Prevalence of visible Sarcocystis aucheniae macrocysts and their association with productive traits in alpacas (Vicugna pacos).

Alpaca farming is one of the main livestock activities in the high Andean regions of Peru, where Sarcocystis aucheniae infection causes economic losses because carcasses containing visible macrocysts are condemned or downgraded during meat inspection. The objective of this study was to estimate the prevalence of visible S. aucheniae macrocysts in alpacas slaughtered at the municipal abattoir of Macusani, Puno Region, Peru, and to evaluate their association with sex, age, live weight, carcass weight, and carcass yield. The methodology included the visual inspection of 1,361 alpaca carcasses following FAO guidelines, with particular attention to anatomical sites commonly affected by macrocysts (the cervical and intercostal muscles). Animals were classified as positive when at least one visible macrocyst was detected. The results showed that, overall, the prevalence of visible S. aucheniae macrocysts was 30.1%, with no significant differences according to sex or age (p > 0.05). Likewise, no statistically significant differences were observed between macrocyst-positive and macrocyst-negative alpacas regarding live weight, carcass weight, or carcass yield (p > 0.05). In conclusion, in the population evaluated, the presence of visible S. aucheniae macrocysts was not associated with the productive traits assessed at slaughter. Because infection intensity and microscopic infections were not evaluated, further studies incorporating complementary diagnostic methods are warranted to better understand the relationship between S. aucheniae infection and productive performance.