Alpaca World Magazine Summer 2005 - Classical MileEnd Alpacas

2500 to 5000 m). Now that alpacasare being raised in North America asfar south as Texas and certainly as farnorth as Alberta and Alaska, a need hasarisen to develop management and dietrecommendations for these animalsunder local conditions. Further, manyowners and breeders are anxious to learnthe effects of age, location, nutrition,and season on growth, reproduction, andfl eece and fi bre properties. This studywas designed to answer some of thesequestions for environments representedby that of Olds, Alberta (latitude, 51° 46’N; longitude, 114°, 5’ W; altitude, 1035m) and San Angelo, Texas (latitude, 31°,26’ N; longitude, 100°, 27’ W; altitude,563 m). The study we embarked uponand are about to describe is just a part ofa larger project in which Custom WoolenMills, Ltd. of Carstairs, AB, Canada, aredeveloping technology to produce highquality yarns and fi nished products usingall grades of domestically producedalpaca. This research was made possibleby a grant from the National ResearchCouncil of Canada through their IndustrialResearch Assistance Program, as wellas contributions from the two academicinstitutions and a private alpaca breeder.Specifi c ObjectivesDetermine the effects of age, location,and nutrition, on body weight, fi breproduction, and quality characteristicsof penned alpaca males. Concurrently,provide Custom Woolen Mills with smallquantities of fully characterised fi bre fortheir textile development work.Materials andMethodsManagementThirty-six alpaca males (yearlingsrepresenting 7 sires) were donated forthis study by R&R Alpacas Ltd., Olds,Alberta, Canada. In May 2002, 18 ofthe alpacas were re-located to theTexas Agricultural Experiment Station’sresearch facilities in San Angelo while theremainder were moved to Olds College.The animals were sheared (yearlingfl eece) soon after arrival and for the next4 months were group-fed free choicewith local hays (~2 kg/hd/d) and acommercially available ration (225 g/d)designed for growing alpacas. Bodyand yearling fl eece weights were usedto assign alpacas to three equivalentgroups (6 animals per treatment, 3animals per rep, 2 reps) at each researchlocation and in September, 2002, theanimals were penned (3 animals per pen,dimensions 3.7 m X 18.3 m) and rationsat both locations were formulated toprovide the same complete diet when fedin equal amounts with a locally availablehay. In Texas, the major roughagecomponent of the diet was sorghum hay.The OFDA 100The mixed ration contained sorghumgrain, alfalfa meal, peanut hulls, soybeanmeal, ammonium chloride, vitamins,minerals, and a coccidiostat. The primaryroughage source in Canada was Timothyhay. The mixed ration contained oat hulls,wheat mill run, alfalfa, light screenings,ammonium chloride, vitamins, minerals,and a coccidiostat. The actual completediet (50% hay, 50% ration) contained13% crude protein, 2% crude fat, 20%crude fi ber (28% acid detergent fi bers,43% neutral detergent fi bers) and 58.5%TDN. Animals were monitored monthlyfor weight and body condition (bodycondition score, 1-5; 1=excessively thin,5=obese). The amounts fed were adjustedover a 7 month period to producemonthly gains of 3% of body weight whilemaintaining body condition scores of 3 orhigher. Fleeces were shorn again in April,2003, and the nutrition treatments wereimmediately imposed. For the next year,one treatment group was fed at the levelthat had been established to produce 3%gain per month (ie 1.23% of bodyweightof mixed ration and 1.23% hay). Thesecond group was fed 10% less (hayand ration) and a third treatment groupreceived 20% less. Animals were weighedand assessed for body condition monthly.Diets were adjusted after each monthlyweighing, and fl eeces were shorn in May,2004, and characterised once more.Sampling and ShearingA mid-side sample (~ 5 x 5 cm) wasremoved from each animal beforeshearing. The following fl eece portionswere shorn, weighed, packaged, andmeasured separately: short leg, long leg,butt, neck, and saddle (see Figure 1).Fleece portions from both sets of animalswere tested at the Wool and MohairResearch Lab in Texas and most traitswere also measured on the Alberta fl eecesat the Natural Fibre Centre in Olds.Side sample and fleece testingThe side samples were tested using anOFDA2000 instrument that measuresaverage fi bre diameter, standard deviation(SD) and coeffi cient of variation (CV) offi bre diameter, average fi bre curvatureand SD and CV of fi bre curvature, comfortfactor and average staple length. Thisinstrument also constructs an ‘along-fi breprofi le’ of average fi bre diameter so thatchanges throughout the year from tipto base are fully documented with thissingle test.The following sub-sampling andtesting procedures were conducted onthe fi ve major portions of each fl eece.FIGURE 1 Five fleece sections by which alpacas were shorn and testedFirst, the individual fl eece portions wereweighed and sub-sampled for staplelength and strength testing. Raw andclean fl eece weights and staple lengthmeasurements were adjusted to a 365day growth period. Each portion wascore sampled (2 x 25g raw cores) andthese samples were used to obtain ‘cleanalpaca fi bre present’ and ‘vegetablematter present’ and subsequently averagefi bre diameter (SD and CV), averagefi bre curvature (SD and CV), comfortfactor, spinning fi neness, along-fi breaverage fi bre diameter (SD and CV), totalmedullation, fl at fi bres, objectionablefi bres, and average fi bre diameter (SDand CV) of the medullated fi bres usingOFDA 100 instrument (Figure 2). Themedullated fi bre characteristics of onlythe white, cream, and light fawn fl eecescould be quantifi ed with the OFDA 100.The staple length, (SD and CV) weremeasured and calculated using 20staples per fl eece portion. The staplestrength (SD and CV), and position ofbreak were also measured on 20 staplesusing an Agritest Staple Breaker. A subsampleof the scoured cores was cardedand then measured for resistance tocompression using an Agritest Resistanceto Compression instrument.Results andstatistical analysisThe effects of age (confounded withyear), location, and nutrition treatmentsand their interactions on all measuredtraits were established using the GLMprocedure of SAS. The experiment at theCanadian location was concluded in May,2004. The Texas portion will continue untilMay, 2005, after which one more set offl eeces will be analysed. Though we arestill in the process of analysing data, weare in a position to share some of ourmajor fi ndings. Space does not permit usto report detailed results here. However,the whole study will be reported in detailin the technical literature at a later date.Age effectsTable 1 summarises the effects of age onbody weight and some of the major fl eeceand fi bre characteristics for the fi rst threeyears of these male alpacas’ lives. No realsurprises. The animals became heavierand grew progressively more and coarserfi bre that contained higher proportionsof medullated fi bres. Recall that whilethe third fl eeces were being grown, allanimals were on restricted feed (designedto produce specifi c, moderate gains) sobody weights and fl eece weights are notexpected to be optimal. A measure offi bre production effi ciency, clean fi breproduced per unit of body weight, actuallydecreased as the animals aged. Thismay be surprising to some but it is fairlycommon in other fi bre producing species.Although clean yield of the second yearfl eeces is higher than the other twoAlpaca World Magazine Summer 2005 | 15