A retrospective study on reproduction in alpacas (<i>Lama pacos</i>) and cria growth after birth in Japan: the relationship between parturition and climate conditions

Alpaca breeding is affected by environmental factors and management on farms. However, this has not yet been examined in detail in Japan. Therefore, we herein investigated the relationship between parturition in 65 alpacas on a Japanese farm and environmental factors. Parturition was observed every month, except for December, and the survival rate of crias was 81.5% (53/65). The gestation length was significantly longer for surviving crias than for dead crias (352.3 ± 17.9 vs. 338.7 ± 20.8 days, P<0.05). Birth weight was higher in surviving crias than in dead crias (6.7 ± 1.1 vs. 5.0 ± 1.0 kg, P<0.05). An analysis of the relationship between parturition and climate revealed a correlation between low ambient temperature one month before parturition and higher birth weights in surviving crias.