National Research Centre on Camel, Bikaner, Rajasthan, India
The tail curling behaviour of pregnant females in the presence of a rutting male was evaluated for its accuracy to diagnose pregnancy in camels through serum progesterone (P4) concentration on day 14-15 after mating and recto-genital palpations. Of the 89 observations for females that did not curl their tails (assumed non-pregnant), 86 (96.6 %) were confirmed to be non-pregnant with P4 <1 ng/ml on day 15. The remaining 3 cases were found to be false negative as they were pregnant with P4 >1 ng/ml. Of the 66 females that curled their tails (assumed pregnant), only 45 (68.1%) were actually pregnant and had P4 >1 ng/ml and 18 (27.2%) were false positive (non-pregnant with P4 <1 ng/ml). Three (4.5%) pregnant females correctly diagnosed through the tail test were diagnosed false negative through P4 concentration as P4 <1 ng/ml. An intriguing aspect was that repeating the tail curling test at weekly intervals could detect non-pregnant status in false positive cases, as well as those pregnant females that lost their pregnancy due to early embryonic deaths. It was concluded that the tail-curling test can be effective in the early detection of non-pregnant females within the breeding herd. A single observation on day 15 could also detect pregnant females with an accuracy of 70%, but the high rate of false positives is a major problem. Repeated weekly tests are necessary to identify those false positive cases and those females that lose their pregnancy due to early embryonic deaths. However, this delayed detection might reduce the overall herd conception significantly if the tail test alone is adopted, as the breeding season is short in camels, thus the simultaneous P4 concentration test on day 15 can detect pregnancy more accurately and would improve reproductive efficiency.
Key words: Camel, evaluation, pregnancy, tail curling