Background: Angoni cattle play an important socio-economic role in Mozambique. The age at first mating (AFM) and season of dam birth (SB) are crucial factors that must be observed to maximize reproductive efficiency and improve the productivity of beef cattle farms.

Objectives: This study aimed to evaluate the effects of AFM and SB on age at first calving (AFC), birth weight (BW) of calves, and calving interval (CI) in Angoni cattle raised under tropical conditions.

Methods: A total of 1,418 records collected over 25 years (1995–2020) at the Angonia Research Station (EZA) were used for analysis. The inclusion criteria comprised: female Angoni cattle with complete reproductive records, known dates of first mating, calving, and birth weights of offspring. Animals with incomplete records, unknown parentage, or those that experienced disease outbreaks or severe nutritional deficiencies during reproductive stages were excluded from the analysis. Data were processed using R version 4.3.2. The effects of AFM and SB on reproductive and productive traits were analyzed using the Kruskal-Wallis test, followed by Dunn’s test for pairwise comparisons in cases of significance. Simple linear regression (least squares method) was applied to assess relationships among AFM, BW, and AFC.

Results: Results showed that AFM significantly influenced BW, AFC, and CI (p < 0.05). SB significantly affected BW and CI (p < 0.05), but not AFC (p > 0.05).

Conclusion: In conclusion, both AFM and SB are key variables influencing reproductive and productive traits in Mozambican Angoni cattle. Greater attention to these factors in herd management practices is recommended to optimize performance in tropical production systems.

Key Words: Age at mating; Season of birth; Angoni Cattle; Mozambique.