Response to selection in Australian Merino sheep. VII. Phenotypic and genetic parameters for some wool follicle characteristics and their correlation with wool and body traits

Jackson, N; Nay, T; Turner, HN; Newton, Turner H

doi:10.1071/ar9750937

Cited by 30 publications

(14 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is due to the effect of in utero competition for nutrients on follicle initiation, with fewer secondary follicles being produced in twin-born lambs (Schinckel 1953;Jackson et al 1975;Hocking Edwards et al 1996), although there is some evidence that these differences in the follicle population do not persist in all Merinos (Thompson et al 2007). Furthermore, nutrition of ewes during pregnancy and lactation affects wool production over the life of both single-and twin-born progeny.…”

Section: Introductionmentioning

confidence: 99%

Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs

2011

View full text Add to dashboard Cite

Abstract. The effect on ewe and lamb production by differential management of single-and twin-bearing Merino ewes during pregnancy and lactation was examined. The hypothesis that the survival and productivity of single-and twin-born progeny is not affected by differential management of single-and twin-bearing ewes was tested. To test this hypothesis, two ewe flocks were monitored on a commercial property in the south-east of South Australia. The body condition score of one flock of ewes was managed according to Lifetimewool recommendations for southern Australian (Lifetimewool flock; n = 464). Lifetimewool recommendations are that body condition score should be 3.0 at mating and then allowed to decline to an average of 2.7, which is maintained until lambing. Twin-and single-bearing ewes were managed as separate mobs after pregnancy scanning to meet their energy requirements. The second flock was managed similarly to the commercial ewe flock and was representative of ewe management practices in the region (normal-practice flock; n = 464). At lambing, the condition score of the Lifetimewool flock was 0.7 condition scores units greater than the normal-practice flock. Ewe clean fleece weight and fibre diameter were greater in the Lifetimewool flock and their lambs had higher survival rates to weaning. Over three shearings, progeny from Lifetimewool ewe flocks produced more clean wool (P < 0.0001) but there was no consistent effect on fibre diameter, staple length or staple strength. Twin-born lambs from ewes managed to Lifetimewool guidelines had a similar liveweight and produced similar quantity and quality of wool to single-born lambs managed to Lifetimewool guidelines, but still suffered higher rates of mortality to weaning. This suggests that it is possible to manage ewes pregnant with twins to ensure that their surviving progeny perform at a level similar to single-born progeny managed under similar targets.

show abstract

Section: Introductionmentioning

confidence: 99%

Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs

2011

View full text Add to dashboard Cite

show abstract

“…The weight and diameter of wool produced by sheep is influenced by the ratio of secondary to primary wool follicles and the number of secondary follicles is genetically controlled (Jackson et al 1975;Hocking Edwards et al 1994). Secondary wool follicles are initiated between Day 80 of fetal life and just before birth and most secondary follicles commence producing a fibre 1-3 weeks after birth (Short 1955a;Hocking Edwards 1999).…”

Section: Introductionmentioning

confidence: 99%

Improving the nutrition of Merino ewes during pregnancy increases the fleece weight and reduces the fibre diameter of their progeny's wool during their lifetime and these effects can be predicted from the ewe's liveweight profile

Thompson

Ferguson

Gordon³

et al. 2011

Anim. Prod. Sci.

View full text Add to dashboard Cite

Abstract. Nutrition of ewes during pregnancy can have permanent impacts on the production potential of their progeny. The hypothesis tested in the experiments reported in this paper was that improving the nutrition of Merino ewes during pregnancy and lactation increases the fleece weight and reduces the fibre diameter of their progeny's wool during their lifetime. In addition, that these effects on the progeny's wool production can be predicted from the ewe's liveweight profile. At sites in Victoria and Western Australia in each of 2 years, a wide range in the liveweight and condition score profiles of Merino ewes was generated by varying the amount of supplements fed from joining to Day 100 of pregnancy and the amount of feed on offer grazed from Day 100 to weaning. The site in Victoria was based on perennial pastures and included both single-and twin-bearing ewes whereas the site in Western Australia was based on annual pastures and included singlebearing ewes only. The production and characteristics of wool from the progeny were measured until 51 months of age at the site in Victoria and 33 months of age at the site in Western Australia. The nutritional treatments and the resulting changes in ewe liveweight had significant impacts on the fleece weight and to a lesser extent the fibre diameter of wool produced by their progeny, but there were no consistent effects on other characteristics of progeny fleece wool. The fleece weight of the progeny was related to the liveweight change during pregnancy of their mothers (P < 0.05) and the relationships were similar for the two experiments at each site. At the site in Victoria, a loss of 10 kg in ewe liveweight between joining and Day 100 of pregnancy reduced fleece weight by~0.2 kg at each shearing until 51 months of age whereas gaining 10 kg from Day 100 of pregnancy to lambing had the opposite effect. The effect of changes in ewe liveweight during late pregnancy on the fleece weight of their progeny at each shearing was of similar magnitude at the site in Western Australia. When evident, the effect of the ewe liveweight profile on the fibre diameter of progeny wool was opposite to the effect on clean fleece weight and the effect of poor nutrition in early to mid pregnancy could be completely overcome by improving nutrition during late pregnancy. Twin-born and reared progeny produced~0.3 kg less clean wool at each shearing (P < 0.001) that was 0.3-mm broader (P < 0.001) than that from single-born progeny at the site in Victoria. However, the effects of varying ewe nutrition and ewe liveweight change during pregnancy on fleece weight and fibre diameter of progeny wool were similar (P > 0.05) for both single-and twin-born or reared progeny. Overall, these results supported our hypothesis and it is clear that the nutritional management of Merino ewes during pregnancy is important for optimal wool production from their progeny during their lifetime.

