NIR technology improves selection for desirable traits in salmon
AbacusBio and New Zealand King Salmon (NZKS) are working closely to incorporate technology – in the form of Near Infra-Red Spectroscopy (NIR) – into the salmon breeding programme.
Well known for its accuracy and precision, NIR also saves time, money and analytical resources when it comes to the annual trait recording of salmon breeding stock.
The NIR machine, bought earlier this year, uses a spectrometer – that measures light intensity as a function of wavelength – to indirectly measure crude fat in salmon fillets.
As part of the set-up, the machine was first calibrated using 120 salmon samples that were taken during harvest. The fat was chemically measured, and calibration equations were developed for the NIR machine, where fat content is predicted from the NIR spectral data.
Chemical analysis is still the most accurate at measuring total lipids, however, it is relatively expensive and time consuming. NIR technology is rapid and low-cost, allowing fat content to become a routinely recorded trait for genetic evaluations.
The team at NZKS led by Jon Bailey recorded NIR spectral data using salmon samples in two forms: one that involved selecting 12 set points from a whole fillet; and the other where fillets were minced, homogenised, and selected at five points. It was found that sample homogenisation was an accurate method, but the fillet is wasted in the process. Also, homogenisation is highly time consuming, with the need for equipment cleaning between sampling. Other concerns of this method include the possible introduction of unwanted products (like water) during handling.
AbacusBio consultant Mark Teviotdale, was trained in the use of the NIR machine software and spectral output. Using the spectral data collected and calibrating against chemically measured fat content, he found that the fat content could be accurately predicted from a subset of four points out of the 12 measured on the whole fillet. This will reduce the NIR sampling time for each fish at next season’s evaluation harvest.
“The integration of NIR and X-ray technologies into trait recording for the NZKS breeding programme provides robust data from which good genetic decisions can be made. Ultimately, it is about ensuring the salmon delivered to both domestic and overseas tables are of a consistently high standard”, Mark said.
Mark and AbacusBio consultant Fiona Hely, will be attending the World Aquaculture Society Conference in Adelaide this year to identify other technologies that can be used in advancing the genetic improvement of New Zealand salmon. Fiona will also be presenting an overview of NZKS’s selective breeding programme.