These projects were conducted to determine the digestibility of forage diets with differing CP levels in llamas and alpacas. The Utah study was designed to compare llama and alpaca nutritional parameters to determine if nutritional recommendations for llamas can be directly extrapolated to alpacas. The first study evaluated the effects of forage quality on blood metabolites and nitrogen balance in mature, intact male llamas (n = 4, 36 ± 4.4 months, 87 ± 17 kg) at high altitude in Letanias, Bolivia (4,267 m = aprox.14,000 ft above sea level). A second experiment was conducted with eight adult gelded camelids (n = 8; 4 llamas, 24-36 months, 90 ± 10.7 kg; 4 alpacas, 24-36 months, 50 ± 4 kg) at Brigham Young University, Provo, UT (altitude 1370 m). Animals were randomly fed barley hay (B) and 80% barley/20% alfalfa hay (BA). A fresh cut grass pasture (P) was included as the third forage for Bolivian llamas. Animals were housed in metabolism crates and diets were fed for a 7 d adjustment period followed by a 5 d collection period. Feed, feed refusal, feces and urine were collected, dried and N content determined by combustion analysis. Venous blood samples were collected on d 12 at 30 min intervals over a 6 h period. Plasma was harvested and analyzed for electrolytes (Na, K, Cl, Ca, Ca++, P, Mg) and metabolites (glucose, non- esterified fatty acids (NEFAs), urea N, creatinine, albumin, total protein (TPP), osmolality (Osm)). Llamas and alpacas demonstrated differences with respect to nitrogen metabolism when consuming forage diets with differing protein concentration. Llamas showed a N maintenance requirement of 0.75 g crude N/ W0.75. Using the standard CP to digestible protein (DP) conversion factor of 0.8, llamas required 0.60 digestible N/W0.75. When consuming the same high protein barley alfalfa diet, llamas had a much greater increase in N retention than alpacas. These species differences indicate that alpacas have a higher N requirement to meet metabolic needs, and extrapolations with respect to nitrogen requirements and balance are not valid between llamas and alpacas. In the Bolivian llama trial, locally grown and harvested hycrested and Siberian wheat grass pasture (P), barley (B), and barley80%/alfalfa20% (BA) hays were fed. The Bolivian llamas were in negative N balance when fed the B and P diets. Dry matter digestibility was greater with the B and BA than P forage, and N digestibility was significantly higher with BA than either the B or P forages. Nitrogen maintenance requirement for Bolivian llamas at 4,267 m was 0.58 compared to 0.75 g crude N/W0.75 for Utah llamas, an increased digestive efficiency and a lower N maintenance requirement at higher altitude.



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Life Sciences; Biology



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llama, alpaca, nitrogen metabolism, blood metabolites, altitude



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Biology Commons