show abstract

“…Despite high correlations between some pelt and follicle characters, selection based on indirect characters has not always resulted in expected responses. For instance, Jackson et al (20) and Rendel and Nay (21) found no increase in clean wool weight when they selected for increased S/P ratio, follicle depth, follicle density, or total follicle number, despite follicle characters changing in the expected direction with selection.…”

Section: Discussionmentioning

confidence: 99%

“…The lambs were born during the spring and were evaluated subjectively for pelt traits (curl type, curl breadth, pattern, luster, color, and final pelt score) by a pelt assessor according to the method described in the guidelines of the Karakul Pelt Assessment Committee of Iran (7). Based on these guidelines, the score of curl breadth in different colors of pelt ranges between 5 and 10 (a score of 5 denotes inferior while a score of 10 denotes excellent), along with scores for luster (5-10), pattern (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), pelt size (0-5), skin thickness (0-5), and curl type , and then the final score of the pelt based on the scores given to the above characteristics is given to the lamb.…”

Section: Methodsmentioning

confidence: 99%

Characteristics of pelt follicles and their relationship with pelt quality in fat-tailed Gray Shirazy sheep*

Safdarian¹,

Hashemi²,

Hashemi³

2017

Turk J Vet Anim Sci

View full text Add to dashboard Cite

IntroductionPelt quality is very important in animal production because together with the size of skin it can determine the price of the skin. Pelt quality is a composite trait, including color and purity, structure and length of guard hair, and density of the wool. The characteristics that cause a pelt to be classified as high quality are difficult to quantify. One skin might be classified as high quality due to a silky appearance of the pelt and another due to the high density and structure of the wool. It is therefore of interest to understand which single traits influence the classification of skin as high quality.Karakul sheep has been raised to produce valuable meat, wool, and milk and high-quality pelts in Fars, Markazi, and Khorasan provinces of Iran and it is called Gray Shirazy, Zandy, and Karakul in these regions, respectively. Although selection is always ongoing for better pelt grades, this sheep has rarely been raised only for pelt production since 1968. Newborn lambs usually have tightly curled black, gray (mixture of black and white wool), brown, and sur-color (mixture of brown and white wool) fur and may be slaughtered for pelt production soon after birth. The finest pelts are often obtained from unborn lambs. The value of a pelt is determined by its particular pattern, which will appeal to the selective buyer. The difference between high-and low-quality pelts could be made with minute deviations in a particular pattern at birth. A few days of postnatal development can result in major changes in the coat that make the pelt totally unfit for utilization in trade (1).The lamb growth rate of Karakul sheep is moderate to high and they produce good-quality meat. These sheep are sometimes categorized as 'broadtail' or 'fat-tailed' sheep, because they store fat in their tails for adaptation and survival in harsh and dry conditions. The wool product of Karakul sheep has been classified as carpet wool and is a mixture of coarse and fine fibers, with color varying from black to various shades of gray and brown. Traditionally,

show abstract

Response to selection in Australian Merino sheep. VII. Phenotypic and genetic parameters for some wool follicle characteristics and their correlation with wool and body traits

Cited by 30 publications

References 17 publications

Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs

Managing the nutrition of twin-bearing ewes during pregnancy using Lifetimewool recommendations increases production of twin lambs

Improving the nutrition of Merino ewes during pregnancy increases the fleece weight and reduces the fibre diameter of their progeny's wool during their lifetime and these effects can be predicted from the ewe's liveweight profile

Characteristics of pelt follicles and their relationship with pelt quality in fat-tailed Gray Shirazy sheep*

Contact Info

Product

Resources

About