Inheritance of Acid Red 1 dye absorption and its relationship to other Merino wool traits

2006 ◽  
Vol 46 (7) ◽  
pp. 943 ◽  
Author(s):  
A. C. Schlink ◽  
S. Ortega ◽  
J. C. Greeff ◽  
M. E. Dowling
Keyword(s):  
Coefficient Of Variation ◽  
Fibre Diameter ◽  
Merino Wool ◽  
Dyeing Performance ◽  
Dye Absorption ◽  
High Heritability ◽  
Acid Red 1 ◽  
Staple Strength ◽  
Wool Dyeing ◽  
Staple Length

Optimising and ensuring the reproducibility of wool dyeing is of significant economic importance to the wool industry. Midside wool from 1824 Merino ewe and ram hoggets was used to estimate the heritability of Acid Red 1 dye absorption in clean wool. Acid Red 1 absorption had a high heritability of 0.45 ± 0.07 and was phenotypically poorly correlated with fibre diameter (–0.11 ± 0.03), the coefficient of variation of fibre diameter (0.05 ± 0.03), curvature (–0.05 ± 0.03), staple strength (–0.02 ± 0.02) and staple length (–0.09 ± 0.03), yield (0.08 ± 0.03) and dust penetration (0.07 ± 0.03). It was not genetically correlated with fibre diameter (–0.05 ± 0.09), the coefficient of variation of fibre diameter (0.02 ± 0.09), curvature (–0.09 ± 0.09), staple strength (–0.07 ± 0.10) or staple length (–0.03 ± 0.08), but weakly genetically correlated with yield (0.18 ± 0.08) and dust penetration (0.24 ± 0.12). Dye absorption was also genetically negatively correlated with wool felting as measured by feltball diameter (–0.26 ± 0.09). Acid Red 1 absorption was not genetically correlated with absorption of the cationic dye Methylene Blue. We suggest that there is a biological basis for differences between wools in dyeing performance and that this variation will depend on the class of dye being evaluated for wool dyeing.

Wool weathering damage as measured by Methylene Blue absorption is linked to suint content

2006 ◽  
Vol 46 (7) ◽  
pp. 927 ◽  
Author(s):  
M. E. Dowling ◽  
A. C. Schlink ◽  
J. C. Greeff
Keyword(s):  
Methylene Blue ◽  
Fibre Diameter ◽  
Moisture Index ◽  
Indirect Measure ◽  
Merino Wool ◽  
Dyeing Performance ◽  
High Heritability ◽  
Staple Strength ◽  
Weather Damage ◽  
Fibre Loss

Weather damage of wool in grazing sheep has long been recognised by the wool industry as a problem, resulting in fibre damage, fibre loss and poor dyeing performance. Merino wool from 3538 ewe and ram hoggets was used to estimate the heritability of Methylene Blue absorption. Methylene Blue absorption has a high heritability of 0.44 ± 0.04 and was strongly genetically correlated with suint index (0.88 ± 0.02) and wool moisture index (0.92 ± 0.03). Methylene Blue absorption was moderately genetically, negatively correlated with measures of clean wool colour and yield and positively with dust penetration. There was no significant correlation between Methylene Blue absorption and dust content or economically important measures of fleece value such as fibre diameter, curvature and staple strength. The strong genetic relationship between Methylene Blue absorption and suint index indicates that Methylene Blue absorption is a very good indirect measure of greasy wool suint content but may not be a satisfactory indicator trait to select for low weather damage.

Genetic parameters for bodyweight, wool, and disease resistance and reproduction traits in Merino sheep. 4. Genetic relationships between and within wool traits

2009 ◽  
Vol 49 (4) ◽  
pp. 289 ◽  
Author(s):  
A. E. Huisman ◽  
D. J. Brown
Keyword(s):  
Coefficient Of Variation ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Selection Decisions ◽  
Different Ages ◽  
Reproduction Traits ◽  
Staple Strength ◽  
Fleece Weight ◽  
Staple Length

The aim of this paper was to describe the genetic relationship among expressions at different ages of seven wool traits: greasy and clean fleece weights, fibre diameter, coefficient of variation of fibre diameter, staple length and strength, and mean fibre curvature. Genetic correlations among measurements at different ages for the same trait were moderate to high, and ranged from ~0.6 for both fleece weights to 0.9 and higher for mean fibre diameter and curvature. Generally, low to moderate genetic correlations (0.3–0.4) were estimated between fleece weights and fibre diameter, clean fleece weight and staple length, and fibre diameter and staple strength. Small positive genetic correlations (0.2) were estimated between greasy and clean fleece weight with fibre diameter coefficient of variation, and between fibre diameter and staple length. Mean fibre curvature had a negative genetic correlation (approximately –0.4) with most other wool traits, the exceptions were staple strength (~0.0) and coefficient of variation of fibre diameter (approximately –0.1). Fibre diameter, staple length and staple strength had negative genetic correlations with coefficient of variation of fibre diameter (–0.15, –0.10, and –0.61, respectively). The results indicate that for most wool traits only one measurement across ages is required to make accurate selection decisions. The relationships between traits are generally moderate to low suggesting that simultaneous genetic improvement is possible.

