scholarly journals The allometric relationship between clean mohair growth and the fleece-free liveweight of Angora goats is affected by liveweight change

2013 ◽  
Vol 53 (2) ◽  
pp. 154 ◽  
Author(s):  
B. A. McGregor ◽  
K. L. Butler ◽  
M. B. Ferguson
Keyword(s):  
South African ◽  
Age Group ◽  
Allometric Relationship ◽  
Merino Sheep ◽  
Genetic Origins ◽  
Likelihood Model ◽  
Cashmere Goats ◽  
Angora Goats ◽  
Fleece Weight ◽  
Birth Parity

Clean fleece weight (CFWt) is affected by liveweight and change in liveweight in Merino sheep, Angora and cashmere goats. However, how these relationships progress as animals age has not been elucidated. Measurements were made over 12 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins including South African, Texan and interbred admixtures of these and Australian sources. Records of breed, sire, dam, date of birth, dam age, birthweight, birth parity, weaning weight, liveweight, fleece growth and fleece quality were taken for does and castrated males (wethers) (n = 267 animals). Fleece-free liveweights (FFLwt) were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. The average of the FFLwt at the start of the period and the FFLWt at the end of the period was calculated (AvFFLwt). Liveweight change (LwtCh) was the change in FFLwt over the period between shearings. A restricted maximum likelihood model was developed for CFWt, after log10 transformation, which allowed the observations of the same animal at different ages to be correlated in an unstructured manner. A simple way of describing the results is: CFWt = κ (AvFFLwt)β, where κ is a parameter that can vary in a systematic way with shearing age, shearing treatment and LwtCh; and β is an allometric coefficient that only varies with LwtCh. CFWt was proportional to FFLwt0.67 but only when liveweight was lost at the rate of 5–10 kg during a shearing interval of 6 months. The allometric coefficient declined to 0.3 as LwtCh increased from 10 kg loss to 20 kg gain during a shearing interval. A consequence is that, within an age group of Angora goats, the largest animals will be the least efficient in converting improved nutrition to mohair.

Variation in mohair staple length over the lifetime of Angora goats

2013 ◽  
Vol 53 (6) ◽  
pp. 479 ◽  
Author(s):  
B. A. McGregor ◽  
K. L. Butler ◽  
M. B. Ferguson
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Cross Sectional ◽  
Genetic Origins ◽  
Age Cohort ◽  
Likelihood Model ◽  
Biological Determinants ◽  
Angora Goats ◽  
Fleece Weight ◽  
Staple Length

Previous work has shown that, within an Angora goat flock, clean fleece weight is proportional to fleece-free liveweight (FFLwt)2/3 and for goats of the same age and cohort, the mean mohair fibre diameter is proportional to FFLwt1/3. This indicates that fibre length might not be related to the size of animals. This study examines how mohair staple length (SL) is related to FFLwt of Angora goats of different genetic origins over their lifetime and how the relationship varies with other lifetime factors. Measurements were made over 11 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins in Australia, including South African, Texan and interbred admixtures of these and Australian sources. Records of breed, sire, dam, date of birth, dam age, birthweight, birth parity, weaning weight, liveweight, fleece growth and fleece quality were taken for castrated males (wethers) (n = 94 animals). FFLwt were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. The average of the FFLwt at the start of the period and the FFLWt at the end of the period was calculated. Liveweight change (LwtCh) was the change in FFLwt over the period between shearings. A restricted maximum likelihood model was developed for SL, which allowed the observations of the same animal at different ages to be correlated in an unstructured manner. Average SL differed from ~12.0 to ~14.5 cm, depending on age. There were no consistent effects of season. At any age, an increase of 10 kg LwtCh between animals results in about a 0.34 (s.e. = 0.087) cm increase in SL. There was no evidence of an effect of FFLwt on SL. The results confirm our hypothesis that within a single age cohort of Angora goats, there is very little, if any, relationship between the liveweight and SL of individual animals. This implies that the biological determinants of size of fibres related to cross-sectional area are substantially different to the size determinants of fibre length.

scholarly journals The allometric relationship between mean fibre diameter of mohair and the fleece-free liveweight of Angora goats over their lifetime

2012 ◽  
Vol 52 (1) ◽  
pp. 35 ◽  
Author(s):  
B. A. McGregor ◽  
K. L. Butler ◽  
M. B. Ferguson
Keyword(s):  
South African ◽  
Fibre Diameter ◽  
Cube Root ◽  
Weaning Weight ◽  
Primary Determinant ◽  
Angora Goats ◽  
Fleece Weight ◽  
Log Normal ◽  
Lifetime Effects ◽  
Birth Parity

