Evaluation of Selected Pulmonary Function Tests in Resting Thoroughbred Horses Having Reversible, Experimentally Induced Respiratory Dysfunctions.

The purpose of the first part of this study was to develop computerized techniques for automation of instrument calibration, data collection and calculation of indices of pulmonary mechanical function in resting and exercising horses. The microcomputer system developed enabled a single trained technician to reliably operate the equipment in an equine pulmonary mechanics laboratory. The first experiment investigated the temporal effects of histamine and methacholine aerosols on indices of pulmonary mechanics derived from the linear equation of motion. Data calculated on a breath-by-breath basis were too variable to be reliably modeled. Following application of averaging techniques, the temporal effects of histamine and methacholine on respiratory rate were the most predictable of all the response variables studied. In experiment two, normal tidal breathing flow-volume loops (TBFVLs) of resting horses were characterized. In excess of 90% of the variance of 10 TBFVL indices were summarized by a factor analysis with three factors. The first factor explained 82% of the total variance and was mainly due to time and volume relationships. Factor 2 was the expiratory flow factor, and explained a further 11% of the variance. The third factor was indicative of the shape of the inspiratory part of the TBFVL and explained 7% of the total variance. The last experiment investigated the effects of three models of obstructive airway disease on TBFVLs. TBFVLs were analyzed using loop shape indices and standardized factor scores. Factor scores were obtained using the standardized factor scoring coefficients determined in experiment two. Under control conditions the factor scores were no different from those obtained in experiment two. Histamine and methacholine inhalation caused significant (P $\u3c$ 0.05) changes in all three of the factor scores. Increased inspiratory resistance caused significant changes (P $\u3c$ 0.05) in the factor score that characterized the inspiratory limb of TBFVLs. The variability of these data implied that the techniques used in these studies were sensitive enough to detect differences between the effects of models of obstructive airway disease in a population of horses, but not to detect individual animals with sub-clinical obstructive airway disease

Shotgun genome sequence and population diversity of Mannheimia haemolytica isolates from sheep in South Africa

Respiratory disease caused by Mannheimia haemolytica is a major economic and welfare concern in the cattle and small stock industry worldwide. Disease occurs due to the interaction of numerous factors, including weaning stress, shipment, inclement weather, and overcrowding coupled with viral and bacterial infections. The whole genome of M. haemolytica strain Mh10517 was analyzed using an Illumina MiSeq high throughput sequencing platform. The genome size is 2.67 Mb with 2,879 predicted gene sequences. The molecular evolution and relatedness of M. haemolytica was investigated using nucleotide sequence data of seven housekeeping gene fragments from 21 ovine isolates. MEGA version 7.0 genomic workbench was used for alignment and analysis of the nucleotide data sets. For each gene fragment, the sequences were compared and isolates with identical sequences were assigned the same allele number. Results suggested that the 21 isolates belonged to six sequence types (ST) and ST 28 accounted for 33% of the isolates. Neighbour joining method was used to produce dendograms based on the concatenated sequences of the seven loci in multilocus allelic profile. There was significant variation between the number of synonymous and non-synonymous substitutions between each sequence pairs (p=0.018) based on results from the Fisher’s exact test of neutrality of sequence pairs. These preliminary data show substantial sequence variations and this supports the hypothesis that ovine isolates of M. haemolytica are more diverse that what has been reported for isolates from other species. These results will advance studies on various aspects of the biology of M. haemolytica in Africa, and the world at large.Poster presented at the University of Pretoria, Faculty of Veterinary Science Faculty Day, September 07, 2017, Pretoria, South Africa.Includes bibliographical referencesab201

Single base-pair deletion in ASIP exon 3 associated with recessive black phenotype in impala (Aepyceros melampus)

No abstract is available.Wildlife Ranching South Africa (WRSA). Patent applications : ZA2014/05233, ZA2015/03778 and PCT/IB/2015/055391.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-20522017-08-31hb2016Equine Research CentreGenetic

