A contemporary group is a set of animals that have had an equal opportunity to perform: same sex, managed alike, and exposed to the same environmental conditions and feed resources. Contemporary groups are the cornerstone of genetic evaluation. They are the best way to account for environmental effects so that remaining differences among animals may be attributed to genetics, ultimately resulting in expected progeny differences (EPDs).
What splits calves into separate contemporary groups?
- Management codes (creep vs. non creep)
- Group codes
- Weaning dates more than three days apart
- Location codes
- Registered vs. commercial dams
- Natural vs. Embryo Transfer (ET) calves, registered vs. other recipients
You can put your new calves into a contemporary group when entering their newborn data (calving a cow), but birth ratios will not be calculated. For example: 2019 Heifer Calves would be a contemporary group for heifer calves born within a certain time-frame in 2019.
When recording weaning and yearling data, a contemporary group can also be assigned at that time. To calculate the weaning ratios and yearling ratios, you will need to make sure the setting is turned on. To check this setting, click on My Account in the top right corner > Account Settings > Cattle Records.
Then scroll down to Record Preferences. A check mark next to "Calculate Adjusted Measurements" indicates the setting is enabled. Registered Breeders: You probably want this disabled (not checked) if you are importing data from your breed association.
Note: The calves must be weaned together in CattleMax and a contemporary group assigned at that time for ratios to be calculated. To calculate the weaning weight ratios each calf must have a Date of Birth, Birth Weight, Weaning Date, Adjusted Weaning Weight, Sex and they must be assigned to a Contemporary group when they are weaned. For CattleMax to calculate the adjusted weaning weight, the dam will need a Date of Birth on her record (for the age of dam adjustment). It is not possible to later add animals to a previously named contemporary group and have the ratios calculated. The same holds true when later entering yearling data.
A ratio is the performance of an individual animal relative to the average performance for his or her contemporaries. Contemporary groups should include as many animals as can be accurately compared.
For example, say we have 10 bull calves at weaning who weighed an average of 600 pounds (lb.). One calf weighed 630 lb., so he is 5% above the average of his contemporaries. His ratio is 105. Ratio = (630 ÷ 600) x 100 = 105
Another calf weighed 570 lb., which is 5% below the contemporary group average of 600 lb. His ratio is 95. Ratio =(570 ÷ 600) x 100 = 95