Small animal selective breeding

what is hip dysplasia

• developmental trait characterised by instabiliity of the hip causing subluxation

why may we not choose to breed based on phenotype

• some diseases have classic phenotypes so we can select against these

what is selection coefficient

• measure of strength of selection imposed

what is liability

• combined effect of all factors, genetic and environmental that renders an animal more or less likely to develop a disorder

describe the mode of inheritance

complex polygenic inheritance

list 4 non genetic factors that contribute to hip dysplasis

• nutrition, hormones, exercise, obesity

what percentage dogs are affected by OA by 1 yearsols

• 20%

what is the prevalence of OA?

• more prevalent in large dog breeds

what is the estimated heritability of OA

• 0.18-.74

what is biphasic distribution

a trait shows two distinct peaks in a population

what is a gene linkage study

• genetic research used to locate genes associated with specific traits/diseases and looking at their inheritance together

what are studies of association

• a type of genetic study used to identify statistical relationships between specific genetic variants and trts/disease

what is the minimum age for a dog to have its hips scored?

• one year

describe how radiographs are scored for HD

• each hip is scored across 9 areas totalling up to 53 points per hip

  • the higher the score, the greater the presence of hip dysplasia

what is BMS?

• breed mean score - for something such as hip dysplasiawh

what is important to look at when evaluating the hip dysplasia BMS?

• the number of dogs that have been tested - the more dogs, the more accurate the number