Comparison of metabolic, hematological, and peripheral blood leukocyte cytokine profiles of dairy cows and heifers during the periparturient period.

The periparturient period presents major physiological challenges for the dairy cow. It is a period that is affected by metabolic stressors, major changes in endocrine status, and altered immune function, which together result in an increased risk of disease. Immunological, hematological, and metabolic profiles from the periparturient period of heifers (primipara) were compared with those of cows (pluripara) to test the hypothesis that at the time of calving they have qualitatively different peripheral blood profiles. Blood samples were collected from 22 Holstein-Friesian animals on 3 occasions: approximately 2 wk before calving, within 24h after calving, and approximately 2 wk after calving. Quantitative PCR was used to measure the expression of a selected set of cytokines and receptors by peripheral blood leukocytes. Additional analyses included hemoglobin concentration, red cell, platelet and white cell counts (total and differentiated), and clinical diagnostic biochemical profiles. Total leukocyte counts, neutrophils, and lymphocytes were higher in heifers than cows before calving and within 24h after calving. Alkaline phosphatase was consistently higher in heifers than cows and several significant differences were observed between the 2 groups with regards to cytokine and cytokine-receptor mRNA expression. The results warrant further investigation from the perspective of identifying risk factors for metabolic and parturient disease in dairy cattle.

Genetic differentiation of water buffalo (Bubalus bubalis) populations in China, Nepal and south-east Asia: inferences on the region of domestication of the swamp buffalo.

Data from three published studies of genetic variation at 18 microsatellite loci in water buffalo populations in China (18 swamp type, two river type), Nepal (one wild, one domestic river, one hybrid) and south-east Asia (eight swamp, three river) were combined so as to gain a broader understanding of genetic relationships among the populations and their demographic history. Mean numbers of alleles and expected heterozygosities were significantly different among populations. Estimates of θ (a measure of population differentiation) were significant among the swamp populations for all loci and among the river populations for most loci. Differentiation among the Chinese swamp populations (which was due primarily to just one population) was much less than among the south-east Asian. The Nepal wild animals, phenotypically swamp type but genetically like river type, are significantly different from all the domestic river populations and presumably represent the ancestral Bubalus arnee (possibly with some river-type introgression). Relationships among the swamp populations (D(A) genetic distances, principal component analysis and structure analyses) show the south-east Asian populations separated into two groups by the Chinese populations. Given these relationships and the patterns of genetic variability, we postulate that the swamp buffalo was domesticated in the region of the far south of China, northern Thailand and Indochina. Following domestication, it spread south through peninsular Malaysia to Sumatra, Java and Sulawesi, and north through China, and then to Taiwan, the Philippines and Borneo.

Congenital bilateral anterior nasal atresia in 16 half-sibling Holstein-Friesian calves.

CASE REPORT: Cases of bilateral anterior nasal atresia, sometimes referred to as arhinia or partial arhinia, are extremely rare in cattle and have only been reported as single events. This report describes the birth of 16 Holstein Friesian calves over a 3-month period, all affected with bilateral atresia of the nares and anterior nasal cavity, with 2 calves having additional severe deviation of the nasomaxillary bones and nasal septum. One affected calf was born with an anatomically normal twin. Parentage testing demonstrated that a single Holstein Friesian bull sired all cases tested. CONCLUSION: This is the first report of multiple cases of bilateral anterior nasal atresia in cattle with evidence that demonstrates a heritable condition.

Relationship between sources of pet acquisition and euthanasia of cats and dogs in an animal shelter: a pilot study.

OBJECTIVE: Approximately 140,000 unwanted dogs and cats are culled in Australia annually. There is a paucity of information linking sources of pet acquisition with subsequent euthanasia, which may inform evidence-based strategies to reduce euthanasia rates. This pilot study aimed to determine whether there is a higher risk of euthanasia related to the source of acquisition for pets surrendered to an animal shelter. METHODS: Data for 5391 dogs and 5581 cats surrendered to one Queensland shelter between January 2006 and December 2009 were analysed. RESULTS: The main sources of acquisition for owner-surrendered dogs were 'shelter' and 'pet shop' and for owner-surrendered cats were 'own litter' and 'shelter'. Euthanasia rates for different sources varied. For adult dogs, acquisition through newspaper advertisements was associated with the highest euthanasia rate. Adult cats obtained as gifts (from friend or family member) had the highest euthanasia rate. For junior cats, the overwhelming source was the owner's own litter (68% of intake) and only kittens acquired as strays were at significantly higher risk of euthanasia. For both dogs and cats, animals acquired from shelters had lower rates of euthanasia than most other sources, which suggests that shelter-sourced animals may be considered a preferred source for pet acquisition to assist in reducing the number of adoptable pets euthanased. CONCLUSION: There was evidence from the study animal shelter that the risk of euthanasia was related to acquisition source. These findings should be confirmed by prospective studies, which should also investigate the interaction between acquisition source and other factors, using larger data sets from a variety of shelters.

