Table 1.
Description of continuous versus binary fertility, growth, and size traits
| Continuous traits | |
|---|---|
| Weeks pregnant (actual) | Fetal age in weeks recorded via manual palpation at pregnancy diagnosis |
| Weeks pregnant (estimated) | A combination of actual fetal age in weeks, with estimated fetal age at the average date of pregnancy diagnosis in heifers born before 2011 |
| Heifer days to calving | Difference in days between the date of bull turn out at the beginning of the breeding season and first calving date |
| Age at first calving | Difference in days between first calving and date of cow’s birth |
| 200-d weight | Heifer weight recorded at approximately weaning |
| 400-d weight | Heifer weight recorded as approximately yearlings |
| 600-d weight | Heifer weight recorded at approximately the start of the breeding season, at ~2 yr of age |
| Mature cow weight (average ≥ 3 yr) | Average of all mature cow weight measurements collected at 3 yr of age or greater |
| Mature cow weight (average ≥ 5 yr) | Average of all mature cow weight measurements collected at 5 yr of age or greater |
| Average daily gain between 200- and 400-d weights |
The difference in weight measured at ~200- and 400-d of age, divided by number of days between measurements |
| Average daily gain between 200- and 600-d weights |
The difference in weight measured at ~200- and 600-d of age, divided by number of days between measurements |
| Average daily gain between 400- and 600-d weights |
The difference in weight measured at ~400- and 600-d of age, divided by number of days between measurements |
|
Binary traits
1 = successful, 0 = unsuccessful | |
|---|---|
| Heifer pregnancy | Ability to successfully conceive prior to 3 yr of age |
| Heifer calving | Ability to successfully calve by 3 yr of age |
| Heifer rebreed | Whether or not a heifer was able to successfully produce a calf the year following her first pregnancy |
| Stayability at 4 yr of age (Stay4) | Ability to produce two calves by 4 yr of age |
| Stayability at 5 yr of age (Stay5) | Ability to produce three calves by 5 yr of age |
| Stayability at 6 yr of age (Stay6) | Ability to produce four calves by 6 yr of age |