The methodology and accuracy of Sheep Ireland star-rating system doesn't stand up - ICSA
The methodology and accuracy of the star-rating system doesn't stand up to objective analysis, argues John Brooks
Even in breeds such as the Belclare where all individual sheep have been recorded since the inception of Sheep Ireland, accuracy figures are as low as 30pc, with a majority falling in the region of 30pc-40pc.
If reliability figures were used, as is the case with cattle, a 30pc accuracy would convert to 9pc reliability and a 40pc accuracy would convert into 16pc reliability.
Could this be the reason that sheep star ratings are so low?
Is inaccurate data therefore the reason that sheep star ratings fluctuate so much in a relatively short period of time? We often see five-star rams going to one star and those with one star going to five stars and everything in between.
How many star ram buyers actually check the star ratings of their purchases after six months or a year?
The problem lies with a recording system that allows breeders to record inaccurate data on important traits such as birth weight, type of birth (single, twin, etc), lambing difficulty score, mortality, weight at 40 days, 80 days, 120 days, as well as type of rearing, etc.
By careful manipulation of this data, unscrupulous breeders can in fact ensure high star ratings for their sheep, thus adding significant monetary value to them.