Invited review: overview of new traits and phenotyping strategies in dairy cattle with a focus on functional traits

Authors: EGGER-DANNER, CHRISTA - Central Association Of Austrian Cattle Breeders(ZAR); Cole, John; PRYCE, JENNIE - Department Of Primary Industries; GENGLER, NICOLAS - University Of Liege; HERINGSTAD, BJORG - Norwegian University Of Life Sciences; STOCK, KATHARINA - United Information Systems Livestock Wv (VIT); BRADLEY, ANDREW - Quality Milk Management Services, Ltc; ANDREWS, LUCY - Holstein Uk

Submitted to: Animal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2014
Publication Date: 2/1/2015
Publication URL: http://handle.nal.usda.gov/10113/60897
Citation: Egger-Danner, C., Cole, J.B., Pryce, J., Gengler, N., Heringstad, B., Stock, K., Bradley, A., Andrews, L. 2015. Invited review: overview of new traits and phenotyping strategies in dairy cattle with a focus on functional traits. Animal. 9(2):191-207.

Interpretive Summary: Advances in breeding goals are based on the needs of breeders, but also influenced by consumers and societal needs, demand higher emphasis on traits related to food safety and efficient and environmentally sound production systems. New fitness traits are growing in importance because of recent declines in animal health and fitness. There is also growing competition for high-quality, plant-based sources of energy and protein, so it is important to use those resources very efficiently in animal production. Successful programs for animal improvement will require a balance between the effort needed to record data and the resulting benefits to farmers.

Technical Abstract: For several decades, breeding goals in dairy cattle focused on increased milk production. However, many functional traits have negative genetic correlations with milk yield and reductions in genetic merit for health and fitness have been observed. Herd management has been challenged to compensate for these effects and to balance fertility, udder health, and metabolic diseases against increased production to maximise profit without compromising long-term welfare. Functional traits, such as direct information on cow health, have also become more important because of growing concern about animal well-being and consumer demands for healthy and natural products. There are major concerns about the impact of drugs used in veterinary medicine on the spread of antibiotic-resistant strains of bacteria that can negatively impact human health. Sustainability and efficiency are also increasingly important because of the growing competition for high-quality, plant-based sources of energy and protein. Disruptions to global environments due to climate change may encourage yet more emphasis on these traits. To be successful, it is vital that there is a balance between the effort required for data recording and subsequent benefits. The motivation of farmers and other stakeholders involved in documentation and recording is essential to ensure good data quality. To keep labour costs associated with recording to a reasonable level, existing data sources should be used as much as possible. Examples include the use of milk composition data to provide additional information about the metabolic status or energy balance of the animals. Recent advances in the indirect use of mid-infrared (MIR) spectroscopy to measure milk have shown considerable promise, and may provide cost-effective alternative phenotypes for difficult or expensive-to-measure traits, such as feed efficiency. There are other valuable data sources in countries that have compulsory documention of veterinary treatments and drug use. Additional sources of data outside of the farm include e.g. slaughter-houses (meat composition and quality) and veterinary labs (specific pathogens, viral loads). At the farm level, many data are available from automated and semi-automated milking- and management systems. Electronic devices measuring physiological status or activity parameters can be used to predict events such as oestrus, and also behavioural traits. Challenges concerning the predictive biology of indicator traits or standardization need to be solved. To develop effective selection programs for new traits, the development of large databases is necessary so that high-reliability breeding values can be estimated. For expensive-to-record traits, extensive phenotyping in combination with genotyping of females is a possibility.