Case definition and metabolic disorders: More accurate phenotypes
Above: Dr Ian Lean
Lead Author: Ian Lean
Project P2: Unlocking the potential of the cow
More accurate definitions (phenotypes) of metabolic disorders are needed to improve research, prevention, and treatment. Imprecise definitions can lead to classification errors that weaken associations or result in unreliable breeding values.
Definition inconsistencies have implications for monitoring feed efficiency, ruminal acidosis, and lameness. For example, residual feed intake (RFI) models are used for calculating feed efficiency but inconsistencies in the definition create the risk of selecting less-fit genotypes.
Relying solely on ruminal pH as an indicator of ruminal acidosis has limited diagnostic value due to the temporal nature and heterogeneity of the rumen. Phenotypic characterisation could be improved with the use of definitions based on more than just pH.
Lameness has low heritability and is often treated as a single disorder, despite being comprised of multiple conditions. This leads to potential errors and data challenges such as under-reporting.
The Dairy UP project is developing ways to address the challenges of definitions of disorders.
About Dairy UP
Dairy UP is a collaborative research, development and extension program for the NSW dairy industry. It aims to unlock the potential of pastures, cows, water and milk to increase productivity and profitability, and de-risk the industry and develop new markets.