Botanical Composition and Nutritional Quality of Alpaca Diets in Two Andean Rangeland Communities

Abstract

Our objectives were to measure alpaca (Lamapacos) diet quality and botanical composition seasonally on 2 high elevation rangesites (bofedal and Altiplano) in the Andes Mountains of Peru. The bofedal site was a perennially green sedge and forb community located at 5,000 m elevation. The Altiplano site, located at 3,190 m, was predominately bunchgrass. We collected diets from freeranging, esophageally fistulated alpacas at each site. Alpaca diets at both sites were highest in grasses during the wet and early dry season. As the dry season progressed, bofedal alpaca diets were comprised largely of sedges and reeds (78%) while Altiplano diets remained predominantly grasses (68%). Forb consumption varied annually between 8 and 29%o of the diet on both sites. Crude protein (CP) in bofedal diets (12.3%) averaged higher than on the Altiplano (10.2%). Values were lowest during August (6.1%) on the Altiplano and in July (8.0%Io) on the bofedal. In vitro organic matter digestibility (IVOMD) of alpaca diets on the bofedal (63%) was similar to the Altiplano site (64%) when averaged for all seasons. IVOMD was lowest during August (49%) at the Altiplano site and in October (50%0) on the bofedal. Low dietary CP and IVOMD during the late dry season (Aug.-Oct.) denote this period as nutritionally critical for both sites. Alpacas are important fiberand meat-producing livestock for highland inhabitants of the Andes mountains of southern Peru and northern Bolivia (Reiner and Bryant 1983). Approximately 2.5 million alpacas graze high-elevation grassland in Peru and Bolivia (Fernandez Baca 1975). Alpacas are physiologically adapted for life at high elevation and are able to graze much of the Andean range where sheep and cattle production is unprofitable. Alpaca grazing sites are primarily chosen in response to forage availability and tradition. Range management in the form of grazing systems or diet supplementation is rare. Little is known about nutritional quality and botanical composition of alpaca diets on the varied range sites they graze. Implementing effective grazing systems or diet supplementation schemes requires this knowledge. We describe the botanical composition and nutritional quality of alpaca diets relative to seasonal forage availability for 2 important rangeland sites (bofedal and Altiplano) in southern Peru. High-elevation rangeland in southern Peru is characterized by 2 major grassland zones: the Altiplano (high plains) of the Lake Titicaca basin (3,100 m elevation) and the mountains surrounding the basin. Mountain rangeland occasionally exceeds 5,800 m. The Altiplano is primarily a zone of sheep production although alpaca numbers are increasing due to a favorable market for alpaca wool. The mountain zone is grazed primarily by alpacas. The wet growing season occurs in November through April in southern Peru. During the rest of the year, there is no precipitation and little forage production. Alpacas grazing in the mountains during the dry season are herded to perennially green, tundra-like Authors are research assistant, Mississippi State University, Department of Wildlife and Fisheries, P.O. Drawer LW, Mississippi State 39762 and associate professor, Department of Range and Wildlife Management, Texas Tech University, Lubbock 79409. This research was carried out as part of the United States Agency for International Development, Title XII, Small Ruminant Collaborative Research Support Program, under Grant DSAN/ XII-G-0049, in collaboration with Instituto Nacional Investigacion y Promocion Agropecuaria, Peru. This is Texas Tech University College of Agricultural Science Publication No. T-9-000. The authors wish to thank Susan Rikert and Timoteo Huisa for laboratory and field assistance. We also thank Universidad Nacional Mayor de San Marcos for their support. Manuscript accepted 27 January 1986. pastures called bofedales. Bofedales are scarce on the Altiplano and are often over-grazed. Physiological differences between alpaca and sheep preclude adapting established sheep management techniques for alpaca. For example, the gestation period for alpacas is almost 1 year (345 days). Females are bred and give birth during January when nutritious forage is available. Alpacas survive the nutritionally stressful dry season while in the late stages of lactation and supporting gestation (Sumar 1983). Weight loss, impaired wool production, and low fertility have been attributed to inadequate dry season nutrition (West 1981).