[en] Data on the reproductive performance of Zebu and crossbred cows raised on smallholder farms were analyzed for a total of 142 calvings. Gynaeacological examinations were carried out at 7 to 10 days intervals starting at 10 to 15 days after calving until pregnancy was confirmed by rectal palpation of the conceptus. Nutritional status of cows was assessed by body condition scoring (BCS) at calving. Ovarian activity was monitored using milk progesterone (P₄) concentrations determined by Radioimmunoassay (RIA). Overall mean (±sd) interval from calving to complete uterine involution, first ovulation and conception were 29 ± 7.4, 104 ± 26.2 and 171 ± 67.1 days, respectively. Uterine involution occurred significantly (P < 0.05) earlier in the Zebu than in the crossbred cows, and in primipara then in pluripara cows. Season of calving and BCS at calving did not influence the interval to uterine involution. Both intervals from calving to first ovulation and to conception were significantly (P < 0.05) affected by genotype and BCS, but not by parity and season of calving. Crossbred cows resumed ovarian activity and conceived significantly earlier than the Zebu cows. Cows with BCS of equal or above 4 at calving had significantly (P < 0.05) shorter intervals form calving to first ovulation and to conception than cows with BCS of less than 4. Milk progesterone profiles revealed that abnormal ovarian activities (acyclic, erratic and cessation of cyclic activity) occurred in 62 and 49% of the Zebu and crossbred cow, respectively. Pregnancy rates were 48 and 60% in the Zebu and crossbred cows. It was concluded that crossbred cows had better post-partum reproductive performance than the Zebu and good body condition at calving improved post-partum reproductive performance in both genotypes of animals. However, establishment of the appropriate level of supplementary feeding for optimum postpartum reproductive performance remains to be investigated. (author). 14 refs, 3 figs, 2 tabs