GenOvis is the Canadian genetic evaluation system for sheep. Genetic trends graphs are now available for the five (5) breeds with the most lambs tested; Dorset-Polled, Polypay, Rideau, Romanov and Suffolk.
In 2011, there were 3124 Dorset-Polled, 1460 Polypay, 10,412 Rideau, 3739 Romanov and 1464 Suffolk lambs entered on the program. The genetic trends of breeds with large numbers of animals tested are a more reliable indicator of the change occurring in the breed.
The genetic trend graphs are derived from the database that is used to run the EPD (estimated progeny difference) evaluations in Canada. This database includes all data collected in Ontario since 1986 and all data collected in Quebec on the old Federal Record of Performance Program and GenOvis since the early 1980s.
There are five (5) graphs for each breed. The graphs show the genetic trends for growth traits, reproductive traits, ultrasound carcass traits and selection indexes. It should be noted that the scale for each graph is different. It is expected that maternal traits will change at a slower rate than the more heritable growth traits.
Genetic trends, like the estimated progeny differences (EPDs) themselves, are reported in the units of the traits. The weight and gain traits are expressed in kilograms; the number born, number weaned and lamb survival traits are in numbers of lambs; ultrasound loin and fat are in millimeters; and the selection indexes have no units since they are a combination of many traits.
Click on the links below to download the genetic trend graphs (PDFs) for each breed:
