An international round trial was conducted across 6 core-test laboratories to investigate the potential of using the IH Series 14 Calibration Tops as a standard reference for calibrating Laserscan and OFDA100 instruments for the measurement of Mean Fibre Curvature. This report is the second in a series of 2 reports to investigate the potential of using the IH Series 14 Calibration Tops as a standard reference for calibrating Laserscan and OFDA 100 instruments for the measurement of Mean Fibre Curvature.The Interwoollabs IH Series 14 Calibration Tops were used as the standard reference material in this trial because there is no other form of calibration standard available for MFC. However, previous research has shown that it is the sample preparation procedures that require calibration rather than the instruments (Fish, 2002). This is because the processes fibres undergo prior to measurement of MFC affect wool MFC. As a result, any calibration of the measurement process for MFC should follow the same procedure, and use the same process that is used for the measurement of greasy wool.Measurements generated on 10 Laserscan and 8 OFDA100 instruments showed that the application of a Mean Fibre Curvature calibration to individual instruments showed potential for reducing the between-instrument variance for scoured top. An improvement in the between instrument SD of 4.6 deg/mm was also noted when the calibration was applied to raw wool samples, demonstrating that the application of a preparation procedure would provide an opportunity to better harmonise the MFC of instruments across the raw wool testing industry.
Angora rabbit fibre is a fine animal fibre that is categorized in specialty fibre groups with cashmere and mohair. In the scope of this study, various marketing strategies for Angora rabbit wool were explained. A new marketing model, so-called "contracted-breeder", has been generated recently and is currently being applied by a domestic breeder in Turkey. These models were evaluated for their potential as a strategy in Angora rabbit wool business and marketing. Some suggestions were highlighted for the future of Angora rabbit rearing in Turkey. A short overview of international Angora wool market and production has also been given for better understanding.
This report summarises the final analysis of the TEAM-3 database. The TEAM-3 Steering Committee is able to report that the TEAM-2 parameters (SL, SS, NED, M* and VMB) are still applicable to processing prediction models. It is shown that processing performance has improved since the late 1980's. Mills are producing tops with Hauteur values, on average, 5.1 mm longer than is predicted using the TEAM-2 general formula and greater differences occur as the Hauteur increases above 75 min. In addition, mills are producing tops with CV of Hauteur values, on average, 2.5% less than predicted by TEAM-2 and Romaine values 2.1% greater than predicted. Mills also achieve more consistent, predictable results with lower standard deviations between actual and predicted Hauteur than in TEAM-2. The regession analyses for Hauteur, CV of Hauteur and Romaine have shown that it is possible to calculate new General Formulae for each of these parameters, although they would be very similar to the TEAM-2 General Formulae published in 1988. The addition of CVD and CVL provide small improvements to the prediction. Similarly, the use of M instead of M* makes little change to any prediction model. It has been identified that there is no, improvement in processing prediction if MFC is added to the prediction model. Three options for future prediction formulae are presented for consideration by the industry.
This study was designed to determine whether weaning weight or birth rank (from multiple or single pregnancy) influence the magnitude of louse infestations and the prevalence and extent of cockle in lambs. Four groups of louse-free lambs were used. Two groups of 19 from the same age cohort but in the upper and lower weaning weight groups respectively, and two groups of 14 lambs from multiple pregnancies and single pregnancies respectively, were each infested with 50 female Bovicola ovis. The lambs were subsequently scored for lice and weighed three. times over the next 8 months. At the conclusion of the trial the animals were slaughtered. The pelts of those in the weaning weight portion of the trial were processed and scored for cockle. Pelts from separate groups of lambs that had not been louse infested but kept as negative controls for cockle, were also examined, some being slaughtered at the beginning of the trial and some at the end. There were always more louse-infested animals in the low weaning weight group, the difference being close to significance on Day 111 post-infestation (P=0.055). The low weaning weight group always had a higher median nymph score than the high weaning weight group. On Day 228 the difference in nymph score was significant (P<0.05) with the proportion of adult lice to nymphs also being significantly (P<0.05) higher on that occasion. There was also a significantly higher median total louse score in the low weaning weight group for Day 196 (P<0.05). When loge (total louse score + 1) was regressed against liveweight on Day 228 the trend was for lighter animals to have higher louse scores (R-2=36%). There was no statistically significant relationship (P>0.05) between louse score and birth rank. The relationship between louse infestations and cockle was significant (P<0.01) with higher louse scores associated with more severe cockle, and more so in the low weaning weight group. There was no significant difference in cockle prevalence between the weight groups. It was concluded that a lamb's rank in the weaning weight spectrum of its age cohort can influence the extent of development of a louse infestation and the extent of cockle. All, or nearly all, lambs will develop cockle once a louse infestation is established, irrespective of weaning weight rank. However cockle will be more extensive when more lice are present and, once an infestation is established, most lighter lambs will eventually have more lice than most heavier lambs.
