Dry Season Forage Selection by Alpaca [Lama pacos] in Southern Peru

Abstract

Two hundred eighty adult female alpacas (Lamapacos) and 200 tui alpacas (young alpacas 3-7 months of age) were grazed on a Festuca-Calamagrostis association at the South American Camelids Research Station, La Raya, Peru, during the dry season and early wet season of 1981 (June-December). Vegetation was sampled monthly during this period for herbage yield by species. Fecal material from both adult female alpaca and tui alpaca was collected monthly for microhistological analyses of food habits. Alpacas were primarily grazers rather than forb eaters during the dry season and early wet period of 1981. Forage classes consumed were different for adult and tui alpaca. Tui alpaca consumed more grass-like plants and forbs than adults during the driest months. Diet indices revealed the following as highly selected, common forage species: Ekharis at%ibracteata, Poa. sp., Cahunagrostis heterophyk, C. vicunarum, AIchemiUa pinnata, Muhtenbergia f&igiata, and Carex spp. Highly selected, trace species were P. gymnontha, M. peruviana, Stipa brachiphylla, Ranunculus lbnosellokies, and TrVolium amabile. Festuca dohkhophylla had been considered by range managers as highly preferred species overall. However, because it was the most abundant species (73% of the total forage yield), F. dolichophyllk had a low selection index during the dry season. Alpacas consumed remarkable quantities of grass seeds (up to 20% of the diet) during the driest months of the year, apparently compensating for low quality forage. The Andes of Peru comprise about 22 million ha of rangeland and support more than 50% of the domestic livestock in Peru (San Juan de Chuquibambilla 198 1). The “Altiplano” or highland plateau accounts for 7 million ha. Large-scale cultivation in the Altiplano is not feasible and economy primarily is dependent upon herding by local pastoralists. There are 4 species of New World Camelids: the alpaca (Luma paces). the llama (L. glama), the vicuna (Vicugna vicugna), and the guanaco (I!.. guanicoe) (Reiner and Bryant 1983). The 2 former species are domesticated and the latter 2 are wild. The entire population of these mammals is distributed in the Andes of Peru, Bolivia, Chile, and Argentina. Most alpacas and llamas are in Peru and Bolivia, a few are in Chile, but practically none occur in Argentina. The alpaca is a dual purpose animal because it produces high quality fiber that is exported, and meat that is needed by a growing population. Because of current husbandry practices, rangelands are severely overgrazed (Holgado et al. 1979). Also, poor grazing practices are confounded with the seasonal distribution of precipitation. About 80% of the rainfall comes during the wet season