Authors:

Introduction:
The alpaca (Lama pacos) is commercially the most important fibre producer of the New World camelidae family. Two breeds of alpaca are recognized; the huacaya and the suri. Our study deals exclusively with the more populous, crimpy-fleeced huacayas. Alpacas are indigenous to the Andean highlands of South America. Of the approximately 3.5 million in the world, most (~ 3.0 million) are in Peru with the majority of the remainder being in Chile and Bolivia. The populations in South America have been fairly static due in part to the lower, more productive altitudes (2600 to 3400 m) being used for sheep and cattle production. In contrast, the population of alpacas in North America has risen from less than 400 in 1984 to around 60,000 today. South American alpacas produce most of the world camelid family’s total production of fibre. Until about 20 years ago, alpacas were considered to be specifically adapted to their native environment. However, successful introductions of the species to Australia, Canada, England, France, New Zealand, the United States, to name but a few countries, have shown that alpacas are more versatile than previously recognized. Husbandry practices, and to a lesser extent production traits, have been documented in their native South American environment (approximate latitude, 5 to 20ºS, approximate longitude, 70 to 80ºW, altitude range, 2500 to 5000 m). Now that alpacas are being raised in North America as far south as Texas and certainly as far north as Alberta and Alaska, a need has arisen to develop management and diet recommendations for these animals under local conditions. Further, many owners and breeders are anxious to learn the effects of age, location, nutrition, and season on growth, reproduction, and fleece and fibre properties. This study was designed to answer some of these questions for environments represented by that of Olds, Alberta (latitude, 51° 46' N; longitude, 114°, 5' W; altitude, 1035 m) and San Angelo, Texas (latitude, 31°, 26' N; longitude, 100°, 27' W; altitude, 563 m). The study we embarked upon and are about to describe is just a part of a larger project in which Custom Woolen Mills, Ltd. of Carstairs, AB, Canada, are developing technology to produce high quality yarns and finished products using all grades of domestically produced alpaca. This research was made possible by a grant from the National Research Council of Canada through their Industrial Research Assistance Program, as well as contributions from the two academic institutions and a private alpaca breeder.


Specific Objectives:
Determine the effects of age, location, and nutrition, on body weight, fibre production, and quality characteristics of penned alpaca males. Concurrently, provide Custom Woolen Mills with small quantities of fully characterized fibre for their textile development work.

