Fostering the ease of calving: pelvic area assessment in <i>Bunaji</i> and <i>Rahaji</i> cows

Abstract

Pelvic area (P.A.) assessment may be used as management tool to reduce the risks associated with dystocia and foster calving ease. Relationship between cow’s P.A. and age can aid prebreeding culling decisions. This study used 100 Bunaji and 50 Rahaji cows, at slaughter, that were grouped according to age in years thus: Bunaji- <1, 1-2, 2-3, 3-4, Rahaji- 2-3, 3 -5. The anterior-end pelvic inlet dimensions i.e. sacro-pubic and is-iliac, were obtained using tape rule, immediately post slaughter, prior to dressing, and age was estimated by dentition. The Mean±S.Ds of P.A. (cm²) and age for Bunaji groups were 269.6±10.83 and 0.8±40.9, 355.64±33.34 and 1.57±0.28, 453.47±34.59 and 2.94±0.29, 584.86±29.14 and 3.15±0.24, respectively, while for Rahaji were 388.6±57.76 and 2.58±30.36, 425.8±73.6 and 3.69±0.32, respectively. The coefficients of correlation and determination were 0.9935(P<0.01) and 98.8% for Bunaji, and, 0.926(P<0.05) and 89.2% for Rahaji. Regression equations were established thus: P.A.(Bunaji) = 117.79y+170.28, P.A.(Rahaji) = 2.1y+428.4 (y= age in years). Our findings showed that P.A. increases with age and suggests that Bunajis should have greater calving ease.