Differences in calpain system,desmin degradation and water holding capacity between commercial Meishan and Duroc × Landrace × Yorkshire crossbred pork

The objective of this study was to examine the differences in calpain system, desmin degradation, pH values and water holding capacity (WHC) between muscles of commercial Meishan and Duroc × Landrace × Yorkshire crossbred pigs. Meishan pork presented better WHC evidenced by lower purge loss at days 1 and 3 and less centrifugation loss at day 1 post mortem (P < 0.05). pH values at 45 min post mortem in Meishan pork were significantly higher compared to crossbred pork (P < 0.05). Calpain‐1 messenger RNA (mRNA) expression was lower in Meishan pork compared to that from crossbred pork (P < 0.05). Additionally, calpain‐1 activity, the ratio of calpain‐1 to calpastatin activity and desmin degradation were lower in Meishan pork compared to those from crossbred pork samples (P < 0.05). The results indicate that the calpain system including mRNA expression and activity were different between commercial Meishan and crossbred pork resulting in difference in the degree of desmin degradation during post mortem aging. pH values at 45 min and 24 h post mortem rather than calpain activity and desmin degradation could explain the higher water holding capacity in commercial Meishan pork.     

A genome‐wide SNP scan in a porcine Large White × Minzhu intercross population reveals a locus influencing muscle mass on chromosome 2

A high‐density single nucleotide polymorphism (SNP) array containing 62 163 markers was employed for a genome‐wide association study (GWAS) to identify variants associated with lean meat in ham (LMH, %) and lean meat percentage (LMP, %) within a porcine Large White × Minzhu intercross population. For each individual, LMH and LMP were measured after slaughter at the age of 240 ± 7 days. A total of 557 F2 animals were genotyped. The GWAS revealed that 21 SNPs showed significant genome‐wide or chromosome‐wide associations with LMH and LMP by the Genome‐wide Rapid Association using Mixed Model and Regression‐Genomic Control approach. Nineteen significant genome‐wide SNPs were mapped to the distal end of Sus Scrofa Chromosome (SSC) 2, where a major known gene responsible for muscle mass, IGF2 is located. A conditioned analysis, in which the genotype of the strongest associated SNP is included as a fixed effect in the model, showed that those significant SNPs on SSC2 were derived from a single quantitative trait locus. The two chromosome‐wide association SNPs on SSC1 disappeared after conditioned analysis suggested the association signal is a false association derived from using a F2 population. The present result is expected to lead to novel insights into muscle mass in different pig breeds and lays a preliminary foundation for follow‐up studies for identification of causal mutations for subsequent application in marker‐assisted selection programs for improving muscle mass in pigs.     

Endogenous endophthalmitis caused by Enterococcus faecalis in a cat

A three‐year‐old male neutered domestic shorthair cat was presented for loss of vision associated with hyperthermia, lethargy and anorexia. Ophthalmic examination revealed a bilateral panuveitis. Cytological examination of aqueous and vitreous humours was performed and revealed a suppurative inflammation associated with numerous cocci. Enterococcus faecalis was identified by bacterial culture from aqueous and vitreous humour. No primary infection site was identified. Active uveitis resolved after systemic antibiotic therapy, but the vision loss was permanent. To the authors’ knowledge, this is the first reported case of endogenous bacterial endophthalmitis secondary to E. faecalis infection in a cat.     

An imputation‐based genome‐wide association study on traits related to male reproduction in a White Duroc × Erhualian F2 population

Boar reproductive traits are economically important for the pig industry. Here we conducted a genome‐wide association study (GWAS) for 13 reproductive traits measured on 205 F₂ boars at day 300 using 60 K single nucleotide polymorphism (SNP) data imputed from a reference panel of 1200 pigs in a White Duroc × Erhualian F₂ intercross population. We identified 10 significant loci for seven traits on eight pig chromosomes (SSC). Two loci surpassed the genome‐wide significance level, including one for epididymal weight around 60.25 Mb on SSC7 and one for semen temperature around 43.69 Mb on SSC4. Four of the 10 significant loci that we identified were consistent with previously reported quantitative trait loci for boar reproduction traits. We highlighted several interesting candidate genes at these loci, including APN, TEP1, PARP2, SPINK1 and PDE1C. To evaluate the imputation accuracy, we further genotyped nine GWAS top SNPs using PCR restriction fragment length polymorphism or Sanger sequencing. We found an average of 91.44% of genotype concordance, 95.36% of allelic concordance and 0.85 of r² correlation between imputed and real genotype data. This indicates that our GWAS mapping results based on imputed SNP data are reliable, providing insights into the genetic basis of boar reproductive traits.     