Diagnosis of prediabetes in cats: glucose concentration cut points for impaired fasting glucose and impaired glucose tolerance.

Diabetes is typically diagnosed in cats once clinical signs are evident. Diagnostic criteria for prediabetes in cats have not been defined. The objective of the study was to establish methodology and cut points for fasting and 2-h blood glucose concentrations in healthy client-owned senior cats (≥8 yr) using ear/paw samples and a portable glucose meter calibrated for feline blood. Of the 78 cats, 27 were ideal (body condition score [BCS] 4 or 5 of 9), 31 overweight (BCS 6 or 7), and 20 obese (BCS 8 or 9); 19 were Burmese and 59 non-Burmese. After an 18-24-h fast and an ear/paw blood glucose measurement using a portable glucose meter, glucose (0.5 g/kg bodyweight) was administered intravenous and blood glucose measured at 2 min and 2 h. Cut points for fasting and 2-h glucose concentrations were defined as the upper limits of 95% reference intervals using cats with BCS 4 or 5. The upper cut point for fasting glucose was 6.5 mmol/L. Of the overweight and obese cats, 1 (BCS 7) was above this cut point indicating evidence of impaired fasting glucose. The cut point for 2-h glucose was 9.8 mmol/L. A total of 7 cats (4 with BCS 8 or 9 including 1 Burmese; 3 with BCS 6 or 7, non-Burmese) were above this cut point and thus had evidence of impaired glucose tolerance. In conclusion, the methodology and cutpoints for diagnosis of prediabetes are defined for use in healthy cats 8 yr and older with a range of BCSs.

Measuring body composition in dogs using multifrequency bioelectrical impedance analysis and dual energy X-ray absorptiometry.

Thirty-five healthy, neutered, mixed breed dogs were used to determine the ability of multifrequency bioelectrical impedance analysis (MFBIA) to predict accurately fat-free mass (FFM) in dogs using dual energy X-ray absorptiometry (DXA)-measured FFM as reference. A second aim was to compare MFBIA predictions with morphometric predictions. MFBIA-based predictors provided an accurate measure of FFM, within 1.5% when compared to DXA-derived FFM, in normal weight dogs. FFM estimates were most highly correlated with DXA-measured FFM when the prediction equation included resistance quotient, bodyweight, and body condition score. At the population level, the inclusion of impedance as a predictor variable did not add substantially to the predictive power achieved with morphometric variables alone; in individual dogs, impedance predictors were more valuable than morphometric predictors. These results indicate that, following further validation, MFBIA could provide a useful tool in clinical practice to objectively measure FFM in canine patients and help improve compliance with prevention and treatment programs for obesity in dogs.

Dosing obese cats based on body weight spuriously affects some measures of glucose tolerance.

The primary objective was to investigate whether dosing glucose by body weight results in spurious effects on measures of glucose tolerance in obese cats because volume of distribution does not increase linearly with body weight. Healthy research cats (n = 16; 6 castrated males, 10 spayed females) were used. A retrospective study was performed using glucose concentration data from glucose tolerance and insulin sensitivity tests before and after cats were fed ad libitum for 9 to 12 mo to promote weight gain. The higher dose of glucose (0.5 vs 0.3 g/kg body weight) in the glucose tolerance tests increased 2-min glucose concentrations (P < 0.001), and there was a positive correlation between 2-min and 2-h glucose (r = 0.65, P = 0.006). Two-min (P = 0.016 and 0.019, respectively), and 2-h (P = 0.057 and 0.003, respectively) glucose concentrations, and glucose half-life (T1/2; P = 0.034 and <0.001 respectively) were positively associated with body weight and body condition score. Glucose dose should be decreased by 0.05 g for every kg above ideal body weight. Alternatively, for every unit of body condition score above 5 on a 9-point scale, observed 2-h glucose concentration should be adjusted down by 0.1 mmol/L. Dosing glucose based on body weight spuriously increases glucose concentrations at 2 h in obese cats and could lead to cats being incorrectly classified as having impaired glucose tolerance. This has important implications for clinical studies assessing the effect of interventions on glucose tolerance when lean and obese cats are compared.

Ingestion of microfilariae from different sources by Culicoides nubeculosus (Diptera: Ceratopogonidae) through an artificial membrane.

Laboratory-hatched Culicoides nubeculosus midges were membrane-fed on cattle blood containing various Onchocerca microfilariae which had been isolated from the hides of red deer (Cervus elaphus) and from Australian and native German cattle. All microfilariae were ingested through the membrane except those of O. tarsicola, which were too large. Onchocerca gibsoni and O. lienalis reached the thoracic musculature, but no further development occurred. Microfilariae of O. flexuosa developed to the "sausage" stage. Microfilariae of O. gutturosa developed to the infective larval stage within 9 days at a temperature of 25 degrees C.

Bull selection and use in northern Australia. 4. Calf output and predictors of fertility of bulls in multiple-sire herds.

On 10 northern Australian properties, the number of calves sired (calf output) by individual bulls in multiple-sire matings was measured by DNA typing for paternity. There were 235 bulls (92 Santa Gertrudis, 25 5/8 Brahman and 119 Brahman) from 37 multiple-sire mating groups. Number of bulls in groups ranged from 2 to 25 and ages of bulls ranged from 2 to 5 years. Mating periods were for 3-12 months and bull mating percentages were 2.5-6%. In all, there were 4251 calves tested and the resolution of paternity ranged from 92.5 to 100% and averaged 97.7% across all sites. This included 9.9% of calves with no potential sires in any of the mating groups. Of the 235 bulls mated, 58% sired 10% or less calves in each of their respective mating groups with 6% not siring any calves. In contrast, 14% sired over 30% of the calves in each of the respective mating groups. When bulls were mated in groups of 8-24, the maximum percent of calves sired by individual bulls was 26+/-7% (mean+/-S.D.) with a range 11-36%. However, when bulls were mated in groups of 2-7, the maximum percent of calves sired by individual bulls was 59+/-19% with a range 24-94%. Calf output of bulls was moderately repeatable across years at four of five sites. Multiple regression models relating pre-mating measures of physical, seminal and behavioural traits to calf output were developed for the three breed groups. In all, only 138 of the 235 bulls were included in the models (40 Santa Gertrudis, 24 5/8 Brahman and 74 Brahman). Sheath and testicular traits, such as scrotal circumference and testicular tone, were generally not related to calf output, the exceptions being sheath depth in Brahman bulls which was negatively related (P<0.05) and scrotal circumference in 5/8 Brahmans which was positively related (P=0.08) to calf output. Dominance was only included in the 5/8 Brahman model but there was no significant relationship between dominance hierarchy and calf output. Semen motility was only related (P<0.05) to calf output in 5/8 Brahmans. However, measures of semen quality based on spermatozoa morphology were important contributors to calf output in the Santa Gertrudis and Brahman models where percent normal spermatozoa was positively related (P<0.01) to calf output. In Santa Gertrudis and Brahman bulls, measures of sexual behaviour in the serving capacity test were related to calf output. In Santa Gertrudis, these were for the number of displays of sexual interest (P<0.05), and mounts (P<0.01), but not number of serves, whilst in Brahman bulls, libido score was positively related to calf output (P<0.05). The models only explained 35-57% of the variation in calf output.

Use of an antigen detection assay to determine mortality of Dirofilaria immitis after thiacetarsamide therapy.

The use of an antigen detection enzyme immunoassay (EIA) to determine the post-treatment infection status of 16 dogs naturally infected with Dirofilaria immitis was investigated. Dogs were treated with thiacetarsamide at a dose rate of 12mg/4.5kg twice daily for 2 days, bled at regular intervals and necropsied 9 weeks later. The infection status of all dogs at necropsy was compared to the ratios of optical density (OD) values from the EIA using fresh plasma samples (day 60/day 0 = R60) and dogs were divided into 2 groups. Using the R60 ratios, those dogs with fewer than 2 live adult worms or immature worms at necropsy ("cleared" dogs) could be differentiated with 95% confidence from those dogs with more than 1 live adult worm ("non-cleared" dogs). Changes in the average OD values from the plasma of "cleared" dogs and "non-cleared" dogs were similar up to 46 days after treatment but diverged significantly thereafter. The efficacy of thiacetarsamide was 50% if all worms were considered and 75% if the presence of immature worms was ignored. The benefits of antigen detection assays for diagnosis and improved patient assessment and the use of an R60 ratio to assess the efficacy of adulticides such as thiacetarsamide are discussed in relation to their practical significance for clinicians.