Body weight-age data from fifty-four Morkaraman and seventy-nine Awassi sheep, from birth to thirty-six months of age, were used to obtain a growth pattern for the breeds, with the use of Brody, logistic, Gompertz, Bertalanffy and Richards non-linear functions. In both breeds, the Brody and Richards models, with equal R-2 as 0.99, were superior to the others. However, Brody was precise on its parameters and easy to interpret than Richards function. As a result of heterogeneity, on the other hand, no curve computed using mean body weights in this study had the ability to uniformly represent every individual (p<0.001). Biological interpretations of the model parameters were discussed.
The aim of this study was to evaluate age and weight at puberty in winter-born hair sheep kept under constant nutritional levels, natural photoperiod (22degrees NL) and highland (215 3 m) conditions during the following summer-autumn season. A total of 27 Pelibuey ewe-lambs born. during January (1.98 +/- 0.03 kg BW), were isolated from rams after birth and kept under pen-fed conditions. The experimental period began in July and continued through late October, for a total experimental period of 100 d. Blood samples were collected twice weekly from each ewe to quantify serum progesterone (P4) concentrations as a marker of either luteal activity (active) or anestrous (inactive) ewe-lambs. Puberty was identified by luteal activity at an average weight and age of 21.6 +/- 4.4 kg and 198.5 +/- 7.0 d, respectively. By the end of the experimental period, only 64.7% of the ewe-lambs achieved puberty. Cumulative percentages of ewe-lambs initiating luteal function were 11.7, 17.6, 41.6 and 64.7 for Jul, Aug, Sept, and Oct, respectively. At the end of the experimental period, 35.3% of the ewe-lambs did not display luteal activity. While serum P4 concentrations were correlated (r=0.19, P=0.01) with both body weight and average daily gain, luteal function increased (P<0.01) from July to October. No differences (P>0.05) in body weight were observed between the cycling and non-cycling ewes. Increases in body weights and a small reduction in photoperiod observed from July to October (1.8 h) paralleled increases in luteal. activity in Pelibuey ewe lambs. Further studies must be designed to better understand the role that these two factors have as possible modulators in the onset of puberty in Pelibuey ewe lambs at this latitude.
Drought and low wool prices have resulted in a decline in Merino sheep numbers, increasing pressure on the Merino as a dual meat and wool animal. A simultaneous phenotypic assortment strategy for dual products was developed to increase the size of animals (for meat sale) as well as reducing the fibre diameter of retained animals (for wool production). The selection strategy outlined in this paper involves ranking the animals using fibre diameter and body weight and allocating them to a wool or meat production group according to their merit for each trait. This assortment can be used in yearlings to identify sale or retained animals or among breeding ewes for mating allocation to improve progeny performance through appropriate mating to either meat or wool sires.
In the recessive black foetal sheep, melanoblasts (precursor pigment cells revealed by ammoniacal silver nitrate staining) migrate to and colonise the epidermis prior to wool follicle development. As the original developing follicles bud from the epidermis, melanocytes are incorporated and these cells colonise the follicle regions including the bulbs that ultimately produce fibre pigmentation. The secondary-derived follicles that bud from the upper outer-root sheath region of the original secondary follicles also become pigmented if melanocytes are present. For the "usual" white Merino wool-bearing skin there is an apparent deficiency of melanoblasts during foetal development of the original wool follicles though these may later migrate and locate in the epidermis. In white sheep likely to develop isolated pigmented wool fibres, the apparent timing of migration of melanoblasts coincided with initiation of primary and original secondary follicles. However, the melanoblasts cannot colonise the foetal epidermis at that critical time of development so only isolated pigmented follicles develop. The gene(s) responsible for producing white coat in sheep remain unidentified and invite modem assessment with the molecular genetic tools now available. Ultimately the most effective and acceptable genetic variation could be specifically and more efficiently selected.