As mean fibre diameter (MFD) is the primary determinant of mohair price we aimed to quantify the lifetime changes in mohair MFD as Angora goats aged and grew. Measurements were made over 12 shearing periods on a population of Angora goats representing the current range and diversity of genetic origins including South African, Texan and interbred admixtures of these and Australian sources. Records of sire, dam, birthweight, birth parity, liveweight, fleece growth and fleece quality were taken for does and castrated males (wethers) (n = 267 animals). Fleece-free liveweights (FFLwt) were determined for each goat at shearing time by subtracting the greasy fleece weight from the liveweight recorded immediately before shearing. A restricted maximum likelihood growth curve model was developed for relating MFD to FFLwt, age and other measurements. A simple way of describing the results is: MFD = κ (FFLwt)β E; where κ is a parameter that can vary in a systematic way with shearing(age), breed, weaning weight, sire, dam and individual; β is a parameter that is the same for nearly the whole study; and E are independent errors from a log-normal distribution. The analysis shows that = 0.34, with s.e. () = 0.021. Thus, mohair MFD was allometrically related to the cube root of FFLwt over the lifetime of Angora goats. However, the allometric proportionality constant differed in a systematic way with age at shearing, genetic strain, weaning weight, sire, dam and individual. For Texan-breed goats, MFD decreased as weaning weight increased (P = 0.00016). The findings indicate that management factors that affect liveweight and weaning weight have lifetime effects on mohair fibre diameter and therefore the value of mohair and the profitability of the mohair enterprise.

Genetic variances for liveweight and fleece traits in Merino, Dohne Merino and South African Meat Merino sheep

2001 ◽  
Vol 41 (2) ◽  
pp. 145 ◽  
Author(s):  
S. W. P. Cloete ◽  
S. J. Schoeman ◽  
J. Coetzee ◽  
J. de V. Morris
Keyword(s):  
South African ◽  
Fibre Diameter ◽  
Phenotypic Variance ◽  
Total Phenotypic Variance ◽  
Weaning Weight ◽  
Merino Sheep ◽  
Genetic Variances ◽  
Variance Ratios ◽  
Fleece Weight ◽  
Variance Estimates

(Co)variance estimates for weaning weight, yearling liveweight, clean fleece weight and fibre diameter at yearling age were obtained for Merino, Dohne Merino and South African Meat Merino flocks maintained on the same property. Direct additive genetic variances for weaning weight [expressed as a ratio of the total phenotypic variance (h2, direct heritability)] were estimated at 0.15 for Merinos, 0.21 for Dohne Merinos and 0.32 for South African Meat Merinos. Corresponding maternal variance ratios (m2, including direct maternal variance and permanent environmental maternal variance) were estimated at 0.15, 0.30 and 0.24, respectively. The correlation between direct and maternal variance ratios was high and negative in Dohne Merinos and South African Meat Merinos (–0.72 and –0.53, respectively). Direct heritability estimates for yearling liveweight were 0.30 for Merinos, 0.33 for Dohne Merinos and 0.45 for South African Meat Merinos. Corresponding maternal variance ratios were only significant in the latter 2 breeds, amounting to 0.13 in Dohne Merinos and 0.12 in South African Meat Merinos. For yearling clean fleece weight, h2 and m2 were estimated at 0.28 and 0.12, respectively, for both Merinos and Dohne Merinos. In the case of South African Meat Merinos, only the h2 estimate was significant, at 0.68. Maternal variance ratios for yearling fibre diameter were not significant in any of the breeds, while h2 ranged from 0.58 in Merinos to 0.75 in South African Meat Merinos. Selection progress for yearling traits seems likely in all breeds, depending on the breeding objectives being strived for.

scholarly journals Wool production in Dohne Merino, Dormer, Merino and South African Mutton Merino lambs

2021 ◽  
Vol 50 (6) ◽  
Author(s):  
D.A. Van der Merwe ◽  
T.S. Brand ◽  
L.C. Hoffman
Keyword(s):  
Growth Rate ◽  
South African ◽  
Crude Protein ◽  
Live Weight ◽  
Quality Analysis ◽  
Merino Sheep ◽  
Wool Growth ◽  
Fleece Weight ◽  
Sheep Production ◽  
One Year

In this study, the wool growth of Dohne Merino, Dormer, Merino and South African Mutton Merino (SAMM) lambs reared on a feedlot diet (10.62 MJ ME/ kg feed, 20.7% crude protein) was monitored from about two months old until the lambs were shorn as yearlings. The 100 cm2 patches on the left sides of the lambs were sheared monthly and the clippings were weighed to determine the wool growth rate. At approximately one year old, the lambs were shorn and the fleeces were weighed. A mid rib fleece sample was also retrieved from each lamb for quality analysis. Merino lambs presented the highest wool growth rates (12.943 g/day) and fleece weights (6.140 kg), whereas Dormer lambs exhibited the lowest values for these traits (8.487 g/day and 3.330 kg, respectively (P <0.05)). The lack of differences between Dohne Merino (9.720 g/day and 4.671 kg) and SAMM (10.553 g/day and 4.158 kg) lambs for these wool growth rate and fleece weight traits was attributed to disparities in live weight (86.8 kg and 105.2 kg, respectively (P <0.05), with heavier SAMM lambs offsetting the expected variations in fleece weight. Wool from Dohne Merino and Merino sheep had the finest fibre diameters (<21 μm), followed by SAMM wool (22–23 μm), with Dormers producing coarse wool (>27 μm). These results could be used as guidelines in sheep production to predict the income contribution of wool from these breeds.

