| Summary: | 碩士 === 國立中興大學 === 獸醫學系暨研究所 === 99 === There is an increasing interest in the application of fecal hormone analysis as an alternative approach to non-invasive reproductive assessment, primarily owing to the relative ease of sample collection from animals. Fecal steroid assays have mainly been used to study female reproduction and provide information regarding the estrus cycle, pregnancy and reproductive disorders. The present study was undertaken to evaluate the use of fecal progesterone (FP4) concentration for early pregnancy diagnosis, mapping the FP4 profile during the estrous cycle and gestation period, in predicting the parturition date and the litter size in dairy goats. This experiment was realized on the dairy goat farm at Chung Hsing University between October 2008 and April 2010. Fecal samples were collected from 17 hand-mated goats 3 times weekly for 22 - 23 weeks, beginning on the day of mating. The levels of FP4 were determined by enzyme linked immunosorbent assay (ELISA). Pregnancy diagnosis was performed at 2 months post-mating by trans-abdominal ultrasonography and confirmed upon birth of offsprings. The results indicated a significant difference in the mean FP4 concentration obtained during days 19 – 20 post-mating between pregnant and non-pregnant does (2492.4 ± 69.0 vs 577.8 ± 82.0 ng/g, p < 0.05). A sensitivity, specificity and accuracy of 100% each was obtained applying FP4 concentration analysis on days 19 – 20 post-mating for pregnancy diagnosis. Mean estrous cycle length was 20.8 ± 0.6 days. A baseline FP4 value of 344.3 ng/g was obtained. The highest FP4 concentrations were recorded during days 9 to 13 of the luteal phase. A significant drop in the FP4 concentration was noted 4 days before the estimated day of estrus (p < 0.05). A gestation length averaging 149.3 ± 0.2 days was observed. 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 beginning 6 days before with a significant drop (p < 0.05) 2 days (from 3884.3 to 1205.0 ng/g) pre-partum. In the present study, a correlation between gestation length and litter size, parity, breed or month of mating was not observed. Average litter size was 2.1 kids. No significant correlation was observed between FP4 concentration and the number of kids born. In conclusion, the measurement of FP4 concentration is a potentially alternative method for monitoring reproductive status in goats.
|
|---|