Jugular vascular access port implantation for frequent, long-term blood sampling in cats: methodology, assessment, and comparison with jugular catheters.

Long-term, frequent venous access for diagnostic, therapeutic, or research purposes in cats is problematic. Frequent blood sampling over extended periods is necessary for some therapeutic regimes and often required for clinical research in veterinary science. In this paper, we describe the implantation of vascular access ports (VAPs) and assess their use for repeated blood sampling over 16 weeks and 38 weeks, as well as the use of jugular catheters for one week. The VAP placement procedure was well-tolerated with few minor complications (minor swelling, contusion, or superficial dermatitis from self-trauma), which were not observed when neck bandages were applied immediately after surgery. Thromboembolism occurred in two cats, but did not occur after switching to a smaller catheter with a rounded tip and taurolidine-citrate locking solution. Although duration of access was much longer with VAPs compared to jugular catheters, patency rates were similar (89% (n=28) to 92% (n=12) after 16 weeks and 75% (n=12) after 38 weeks for VAPs; 88% (n=49) after one week for jugular catheters). Behavioural reactions to blood collection from 30 cats-assessed over 16 weeks and comprising 378 collections-were absent or minor in 99% of collections. These findings indicate that VAPs offer a viable alternative to jugular catheters for studies requiring frequent blood sampling and lasting more than 2 weeks.

Real-time PCR genotyping and frequency of the myostatin F94L mutation in beef cattle breeds.

This research developed two real-time PCR assays, employing high-resolution melt and allele-specific analysis to accurately genotype the F94L mutation in cattle. This mutation (g.433C > A) in the growth differentiation factor 8 or myostatin gene has recently been shown to be functionally associated with increased muscle mass and carcass yield in cattle. The F94L mutation is not, like other myostatin mutations, associated with reduced fertility and dystocia. It is therefore a candidate for introgression into other breeds to improve retail beef yield and the development of a simple and accurate test to genotype this specific mutation is warranted. Variations in the efficiency of enzyme cleavage compromised the accuracy of genotyping by published methods, potentially resulting in an overestimation of the frequency of the mutant allele. The frequency of the F94L mutation was determined by real-time PCR in 1140 animals from 15 breeds of cattle in Australia. The mutation was present in Simmental (0.8%), Piedmontese (2%), Droughtmaster (4%) and Limousin (94.2%) but not found in Salers, Angus, Poll Hereford, Hereford, Gelbvieh, Charolais, Jersey, Brahman, Holstein, Shorthorn or Maine Anjou. The low prevalence of F94L in all beef breeds except Limousin indicates the significant potential for this mutation to improve retail yield in Australian beef cattle.

Reproduction in female Onchocerca gibsoni.

The embryonic stages in the uteri of adult female Onchocerca gibsoni were studied to determine the reproductive potential of this worm. It was concluded that female O. gibsoni undergo cyclic phases of reproduction, each lasting about 14.5 weeks. Once insemination occurred and a cycle commenced, the rate of embryonic development was reasonably constant irrespective of the age of the worm. Mature young females had fewer embryos than older females but both contained a similar proportion (about 19%) of abnormal embryos. In comparison to the older female worms, a greater proportion of mature young females were in the early phase of a reproductive cycle and fewer were actively reproducing. This difference was considered to be due to a greater access of males to older than to recently mature females. There were marked similarities between these observations with O. gibsoni and those reported for O. volvulus, providing further evidence of the usefulness of O. gibsoni as a model for O. volvulus.

A new transferrin allele in Australian goats.

Subdivision of TF B into two variants, B1 (faster) and B2 (slower) in Australian goat breeds was accomplished by high voltage, thin layer polyacrylamide gel electrophoresis at pH 7.9. The genes controlling the caprine transferrins were shown to be autosomal codominant alleles, TFA, TFB1, TFB2 and TFC and in the various breeds of goats, the alleles were in Hardy-Weinberg equilibrium. TFA was the most common allele in the Australian and Texan Angora, Cashmere and Dairy breeds with gene frequencies ranging from 0.652 to 0.977. TFB1 and TFB2 occurred in all four breeds while TFC was only observed in very low frequencies in Australian Angora and Cashmere breeds.

Genetic polymorphism of plasma vitamin D-binding protein (GC) in Australian goats.