IN THIS ISSUE – March 2009

Psychological stress in Australian veterinarians  ▪  Intravenous Alfaxan-CD® in young cats  ▪  Worm infections in Merino ewes  ▪  Congenital hypovitaminosis A in beef cattle  ▪  Fenugreek and kangaroo gait  ▪  Dysgerminoma in a mare  ▪  Plant poisonings in alpacas     

In this issue – July 2009

Musculoskeletal disorders in Queensland veterinarians  ▪  Australian surveillance for avian influenza viruses in wild birds  ▪  Splenic lymphoma in an echidna  ▪  Post-thaw motility of equine semen  ▪  Serum cobalamin concentrations in cats  ▪  Acute toxicity of snail and slug bait in dogs  ▪  Topical hydrocortisone aceponate for flea-allergy dermatitis in dogs  ▪  Activated coagulation times in normal cats and dogs  ▪  Acquired arachnoid cyst in a cat     

IN THIS ISSUE – APRIL 2009

The laboratory network in Australia and New Zealand  ▪  Difficulties in tracing pigs after auction  ▪  Long-acting moxidectin in sheep  ▪  Crutching and dicyclanil for breech strike  ▪  Nonsurgical alternative to mulesing  ▪  Heimlich valve drainage in dogs  ▪   Extradural haematoma after snake bite  ▪  Metastatic mast cell neoplasia  ▪  Ectoparasitic dermatitis in wallabies     

IN THIS ISSUE – May 2009

Australian poultry industries and highly pathogenic avian influenza  ▪  Diagnosis of canine splenic disorders  ▪  Dermatoses caused by immature Ixodes spp.  ▪  Seizures during medetomidine sedation and local anaesthesia  ▪  Inherited diseases of Holstein-Friesian cattle  ▪  Oral and topical triclabendazole  ▪  Double-outlet right ventricle in a filly     

In this issue – August 2009

Post-weaning mortality of Merino sheep  ▪  Transcutaneous ultrasound over the right flank for pregnancy diagnosis in cows  ▪  Right flank transcutaneous vs transrectal ultrasound for pregnancy diagnosis in cows  ▪  Ultrasound of soft tissue tumours in dogs  ▪  Idiopathic hypereosinophilic syndrome in a Rottweiler  ▪  Toxicity from accidental oral dosing of a topical endectocide  ▪  Scrub-itch mite in an endangered wallaby  ▪  Cerebellar cortical degeneration in a koala     

In this issue – June 2009

Bandaging and second intention healing in distal limbs of horses  ▪  Auricular chondrosis in a horse  ▪  National survey of antimicrobials in the Australian pig industry  ▪  Analgesia for knife and ring castration in lambs  ▪  Incidence of lymphoma in a colony of baboons  ▪  Viruses in black tiger prawns from Weipa  ▪  Sacral osteochondrosis in German Shepherd Dogs  ▪  Congenital pyloric obstruction from a gastric hyperplastic polyp     

Intraoral diode laser epiglottectomy for treatment of epiglottis chondrosarcoma in a dog

Laryngeal tumours are rare in dogs. Surgery is the treatment of choice, but it is usually palliative in malignant conditions, due to advanced stage of the tumour at the time of diagnosis. In veterinary medicine, little information is available about the use of diode laser in laryngeal oncological surgery. In the case reported here, a dog with an epiglottic chondrosarcoma was successfully treated with diode laser epiglottectomy. The surgical technique and follow up are described.