Environmental effects on fleece and body traits of South Australian Angora goats

Gifford, D. R.; Ponzoni, R. W.; Burr, John; Lampe, RJ

doi:10.1016/0921-4488(90)90042-5

Cited by 15 publications

(4 citation statements)

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“…The results obtained in this research indicated that the overall least squares means for kid weight at different ages were similar with the results reported by Horst et al (1993) and Gunes et al (2002) in Turkish Angora goats, Nicoll (1985) in New Zealand Angora goats, Gifford et al (1990) in Australian Angora goats, Koratkar et al (1990) in Indian Angora goats and Said et al (1990) in Iraq Angora goats. The least square mean for yearling greasy fleece weight was lower than those reported for Angora goat by Yalcin et al r p : phenotypic correlations between traits 1and 2; r d : direct genetic correlation between trait 1 and trait 2; r m : maternal additive genetic correlation between trait1 and trait 2; r c : maternal permanent environmental correlations between traits 1and trait 2; r e : environmental correlations between traits 1and trait 2; a For traits abbreviations see footnote of Table 1.…”

Section: Discussionsupporting

confidence: 89%

“…These results obtained from this research are in agreement with other results reported by Nicoll (1985), Horst et al (1993) and Wenzhong et al (2005). Although the results reported by these workers indicated that the age of dam and type of birth effects would be expected to be of lesser important at post weaning traits (Nicoll, 1985;Gifford et al, 1990;Wenzhong et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

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Genetic and Phenotypic Parameter Estimates of Body Weight at Different Ages and Yearling Fleece Weight in Markhoz Goats

Rashidi¹,

Sheikhahmadi²,

Rostamzadeh³

et al. 2008

Asian Australas. J. Anim. Sci

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The objective of the present study was to estimate genetic parameters for economic traits in Markhoz goats. Data collected from 1993 to 2006 by the Markhoz goat Performance Testing Station in Sanandaj, Iran, were analyzed. The traits recorded as body weight performance at birth (BW), weaning (WW), six month (6MW), nine month (9MW), yearling (YW) and yearling fleece weight (YFW) were investigated. Least square analyses were used for estimation of environmental effects. Genetic parameters were estimated with single and multi trait analysis using restricted maximum likelihood (REML) procedures, under animal models. By ignoring or including maternal additive genetic effects and maternal permanent environmental effects, five different models were fitted for each trait. The effects of sex, type of birth, age of dam and year of birth on the all body weights were significant (p<0.01), but had no effects on YFW except year of birth. Age of kids had significant influences on WW and 6MW (p<0.01). A log likelihood ratio test was carried out for choosing the most suitable model for each trait. Total heritability estimates for YFW and growth traits varied from 0.16 for YFW and WW to 0.41 for YW. For all traits, maternal heritability was lower than direct heritability, ranging from 0.06 for BW to 0.01 for 6MW and 9MW. The magnitude of c 2 was more substantial for BW than the others, and relative importance was reduced from 0.12 for BW to 0.04 for 9MW. The direct additive genetic correlations estimates were positive and varied from 0.21 between BW-YW to 0.96 between WW-6MW. Direct additive genetic correlations between YFW and body weight traits were positive and ranged from 0.14 between BW-YFW to 0.67 between 6MW-YFW. For all traits, the corresponding estimates for phenotypic correlation were positive and lower than genetic correlations. The maternal additive genetic correlations between various traits were varied and ranged from -0.19 between 9MW-YFW to 0.96 between 6MW-9MW. The estimates of the maternal permanent environmental correlations between various traits were positive and ranged from 0.33 between WW-YFW to 0.93 between WW-6MW. Also, the environmental correlations between various traits ranged from 0.01 between BW-YFW and WW-YFW to 0.70 between 9MW-YW. Estimates of genetic parameters for various traits in this study confirm that selection should be applied on WW for genetic improvement in Markhoz goats.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Genetic and Phenotypic Parameter Estimates of Body Weight at Different Ages and Yearling Fleece Weight in Markhoz Goats

