I-Corps: Prognostic test for dairy heifer selection

University Of California-Davis, Davis CA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is to develop an assay to identify calves that will not survive to 2 years of age or will be low milk producers. The goal of the proposed technology is to reduce the number of calves that must be raised by dairies as replacements so dairies may focus their resources on raising healthy, efficient, productive calves and reduce costs, feed waste, and methane and manure production. During the first 24 months of age, heifer death loss and culling can be as high as 20% resulting in a loss of $1800-$2400 per heifer. Currently, dairies are faced with raising these heifers to a productive age (2 years old) to determine which heifers to keep and which to cull when they only need to keep 50% as replacements. This adds approximately $900,000 in costs per year to feed and care for heifers that should have been sold and raised for beef at less than 1 week of age, making heifer raising the second largest cost for a dairy. In addition, the proposed technology also may be used to enable the development of other products that promote energy efficiency, milk production and health such as cardiolipin, prebiotics, probiotics, supra levels of vitamins as well as the development of novel therapies for diseases such as ketosis, fatty liver, obesity, and hypocalcaemia. This I-Corps project is based on the development of a prognostic assay of mitochondrial function to identify calves that will not survive to 2 years of age or will be low milk producers. Mitochondria are cellular energy generators and play a key role in metabolic flexibility - the ability of mitochondria to respond to physiological changes such as immune challenge, energy restriction, lactation, and gestation. Mitochondria have their own genome and are maternally inherited, however, current genetic tests do not include their impact on milk production or longevity. The proposed prognostic assay is based on measuring mitochondrial activity and includes distinct relationships between age, level of milk production, and specific mitochondrial enzyme activities within the electron transport chain. The proposed assay has been shown to predict death and culling based on data from calves tested at 3-5 days of age and followed through to their second lactation. This suggests that the assay results may predict survivability and could be used to identify potential interventions that support mitochondrial function resulting in improved immune function and milk production. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.