temperature on gas emissions and hydrochemistry in (a) peat and (b) soil from a Sitka spruce plantation. A thermal gradient was applied along an aluminium bar, allowing soil to be incubated contemporaneously from 2 to 18 °C. The approach demonstrated clear differences in the biogeochemical responses of the two soil types to warming. The peat showed no significant emission of CH₄ at temperatures below 6 °C, while above 6 °C, a marked increase in the rate of release was apparent up to 15 °C (Q₁₀ = 2.5) with emissions being similar between 15 and 18 °C. Conversely, CH₄ emissions from the forest soil did not respond to warming. Nitrate availability in the peat decreased by 90% between 2 and 18 °C (P < 0.01), whereas concentrations in the forest soil did not respond. Sulphate availability in the peat decreased significantly with warming (60%, P < 0.01), while the forest soil showed the opposite response (a 30% increase, P < 0.01). Conventionally, thermal responses are studied by incubating individual soil samples at different temperatures, involving lengthy preparation and facilities to incubate samples at different temperatures simultaneously. Data collected on a given thermal response is usually limited and thus interpolated or extrapolated. The thermal gradient method overcomes these problems, is simple and flexible, and can be adapted for a wide range of sample types (not confined to soil). Such apparatus may prove useful in the optimization of management practices to mitigate the effects of climate change, as thermal responses will differ depending on land use and soil type.     

Quarantine requirements for the importation of black rhinoceros from Zimbabwe into Australia

SUMMARY The proposal by the Zoological Parks Board of New South Wales to import 10 southern black rhinoceros (Diceros bicornis) from Zimbabwe as part of an international project for conservation of the species presented the Australian Quarantine and Inspection Service (AQIS) with a unique challenge. This importation is, at least in the modern era, the first importation of live herbivores from the African continent. Many of the serious animal diseases in the world are endemic in parts of Africa. Knowledge of which of these diseases infect wild species and may be transmitted from the wild species to domesticated species, is limited. This paper describes the strategies adopted by AQIS to facilitate the importation of rhinoceros while maintaining protection of Australian consumers, rural industries, domestic livestock and fauna against the entry and spread of unwanted pests and diseases.     

Habituation by the immature fowl in response to repeated injections of corticotrophin.

1. Immature birds treated for 7 d with corticotrophin (30 IU/kg, one injection per day) had significantly poorer growth rates and decreased adrenal cholesterol concentrations. Plasma glucose, corticosterone and cholesterol concentrations and adrenal weight were within the normal range 24 h after the last injection.

2. The responses of birds pretreated as described above to a single injection of corticotrophin (30 IU/kg) were determined.

3. A similar degree of hyperglycaemia had developed in both groups after 2 h but thereafter the responses differed: the concentration of plasma glucose did not increase further in those pretreated with corticotrophin and had begun to decrease at 6 h, whereas that of the birds pretreated with saline increased progressively.

4. The concentrations of plasma corticosterone had increased similarly in the two groups to a peak at 2 h but there was a significantly more rapid decrease in the birds pretreated with corticotrophin.

5. Both groups showed a transient hypercholesteraemia but the increase was significant only in the group that had previously received saline.

6. There were decreases in the concentrations of adrenal cholesterol in both groups. The decrease, in absolute terms, was 2–4 times greater in the group receiving corticotrophin for the first time: percentage changes were similar, however.     

The tryptophan requirement of broiler chicks.

The "available" tryptophan requirements of male and female broiler chicks were determined at 7-d intervals from 0 to 56 d, using a diet-dilution technique. Availability of tryptophan in the diets was estimated by growth assay with chicks. 2. The tryptophan requirements were 2.4 (males) and 2.2 g/kg of diet (female) from 0-7 d, and 1.7 g/kg (males and females) from 7-35 and 35-56 d. The absolute requirement of the chick for tryptophan increased with age and was significantly different for male and female birds. 3. A highly significantly predictive equation relating tryptophan requirement to mean body weight and gain was established.     

The effects of restricted feeding on adrenal cortical activity in the immature domestic fowl

1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens.

2. Restricted birds were lighter throughout the experiment.

3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time.

4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds.

5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks.

6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyper‐lipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.     

Computed tomographic anatomy of the canine cervical vertebral venous system

Computed tomographic (CT) venography of the cervical vertebral canal was performed in six, clinically normal, adult mixed-breed dogs from 14 to 23 kg. After dogs were euthanized and saline perfused, a gelatin and iothalamate mixture was injected into the right external jugular vein. Contiguous, 4-mm-thick CT images were obtained with dogs in sternal recumbency. Dogs were kept in the same position as for the CT scan and frozen to approximately -8 degrees C. All post-contrast CT images were analyzed using similar bone window and level settings. Additional multiplanar reformatted dorsal images were obtained in all dogs. The frozen cadavers were sectioned through the cervical region extending from the occiput to T1 at approximately 8-mm intervals. The frozen sections were then compared with the CT images. The CT appearance of the normal cervical vertebral venous system was described and illustrated. Components such as the internal vertebral venous plexus, interarcuate veins, intervertebral veins, and vertebral veins were clearly identified on the CT images.     

Repeat patient testing shows promise as a quality control method for veterinary hematology testing

Background

Repeat patient testing‐based quality control (RPT‐QC) is a potential method for veterinary laboratories (eg, that have a limited budget for quality commercial control material [QCM] or that wish to use material with a species‐specific matrix).

Objectives

To determine whether total error (TE_a), probability of error detection (Ped), and probability of false rejection (Pfr) similar to that achievable with QC materials can be controlled using RPT‐QC

Methods

Control limits (WBC, RBC, HGB, HCT, MCV, and PLT) for the Advia 120 (n = 23) and scil Vet ABC (n = 22) were calculated using data from normal canine specimens from a routine caseload. Specimens were measured at accession and again after 24 hours. Control limits were validated using 23 additional canine specimens tested similarly. Achievable TEa, Ped, and Pfr were investigated using the Westgard EZRules3 and compared to those achievable with commercial QCM.

Results

Theoretical performance of RPT‐QC and commercial QCM‐QC are similar for 1‐3s with both n = 1 and 1‐3s with n = 2 for all measurands and both instruments. Achievable TE_a values for RPT‐QC were close to ASVCP recommendations for most measurands; exceptions were PLT (both instruments) and WBC (scil Vet ABC).

Conclusions

Repeat patient testing‐based quality control advantages include a species‐specific matrix, low‐cost, and absence of QC material deterioration over time (since a fresh specimen is used each day). A potential disadvantage is daily access to normal canine specimens. A challenge is determining control limits, which has a subjective element. Further study is needed to confirm actual RPT‐QC performance and to determine if RPT‐QC with abnormal patient specimens is feasible.