Fecal progesterone analysis for monitoring reproductive status in dairy goats
The present study was undertaken to evaluate the use of fecal progesterone (FP4) concentration for early pregnancy diagnosis, estrus detection, and predicting the litter size and parturition date in dairy goats. Fecal samples were collected from 17 hand-mated goats 3 times a week for 22-23 weeks, beginning on the day of mating. The levels of FP4 were determined by enzyme-linked immunosorbent assay (ELISA). Significant positive correlations were found between the levels of serum P4 and FP4 (r = 0.8787, n = 13). Pregnancy diagnosis was performed at 2 months postmating with transabdominal ultrasonography and confirmed upon birth of the offspring. The results indicated a significant difference in the mean FP4 concentration obtained during days 19 and 20 postmating between the pregnant and nonpregnant does (2492.4 ± 239.1 vs. 577.0 ± 112.9 ng/g, P < 0.05). A significant drop in the FP4 concentration was noted 3 days prior to the detected day of estrus (P < 0.05). The mean weekly FP4 profile obtained in this study showed a progressive increase from week 7 to 14 until a plateau was reached between weeks 15 and 21, and then a rapid decline began 5 to 6 days prepartum, with a significant drop 1-2 days prepartum (from 3884.3 ± 576.0 to 1205.0 ± 339.0 ng/g, P < 0.05). No significant correlation was observed between the FP4 concentration and the number of kids born. In conclusion, the measurement of FP4 concentration could potentially be an alternative method for early pregnancy diagnosis, prediction of estrus, and parturition in dairy goats.
Key words: Fecal progesterone, pregnancy, estrus, dairy goat