Selection response to fleece weight, wool characteristics, and heritability estimates in yearling Romney sheep

Wuliji, T.; Dodds, K. G.; Andrews, R. N.; Turner, Pavla

doi:10.1016/j.livsci.2010.06.003

Cited by 13 publications

(5 citation statements)

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“…In Arabi breed generally the male are heavier than female and produce higher greasy wool than female [1], but maybe it is not significant difference between body weights in different ages of studied sheep. The effects of sex and age on fleece weight were not in agreement with previous findings [14,15].They reported that, in yearling Romney sheep as well as Awassi sheep, the males were significantly heavier than females, but females had higher wool than males, and there was no significant effect of sex on each wool characteristics. Age had a significant influence on body weight and greasy fleece weight, but males and females had similar output.…”

Section: Resultsmentioning

confidence: 52%

Evaluation certain environment factors on wool characteristics of Arabi sheep breeds

Taherpour¹,

Salehi²,

Mirzaei³

2012

OJAS

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Evaluation and grading of wool based on sex and age can help to improve economic value of wool. This study was conducted to investigate the wool production and fleece characteristics of Arabi sheep in Khuzestan province The right mid-side wool samples were taken from 90 Arabi sheep (1 -4 years; 16 male and 74 female) by hand shearing. The staple length of shoulder, flank and rump were 13.18 ± 0.27, 13.31 ± 0.22 and 14.27 ± 0.25 cm, respectively. The greasy fleece weight, wool wax, vegetable matter, yield percentage, fiber diameter and its coefficient variation measures were 1.72 ± 0.06 Kg; 2.77% ± 0.12%; 0.54% ± 0.07%; 73.36% ± 0.68%; 30 ± 0.41 μm; 30.23% ± 0.3% respectively. Correspondingly, the medulated fibers, true wool fiber and Kemp fibers were 21.6% ± 1.9%, 76.1% ± 2.04% and 2.5% ± 0.57% respectively. Age and sex had a significant influence on staple lengths. Fleece weight (P < 0.01) and wool wax were (P < 0.05) affected by sex. There was no significant interaction between age and sex groups for fiber characteristics, but it was important for staple between body location (P < 0.05). There were a low considerable kemp and CV of wool diameter percentage on Arabi sheep in comparison with the other Iranian native sheep. The wide variation in fleece weight (0.8 -3.9 kg); mean staple lengths (8.8 -19.2 cm); medulated and kemp (0 -84.04 and 0% -30.22%); fiber diameter (24.9 -37.43 μm) suggest potential for improvement of economical traits.

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Section: Resultsmentioning

confidence: 52%

Evaluation certain environment factors on wool characteristics of Arabi sheep breeds

Taherpour¹,

Salehi²,

Mirzaei³

2012

OJAS

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“…Fleece weight has previously been reported as having a significant negative correlation with methane yield (Pinares-Patiño et al, 2013). This is an interesting relationship as the expectation would be that a bigger ewe would have a heavier fleece (Wuliji et al, 2011), and increased fleece weight, given a set body weight, is associated with increased feed intake during ad libitum feeding (Schinckel, 1960). The underpinning mechanism for increased wool growth associated with lowered methane yield is unknown, but it reflects that selection for changing methane emissions and the resulting impact on rumen outflow may have effects on the animal that are yet to be understood.…”

Section: Discussionmentioning

confidence: 79%

Impact of breeding for reduced methane emissions in New Zealand sheep on maternal and health traits

