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The objective of this experiment was to assess the reproductive and productive performance of Nguni cattle distributed among 11 farms in four regions of South Africa. Only data of registered Appendix A to Stud Proper Nguni animals from the Agricultural Research Council of South Africa’s database were used. Data were collected from 2061 dams and 3285 calves between 1990 and 2009. Overall means for age at first calving (AFC) and calving intervals (CI) were 33.79 ± 4.90 months and 400.29 ± 78.70 days, respectively. Dry season-born heifers had lower AFC than wet season-born heifers. Dry seasons 4 and wet seasons 1 had lower CI than seasons 2 and 3, indicating that conceptions take place between December and May. Average growth weights of calves were 24.87 ± 3.13, 151.91 ± 21.09, 169.25 ± 23.68 and 237.96 ± 27.34 kg at birth (BW), weaning (WW), 12 months (YW) and 18 months of age, respectively. BW was higher in dry seasons 4 and wet seasons 1; WW and YW were higher in dry than in wet seasons. This is the first study demonstrating that performance of Nguni cattle is influenced by ecological regions of the dam’s origin, year-season of birth/calving, breeder’s management, parity and herdbook status, confirming that environment-genotype interactions influence the performance of Nguni cattle in southern Africa. This stimulated a follow-up study on the use of geographic information systems to specifically identify factors influencing the reproductive and productive performance of Nguni cattle in southern Africa.

The objective of this study was to assess the reproductive performance of two Nguni ecotypes (Nguni and Landim) raised in a subtropical environment to enhance strategies for livestock development and restocking programmes within the southern African region. Reproduction data collected between 1996 and 2009 from 365 cows of the Landim and Nguni ecotypes were analysed. From the results, ecotype, place of birth, year and season of birth/calving had significant effects on age at first calving (AFC) and calving interval (CI). Overall means for AFC and CI were 1,071 ± 166 days and 432 ± 85 days, respectively, while average calving rate was 88.0 ± 4.7%. Heifers born in the dry season had lower AFC than heifers born in the wet season. Heifers born at Impaputo Breeding Center were the youngest at first calving, followed by the South African born ones. Heifers of the Landim ecotype also calved younger than heifers of the Nguni ecotype. CI was shorter in wet seasons (main breeding seasons) than in dry seasons. Interaction between ecotype and year-season (p < 0.005) showed that, in wet and dry seasons, Nguni cows had shorter CI than the Landim. This study demonstrates for the first time a possible genotype-by-environment interaction between Nguni ecotypes. This might aid future cattle development and restocking programmes in southern Africa taking into consideration the adaptation of indigenous genotypes and climate change.