Effects of calving difficulty on the subsequent reproductive performance and milk production of Holstein, Brown Swiss and their crosses

• The incidence of calving difficulty was recorded in purebred and crossbred cows.
• Effect of calving difficulty on the subsequent reproductive indices were evaluated.
• Pure BS and BF cows can cope with the difficult levels of calving in subtropics.

Calving ease affects the welfare of cow and has economic implications for the farm. The degree of calving difficulty varies from no assistance needed to surgery being required. The aim of this study was to estimate the incidence of calving difficulty and evaluate the effects of calving ease on the subsequent reproductive and production performance of pure Holstein (HO), Brown Swiss (BS) and their F1 crosses (BF) under Egyptian conditions. The pure BS and BF heifers had significantly (P<0.05) higher incidence of calving ease (87.9 and 83.8%, respectively) when compared with pure HO heifers (78.6%). Furthermore, the incidence of calvings of the most severe level was lowest in pure BS heifers. The reproductive function of pure BS and BF cows was not affected by difficult levels of calving, although their subsequent reproductive indices were reduced to some extent at the very difficult calving conditions (category C). In contrast, pure HO cows at very difficult level (category C) had significantly (P<0.05) longer calving interval and days open (474 and 198 d, respectively), compared with those calved without difficulty (396 and 149 d, respectively). Pure HO cows experienced very difficult calvings had decreased Total-MY, 305-MY and Peak-MY at a rate of 34.6, 35.2 and 40.9%, respectively when compared with those calved without difficulty. However, production indicators of pure BS and BF cows were more tolerant with conditions of calving difficulty. In conclusion, pure BS and BF cows can cope with the difficult levels of calving under Egyptian conditions, while pure HO had lower fertility and milk yield parameters under the same conditions.