et al. 2022

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Enteric methane emissions from ruminants account for ∼35% of New Zealand’s greenhouse gas emissions. This poses a significant threat to the pastoral sector. Breeding has been shown to successfully lower methane emissions, and genomic prediction for lowered methane emissions has been introduced at the national level. The long-term genetic impacts of including low methane in ruminant breeding programs, however, are unknown. The success of the New Zealand sheep industry is currently heavily reliant on the prolificacy, fecundity and survival of adult ewes. The objective of this study was to determine genetic and phenotypic correlations between adult maternal ewe traits (live weight, body condition score, number of lambs born, litter survival to weaning, pregnancy scanning and fleece weight), faecal and Nematodirus egg counts and measures of methane in respiration chambers. More than 9,000 records for methane from over 2,200 sheep measured in respiration chambers were collected over 10 years. Sheep were fed on a restricted diet calculated as approximately twice the maintenance. Methane measures were converted to absolute daily emissions of methane measured in g per day (CH4/day). Two measures of methane yield were recorded: the ratio of CH4 to dry matter intake (g CH4/kg DMI; CH4/DMI) and the ratio of CH4 to total gas emissions (CH4/(CH4 + CO2)). Ewes were maintained in the flocks for at least two parities. Non-methane trait data from over 8,000 female relatives were collated to estimate genetic correlations. Results suggest that breeding for low CH4/DMI is unlikely to negatively affect faecal egg counts, adult ewe fertility and litter survival traits, with no evidence for significant genetic correlations. Fleece weight was unfavourably (favourably) correlated with CH4/DMI (rg = −0.21 ± 0.09). Live weight (rg = 0.3 ± 0.1) and body condition score (rg = 0.2 ± 0.1) were positively correlated with methane yield. Comparing the two estimates of methane yield, CH4/DMI had lower heritability and repeatability. However, correlations of both measures with adult ewe traits were similar. This suggests that breeding is a suitable mitigation strategy for lowering methane yield, but wool, live weight and fat deposition traits may be affected over time and should be monitored.

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“…The effect of year on clean fleece weight was nominal, explaining only approximately 1% of the variation. Wool characteristics are moderately (0.24 to 0.36 h 2 ; Wuliji et al, 2011) to highly (0.37 to 0.56 h 2 ; Safari et al, 2005) heritable, and wool traits would be expected to change with market demands. Over the time period reflected in this paper, there was a robust drive for meat production (Jones, 2004).…”

Section: Resultsmentioning

confidence: 99%

“…Wool price (average market price of all wool grades), surprisingly, did not correlate (P ≥ 0.5) to spinning count (a measure of wool quality) at any of the time lags investigated (Table 1). Wool characteristics are moderately (0.24 to 0.36 h 2 ; Wuliji et al, 2011) to highly (0.37 to 0.56 h 2 ; Safari et al, 2005) heritable, so it is somewhat surprising that as the wool market declined (Richardson 2001;Jones, 2004), wool diameter did not increase as market forces favored lamb production over wool production. However, in a declining wool market, finer wool would always garner a higher price.…”

Section: Resultsmentioning

confidence: 99%

50 years of the Wyoming ram test: How sheep have changed

Burton

Ludden

Stobart

et al. 2015

Journal of Animal Science

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Production characteristics of white-faced rams have been systematically evaluated over a 140-d test in Wyoming since 1961. Individual test records ( = 4,240) from rams on test were analyzed to determine change over the past 52 yr. Although rams on test are not older, weight on and off test has increased ( < 0.001) since 1961. Weight off test increased 22.7 kg and contributed to an increase ( < 0.001) in clean fleece weight. Rate of gain ( < 0.001) almost doubled over this 50-yr period. Growth efficiency improved from 0.23 ± 0.01 kg/d from 1961 to 1966 to 0.39 ± 0.01 kg/d from 2008 to 2013. Cubic, rather than linear, effects better explain the change in growth characteristics, suggesting a plateau or tapering of these traits. Wool characteristics remain an important component of the test index, and despite increases in body size and gain, wool diameter was unchanged ( > 0.15). Average daily gain correlated ( > 0.67; < 0.001) with lamb and feeder lamb price, with the strongest correlation at a 2-yr ( > 0.76) time lag. U.S. sheep inventory was negatively correlated ( > -0.72; < 0.001) with sheep price and ADG, with the greatest correlation at no time lag. Wool price 0, 2, or 5 yr prior did not correlate ( < 0.1; ≥ 0.5) with spinning count. Influences on white-faced ram selection appear to have largely impacted growth traits while avoiding negative impacts on wool quality.

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Selection response to fleece weight, wool characteristics, and heritability estimates in yearling Romney sheep

Cited by 13 publications

References 13 publications

Evaluation certain environment factors on wool characteristics of Arabi sheep breeds

Evaluation certain environment factors on wool characteristics of Arabi sheep breeds

Impact of breeding for reduced methane emissions in New Zealand sheep on maternal and health traits

50 years of the Wyoming ram test: How sheep have changed

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