Genetic evaluation of production traits between and within flocks of Merino sheep. I. Hogget fleece weights, body weight and wool quality

1989 ◽  
Vol 40 (2) ◽  
pp. 433 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins
Keyword(s):  
Body Weight ◽  
Environmental Effects ◽  
Genetic Variance ◽  
Research Centre ◽  
Production Traits ◽  
Merino Sheep ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight

Wool production traits were measured on Merino hogget ewes in an unselected multiple-bloodline flock over a 7-year period at Trangie Agricultural Research Centre, N.S.W. The traits measured were greasy fleece weight (GFW), skirted fleece weight (SKFW), yield (Y), clean fleece weight (CFW), fibre diameter (FD), body weight (BWT) and staple length (SL). These measurements were used to examine genetic differences between and within flocks of Merino sheep, and to estimate heritability of and genetic and phenotypic correlations among these traits. Significant strain, flock within strain and flock effects were present for all traits. Interactions between these effects and year were non-significant. Within-flock genetic variance was always larger than between-flock within strain genetic variance for each trait. The influence of environmental effects on these traits was also examined. The environmental effects of birth-rearing type, age at observation and age of dam together accounted for about 7-10% of the total within-flock variation in fleece weights and body weight.After adjusting for significant environmental effects, paternal half-sib heritability estimates were 0.29 �. 0.06 for GFW, 0.22 � 0.05 for SKFW, 0.35 � 0.05 for Y, 0.30 �0.06 for CFW, 0.48 �0.07 for FD, 0.34 �. 0.06 for BWT and 0.44 �0.07 for SL. Estimates for genetic and phenotypic correlations were in agreement with published estimates except for the genetic correlation between CFW and FD (0.40 �. 0.11), and the genetic correlations involving BWT, which were essentially zero. The implications of the results of this study for the genetic improvement of Merino sheep for wool production are discussed.

Studies on improvement of the productivity of Turkish Angora goats by crossing with South African Angora goats

2002 ◽  
Vol 45 (2) ◽  
pp. 115-122 ◽  
Author(s):  
H Günes ◽  
P Horst ◽  
M Evrim ◽  
A Valle-Zárate
Keyword(s):  
South African ◽  
Angora Goats

scholarly journals Genetic Diversity and Population Structure in South African, French and Argentinian Angora Goats from Genome-Wide SNP Data

PLoS ONE ◽  
2016 ◽  
Vol 11 (5) ◽  
pp. e0154353 ◽  
Author(s):  
Carina Visser ◽  
Simon F. Lashmar ◽  
Este Van Marle-Köster ◽  
Mario A. Poli ◽  
Daniel Allain
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
South African ◽  
Snp Data ◽  
Genome Wide ◽  
Angora Goats

Exploring online and offline shopping motivational values in Malaysia

2018 ◽  
Vol 30 (2) ◽  
pp. 352-379 ◽  
Author(s):  
Rachel Mei Ming Wong ◽  
Shiet Ching Wong ◽  
Guek Nee Ke
Keyword(s):  
Factor Analysis ◽  
Factor Model ◽  
Elaboration Likelihood Model ◽  
Elaboration Likelihood ◽  
Age Group ◽  
Content Type ◽  
Societal Values ◽  
Gender And Age ◽  
Likelihood Model ◽  
Motivational Values

Purpose The purpose of this paper is to combine the elaboration likelihood model and hedonic/utilitarian values into a coherent model of shopping motivational values for online and offline Malaysian shoppers. Once these values were identified, they were compared to one another based on shopping channel, gender, and age group. Design/methodology/approach The Shopping Motivational Value Questionnaire was developed by the researcher after extensive literature review and measured the respondent’s perception toward shopping motivational values in both shopping channels. Data were collected from 306 Malaysians above the age of 21, and analyzed using exploratory factor analysis and pairwise t-test techniques. Findings The factor analysis revealed a three-factor model of shopping motivational values. Gratification Values were the most important to shoppers, followed by Essential and Societal Values. Shoppers perceived all these motivational values as important when shopping offline as compared to online, regardless of gender and age group. Research limitations/implications The results of the factor analysis revealed a three-factor model of shopping motivational values: Gratification Values which were the most important to shoppers, followed by Essential and Societal Values. These values were then compared to one another based on shopping channel, gender, and age group. Results indicate that shoppers perceived all these motivational values as important when shopping offline rather than online, regardless of gender and age group. Moreover, the perception of shoppers toward specific product categories and other shopping channels were not taken into account. Originality/value This study attempted to combine the elaboration likelihood model and hedonic and utilitarian values into a coherent model. A questionnaire was developed by the researcher with these two theoretical models as its foundation. Additionally, the shopping motivational values of this study have been formulated to be compatible to both shopping channels.

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