Body weight increase of alpaca (Lama pacos) from birth to 6 month old in four regions of Chile

Abstract

Body weight in alpacas from birth up to 6 month of age was studied in 4 different regions of Chile. Animals were located in the Andean high plateau (I region) (n=37); Magallanes (XII region) (n= 12); coastal dryland (VI region) (n=20, and semiarid interior valley nearby the Andean mountains (metropolitan region) (n=32). Each animal was weighed at birth and then once a month. No statistical differences in body weight by sex were observed in any group. All newborns double their birth weight at the second month of age, except in Magallanes where it took them 3 months. At six month of age, body weight in the subjects at the Andean high plateau represent 54.64% of mature weight and 179.26% of birth weight being the higher values obtained. The lower values correspond to the subjects in Magallanes 31.41% and 123.75% respectively. The best average weight gains were observed during the first month in all groups. After the fifth month animals continued to grow but with a declining rate of growth as compared to the first month. Again, the slower declining was observed in alpacas in the Andean high plateau and the higher declining was seen in the Magallanes and coastal dryland alpacas. Equations describing weight as a function of age monthly growing alpacas for each region were developed.