Quantitative genetics of traits associated with hip dysplasia in a canine pedigree constructed by mating dysplastic Labrador Retrievers with unaffected Greyhounds

OBJECTIVE: To determine the genetic influence on expression of traits associated with canine hip dysplasia. ANIMALS: 193 dogs from an experimental canine pedigree. PROCEDURE: An experimental canine pedigree was developed for linkage analysis of hip dysplasia by mating dysplastic Labrador Retrievers with nondysplastic Greyhounds. A statistical model was designed to test the effects of Labrador Retriever and Greyhound alleles on age at detection of femoral capital epiphyseal ossification, 8-month distraction index, and 8-month dorsolateral subluxation score. RESULTS: The additive effect was significant for age at detection of femoral capital epiphyseal ossification. Restricted maximum likelihood estimates (+/-SD) for this trait were 6.4+/-1.95, 10.2+/-2.0, 10.8+/-3.1, 11.4+/-2.1, and 13.6+/-4.6 days of age for Greyhounds, Greyhound backcross dogs, F1 dogs, Labrador Retriever backcross dogs, and Labrador Retrievers, respectively. The additive effect was also significant for the distraction index. Estimates for this trait were 0.21+/-0.07, 0.29+/-0.15, 0.44+/-0.12, 0.52+/-0.18, and 0.6+/-0.17 for the same groups, respectively. For the dorsolateral subluxation score, additive and dominance effects were significant. Estimates for this trait were 73.5+/-4.1, 71.3+/-6.5, 69.1+/-6.0, 50.6+/-12.9, and 48.4+/-7.7%, respectively, for the same groups. CONCLUSIONS: In this canine pedigree, traits associated with canine hip dysplasia are heritable. Phenotypic differences exist among founder dogs of each breed and their crosses. This pedigree should be useful for identification of quantitative trait loci underlying the dysplastic phenotype.     

An outbreak of low pathogenic avian influenza in a mixed-species aviculture unit in Dubai in 2005.

This case describes an outbreak of low pathogenic hemagglutinin 9 neuraminidase 2 avian influenza virus (AIV) in two white-bellied bustards (Eupodotis senegalensis), one stone curlew (Burhinus oedicnemius), and a blacksmith plover (Antibyx armatus) in a private zoologic collection in Dubai, United Arab Emirates. The four birds showed signs of respiratory disease, and all died as a result of disease or euthanasia. Attention has been paid to the diagnostic process and common differential diagnosis for upper respiratory tract disease in bustards, curlews, and plovers. To the knowledge of the authors, AIV has not been previously described in these species.     

Selection of families and parents of sugarcane (Saccharum spp.) through mixed models by joint analysis of two harvests

At present, the sugarcane (Saccharum spp.) breeding programs from around the world have practiced early family selection, because in the early stages of breeding the evaluated characteristics have shown low heritability. This study aimed to select through restricted maximum likelihood/best linear unbiased prediction also known “mixed models” the best families among the 78 that comprise the RB05 sugarcane series, stage T1, of Programa de Melhoramento Genético da Cana-de-açúcar of the Rede Interuniversitária para o Desenvolvimento do Setor Sucroalcoleiro, Brazil. The experiments, conducted during 2007/2008 and 2008/2009 in Paranavaí, PR were implemented using an incomplete-block design with five replicates of each family. Each plot was composed of two planting rows of 5 m, spaced from each other by 1.40 m and spacing between plants was of 0.50 m, containing ten seedlings for planting row, resulting in a total of 20 individuals per replicate of each family. The characteristics evaluated were Brix (°Brix), ton of stalk per hectare (TCH) and ton of °Brix per hectare (TBH). The joint analysis obtained from these three traits in both harvests favored the selection of 35–41 families. The analysis also favored the selection of the best parents. The top five families for Brix were: F41M60, F02M77, F41M82, F61M38 and F62M35; to TCH were F66M30, F35M06, F78M45, F70M30 and F57M46 and for TBH the five elites families were F66M30, F35M06, F78M45, F70M30 and F01M39. The five best sugarcane parents for Brix were RB835486, SP91-1049, SP80-3280, RB72454 and RB925211; to TCH were IAC87-3396, RB941531, RB855511, RB915141 and RB957689, and for TBH the elite were IAC87-3396, RB855511, RB957689, RB941531 and RB855563. As each harvest season had different order of the best families, the joint analysis proved to be a primordial tool for plant breeders.     

