Evaluation of Biochemical Determinants of Successful Conception in Dairy Cows in and around Bishoftu, Ethiopia
No Thumbnail Available
Date
2024
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Abeba University
Abstract
The influence of biochemical characteristics of cervical mucus at the time of estrus were evaluated on conception rates of normal-cycling and repeat-breeding dairy cows. A total of 62 Holstein-Friesian dairy cows, 38 normal-cycling and 24 repeat-breeding cows, were included in the study. Vaginal electrical resistance (VER) was measured before artificial insemination and cows were categorized into three VER groups (150-180, 181-220 and >220 Ω). The cows were also grouped into three body weight ranges (300-350, 351-400 and 401-450 kg). Cervical fluid parameters including pH, spinnbarkeit, sperm penetration and crystallization patterns were measured or scored and pregnancy was diagnosed by ultrasonography after 30 days post-AI The overall conception rate was 54.84% with a significant difference (P<0.05) between normal cycling cows (63.2%) and repeated breeders (41.7%). The mean (±SD) VER was in the order
of 219.03±66.17Ω and 221.67±41.77Ω for normal-cycling and repeated breeding cows, respectively. The average pH and spinnbarkeit value of cervical fluid were 7.38±0.32, 5.76±2.2cm in normal cycling and 7.32±0.27, 5.85±3.77cm in repeat breeder cows, respectively. The mean(±SD) VER of pregnant and nonpregnant cows were 202.15±31.15Ω and 241.79±73.56Ω, respectively. Body weight, timing of insemination and VER showed significant effects (P<0.05). Conception rates were highest for cows weighing 351- 400 kg(75%), inseminated 7-12 hours (71.43%) after standing estrus and VER of 181-220 Ω 84.21%).
Interestingly, although there was some tendency for influence of the cervical fluid pH, this was not statistically significant, but sperm penetration, spinnbarkeit value and crystallization patterns of cervical fluid did (P<0.05). Cows with normal sperm penetration (72.2%), spinnbarkeit of 7-9 cm (87.5%) and typical crystallization patterns of cervical mucus (76.47%) had comparatively higher conception rates. In conclusion, sperm penetration, spinnbarkeit, vaginal electrical resistance and crystallization pattern are useful predictors of optimal insemination timing in Holstein cows.
Description
Keywords
Dairy cows, Cervical fluid, Conception rate, Crystallization pattern, Sperm penetration, Vaginal electrical resistance