Materials and Methods:
Management
Thirty-six alpaca males (yearlings representing 7 sires) were donated for this study by R&R Alpacas Ltd., Olds, Alberta, Canada. In May 2002, 18 of the alpacas were re-located to the Texas Agricultural Experiment Station’s research facilities in San Angelo while the remainder were moved to Olds College. The animals were sheared (yearling fleece) soon after arrival and for the next 4 months were group-fed free choice with local hays (~2 kg/hd/d) and a commercially available ration (225 g/d) designed for growing alpacas. Body and yearling fleece weights were used to assign alpacas to three equivalent groups (6 animals per treatment, 3 animals per rep, 2 reps) at each research location and in September, 2002, the animals were penned (3 animals per pen, dimensions 3.7 m X 18.3 m) and rations at both locations were formulated to provide the same complete diet when fed in equal amounts with a locally available hay. In Texas, the major roughage component of the diet was sorghum hay. The mixed ration contained sorghum grain, alfalfa meal, peanut hulls, soybean meal, ammonium chloride, vitamins, minerals, and a coccidiostat. The primary roughage source in Canada was Timothy hay. The mixed ration contained oat hulls, wheat mill run, alfalfa, light screenings, ammonium chloride, vitamins, minerals, and a coccidiostat. The actual complete diet (50% hay, 50% ration) contained 13% crude protein, 2% crude fat, 20% crude fiber (28% acid detergent fibers, 43% neutral detergent fibers) and 58.5% TDN. Animals were monitored monthly for weight and body condition (body condition score, 1-5; 1=excessively thin, 5=obese). The amounts fed were adjusted over a 7-month period to produce monthly gains of 3% of body weight while maintaining body condition scores of 3 or higher. Fleeces were shorn again in April, 2003, and the nutrition treatments were immediately imposed. For the next year, one treatment group was fed at the level that had been established to produce 3% gain per month (i.e. 1.23% of bodyweight of mixed ration and 1.23% hay). The second group was fed 10% less (hay and ration) and a third treatment group received 20% less. Animals were weighed and assessed for body condition monthly. Diets were adjusted after each monthly weighing, and fleeces were shorn in May, 2004, and characterized once more.
Sampling and Shearing
A mid-side sample (~ 5 x 5 cm) was removed from each animal before shearing. The following fleece portions were shorn, weighed, packaged, and measured separately: short leg, long leg, butt, neck, and saddle (see Figure 1). Fleece portions from both sets of animals were tested at the Wool and Mohair Research Lab in Texas and most traits were also measured on the Alberta fleeces at the Natural Fibre Centre in Olds.
Side sample and fleece testing
The side samples were tested using an OFDA2000 instrument that measures average fibre diameter, standard deviation (SD) and coefficient of variation (CV) of fibre diameter, average fibre curvature and SD and CV of fibre curvature, comfort factor and average staple length. This instrument also constructs an “along-fibre profile” of average fibre diameter so that changes throughout the year from tip to base are fully documented with this single test.
The following sub-sampling and testing procedures were conducted on the five major portions of each fleece. First, the individual fleece portions were weighed and sub-sampled for staple length and strength testing. Raw and clean fleece weights and staple length measurements were adjusted to a 365 day growth period. Each portion was core sampled (2 x 25g raw cores) and these samples were used to obtain “clean alpaca fibre present” and “vegetable matter present” and subsequently average fibre diameter (SD and CV), average fibre curvature (SD and CV), comfort factor, spinning fineness, along-fibre average fibre diameter (SD and CV), total medullation, flat fibres, objectionable fibres, and average fibre diameter (SD and CV) of the medullated fibres using OFDA 100 instrument (Figure 2). The medullated fibre characteristics of only the white, cream, and light fawn fleeces could be quantified with the OFDA 100. The staple length, (SD and CV) were measured and calculated using 20 staples per fleece portion. The staple strength (SD and CV), and position of break were also measured on 20 staples using an Agritest Staple Breaker. A sub-sample of the scoured cores was carded and then measured for resistance to compression using an Agritest Resistance to Compression instrument.

Results and statistical analysis:
The effects of age (confounded with year), location, and nutrition treatments and their interactions on all measured traits were established using the GLM procedure of SAS. The experiment at the Canadian location was concluded in May, 2004. The Texas portion will continue until May, 2005, after which one more set of fleeces will be analyzed. Though we are still in the process of analyzing data, we are in a position to share some of our major findings. Space does not permit us to report detailed results here. However, the whole study will be reported in detail in the technical literature at a later date.
Age effects
Table 1 summarizes the effects of age on body weight and some of the major fleece and fibre characteristics for the first three years of these male alpacas’ lives. No real surprises. The animals became heavier and grew progressively more and coarser fibre that contained higher proportions of medullated fibres. Recall that while the third fleeces were being grown, all animals were on restricted feed (designed to produce specific, moderate gains) so body weights and fleece weights are not expected to be optimal. A measure of fibre production efficiency, clean fibre produced per unit of body weight, actually decreased as the animals aged. This may be surprising to some but it is fairly common in other fibre producing species. Although clean yield of the second year fleeces is higher than the other two years, this is more likely an effect of year (confounded with age) and not a true age effect. Fibre curvature (a direct measure of crimp in the fully relaxed fibres) decreased slightly as the fibres coarsened. Note that these levels of fibre curvature, though typical for alpaca, are very low compared to wool from fine-wool sheep, for example. Staple length in the first (or cria) fleece was significantly longer than that in the second and third fleeces. This is not an unusual phenomenon in alpacas. Resistance to compression followed the reverse trend, being mainly influenced by increasing fibre diameter, in this particular case. Staple strength also increased with age and even at the lowest level (first fleeces) it is well above the minimum required for efficient textile processing (~35 N/ktex). (Insert Table 1 here).

