Tag: "fiber"

  • Twelve adult male alpacas were given either 0·67 (low) or 2·0 (high) × assumed maintenance requirements for a period of 6 weeks after which time each was transferred to the alternative level of nutrition for a further 6 weeks. Fibre samples were taken from two 10-cm2 areas on the mid-side position of each animal at 2, 6, 8 and 12 weeks, and measurements of fibre weight, yield (clean fibre weight/raw fibre weight), fibre diameter and fibre length made on the samples collected at weeks 6 and 12. The higher level of feeding resulted in higher clean fibre weight (low = 0·42 (s.e. 0·03); high = 0·53 (s.e. 0·04)mg/cm2 per day, P < 0·001) and fibre growth rate (low = 186 (s.e. 10); high = 223 (s.e. 14) yon/day, P < 0·05). Changes in yield (low = 0·917 (s.e. 0·006); high = 0·929 (s.e. 0·009)) and mean fibre diameter (low = 31·4 (s.e. 1·9); high = 32·1 (s.e. 1.6) \xm) were not statistically significant. Calculations showed that the increased weight of fibre attributed to the higher level of nutrition could be explained in terms of the observed increases in fibre-length and diameter but that, unlike the sheep in which the ratio fibre length: diameter remains relatively constant under varying nutritional regimes, the effect of nutrition in the alpaca has a proportionally larger effect on fibre length than on fibre diameter. more »
  • For those seeking a short answer: no. There is no significant difference in the results of measurements for micron or CV made on midside fleece samples between different types of machines. But the answer can be made longer. Curvature, when measured using the same samples, showed significant variations between optical and laser methodology. And optical methods of measurement proved less reliable when trying to assess whole fleeces using grid samples, due largely to the limitations of sampling. To better understand the discussion, one must first understand the different methods used for measuring fibre, and their application in different types of testing machines. more »
  • The accurate and objective measurement of various characteristics of natural fibre is known as “fibre metrology”. Measurements are useful in describing the fleece characteristics of any one animal, and can be used to compare the fibre characteristics of animals within the same herd, animals in different herds, or of the same animal at different times. They can be used to compare the progeny of one sire with the progeny of another to assist in formulating breeding strategies. They are used when fleece is sold by description, and processors may use them to predict the performance of pooled fibre during processing. Care needs to be exercised, however, in making these comparisons, as there are many non-genetic factors which may influence these measurements. Before comparing the characteristics of two fleeces, one needs to take into account the influence of such factors as the sex, age, nutrition, colour, and general health of the alpacas from which the fleeces were taken, the climate in which the fleeces were grown, and whether or not a female was lactating, or a male working as a stud sire. Other considerations should include the length of the fibre sampled, the site from which the fibre was sampled, and the technique used to measure the fibre. more »
  • While many alpaca breeders have incorporated objective fibre measurement into their herd management strategies, ‘Fibre Growth Profiles’ are becoming popular for monitoring pre and post natal nutrition, particularly during the critical period of secondary follicle development in unborn crias. ‘Fibre Growth Profiles’ are linear graphs depicting variation in diameter along the fibres. This allows alpaca breeders to track nutritional intake of both the pregnant female and the cria in order to manage the development of secondary follicles, and thereby maximise potential for fibre density, fleece weight and fibre diameter. more »
  • When I first became involved with fibre testing alpacas over 15 years ago, about the only figure on alpaca fibre test reports that received any interest was the average fibre diameter (microns). Thankfully, SD is now co-starring alongside micron, as breeders appreciate the need to reduce fibre variability when breeding towards quality fleeces. Most alpaca fibre testing these days is carried out using OFDA2000 fibre testing equipment. OFDA2000 equipment measures the full length of the fibre sample. It can measure fibre samples after the samples are ‘scoured’ or cleaned of lanolin, seeds, grass etc, or it can be used to test raw fibre samples using capabilities to offset the presence of impurities on the fibres. more »