Staple strength of fine, medium and strong wool Merino wethers under drought conditions

2006 ◽  
Vol 46 (9) ◽  
pp. 1123
Author(s):  
M. A. Friend ◽  
G. E. Robards
Keyword(s):  
Coefficient Of Variation ◽  
Management Strategies ◽  
Fibre Diameter ◽  
Summer Rainfall ◽  
Arid Environment ◽  
Strongly Correlated ◽  
Rainfall Events ◽  
Treatment Groups ◽  
Effect Of Treatment ◽  
Staple Strength

Fine, medium and strong wool Merino wethers (n = 72, 4 years old) were grazed together on drought-affected pastures in a semi-arid environment. In order to examine the hypothesis that restricting liveweight gains at the break of drought would improve staple strength, sheep were allocated to restricted grazing in a 5-ha paddock (drought group), or unrestricted grazing in a 20-ha paddock (drought-break group) when it was judged that the drought had broken in the region. Wool staples from all sheep broke at a point coinciding with summer rainfall events before allocation to treatment groups, and staple strength did not differ between treatments. Medium wool sheep (22.0 ± 1.6 N/ktex) produced wool of lower (P<0.001) staple strength than fine (30.0 ± 1.6 N/ktex) or strong (30.2 ± 1.6 N/ktex) wool sheep. Restricting the measurement of staple strength to the period when treatments were applied revealed no effect of treatment on staple strength, despite the fact that wethers in the drought-break group experienced a greater (P<0.001) liveweight gain (6.62 ± 0.37 kg) after allocation to their treatment than those in the drought group (–3.24 ± 0.37 kg). Staple strength was most strongly correlated with coefficient of variation of fibre diameter (r = –0.65; P<0.001); a result that was observed for all strains and treatment groups. The results indicate that coefficient of variation of fibre diameter is correlated with staple strength regardless of strain, and that management strategies designed to limit fibre diameter variability during a drought need to be applied not only at the break of a drought.

Increasing lamb output by crossing commercial Merino ewes with South African Meat Merino rams

2000 ◽  
Vol 40 (1) ◽  
pp. 11 ◽  
Author(s):  
S. W. P. Cloete ◽  
A. Durand
Keyword(s):  
Survival Rate ◽  
South African ◽  
Coefficient Of Variation ◽  
Fibre Diameter ◽  
Combined Effect ◽  
Weaning Weight ◽  
Slaughter Weight ◽  
Ram Lambs ◽  
Staple Strength ◽  
Fleece Weight

Commercial Merino ewes were randomly allocated to 1 of 2 groups, which were joined either to commercial Merino or South African Meat Merino rams during October 1996 and 1997. Merino rams were involved in 161 joinings, and South African Meat Merino rams in 157 joinings. The proportions of ewes that lambed were independent of the breed of the sire when expressed relative to the number of ewes joined (0.809 and 0.801 in ewes joined to South African Meat Merino and Merino rams, respectively). The proportion of multiple lambs was similarly not affected by the breed of the service sire. Lambs sired by South African Meat Merino rams were on average ( s.e.) heavier (4.17 0.07 v. 3.86 0.07 kg; P<0.01) at birth. They also tended to have a better (0.69 v. 0.59; P<0.10) survival to weaning, and were heavier (26.9 0.6 v. 22.8 0.6 kg; P<0.01) at weaning than purebred Merino contemporaries. The combined effect of the tendency towards an improved survival rate as well as the increased lamb weaning weight resulted in a 36% increase (P<0.01) in lamb output in Merino ewes joined to South African Meat Merino ewes compared with ewes joined to Merino rams. Higher (P<0.01) proportions of ram lambs sired by South African Meat Merino rams reached slaughter weight (about 40 kg) before the onset of the dry Mediterranean summer than purebred Merinos. Two-tooth ewes sired by South African Meat Merino rams were heavier (P<0.01) at 2-tooth age (53.0 0.6 v. 52.0 0.6 kg) than purebred Merinos. The 2-tooth greasy fleece weight of South African Meat Merino sired 2-tooth ewes were lower (3.85 0.08 v. 4.66 0.09 kg; P<0.01), with a lower (66.8 0.6 v. 70.5 0.7 %; P<0.01) clean yield than that of purebred Merinos. This resulted in a marked difference in clean fleece weight between the 2 types (2.56 0.06 v. 3.28 0.06 kg, respectively). Wool produced by South African Meat Merino sired 2-tooth ewes was generally broader (21.8 0.3 v. 20.3 0.3 m; P<0.01) and shorter (87.3 1.3 v. 96.4 1.4 mm; P<0.01) than that of their purebred Merino contemporaries. The coefficient of variation of fibre diameter as well as staple strength was independent of the breed of the sire. Liveweight of adult ewes and wool traits were independent of the breed of the service sire.

