Feeding selection of sheep and alpaca on puna tussock rangelands grazed previously by cattle

Abstract

Sequential grazing by several livestock species has potential benefits in biodiversity conservation, resource use efficiency, animal productivity and profitability. Our objective was to assess diet composition and nutritional quality for alpacas and sheep in mono grazing and sequential grazing of either species after cattle, on puna tussock rangelands in Peru. Four experimental plots in each of two blocks were randomly assigned to one of four treatments: mono grazing by sheep, mono grazing by alpaca, sequential grazing of cattle followed by sheep, and sequential grazing of cattle followed by alpaca. Simulated diet (hand plucked that mimicked the animal´s foraging) and vegetation samples were collected in the wet and dry seasons. The botanical composition was determined by a macroscopy point technique, diet selection by the Ivlev´s elective index, and diet nutritional quality by routine forage analyses (digestibility, crude protein, and neutral detergent fiber). Both the alpacas and sheep selected less tall tussock grasses and more forbs in the sequential grazing than in mono grazing in both the wet and dry seasons, and more leaf and green biomass in sequential grazing than mono grazing in the dry season. This grazing behavior was reflected in greater avoidance of the tall grasses and higher preference for leaf and green biomass in the sequential grazing than in mono grazing. The differences in diet selection between the different grazing managements resulted in a diet higher in crude protein in sequential grazing than in mono grazing. Sequential grazing of cattle followed by either alpacas or sheep modified the diet selection of the two latter species, improving the nutritional quality of the diet.