The prediction of ash content of laboratory-scoured core samples utilising Near Infrared Reflectance Analysis (NIRA) has been investigated. Modified Partial Least Squares (MPLS) Regression was found to underestimate ash content when the sample being tested contained significant quantities of dag. The underestimation was not a consequence of saturation of the NIRA detector but rather appeared to be due to an inability of the MPLS technique to adequately account for dag which was present in the sample but masked by wool.Application of Artificial Neural Networks (ANN) Regression to the calibration data set produced improved results. The underestimation at higher ash levels was not as evident, indicating that ANN is better able to utilise the spectral information to predict total ash content.High levels of dag were found to adversely affect the repeatability of the IWTO-19 method for determining ash content. Uneven distribution of dag within samples was believed to be responsible. This finding has implications for NIRA, as any method of prediction can only be as good as the reference method to which it is calibrated.
This report summarises the results of the 2(nd) phase of a substantial trial carried out by Australian Wool Innovation Ltd. (AWI) in which the performance of the two common on-farm fibre diameter measurement technologies (OFDA2000 using midside samples and Sirolan Fleecescan using sampling of the whole skirted fleece) were compared with traditional midside sampling followed by laboratory fleece measurement, and with the outcomes of IWTO Certification of lots prepared using these technologies. In this phase, only Mean Fibre Diameter measurements were considered. The specific processes evaluated in this phase were the measurement-assisted classing of single mob wool clips, and the ranking of individual sheep. The evaluation was carried out on one superfine and one fine-wool property in Victoria, and a medium-wool property in South Australia.The work illustrated that these two specific on-farm sampling and measurement technologies (i.e. OFDA2000 measurement on midside samples and Fleecescan measurements on the skirted fleece) produced very similar outcomes with slightly lesser precision than laboratory fleece testing carried out on midside samples in accordance with AS/NZS 4492. There was a strong relationship between the two on-farm technologies and their ability to measure Mean Fibre Diameter compared with certificate testing, and when used for fleece classing, they both produced lines of wool of different diameters in the expected order (i.e. the line that was expected to be finest was the finest, etc). Biases were observed between the expected classed line diameters and the certified test results (from -1.1 mum to +0.9 mum), and these varied from property to property. The phenomenon sometimes called "Micron creep" was similarly observed for both technologies and would also be expected to exist if laboratory measurements were to be used for fleece classing. From both the fleece classing and sheep selection results it can be concluded that the precisions of the two on-farm technologies for mean fibre diameter are near equal.Finally, it was concluded that the larger the range in diameter within a flock, and the more precise the measurements, the more likely it is that classed lot measurements and animal selections using different instruments or systems will be consistent.
AWTA Ltd has commenced a trial to examine the processing characteristics of individual sale lots comprised of 'atypical' wool types. Such an investigation complements the commercial processing of consignments in the TEAM3 trial. Initial analyses of Hauteur prediction using the current TEAM2 formula have highlighted under-prediction of belly-wool types. Other results indicate that a new parameter, Decrimping Ratio, has the potential to differentiate between wool lots with extreme levels of staple crimp. For example, belly-wool types typically have high levels of staple crimp and high Decrimping Ratios. The incorporation of Decrimping Ratio into future prediction formulae is being evaluated as a means of improving prediction accuracy for wool lots with atypical Decrimping Ratios.
This study investigated the effects of synchronisation with additional follicle stimulating hormone (FSH) treatment on follicular growth and oocyte quality in adult ewes, with the aim of maximising the number of high quality oocytes, obtained by ovum pick-up (OPU), suitable for in vitro embryo production (IVP). Nine crossbred (Merino cross) ewes were split into two groups, which were synchronised and alternately treated with FSH throughout the experimental period. Three replications of OPU were conducted on a fortnightly basis over a six week period. FSH treated donors yielded more follicles (12.5 vs 6.5; p < 0.001) and oocytes (7.0 vs 2.5; p < 0.001) per ewe per OPU compared with synchronised donors (control). FSH treatment did not significantly affect oocyte grade (Grade 1 oocytes: FSH treated, 68.5%; synchronised, 51.4%; p = 0.208) or cleavage rate (FSH treated, 50.0%; synchronised, 76.6%; p = 0.204) contrary to previous studies. Higher quality oocytes were also shown to increase the chance of cleavage (Grade 1 oocytes, 62.9%; Grade 2 oocytes, 33.3%; p = 0.005). The number of oocytes recovered decreased with each successive OPU session (OPU1, 59.4%; OPU2, 49.2%; OPU3, 35.2%; p = 0.003), although oocyte quality did not deteriorate (Grade 1 oocytes: OPU,, 54.3%; OPU3, 74.7%; p = 0.138). This study demonstrated that FSH treatment in addition to synchronisation could be used in IVP programs without loss of oocyte quality, increasing the number of oocytes available, and hence increasing the efficiency of adult sheep embryo transfer programs.
The presumed importance of staple strength needs to be re-examined. The author's experience with overseas spinners is that it is commonly assumed that low staple strength (SS) necessarily means a low strength top and poor spinning performance. However, staple strength is found to have almost no relationship to the average strength of bundles of fibres in the resulting tops or with the subsequent yam strength and spinning performance, apart from its effect via the length of the top. Staple strength does have a relationship to breakage and losses in topmaking that seems to be more pronounced at low staple strength, but the size of the effects actually due to SS appear to be smaller than those suggested by the TEAM2 regression coefficients. Given the large dependence of price on SS for superfine wool it is important to better quantify the effects of SS and to examine if longer staple length can be used to compensate for lower SS, leading to a cheaper top that performs similarly.Breakage in processing should be dependent on individual fibre strength, plus other factors such as degree of entanglement. Staple strength is influenced by factors beside individual fibre strength and so may not relate as well to breakage in processing. Studies of the components of SS are reviewed and it is shown that SS should depend on (D-min/ D)(2) and the extent to which fibres share the load. The latter is dependent on the load/extension curves of the component fibres and on the spread in straightened fibre lengths between the staple-breaker jaws relative to the single fibre elongation. Hence, SS should be expected to have limitations as a predictor of fibre breakage and it would be desirable to establish if single fibre strength is a significantly better indicator of breakage in processing and downstream performance.
Calculations have been made to show the effect of different class intervals of the frequency distribution histogram on the Mean Fibre Curvature (MFC) and the Standard Deviation of Fibre Curvature (SDFC).Results show that there is very little impact on the MFC and SDFC between class intervals between 1 to 40 deg/mm in size. However, results have also shown a small impact on the MFC and SDFC at 120 deg/mm. due to the asymmetrical nature of the FC distribution.
The 2003 Australian Wool Innovation Ltd (AWI) On-Farm Fibre Measurement (OFFM) Instrument Evaluation Trial was a direct outcome of market research commissioned by AWI, which indicated an increasing need by wool producers for an independent and objective assessment of the commercial application of the two current OFFM technologies (OFDA2000 and Sirolan Fleecescan(TM). AWI established an Expert Advisory Group to provide assistance and guidance with the design and implementation of the trial and the analysis and interpretation of the trial results.
The relationship between TEAM predictions of hauteur, coefficient of variation in hauteur and romaine, the actual processing performance as well as the difference between actual and predicted (A-P) processing performance was established for four different Merino studs. The four studs represented the diverse range of Merino types run in Australia. The stud itself was the major source of variation for the TEAM predictions, actual processing performance and the A-P differences. Including wool traits additional to those already contained in the TEAM formulae, such as the coefficient of fibre diameter and fibre curvature did not account for a significantly higher proportion of the residual variation in any of the processing traits, be they predicted or actual. The particular selection system used to rank sheep for breeding was found to have no direct impact on processing performance. Rather it is how the selection system impacts upon the raw wool traits expressed by each animal that determines processing performance. This initial study indicates that Merino breeders can use the TEAM formulae with confidence to link their breeding programs to processing performance. The challenge for Merino breeders is to economically incorporate the additional measurements of staple length and strength into their breeding programs.
For a number of years the Merino industry has debated the merits of alternative sheep selection systems. In 1996 the Selection Demonstration Flocks were established to highlight the strengths and weaknesses of alternative sheep selection systems. Three selection demonstration flocks (SDFs) of 200 breeding ewes in each flock were established. A fourth, randomly selected flock of the same size has been maintained as a control group. The SDFs represent: 1. Selection predominantly driven by measurement and performance recording; 2. Selection by visual and tactile appraisal by professional sheep classers, and 3. Selection using the technological package of advocates of the 4 soft rolling skin' or 'elite wool flock' approach. A meat Merino line (FM+) has been introduced to demonstrate the attributes of both fibre plus meat traits in conventional Merinos.Results for the fifth (2001) drop from the original flocks and the second drop of the meat Merino line are presented and discussed. The results from selected ewes originating from earlier drops (1997, 1998, 1999 and 2000) are also reported. All selection systems have made significant gains in comparison with the Control flock and after two years of results the FM+ is clearly superior in meat production traits. In previous years (1997, 1998, 1999 and 2000) the rate of genetic improvement has been very similar between selection systems. The 2001 drop provides the first indication of divergence between the selection lines. Further years of results will confirm whether differences are due to selection methods.