The fibre diameter profile of wool staples from individual sheep

1979 ◽  
Vol 30 (1) ◽  
pp. 163 ◽  
Author(s):  
N Jackson ◽  
AM Downes
Keyword(s):  
Coefficient Of Variation ◽  
Fibre Diameter ◽  
Average Diameter ◽  
Seasonal Effects ◽  
Genetic Studies ◽  
Phenotypic Differences ◽  
Mean Diameter ◽  
Local Areas ◽  
Mean Variance ◽  
Staple Length

Variation in fibre diameter along the staple was measured on duplicate staples from five sheep from each of four lines selected for high and low staple length and high and low fibre diameter. It was found that the high and low fibre diameter lines differed in mean diameter and in variance along the staple, but did not differ in coefficient of variation along the staple. The high and low staple length lines also differed in mean diameter, but did not differ in variance or coefficient of variation along the staple. Individual sheep within selection lines differed in mean, variance along the staple, and coefficient of variation along the staple. The measurement technique was found to be highly repeatable between duplicate staples sampled from the same animal. Susceptibility to seasonal effects at particular positions along the staple was tested by analysing the interaction between staple segments and other factors, and was described by regressing the diameter at a position on the average diameter of all sheep at that position. It was found that the high and low fibre diameter lines differed in susceptibility (thus described) while the high and low staple length lines did not so differ. Individual sheep within selection lines also differed in susceptibility. The application of measured variation in diameter along the staple to sheep breeding must await more extensive genetic studies. The present study simply unmasks some previously unnoticed genetic and phenotypic differences and checks on the accuracy of the measurement method. It shows that there are non-susceptible individual animals and selection lines for which the variance of diameter along the staple is very low, and hence there exists the potential to reduce this variation on a nation-wide basis, or in local areas, if such a reduction be thought desirable from a woolprocessing viewpoint.

Predicted responses in Merino sheep from selection combining visually assessed and measured traits

2010 ◽  
Vol 50 (10) ◽  
pp. 976 ◽  
Author(s):  
S. I. Mortimer ◽  
K. D. Atkins ◽  
S. J. Semple ◽  
N. M. Fogarty
Keyword(s):  
Fibre Diameter ◽  
Selection Combining ◽  
Breeding Programs ◽  
Dual Purpose ◽  
Merino Sheep ◽  
Merino Wool ◽  
Wool Quality ◽  
Staple Strength ◽  
Fleece Weight ◽  
Australian Merino

Visually assessed traits for wool quality and ease of management are important to Merino sheep breeders and need to be considered in breeding programs. The present study reports on the predicted correlated responses in visual traits from selection using a range of standard MERINOSELECT™ indices available for use in Australian Merino breeding programs. The effect of including a visual trait in the index is also reported. The visual scored traits were classer grade, wool quality (handle, character and colour), conformation (neck and body wrinkle, front and back leg structure) and fleece rot. The indices covered a range of micron premiums of varying emphasis on increasing fleece weight and reducing fibre diameter. The indices were for Merino wool enterprises (Merino 14%, Merino 7% and Merino 3.5%) and Merino dual purpose wool and meat enterprises (Dual Purpose 7% and Dual Purpose 3.5%). The breeding objectives for the indices included fleece weight, fibre diameter, coefficient of variation of fibre diameter, staple strength, bodyweight and reproduction. Selection over 10 years using the standard MERINOSELECT™ indices is predicted to result in a small correlated improvement in the wool quality traits and classer grade, with a slight deterioration in fleece rot score. The improvement in wool handle, character and colour are greater with those indices that have a greater emphasis on reducing fibre diameter than with those increasing fleece weight. Indices with more emphasis on increased fleece weight than on reduced fibre diameter are predicted to result in small increases in neck and body wrinkle scores and a slight deterioration in wool colour. Inclusion of classer grade, handle, character or colour provided slight extra gains in fleece weight for indices that emphasised reduced fibre diameter through increased accuracy of selection.