Polymorphism at the GC locus in goats was detected using isoelectric focusing (pH 4.5-5.4) and immunoblotting with antiserum to human GC. Three variants, designated A, B and C in order of decreasing mobility to the anode, were detected and were shown to be controlled by three codominant alleles, GCA, GCB and GCC. GCA and GCB occurred in all four breeds (Australian and Texan Angora, Cashmere and Dairy) with GCA being the most common and having gene frequencies ranging from 0.851 to 0.993. GCC was found only in Australian Angora and Cashmere animals. The products of the three GC alleles had isoelectric points in the range pH 4.63-4.95 and M(r) of approximately 54,375. The major isoforms of the three alleles were shown to contain sialic acid. Linkage between the GC and albumin loci was unable to be demonstrated due to the low frequency of ALBA (0.02) in the Cashmere breed.

Caprine plasma proteinase inhibitors--I. Partial characterization.

1. Using two-dimensional electrophoresis (IEF, pH 3.5-6.0 and PAGE, 11.5% T, pH 7.9) the caprine plasma proteinase inhibitors were classified into six distinct classes, designated PIA, PIB, PIC, PID, PIE and PIF. Differentiation of the six inhibitors was based on electrophoretic criteria, their abilities to inhibit bovine trypsin and chymotrypsin and their crossreactions with antisera to human alpha 1-antitrypsin and alpha 1-antichymotrypsin. 2. Polymorphic variants were identified for five of the protein systems (PIA, PIB, PIC, PID and PIE) and the electrophoretic data indicated that the variants were controlled by allelic genes. PIF proteins were poorly resolved and invariant. 3. Treatment of selected plasmas with neuraminidase demonstrated that the microheterogeneity observed in the PIA, PIB, PIC and PID proteins was attributable to sialic acid additions. 4. The inhibitory activities of all six caprine proteinase inhibitors were unaffected by chemical oxidation with chloramine-T.

Caprine plasma proteinase inhibitors--II. Genetic analysis.

1. Analysis of the inheritances of the variants of five caprine plasma proteinase inhibitor systems in families demonstrated a genetic control of codominant alleles at five loci. 2. The PIA, B, C, D and E proteins are controlled by four (PIA1,2,3,4), three (PIB1,4,0), three (PIC2,3,0), five (PID1,2,3,4,0) and two (PIE1,2) alleles respectively. Null alleles were postulated for the PIB, PIC and PID systems. 3. The frequencies of the alleles differed substantially between the Australian and Texan Angoras and Cashmere breeds of goats. 4. The combined exclusion probability for the five PI systems was as high as 0.82 in the Cashmere breed, indicating the potential of the proteinase inhibitor proteins for parentage control purposes.

Caprine blood groups. 2. The C, G, H, I, J, K, L, N, and Q systems.

Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles, C12, C25, and C-. A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G10.19.20, G10.19, G10.20, G10, G19, G20) and a recessive allele (G-). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively.

Caprine blood groups. 1. The B system.

Twelve of 24 monospecific caprine reagents produced by absorption of alloimmune antisera identified a complex blood group system of goats which was designated B, based on the results of a small comparison test with ovine reagents. The frequencies of the 12 B factors differed significantly among the Australian Angora, Texan Angora, Cashmere, and Dairy goat breeds. Three of the antigens detected by the reagents were shown to be related as linear subtypes, designated Ba1, Ba2, and Ba3, and inherited as alleles. The segregations of B factors in 80 sire groups involving 1086 offspring demonstrated that groups of B factors (phenogroups) segregated as products of allelic genes.

Estimations of the efficacy and reliability of paternity assignments from DNA microsatellite analysis of multiple-sire matings.

It is important for bovine DNA testing laboratories to provide the cattle industry with accurate estimates of the efficacy and reliability of DNA tests offered so that end users of this technology can adequately assess the cost-benefits of testing. To address these issues for bovine paternity testing, paternity exclusion probability estimates were obtained from breed panel data and were predictive of the efficacy of the DNA tests used in 39 multiple-sire mating groups, involving 5960 calves and 505 bulls. Paternity testing of these mating groups has demonstrated that the majority involve a variable proportion of unknown sires and this impacts on the reliability of sire allocation. Mathematical models based on binomial or beta-binomial probability distributions were used to estimate the reliability of single-sire allocations from multiple-sire matings involving unknown sires. Reliability of 98-99% is achieved when the exclusion probability is 0.99 or greater, after allowing for up to 20% unknown sires. When the exclusion probability drops below 0.90 and there are 20% unknown sires, the reliability is poor, bringing into question the benefits of testing. This highlights the need for DNA testing laboratories to offer paternity tests with an exclusion power of at least 99%.