The Alpaca Library Catalogue

The inheritance of the two types of fleece, Suri and Huacaya, observed in Alpaca (Lama pacos L.) is still not clearly defined. The objective of this work is to investigate the patter of inheritance of these two phenotypes, throughout 588 Suri x Suri and 2126 Huacaya x Huacaya offspring. The single gene and the three two-phenotype epistatic models were tested in the 19 Suri x Suri segregating families. The single dominant gene hypothesis best fitted our segregation data and could be, therefore, accepted (Gt=20.276, P=0.378). The gene frequency of the recessive Huacaya allele was 0.295, being the frequency of the dominant Suri allele 0.705. The frequency of heterozygotes, estimated in the whole population and among dominant individuals, was 0.416 and 0.455, respectively, with a “carrier” Suri to Huacaya ratio of 4.780. In three Huacaya families, 3 Suri were born, as a result of a new dominant mutation on some germinal lines of Huacaya animals. The direct mutation rate can be estimated at 0.0014. more »

Phenotypic and genetic parameters for young Australian Alpacas are presented and compared with Alpaca reports in the literature, as well as with estimates for South Australian (SA) Merino sheep. The traits studied were greasy and clean fleece weight (GFW and CFW), fibre yield (YLD), mean fibre diameter (FD), coefficient of variation of FD (CVFD), staple length (SL) and live weight (LW). Most mean values fell within those found in the literature, except for YLD, which was greater in our study. YLD, FD, SL and LW were greater than for Merino sheep, whereas the opposite was true for GFW and CFW. The heritability was high (0.37 or greater) for all traits. The estimate for LW fell within the range in the literature, whereas for GFW and SL our values were greater. Relative to those for SA Merino sheep our estimates were greater for GFW, CFW, CVFD and LW, whereas they were lower for the remaining traits, except for SL, which had the same value. Phenotypic correlations from the literature were in broad agreement with ours. Those from SA Merino hoggets, except for some correlations involving YLD and SL, were in remarkable agreement with ours. The practical implications of the findings are discussed. more »

This paper reviews genetics of fibre production and fleece characteristics in small ruminants, Angora rabbit and South American camelids with a special distinction between single-coated (SC) and double-coated (DC) species. Considering the biology of fibre production, there are variations in coat composition and structure, fibre growth pattern and fibre structure and quality between these two main kinds of fibre-producing animals. In SC species, all fibres are nearly similar in dimensions and are produced from individual follicles that have a very long period, essentially permanent, of active growth without a synchronous phase of rest between follicles. In contrast, in DC species the fleece comprises a coarse outer coat and a fine inner coat with variations of coat composition and structure, and fibre growth pattern according to the season with a well-defined duration of fibre growth. Genetic basis of hair growth pattern, coat composition and fibre structure are different between species. In small ruminants, these coat characters are additive and because of several genes whereas in rabbit, several autosomal recessive genes determine fibre growth, coat composition and structure. In alpaca, the fleece type (Suri or Huacaya) is determined by a single dominant gene. This paper also reviews genetic parameters of fibre production traits in Angora goat, Angora rabbit and alpaca in which many aspects of the genetic basis of fibre production are analogous. There are many traits controlling both fibre quality and fibre quantity, and most of these traits tend to be moderately to strongly inherited so that a rapid genetic progress in any traits is possible and indeed has been achieved. However, there are differences in breeding programmes. In DC Angora rabbit, selection for one single trait, the easy measurable total fleece weight has general beneficial effects on fleece quality. However, because of antagonistic relations between qualitative and quantitative traits in SC species, achieving this goal requires a multi-trait selection index approach. Gene mapping studies have recently identified several putative quantitative trait loci and major genes affecting fibre and fleece characteristics in sheep, goat and rabbit are reviewed. The whole genome sequence of sheep and rabbit will be available in the near future and the use of high-density single nucleotide polymorphism chip will allow fine mapping and dissection of the genetic basis of many production traits including fibre production and fleece characteristics. The application of these techniques will thus contribute to improving the efficiency, profitability and sustainability of small ruminant and rabbit fibre production. more »

Four fibre traits (fibre diameter, FD; coefficient of variation of FD, comfort factor; and standard deviation of FD) were jointly analysed with six subjectively scored type traits (fleece density, crimp, lock structure, head, coverage, and balance) in two breeds of Peruvian Altiplano alpaca (Suri, SU; and Huacayo, HU) to ascertain their genetic relationship. A total of 2405 fibre records and 2194 type scores were available for the HU breed whereas these figures were 709 for fibre records and 650 for type scores for the SU breed. Estimated heritabilities for fibre traits were moderate to high, ranging from 0.565 to 0.699 in the SU breed and from 0.255 to 0.417 in the HU breed. Genetic and permanent environmental correlations between fibre related traits were extremely similar across breeds suggesting that these traits are fairly the same. Heritabilities estimated for the type traits tended to be lower than those estimated for the fibre traits particularly in the SU breed (ranging from 0.173 to 0.272). Fibre and type traits were, in general, genetically poorly correlated except for crimp in the HU breed, which had favourable correlations, from moderate to high, for fibre traits. In Altiplano areas in which fibre performance recording could not be implemented, crimp scoring makes it feasible to carry out mass selection in the Huacayo breed and furthermore include rural communities in national or regional selection programmes. more »

An investigation of commercially important alpaca fibre attributes aimed to identify the influence of management and production variables on alpaca fibre and to quantify the relative economic value of fibre production. Fleeces from five farms in southern Australia (n = 1100) were measured using midside samples and standard tests and were assigned a relative economic value based on an analysis of market price data. Greasy fleece (GFW) and saddle weights of Huacayas peaked at 2 years and Suris at 3 years of age and then declined with increases in age until 6 years of age. GFW of Huacaya were not affected by mean fibre diameter (MFD). In Suris, GFW increased with MFD reaching a peak at 29–33 μm. Mean ± S.D. of clean washing yield was 92.0 ± 1.5%. The proportion of the fleece as saddle, neck and skirting components was (mean ± S.E., %): saddle 55.9 ± 0.9, neck 16.3 ± 0.5, skirtings 27.8 ± 0.6. About, 10% of Huacayas had fleeces with MFD < 24.0 μm, while 14% of Suris had fleeces < 24.0 μm. Both Huacayas and Suris had about 50% of fleeces with mean fibre diameter > 29.9 μm. One-third of Huacaya and Suri saddles had 50% of their fibres medullated. For Huacaya and Suri alpaca, the incidence of medullated fibres increased linearly from 10 to 60% by weight as MFD increased from 20 to 36 μm. The ratio of medullated fibre diameter to MFD declined as MFD increased. For Huacaya, there was no change in average staple length as MFD increased. Huacaya alpaca had a greater fibre curvature than Suri alpaca. Data on resistance to compression and staple strength was correlated with other fibre attributes. The price declined by 11% per 1 μm increase in MFD from 22 to 26 μm and by 5% per 1 μm increase between 27 and 34 μm. The total relative economic value increased with increasing GFW and with increasing saddle weight up to 2.5 kg. Total relative economic value declined as MFD increased above 23 μm, increasing live weight above 60 kg and with increasing age above 2 years for Huacaya and 3 years for Suri. The productivity and economic returns from fleece production of Huacaya and Suri breeds was similar. The Australian industry needs to implement commercial mating, shearing and culling strategies to maximise production and returns from animals aged less than 3 years. The main driver of economic value from fleece production was lower MFD of the fleece. more »