Association between rump score and course of parturition in cows

Abstract. Analysis was made of the effect of rump angle and rump width, assessed using a 9-point scoring system, on the course of parturition in cows representing the active population in Pomorze and Kujawy regions of Poland. GLM and FREQ procedures of the SAS package were used in the statistical calculations. The most frequent score for rump angle was 5 (44 % of all scores) and that for rump width was 6 (30 % of all scores). Human intervention was required for 7 % of calvings, of which dystocia (surgical treatment, injury to the cow or calf, embryotomy) occurred in 0.19 % and caesarean section was performed in 0.11 % of the cases. The course of parturition was affected to a greater extent by rump angle (P<0.01) than by rump width. The largest proportion of difficult parturitions (over 8 %) was noted when the cows that calved received rump angle scores of 1–2 or 8–9 points, while raised rump (1–2 points) increased the proportion of dystocia and caesarean sections. The average score for rump angle in the case of unassisted and easy calvings was 4.95 and 5.02 points, respectively (corresponding to the most desirable, slightly sloping rump), and 4.6 points in the case of dystocia and caesarean sections. A much higher proportion of difficult parturitions and dystocia was also found in cows with too narrow a rump scored as 1–2 points and in those with a wide rump (8–9 points).