Rashidi¹,

Sheikhahmadi²,

Rostamzadeh³

et al. 2008

Asian Australas. J. Anim. Sci

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“…For example, the Sonora test results for Texan Angora bucks in 2010 showed med and kemp averages of 0.28 and 0.11%, respectively. Total medullation is 1.22%, considerably more than 0.28 and 0.35% reported by Snyman (2002) for South African Angora populations and considerably less than 3.8-10.1% reported by Gifford et al (1990) for an Australian Angora population. Using the Newman and Paterson (1999) criterion that first class mohair must have less than 2% kemp, the Tajik fleeces would qualify as first class.…”

Section: Mohair Medullationmentioning

confidence: 69%

“…Culling highly medullated goats would improve current flock mohair quality but genetic improvement through selection would be slow if heritability of medullation is low as it is in other Angora goat populations (e.g. Gifford et al, 1990). An option is to reduce medullation through introduction of genetically medullation-free animals (Newman and Paterson, 1999).…”

Section: Practical Implicationsmentioning

confidence: 99%

Evaluation of mohair quality in Angora goats from the Northern dry lands of Tajikistan

Kosimov

KOSIMOV

Rischkowsky

et al. 2013

Small Ruminant Research

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Mohair quality of Angora goats in the Sogd Province of Tajikistan was assessed in spring and autumn 2007 and 2008 by inspecting and sampling a total of 797 goats of both sexes, different ages and several coat colors from 15 randomly selected flocks. Fiber fineness was assessed visually on the Bradford scale, staple length was measured with a ruler. Midside fleece samples were analyzed with an OFDA instrument to determine average fiber diameter, standard deviation, coefficient of variation (CVFD), comfort factor, fiber curvature and fiber length. On a subset of 153 goats, kemp and med fiber percentage was determined inspecting 300 fibers of each goat with a projection microscope. Mixed model procedures were used to analyze the data. Residuals of the model were used to calculate correlations. The random flock effect was significant for all traits and the fixed sex, age, and color effects were significant for most traits. In spring shearing data, fiber diameter of males were 2.7 µm coarser than females and increased with age: 27.3 µm (one year old), 31.3 µm (two years old), 34.6 µm (three to five years old) and 37.0 µm (six years and older). Mohair fiber length ranged 137.3-174.7 mm between ages. Six month old kid mohair (autumn shearing) was finest (24.4 µm) and shortest (95.1 mm). White mohair was approximately 3 µm coarser than brown and grey mohair. CVFD was not affected by sex and age but related to color with white mohair having a lower CVFD. Comfort factor and visual Bradford count decreased with age. Average med and kemp percentages were 0.88 and 0.34. Almost 20% of goats had 2% or more medullated fibers. The phenotypic correlation between fiber diameter and med percentage was 0.40 and between fiber diameter and kemp percentage -0.08. On average, visual Bradford count underestimated fiber diameter by about 4.1 µm. The correlation between fiber diameter and Bradford count was -0.28. Thus, visual assessment of fiber diameter is imprecise and reduction of fiber diameter through selection would therefore require analysis of fleece samples. The correlation between staple length and fiber length was 0.78. Thus, ruler determination of staple length measured on the live animals is a good estimator of fiber length measured on the fleece sample. In comparison with South African mohair, Tajik mohair is not only white, has long fibers, is rather coarse and medullated. Given the high variation between and within flocks in fiber diameter and medullation there is room for culling inferior animals and improve current mohair quality.

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Phenotypic and genetic parameters of fleece traits and live weight in South Australian Angora goats

Gifford¹,

Ponzoni²,

Lampe³

et al. 1991

Small Ruminant Research

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Environmental effects on fleece and body traits of South Australian Angora goats

Cited by 15 publications

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Genetic and Phenotypic Parameter Estimates of Body Weight at Different Ages and Yearling Fleece Weight in Markhoz Goats

Genetic and Phenotypic Parameter Estimates of Body Weight at Different Ages and Yearling Fleece Weight in Markhoz Goats

Evaluation of mohair quality in Angora goats from the Northern dry lands of Tajikistan

Phenotypic and genetic parameters of fleece traits and live weight in South Australian Angora goats

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