Inclusion of skin follicle traits in selection indices in breeding programs improves genetic gain in Australian fine-wool Merinos

2007 ◽  
Vol 58 (9) ◽  
pp. 921 ◽  
Author(s):  
M. Asadi Fozi ◽  
J. H. J. Van der Werf ◽  
A. A. Swan
Keyword(s):  
Body Weight ◽  
Coefficient Of Variation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Selection Criterion ◽  
Breeding Programs ◽  
Breeding Objectives ◽  
Staple Strength ◽  
Fleece Weight

Genetic parameters for skin follicle traits, wool traits, body weight, and number of lambs weaned per ewe joined were estimated for 5108 10-month-old Australian fine-wool Merinos born between 1990 and 1996. These animals were descended from 261 sires and 2508 dams. The skin follicle number index that is based on skin surface area, and primary, secondary, or total follicle density were introduced as possible early-age selection criteria estimated at 6 months of age. Heritability estimates for total, secondary, and primary follicle number index were 0.45 ± 0.04, 0.46 ± 0.04, and 0.38 ± 0.04, respectively. The genetic correlations of total follicle number index with clean fleece weight, mean fibre diameter, staple strength, coefficient of variation of fibre diameter, body weight, and number of lambs weaned were 0.16, –0.67, 0.00, 0.03, 0.22, and 0.22, respectively. Responses to selection on indices including and excluding follicle traits were calculated based on the genetic parameters estimated, and with annual responses calculated using an optimised age structure. On average, 10% greater response was predicted when total follicle number index was used as an additional selection criterion in different micron premium scenarios. In comparison, skin follicle density had a smaller effect on genetic improvement. The extra response was ~1%. Similar index responses were obtained when total follicle number index was used as a replacement selection criterion for clean fleece weight, mean fibre diameter, and coefficient of variation of fibre diameter for breeding objectives with low emphasis on fibre diameter. In objectives with high emphasis on fibre diameter, unfavourable correlated responses in staple strength and CV of fibre diameter limited the effectiveness of using total follicle number index as a selection criterion. Although the use of total follicle number index as an additional selection criterion can be favourable for some breeding objectives, measuring this trait is currently cost prohibitive to inclusion in Merino breeding programs.

Genetic parameters for visually assessed traits and their relationships to wool production and liveweight in Australian Merino sheep

2009 ◽  
Vol 49 (1) ◽  
pp. 32 ◽  
Author(s):  
S. I. Mortimer ◽  
D. L. Robinson ◽  
K. D. Atkins ◽  
F. D. Brien ◽  
A. A. Swan ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Quality Traits ◽  
Production Traits ◽  
Merino Sheep ◽  
Wool Production ◽  
Breeding Objectives ◽  
Wool Quality ◽  
Staple Length

Heritability was estimated for a range of visually assessed traits recorded on Merino sheep, together with the phenotypic and genetic correlations among the visually assessed traits and correlations of the visually assessed traits with measured wool production traits and liveweight. Data were derived from four research resource flocks, with a range of 12 958 to 57 128 records from animals with 478 to 1491 sires for the various traits. The estimates of heritability were high for the wool quality traits of handle, wool character and wool colour (0.33–0.34) and the conformation traits of face cover, neck wrinkle and body wrinkle (0.42–0.45), moderate for front leg structure (0.18) and low for back leg structure (0.13). Fleece rot score had low heritability (0.14), while classer grade was moderately heritable (0.20). Estimates of genetic correlations among the visually assessed wool quality traits were low to moderate in size and positive (0.17–0.47). Genetic correlation estimates among the assessed conformation traits were generally very low, except for the genetic correlations between scores for neck and body wrinkle (0.92 ± 0.01) and front and back leg structure (0.31 ± 0.09). Fleece rot score had low positive genetic correlations with neck and body wrinkle scores (0.18 ± 0.05 and 0.15 ± 0.05, respectively) and classer grade (0.26 ± 0.06). Classer grade was slightly positively correlated with the wool quality traits (0.17–0.45) and leg structure traits (0.21–0.25). The genetic correlations among the visually assessed traits were generally neutral to favourable. The visually assessed wool quality traits had low to moderate favourable genetic correlations with mean and coefficient of variation of fibre diameter (0.19 –0.47), but negative correlations with clean wool yield (–0.26 to –0.37). Face cover was unfavourably correlated with staple length (–0.27 ± 0.04) and liveweight (–0.23 ± 0.02). Neck and body wrinkle scores were genetically associated with higher greasy (0.33–0.39) and clean fleece weights (0.19–0.22), greater coefficient of variation of fibre diameter (0.24–0.26) and fibre curvature (0.27–0.28), but with reduced yield (–0.26 to –0.28) and staple length (–0.34 to –0.41). Fleece rot score was genetically correlated with clean fleece weight (0.26 ± 0.05) and coefficient of variation of fibre diameter (0.27 ± 0.04). Classer grade was favourably correlated with greasy and clean fleece weights (–0.41 to –0.43), staple length (–0.29 ± 0.04), liveweight (–0.36 ± 0.03) and coefficient of variation of fibre diameter (0.27 ± 0.03). Most genetic correlations between the visually assessed traits and the measured production traits and liveweight were close to zero and less than 0.2 in magnitude. This study provides accurate values for the parameter matrix required to incorporate visually assessed traits into breeding objectives and the genetic evaluation programs used in the Australian sheep industry, allowing the development of breeding objectives and indexes that optimally combine visually assessed performance and measured production in Merino sheep.

