title: Dystocia in Friesian cows and its effects on postpartum reproductive performance and milk production.
abstract: A total of 1,243 records for 585 dairy Friesian cows from 1997-2004 were used to study the factors affecting dystocia and its effects on reproductive performance and milk production. The overall incidence of dystocia was 6.9%. The percentage of dystocia decreased with increasing live body weight, age, and parity of cows (P < 0.05); however, it increased with increasing birth weight of calves (P < 0.05). The highest percentage of dystocia was detected in winter season, but the least percentage was in summer season (P < 0.05). The percentage of incidence of dystocia was significantly (P < 0.05) higher with winter feeding compared to summer ration (8.2% vs. 5.1%). The percentage of incidence of dystocia was significantly (P < 0.05) higher with twinning than single calving (15.5% vs. 6.5%), while not significantly affected by the sex of born calves. Incidence of dystocia had adverse effects on reproductive performance and milk yield. The service interval, service period, days open, and calving interval were significantly (P < 0.05) longer in cows afflicted with dystocia compared to normal cows. The conception rate was lower (P < 0.05), but the number of service per conception was higher (P < 0.05) in cows afflicted with dystocia compared to normal cows (60.5% vs. 73.0% and 3.4 vs. 2.7, respectively). Average daily milk yield was lower (P < 0.05) by 1 kg for cows with incidence of dystocia compared to normal cows.
authors.affiliation: Animal Production Research Institute, Agricultural Research Center, Nadi El-Said Street, Dokki, Giza, Egypt, gaafar356@hotmail.com
authors.forename: H M A
authors.initials: HM
authors.lastname: Gaafar
authors.forename: Sh M
authors.initials: ShM
authors.lastname: Shamiah
authors.forename: M A Abu
authors.initials: MA
authors.lastname: El-Hamd
authors.forename: A A
authors.initials: AA
authors.lastname: Shitta
authors.forename: M A Tag
authors.initials: MA
authors.lastname: El-Din
mesh_terms: D000367:Age Factors; D000818:Animals; D001835:Body Weight; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology* / Q000503:physiopathology*; D004420:Dystocia / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D004534:Egypt; D005260:Female; D008892:Milk / Q000706:statistics & numerical data*; D010298:Parity; D011247:Pregnancy; D012098:Reproduction / Q000502:physiology*; D012621:Seasons