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  • Impact of Mycotoxins and of a Mycotoxin Deactivator on Alpacas Grazing Perennial Ryegrass Infected with Wild Endophyte (Neotyphodium spp.)

    Liveweight gain, animal health and the effectiveness of a mycotoxin deactivator were studied on an old pasture that contained 61% perennial ryegrass. Sixty-seven percent of the ryegrass population was infected with endophyte (Neotyphodium spp.). The pasture was fenced into two halves and two groups of 28 alpaca male weaners were rotated between the two plots. Nine to 10 Suris and 18–19 Huacayas were allocated to each group. One group was fed a concentrate supplement (100 g/head per day) and the other was fed the same supplement to which was added the toxin deactivator, Mycofix® Plus (5 g/100 g). Mean liveweight gain on the low-quality pasture over late summer and early autumn was not significantly (P > 0.05) different between the groups. For the control group it was 41 g/day but individual rates of gain ranged from 67 to 0 g/day, depending on the severity of signs of perennial ryegrass toxicosis (r = 0.82, P < 0.001). Liveweight gain was independent of neurotoxic signs in the Mycofix® Plus treated group. Ergovaline concentration in perennial ryegrass varied from 0.43 to a peak in early autumn (March) of 1.05 mg/kg. Mean urine lysergol alkaloid concentration peaked in mid-summer (January) at 109 ng/mg creatinine (control group) and was consistently lower in the Mycofix® Plus group, although the difference approached significance (P = 0.06) only in March. Lolitrem B concentration in perennial ryegrass varied from 0.78 to 1.57 mg/kg. Neurotoxic signs in alpacas were observed throughout the study and peaked in early autumn, coinciding with peak lolitrem B concentration; at this time, 84% of alpacas exhibited neurotoxic signs. Over the 145-day study, the Mycofix® Plus treated group exhibited a lower mean rating of perennial ryegrass toxicosis signs (P < 0.05). Variation in liveweight gain and signs of toxicosis were not associated with significant differences in liver enzyme activity. more »
  • Blood Mineral, Trace-Element and Vitamin Concentrations in Huacaya Alpacas and Merino Sheep Grazing the Same Pasture

    We aimed to determine whether the concentration of minerals and trace constituents in blood of Merino sheep and Huacaya alpacas grazing the same pasture differed with species and time of sampling. Blood samples and pasture samples were collected at frequent intervals over a period of 2 years for mineral and trace-nutrient assay. The concentration of the minerals and trace nutrients in the grazed pasture usually met the dietary needs of sheep at maintenance, apart from potassium, sulfur, cobalt and Vitamin E in occasional samples. Restricted maximum likelihood mixed model analysis indicated a significant (P < 0.001) species by month by year interaction for all blood constituents assayed, a significant (P < 0.05) species by coat shade interaction for plasma Vitamin D, E and B12 and a significant (P < 0.001) species by month by Vitamin D interaction for plasma phosphorus concentrations. In general, plasma calcium concentrations were greater in sheep than in alpacas but plasma magnesium concentrations were greater in alpacas than in sheep. There was no consistent difference between the two species in plasma phosphorus concentrations although low values were recorded in individual sheep and alpacas. Plasma Vitamin D concentrations were more responsive to increasing hours of sunlight in alpacas than they were in sheep. Sheep had consistently higher concentrations of plasma copper, zinc and Vitamin B12 and higher concentrations of blood selenium but lower concentrations of plasma selenium and Vitamin A, than did alpacas. No consistent difference was observed between the two species in plasma Vitamin E concentrations. more »
  • Methane Emission by Alpaca and Sheep Fed on Lucerne Hay or Grazed on Pastures of Perennial Ryegrass/White Clover or Birdsfoot Trefoil

    Based on the knowledge that alpaca (Lama pacos) have a lower fractional outflow rate of feed particles (particulate FOR) from their forestomach than sheep (San Martin 1987), the current study measured methane (CH4) production and other digestion parameters in these species in three successive experiments (1, 2 and 3): Experiment 1, lucerne hay fed indoors; Experiment 2, grazed on perennial ryegrass/white clover pasture (PRG/WC); and Experiment 3, grazed on birdsfoot trefoil (Lotus corniculatus) pasture (Lotus). Six male alpaca and six castrated Romney sheep were simultaneously and successively fed on the forages either ad libitum or at generous herbage allowances (grazing). CH4 production (g/day) (using the sulphur hexafluoride tracer technique), voluntary feed intake (VFI), diet quality, and protozoa counts and volatile fatty acid concentrations in samples of forestomach contents were determined. In addition, feed digestibility, energy and nitrogen (N) balances and microbial N supply from the forestomach (using purine derivatives excretion) were measured in Experiment 1. Diets selected by alpaca were of lower quality than those selected by sheep, and the voluntary gross energy intakes (GEI, MJ) per kg of liveweight0·75 were consistently lower (P0·05) in their CH4 yields (% GEI) when fed on lucerne hay (5·1 v. 4·7), but alpaca had a higher CH4 yield when fed on PRG/WC (9·4 v. 7·5, P more »
  • Botanical Composition and Nutritional Quality of Alpaca Diets in Two Andean Rangeland Communities

    Our objectives were to measure alpaca (Lama pacos) diet quality and botanical composition seasonally on 2 high elevation range-sites (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 free-ranging, 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% 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%) 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%) on the bofedal. Low dietary CP and IVOMD during the late dry season (Aug.-Oct.) denote this period as nutritionally critical for both sites. more »
  • Dry Season Forage Selection by Alpacas in Southern Peru

    Two hundred eighty adult female alpacas (Lama pacos) 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: Eleocharis albibracteata, Poa. sp., Calamagrostis heterophylla, C. vicunarum, Alchemilla pinnata, Muhlenbergia fastigiata, and Carex spp. Highly selected, trace species were P. gymnantha, M. peruviana, Stipa brachiphylla, Ranunculus limoselloides, and Trifolium amabile. Festuca dolichophylla 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. dolichophylla 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. more »
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