An evaluation of Merino wool quality:I. The incidence of coarse fibres in two Australian Merino flocks

1970 ◽  
Vol 74 (1) ◽  
pp. 91-98 ◽  
Author(s):  
J. R. Gallagher ◽  
N. T. M. Yeates
Keyword(s):  
Fibre Diameter ◽  
Length Distribution ◽  
Fibre Length ◽  
Merino Wool ◽  
Modal Length ◽  
Homogeneity Of Variance ◽  
Posterior Direction ◽  
Consequent Improvement ◽  
Australian Merino ◽  
Staple Length

SUMMARYThe fibre length and diameter distributions of the wool of two Merino flocks were evaluated at the neck, mid-side and breech positions, to determine the incidence of fibres which were off-type by reason of excessive length, diameter or possession of a medulla.The ranges of fibre lengths for 10·5–11·0 months' growth were 1·0–17·5 cm. in flock 1 and 1·0–16·5 cm in flock 2. There was no evidence of a bi-modal length distribution in either flock.Fibre diameters at 15–16 months were observed in the range 6–69 μ in flock 1 and 5–52 μ in flock 2. Medullated fibres ranged from 7 to 50 μ in flock 1 and 5–64 μt in flock 2. The incidence of medullation increased in an antero-posterior direction from 0·17 to 0·28% in flock 1 and 0·11 to 0·28% in flock 2.Tests for homogeneity of variance were applied to the estimates of fleece characters in this study as well as estimates of other workers. From these comparisons it is suggested that sheep in the present study are representative of the Merino breed in staple length, fibre diameter and to a lesser extent crimp frequency. The considerable between-animal variation in the observed incidence of medullation should aid in selection against that character with a consequent improvement in wool quality.

Do price premiums for wool characteristics vary for different end products, processing routes and fibre diameter categories?

2016 ◽  
Vol 56 (12) ◽  
pp. 2146
Author(s):  
David Cottle ◽  
Euan Fleming
Keyword(s):  
Fibre Diameter ◽  
Price Setting ◽  
Hedonic Models ◽  
Price Premiums ◽  
Australian Wool ◽  
Breeding Selection ◽  
Staple Strength ◽  
Log Price ◽  
Using Data ◽  
Staple Length

No Australian wool price hedonic studies have separated auction data into different end product-processing groups (PPR) on the basis of all fibre attributes that affect the suitability of wool sale lots for PPR. This study was conducted to assess: (1) whether including information about PPR groupings is more useful in understanding price than clustering by broad fibre diameter (FD) categories, and (2) if the ‘noise’ of macroeconomic effects on price can be reduced by using a clean price relative to the market indicator (RelPrice) formula or a log RelPrice formula compared with log price or clean price. Hedonic models using data derived from 369 918 Australian auction sale lots in 2010–2011 were estimated for these four dependent price variables. Linear FD models predicted less of price’s variance than quadratic or exponential models. Segmenting wool sale lots into 10 PPR before wool price analyses was found to increase the proportion of price variance explained and thus be worthwhile. The change in price with a change in FD, staple length and staple strength differs significantly between PPR. Calculating RelPrice or log RelPrice appears a better price parameter than clean price or log price. Comparing the RelPrice and clean price models, the mean absolute percentage errors were 6.3% and 16.2%, respectively. The differences in price sensitivity to FD, staple length and staple strength across PPR implies a complex set of price-setting mechanisms for wool as different users place different values on these wool properties. These price-setting mechanisms need to be incorporated in hedonic models for agricultural products that possess this characteristic. The wool price premiums can be used to estimate relative economic values when constructing sheep breeding selection indexes and can help determine the most profitable wool clip preparation strategies.

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