Effects of location
We designed the diets and the treatments in such a way that the animals maintained at both locations would gain weight at a similar rate, that being 3% per month for the Treatment 1 animals with animals in Treatments 2 and 3 gaining at slower rates. In fact, gains across all three treatments in Texas in the third year of the study averaged 2.1% per month while those in Alberta averaged 2.8% per month. As explained earlier, the diets fed to the animals at the two locations were very similar in terms of gross chemical composition (% crude protein, % crude fiber, etc.) but differed in terms of actual components and therefore specific proteins, etc. Thus, it is unclear at this point whether the higher rate of gain observed in Alberta was an effect of location, diet, or both.
Table 2 summarizes the body weight and fleece characteristics for animals at the two study locations. At the end of their third year, alpacas in Alberta were 13 kg heavier than their contemporaries in Texas. The Alberta group produced more fibre (~13 % clean) but fibre production efficiency was similar in both locations (~35g clean fiber per kg body weight). Fibre produced by the Alberta alpacas was coarser (~2.5 microns), longer (1.3 cm), slightly weaker (7.0 N/ktex), and had higher resistance to compression (1.5 kPa) than the Texas produced fibre. Clean yield, fibre curvature, and total medullation were not different between locations. (Insert Table 2 here)

Effects of nutrition
These effects are summarized in Table 3 and are potentially the most interesting. Although arithmetic differences in body weight are present among treatments, the differences were not significant (either overall, data shown, or within location, data not shown). In contrast, fibre production did respond in a positive and significant manner to intake. Treatment 1 animals produced 20% more fibre (clean) than Treatment 3 alpacas that received 20% less ration and hay. Furthermore, fibre production efficiency declined with declining intake, with Treatment 1 animals producing fibre at a rate 14% higher than the alpacas in Treatment 3. Normally, one would expect greater fibre production to be accompanied with higher fibre diameters and/or longer staple lengths. Arithmetically, fibre diameter follows the logical pattern but the differences are not significant. There is no indication whatsoever that staple length was affected, so we are led to the conclusion that the increased production is most likely a result of increased fibre diameter. Another explanation could involve proportion of active follicles in any particular treatment group but having no follicle data, we would only be able to speculate.
At this point, we should emphasize that most of the data presented were obtained from the saddle portion of the fleeces (fleece weights and fibre production per unit of body weight being the exceptions). To obtain a complete picture, the proportions and properties of all the other fleece portions (neck, butt, long leg, short leg) will also have to be accounted for. Unfortunately, this is beyond the scope of this preliminary report but as mentioned previously, a complete report will be forthcoming soon. (Insert Table 3 here).

Variability in traits
Genetic improvement for a particular trait can only be achieved if heritability and variability exist for that trait. An additional outcome of this experiment, in which we have measured many traits on numerous alpaca males over a three-year period, is that we have been able to document the variabilities in each trait. When comparing variabilities of traits having different mean values, the coefficient of variation (CV) is the most useful statistic because it is a measure of variability that is independent of the mean. Table 4 lists the CV’s for some of the major traits measured during our experiment. With the exception of staple length, it can be seen that most of the CV’s are quite high and the CV for total medullation is very high. (Insert Table 4 here)

Conclusions:
Effects of age, location, and nutrition have been reported for two groups of young male alpacas maintained under similar conditions in Alberta and Texas. Changes due to increasing age (one through 3 years) followed the expected pattern. As the alpacas aged and grew larger, fleece weight, fibre diameter, staple strength, resistance to compression, and proportion of medullated fibres all increased. In contrast, fibre production per unit of body weight, fibre curvature, and staple length showed declines. Clean yield was not affected.
Effects attributable to location may be complicated by different diets but at this point our data indicates that when fed very similar diets, animals grew faster at the northern location and attained significantly higher body weights. These larger animals produced more fibre that was coarser and longer than their contemporaries in Texas.
Finally, young alpaca males fed to gain at modest rates (2-3% increase in body weight per month) produced more fibre that tended to be slightly coarser than animals that received 20% less food. In all other measured traits, fleeces produced in the three nutrition treatments were very similar.





















