Time points | Hormonal levels |
---|
| Progesterone (ng/dl) | Estrogen (pg/dl) | Cortisol (ng/dl) |
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First GnRH injection | 0.54 ±0.17b | 21.41 ±0.99a | 0.49 ±0.04b |
PGF2α injection | 10.43 ± 0.17a | 16.56 ± 0.78b | 1.08 ± 0.02a |
Second GnRH injection | 2.07 ± 1.12b | 25 ± 1.83a | 0.5 ±0.02b |
- Concentrations (means ± standard error of mean (SEM)) of estrogen, progesterone and cortisol in serum from Holstein cows at the time of the initial treatments with GnRH and PGF2α in the GPG program. Means with different superscripts (a,b) are significantly different between time points (P < 0.05)