A brief note on the information-seeking behavior of UK leisure horse owners

Equine welfare charities have identified the education of (primarily novice) horse owners as the principal route to tackling the majority of equine welfare problems in the United Kingdom. To reach and educate owners effectively, we must understand where they seek advice about issues that arise when owning or caring for a horse. Questions regarding information-seeking behavior were included in an Internet survey completed by a convenience sample of 1,326 UK leisure horse owners, recruited online and through electronic and postal mail shots to equestrian clubs and establishments. The questions asked where the owners sought advice regarding 4 different subject areas: horse behavior, health, stable care, and training. Respondents were asked to select their main sources of information from a list of 7—books/magazines, vet/farrier, instructor, Internet/forums, friends/family, tack shops, and other. Although books/magazines were the most frequently used information source across all 4 subject areas overall, there were differences between the 4 subject areas in the most commonly selected sources (χ² = 992, P < 0.001) and the number of sources consulted (χ² = 254, P < 0.001). Vets/farriers were the source consulted most frequently for health advice (Z = ?13.32, P < 0.001), instructors for training advice (Z = ?3.93, P < 0.001), and books/magazines for advice regarding both behavior (Z = ?9.49, P < 0.001) and stable care (Z = ?8.26, P < 0.001). Despite the survey mode and that many participants were recruited online, Internet/forums were only the third to the fifth most used of the 7 information sources, depending on the subject area. Logistic regression analyses identified significant associations between owner demographics (age, self-rated skill level, and self-reported rider type) and the likelihood of selecting a particular source for advice regarding a specific subject area. The findings have important implications for those trying to reach the horse-owning population to disseminate research findings and ultimately improve the welfare of their horses.     

Infectivity of seropositive dogs, showing different clinical forms of leishmaniasis, to Lutzomyia longipalpis phlebotomine sand flies

Visceral leishmaniasis (VL) is a growing zoonosis with an increasing number of new cases and a rapid geographical spreading of the disease. In the present study, a canine survey was carried out in the city of Montes Claros (320,000 inhabitants), an endemic area of American visceral leishmaniasis in the state of Minas Gerais, Brazil. A total number of 4795 dogs were examined by serology, which showed a rate of seropositivity of 5%. Isoenzymatic analysis confirmed Leishmania infantum chagasi as the local aetiological agent of CVL. Canine tissues were assayed for the presence of Leishmania parasite DNA using different techniques. The infectivity of asymptomatic, oligosymptomatic and symptomatic seropositive dogs was tested by xenodiagnosis using laboratory reared Lutzomyia longipalpis. Rates of infection of 5.4%, 5.1% and 28.4% were found for the phlebotomine sand flies that fed in asymptomatic, oligosymptomatic and symptomatic dogs, respectively. Our results indicate that, under experimental conditions, symptomatic dogs are about four times more infective to VL vectors than oligosymptomatic or asymptomatic animals. The lower infectivity rates of dogs displaying any of the last two clinical forms of leishmaniasis, however, must be taken into account in the epidemiology of CVL.     

Lymphocyte sequestration through S1P lyase inhibition and disruption of S1P gradients

Lymphocyte egress from the thymus and from peripheral lymphoid organs depends on sphingosine 1-phosphate (S1P) receptor-1 and is thought to occur in response to circulatory S1P. However, the existence of an S1P gradient between lymphoid organs and blood or lymph has not been established. To further define egress requirements, we addressed why treatment with the food colorant 2-acetyl-4-tetrahydroxybutylimidazole (THI) induces lymphopenia. We found that S1P abundance in lymphoid tissues of mice is normally low but increases more than 100-fold after THI treatment and that this treatment inhibits the S1P-degrading enzyme S1P lyase. We conclude that lymphocyte egress is mediated by S1P gradients that are established by S1P lyase activity and that the lyase may represent a novel immunosuppressant drug target.     

Coronaviruses in cattle

Bovine coronaviruses are spread all over the world. They cause two types of clinical manifestations in cattle either an enteric, calf diarrhoea and winter dysentery in adult cattle, or respiratory in all age groups of cattle. The role of coronaviruses in respiratory infections is still a hot topic of discussion since they have been isolated from sick as well as healthy animals and replication of disease is rarely successful. Bovine coronavirus infection is characterised by high morbidity but low mortality. The laboratory diagnosis is typically based on serological or molecular methods. There is no registered drug for the treatment of virus infections in cattle and we are limited to supportive therapy and preventative measures. The prevention of infection is based on vaccination, biosecurity, management and hygiene. This paper will cover epidemiology, taxonomy, pathogenesis, clinical signs, diagnosis, therapy, economic impact and prevention of coronavirus infections in cattle.

     

Application of platelet-rich plasma in the in vitro production of bovine embryos

Tropical Animal Health and Production - The aim of this study was to replace fetal bovine serum (FBS) with platelet-rich plasma (PRP) for in vitro production of bovine embryos. The maturation media...