ABSTRACT
Control of estrus is essential for the efficiency of any breeding program in animal farms, artificial insemination, hand mating and predicting parturition dates. A total of 18 adult does were used to study estrous activity (EA) detected by a buck goat (BG) and frequent vaginal inspection (FVI) device and its association with cervical mucus (CM) characteristics and progesterone (P4) profile allover year round. All does were housed in semi-open pens under Upper-Egypt climatic conditions, fed maintenance ration (0.8 – 1.2 Kg dry matter/day/animal) and exposed to 2 fertile males 2 times/day for 1/2 h. for estrous detection (ED). A doe that stands and to be mounted by BG is in "estrus" while a doe that in estrus and the estrus was not detected by BG was calculated as "silent estrus or silent ovulation". Cervical mucus of both does was withdrawn by vaginal speculum to determine the physical characteristics; color, texture, elasticity, pH and volume as well as the mineral elements; Na, K, Cl, P, Cu and Zn. Estrous cycles (EC) were classified to 3 types; normal (17 - 26 d.), long (> 26 d.) and short (< 17 d.). Quantitative and qualitative variables were statistically analyzed by GLM and Chi-square test procedures, respectively, as well as Duncan's test. Results revealed that estrus detected by BG was significantly (P<0.05) higher in autumn (78/86, 90.70 %) than in spring (3/11, 27.27 %). While estrus detected by FVI was higher in spring (8/11, 72.73 %) than in autumn (8/86, 9.30 %). Total number and percent estrus detected throughout the year was significantly (P<0.01) higher in does detected by BG (151, 67.11 %) than that detected by FVI (74, 32.89 %). Normal EC was significantly higher in does detected by BG than by FVI, while short and long EC were higher in does detected by FVI than by BG. Estrous duration was significantly (p<0.01) longer of does detected by BG than by FVI, and most estruses occurred in morning. CM color was fluctuated between watery-milky during estrus and creamy during post-estrus of both does. CM texture, elasticity, and volume were more pronounced in the estrus detected by BG than by FVI. CM pH increased relatively in the estrus detected by BG than by FVI. Full arborization was observed with the watery mucus during estrus than post-estrus of both does. Mean Na concentration was significantly (p<0.05) higher in post-estrus than in estrus of does detected by BG than by FVI. Mean K, P and Cu concentrations were not significantly influenced by ED device, but K and P rose relatively in estrus than post-estrous of does, while Cu was the same value during estrus and post-estrous phases. Mean Cl and Zn were significantly (p<0.05) influenced by ED device, Cl was higher in estrus than post-estrus, while Zn was higher during estrous of does detected by BG than by FVI. Significant (P<0.01) negative and positive correlations were found between K and P, and K and Cu, respectively during estrus. While there was positive significant (P<0.05) correlation between Na and K during post-estrus Mean P4 concentration of EC was significantly (p<0.01) higher in does detected by BG (3.16±0.25 ng/ml) than by FVI (0.68±0.22 ng/ml). P4 was higher in autumn and winter than spring and summer of does detected by BG, while does detected by FVI, P4 was higher in winter than the other seasons. So, BG has an effect on quality of estrus. It could be concluded that although the presence of BG, but was not able to detect does in silent estrus which was higher in spring than in autumn. FVI device contributed by 32.89 % in ED in periods BG was inactive in it, hence FVI could be easily applied in animal farms for overcome silent estrous problem and increase reproductive capacity in the flock. Not all Damascus does goat showed their EA allover year round, but the preferable period of EA was in autumn and winter and not in spring or summer. Full arborization was associated with the watery mucus, K, P, Cu and P4 < 1.0 ng during estrus phase.