Equine encephalosis in Thoroughbred foals on a South African stud farm

Thoroughbred foal body temperature data were collected from shortly after birth until shortly after weaning during the 2007/2008 season on a stud farm in the Western Cape Province of South Africa. Equine encephalosis (EE) caused by EE virus (EEV) serotype 4 (EEV-4) occurred in the foal group during the first autumn after their birth (March and April 2008). A descriptive study was undertaken to provide data on the EEV maternal antibody status, the association between pyrexia and EEV infection, and the incidence of infection amongst the foals prior to and during the episode. This included the frequent capturing of foal body temperature data and regular collection of serum and whole blood during pyretic episodes. Infection by EEV was determined using both virological and serological methods. A high EE incidence of at least 94% occurred amongst the foal cohort, despite the fact that 37% of foals had previously shown maternal antibody to EEV-4. Pyrexia in foals was not directly associated with EE infection and 41% of infected foals showed no detectable pyretic episode. Information obtained from this EE episode showed the high incidence of EEV infection in foals during the first autumn after their birth. Monitoring foal body temperature can alert farmers to outbreaks of infectious disease, such as EE. These results are relevant to the epidemiology of EE and facilitate greater understanding of it as a differential diagnosis of African horse sickness (AHS), given that EE and AHS have similar epidemiologic profiles.The Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, South Africa.http://www.ojvr.orgam201

Development of real-time reverse transcription polymerase chain reaction assays to quantify insulin-like growth factor receptor and insulin receptor expression in equine tissue

The insulin-like growth factor system (insulin-like growth factor 1, insulin-like growth factor 2, insulin-like growth factor 1 receptor, insulin-like growth factor 2 receptor and six insulinlike growth factor-binding proteins) and insulin are essential to muscle metabolism and most aspects of male and female reproduction. Insulin-like growth factor and insulin play important roles in the regulation of cell growth, differentiation and the maintenance of cell differentiation in mammals. In order to better understand the local factors that regulate equine physiology, such as muscle metabolism and reproduction (e.g., germ cell development and fertilisation), real-time reverse transcription polymerase chain reaction assays for quantification of equine insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were developed. The assays were sensitive: 192 copies/μL and 891 copies/μL for insulin-like growth factor 1 receptor, messenger ribonucleic acid and insulin receptor respectively (95% limit of detection), and efficient: 1.01 for the insulin-like growth factor 1 receptor assay and 0.95 for the insulin receptor assay. The assays had a broad linear range of detection (seven logs for insulinlike growth factor 1 receptor and six logs for insulin receptor). This allowed for analysis of very small amounts of messenger ribonucleic acid. Low concentrations of both insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were detected in endometrium, lung and spleen samples, whilst high concentrations were detected in heart, muscle and kidney samples, this was most likely due to the high level of glucose metabolism and glucose utilisation by these tissues. The assays developed for insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid expression have been shown to work on equine tissue and will contribute to the understanding of insulin and insulin-like growth factor 1 receptor physiology in the horse.http://www.ojvr.orgam201

Predictors of foaling outcomes in barren and maiden thoroughbred mares in South Africa

Population demographics and reproductive performance of Thoroughbred populations have been described, but the most recent assessment of the South African Thoroughbred population was reported two decades ago. Objectives of this study were to report demographic data for selected Thoroughbred breeding populations and to analyse selected mare-level variables in association with foaling outcomes, as predictors of reproductive performance. The National Horseracing Authority of Southern Africa's stud health scheme requires annual screening of Thoroughbred stallions, maiden and barren mares for venereal pathogens prior to breeding. In 2018 and 2019, 1 065 and 1 207 horses were sampled, respectively. Demographic data were sourced from laboratory sample submission forms that accompanied samples and supplemented by data gathered from the annual Thoroughbred foal identification programme. Univariate analysis of candidate predictors of successful foaling outcomes was performed followed by assessment in a multivariable model. Median ages of mares and stallions tested in 2018 and 2019 were nine and 11 years, respectively. Nearly twice the number of barren compared to maiden mares were tested in each year, and failure to conceive was the most common reported reason for classification as barren. Of mares tested in 2018 and 2019, 68.1% (95% CI 65.1-70.9) and 63.3% (95% CI 60.4-66.1), respectively, subsequently produced foals that were presented for identification. Mare age, rather than reproductive status, was a significant predictor of having a foal presented for identification. In conclusion, novel demographic data were described for South African Thoroughbred populations. Seasonal foaling rate as the selected measure of reproductive performance for sampled mares ranged from 63.3% to 68.1% and declined with increasing mare age.http://www.jsava.co.zaEquine Research CentreProduction Animal Studie

Broiler pulmonary hypertension syndrome. II. The direct measurement of right ventricular and pulmonary artery pressures in the closed chest domestic fowl

