Effect of Body Condition Score at Calving on Ovarian Activity and Subsequent Reproductive Characteristics during Postpartum Period in Crossbred Cows تأثير حالة الجسم عند الولادة على النشاط المبيضى والخصائص التناسلية اثناء فترة مابعد الولادة فى الأبقار الخليطة

The present investigation aims to determine the effect of body condition score (BCS) at calving on ovarian activity and subsequent reproductive characteristics during postpartum period in crossbred cows. Thirty-six crossbred cows (Baladi cows x Friesian cows) week post-calving were used and divided into three groups of 12 cows for each group (BCS: less than 3 equal to 3 and more than 3) according to BCS. The results demonstrated that, uterine involution period, first ovulation and estrous was significantly longer, than (P <0.05) (38.4±3.4, 51.2±3.8 and 65.6±2.5, days) in cows with BCS ˂3, compared to cows with BCS equal 3 (30.2±2.2, 38.4±3.4 and 45.9±7.1, days), or more than 3 score (28.4±3.9, 30.5±2.6 and 43.2±5.3, days), respectively. The first service and conception was significantly longer (P <0.05) than (95.3±9.3 and 123.5 ±12.4, days) in cows with BCS ˂3 compared to cows with BCS equal 3 (71.2 ±6.6 and 102.3±13.1, days) to or more than 3 score (68.1±8.5 and 96.3±11.6, days), respectively. Lower NS/C in BCS ˃3 was (1.7±0.6, service) and equal 3 was (1.9±0.5, service) in comparison with those cows had BCS ˂3 was (2.7±0.4, service). The CR was significantly higher (P <0.05) than 50 and 60% in cows with a BCS equal 3 to or higher than 3 score compared to in cows with BCS less (30%) than 3, respectively. In conclusion, the current results indicated a significant effect of BCS at calving on recovery of ovarian activity and subsequent reproductive characteristics, during postpartum period in crossbred cows.