Table 1. Effects of age on body weight, fiber production, and fiber properties of alpaca males
Age
1 2 3
Body weight, kg 40.0c 58.7b 76.5a
Whole fleece
Grease fleece weight, g 2438b 2452b 2938a
Clean fleece weight, g 2205b 2334b 2662a
Clean fiber / unit of body weight, g/kg 56.6a 40.1b 35.2c
Saddle only
Clean alpaca fiber present, % 90.3a 95.5b 89.9a
Average fiber diameter, microns 22.7c 25.4b 28.5a
Average fiber curvature, deg/mm 37.0a 36.5a 33.1b
Total medullation, fibers per 10,000 1338b 1553b 2373a
Average staple length, cm 16.3a 11.8b 11.0b
Average staple strength, N/ktex 54.8c 81.3a 71.5b
Resistance to compression, kPa 4.8c 5.2b 5.7a
a,b,c Within a row, means that have different superscript letters differ, P < 0.05




Table 2. Effects of location on body weight, fiber production, and fiber properties of alpaca males
Location (year 3)
Alberta Texas
Body weight, kg 82.6a 69.4b
Whole fleece
Grease fleece weight, g 3125a 2740b
Clean fleece weight, g 2817a 2500b
Clean fiber / unit of body weight, g/kg 34.6 36.3
Saddle only
Clean alpaca fiber present, % 89.1 90.5
Average fiber diameter, microns 29.7a 27.0b
Average fiber curvature, deg/mm 34.7 31.7
Total medullation, fibers per 10,000 2290 2191
Average staple length, cm 11.7a 10.4b
Average staple strength, N/ktex 68.1b 75.1a
Resistance to compression, kPa 6.4a 4.9b
a,b,c Within a row, means that have different superscript letters differ, P < 0.05



Table 3. Effects of nutrition on body weight, fiber production, and fiber properties of alpaca males
Nutrition treatment (year 3)
1 2 3
Body weight, kg 77.3 77.7 73.1
Whole fleece
Grease fleece weight, g 3234a 2927ab 2637b
Clean fleece weight, g 2895a 2668ab 2410b
Clean fiber / unit of body weight, g/kg 37.7a 35.7ab 32.9b
Saddle only
Clean alpaca fiber present, % 88.6 90.1 90.7
Average fiber diameter, microns 28.8 28.5 27.9
Average fiber curvature, deg/mm 32.2 32.6 34.9
Total medullation, fibers per 10,000 2530 2814 1868
Average staple length, cm 11.0 10.9 11.2
Average staple strength, N/ktex 72.2 71.8 70.7
Resistance to compression, kPa 5.8 5.5 5.7
a,b,c Within a row, means that have different superscript letters differ, P < 0.05



Table 4. Variability in traits measured on three-year-old alpaca males

Mean SD CV
Body weight, kg 76.3 12.4 16.3
Grease fleece weight, g 2910 533 18.3
Clean fleece weight, g 2641 462 17.5
Clean fiber / unit of body weight, g/kg 35.4 6.2 17.5
Clean alpaca fiber present, % 89.9 2.9 3.2
Average fiber diameter, microns 28.5 3.7 13.0
Average fiber curvature, deg/mm 33.2 6.6 19.9
Total medullation, fibers per 10,000 2262 1200 53.1
Average staple length, cm 11.1 1.41 12.7
Average staple strength, N/ktex 71.4 13.4 18.8
Resistance to compression, kPa 5.7 1.1 19.3