A technique for the catheterisation of the right ventricle and pulmonary artery of the domestic fowl is described. Mean peak systolic, minimum diastolic and mean pressures measured in the right ventricle and pulmonary artery of a group of clinically normal broilers housed at a medium altitude of 1 300 m were 24,3; 8,1; 17,8; 25,0; 22,1 and 22,3 mm Hg respectively. The pulmonary artery pressures are different from those reported elsewhere using the open chest technique. These differences are possibly due to both the effect of opening the thoracic cavity and the hypoxic pressor effect at this altitude.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Evaluation of the efficacy of d-penicillamine and trientine as copper chelators using an in vitro technique involving ovine red blood cells

An in vitro technique for haemolysing ovine red blood cells with copper sulphate was standardized to induce c 50% haemolysis with 0,5 mM CuSO₄ after incubation for 14 h at 38°C. This technique was then applied to test the efficacy of trientine and d-penicillamine in preventing haemolysis. Trientine concentrations of 0,5; 1,0 and 1,5 mM were found to be the most effective (P<0,05) in reducing copper-induced haemolysis. One and 1,5 mM concentrations of d-penicillamine were also effective (P< 0,05), but in this experiment a 0,5 mM concentration failed to protect the erythrocytes.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Palabora Mining Company.mn201

The carrier prevalence of severe combined immunodeficiency, lavender foal syndrome and cerebellar abiotrophy in Arabian horses in South Africa

REASONS FOR PERFORMING STUDY : The carrier prevalence of severe combined immunodeficiency (SCID), lavender foal syndrome (LFS) and cerebellar abiotrophy (CA) in Arabian foals in South Africawas determined in order to quantify the potential impact of these conditions locally. Furthermore, the carrier prevalence of SCID prior to and following the introduction of a genetic test was compared to evaluate the effect of testing in the population. OBJECTIVES : To estimate the carrier prevalence of SCID, LFS and CA in registered purebred Arabians born in South Africa in the 2004/5 and 2009/10 foaling seasons and compare the changes in prevalence in these disorders between the 2 groups of foals. STUDY DESIGN : Cross-sectional survey. METHODS : Samples were collected from individuals randomly selected from 2 populations of purebred Arabian foals born during the 2004/5 and 2009/10 foaling seasons. Genetic testing for SCID, LFS and CA was performed on DNA extracts using specific polymerase chain reactions, with the products being analysed using fragment analysis on a genetic analyser. RESULTS : The carrier prevalence of LFS and CA for the 2009/10 season was 11.7% (95% confidence interval [CI] 7.6–17.0%) and 5.1% (95% CI 2.5–9.1%), respectively, with no statistically significant change in prevalence between the 2004/5 and 2009/10 foaling seasons. However, the carrier prevalence of SCID was found to have decreased significantly from 6.4% (95% CI 4.8–8.3%) in the 2004/5 foals to 3.4% (95% CI 2.2–5.1%) in the 2009/10 foals (P = 0.009). CONCLUSIONS: The results of this study indicate that genetic screening of Arabian horses for SCID may have played a role in significantly reducing the carrier prevalence within the breeding population and thereby reducing the birth of clinically affected individuals. This study provides an indication of the positive effect of genetic screening for specific conditions in horses.Veterinary Genetics Laboratory, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.http://onlinelibrary.wiley.com/journal/10.1001/(ISSN)2042-3306hb201

The clinical pathology of heartwater. I. Haematology and blood chemistry

Clinical pathological studies were undertaken in 5 calves with experimentally-induced heartwater. The most important findings include a progressive anaemia which may be associated with bone marrow depression and fluctuations in the total and differential white cell count, of which an eosinopenia and a lymphocytosis were the most marked. A severe drop in serum protein, especially in the albumin levels, was observed in all 5 cases . This disease is probably associated with an increased capillary permeability, as the protein content of the pericardial fluid in 1 case that died, approximated that of the serum. The osmolality of the effused fluid was also higher than that of the blood. No significant changes in the serum electrolyte levels occurred, except for total calcium levels which tended to decrease to below normal during the acute stage of the disease. Marked increases in total bilirubin were recorded. This, however, was not associated with liver pathology or haemolysis and may possibly be ascribed to a fasting hyperbilirubinaemia. Darkening of plasma colour was associated with peak rises in total biluribin. Increases in both blood urea and creatinine levels indicate interference with renal glomerular filtration during the acute stage of the disease.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201