Just over four years ago NZM embarked on an ambitious project to develop an estimated breeding value (EBV) for footrot. Click here for an update from Dr. Mark Ferguson on the project's progress.
What is the FeetFirst project?
The overall objective of FeetFirst is to raise fine-wool sheep productivity, as well as enable new growers in higher rainfall areas to transition to fine-wool sheep, by developing a new tool for identifying animals with better genetic resistance to footrot.
Utilising breeding values and genomic technology, the FeetFirst project is developing a genomic breeding value (gBV) for footrot resistance in fine-wool sheep. Breeders will be able to use the gBV to predict an animal's genetic resistance to footrot when making breeding selections.
FeetFirst is led by The New Zealand Merino Company, and co-funded by Merino New Zealand Incorporated (Merino Inc.) and the Ministry for Primary Industries.
Central progeny test results
A core component of the central progeny test (CPT) is to determine the genetic resistance of rams to footrot by testing the performance of their progeny in the same environment. Each year, all of the wether hoggets from the CPT are exposed to footrot at the same time. Once a challenge has been established in the mob, each hoof of each animal is scored using a 0 to 5 scale (click here for more information). Using this data, breeding values for footrot resistance are generated for the sire of each progeny group. With each year of the CPT, we are building a bigger, richer data set, which is improving the accuracy of the footrot breeding value - not only for the rams entered in the CPT, but for their relatives also.
We add the CPT data to the data collected from the individual studs that challenge their stud flock for footrot, along with the original FeetFirst data that was collected from commercial flocks from 2013 to 2015 and the data from the ram challenge that NZM and AgResearch undertook in 2013-14.
Investigation into the effectiveness of the Lincoln footrot gene marker test
As part of the wider FeetFirst project, we undertook an evaluation of the relationship between the Lincoln footrot gene marker test (LFGMT) and the incidence and severity of footrot in rams and their progeny. A summary of the results can be found here.
While the evaluation did not find a strong relationship between the LFGMT and resistance to footrot, the positive news for the industry is that the wider FeetFirst project is showing that there is exploitable genetic variation in the resistance of fine-wool sheep to footrot in the New Zealand sheep population. By shifting the focus from a gene marker test to a breeding value, the New Zealand fine-wool industry will soon have a more accurate tool to successfully breed for increasing tolerance to footrot.