Table 1.
Effect of treatment on number of follicles and CL, percentage of superovulated heifers, and ovulation rate for Holstein heifers induced to superovulate using a long-acting recombinant bovine FSH preparation (LArbFSH) or a pituitary-derived FSH preparation (Folltropin).
| Item | Folltropin | A50-LArbFSH | A100-LArbFSH | B50-LArbFSH | P value |
|---|---|---|---|---|---|
| n | 14 | 14 | 14 | 14 | |
| Follicle numbera (min-max) | 25.7 ± 3.2a (7-51) | 5.9 ± 0.9c (0-11) | 16.6 ± 3.1b (2-39) | 18.9 ± 3.2ab (4-37) | <0.01 |
| CL numberb (min-max) | 19.1 ± 2.4a (7-32) | 2.6 ± 0.9b (0-11) | 15.9 ± 2.9a (2-42) | 16.1 ± 3.0a (2-39) | <0.01 |
| % Superovulatedc (n) | 100 ± 0.0a (14) | 28.6 ± 12.5b (4) | 85.7 ± 9.7a (12) | 92.9 ± 7.1a (13) | <0.01 |
| Ovulation rated | 76.0 ± 4.8a | 38.7 ± 10.6b | 88.0 ± 4.2a | 80.8 ± 4.9a | <0.01 |
Within a row, means with different superscripts (a, b) differ (P < 0.05).
Heifers treated with Folltropin received 300 mg of FSH (Folltropin) in eight decreasing doses administered im at 12-hour intervals over a 4-day period, heifers treated with A50-LArbFSH received 50 μg of LArbFSH (type A) in a single im injection, heifers treated with A100-LArbFSH received 100 μg of LArbFSH (type A) in a single im injection, and heifers treated with B50-LArbFSH received 50 μg of LArbFSH (type B) in a single im injection.
Measured immediately before hCG treatment.
Measured immediately before embryo collection.
Heifers with three or more CL at the time of embryo collection.
Measured immediately before embryo collection, one heifer treated with A50-LArbFSH was excluded because no follicles greater than 9 mm or CL were detected.