Shearing Merino ewes at different stages of pregnancy: effects on fleece characteristics of progeny

2010 ◽  
Vol 50 (6) ◽  
pp. 603 ◽  
Author(s):  
E. H. van Reenen ◽  
P. R. Kenyon ◽  
R. G. Sherlock ◽  
R. E. Hickson ◽  
S. T. Morris
Keyword(s):  
Skin Biopsy ◽  
Fibre Diameter ◽  
Late Pregnancy ◽  
Secondary Follicle ◽  
Staple Strength ◽  
Fleece Weight ◽  
Yield Colour ◽  
Staple Length

Shearing strong-wool ewes at different stages of pregnancy has been shown to influence the follicle population of the offspring which may result in a finer, heavier fleece. The aim of this study was to investigate the effect of shearing time of Merino ewes on the liveweight, fleece characteristics and follicle population of their progeny. Pregnant Merino ewes were allocated to one of three shearing times; mid-pregnancy (d106; 106 days from the introduction of the ram), late-pregnancy (d141) and post-lambing (d191). A skin biopsy was taken from the mid-side of 128 lambs at d359 (~7 months of age) and analysed for primary and secondary follicle density. Mid-side wool samples were collected at d359, d499 and d716. Samples from d359 and d716 were analysed for washing yield, colour and fibre diameter. Greasy fleece weight was measured on d499 and a mid-side sample was taken to measure staple length and staple strength. Shearing time of Merino ewes had no effect on lamb liveweight at any stage of the experiment. Lambs born to ewes shorn during pregnancy had a lesser (P < 0.05) follicle density, secondary follicle density, follicle number index (FNI) and secondary FNI than those born to ewes shorn post-lambing. However, there was no effect (P > 0.05) of dam shearing treatment on fleece characteristics of progeny. The results indicate that, under the conditions of this study shearing Merino ewes in mid-to-late pregnancy did not alter the fleece characteristics of their progeny.

scholarly journals The wool production and reproduction of Merino ewes can be predicted from changes in liveweight during pregnancy and lactation

2011 ◽  
Vol 51 (9) ◽  
pp. 763 ◽  
Author(s):  
M. B. Ferguson ◽  
A. N. Thompson ◽  
D. J. Gordon ◽  
M. W. Hyder ◽  
G. A. Kearney ◽  
...  
Keyword(s):  
Fibre Diameter ◽  
Late Pregnancy ◽  
Reproductive Rate ◽  
Breeding Cycle ◽  
Wool Production ◽  
Condition Score ◽  
Pregnancy And Lactation ◽  
Influence Of Food ◽  
Staple Strength ◽  
Fleece Weight

Defining the nature of the relationship between change in liveweight throughout a breeding cycle and ewe wool production and reproduction would be useful for developing management guidelines for Merino ewes. In this paper we tested the hypotheses that (1) feed on offer has variable effects on liveweight profiles of individual ewes; and (2) liveweight profiles of individual ewes can be used to predict their fleece wool production and reproductive performance. At sites in Victoria and Western Australia in 2001 and 2002, pregnant Merino ewes were exposed to 10 nutritional treatments. In each of the four experiments, ewes in average condition score 3 at artificial insemination were fed to achieve either maintenance or loss of a condition score over the first 100 days of pregnancy before grazing one of five levels of feed on offer between Day 100 and lamb weaning. Across all four experiments, the average difference in ewe liveweight between extreme treatments was: 7.0 kg (range 4.7–8.7 kg) at Day 100 of pregnancy; 11.9 kg (range 4.9–17.8 kg) at lambing; and by weaning was 13.9 kg (range 8.8–22.7 kg). Liveweight at joining and liveweight change during pregnancy and lactation of individual Merino ewes were significantly related to their clean fleece weight, fibre diameter and staple length and thus the second hypothesis was supported. Heavier ewes at joining produced more wool that was longer and broader and this effect was consistent across both sites and years. A 10-kg loss in ewe liveweight between joining and mid pregnancy, mid pregnancy and lambing or during lactation reduced clean fleece weight by 0.4–0.7 kg and fibre diameter by 0.5–1.4 um. At the Victorian site, where ewes were shorn in summer, a loss of 10 kg in liveweight between joining and Day 100 of pregnancy reduced staple strength by 5 N/ktex. As expected the influence of food on offer on changes in ewe liveweight was different between years and sites and between late pregnancy and lactation due to a complex group of pasture and animal factors. Therefore, managing changes in ewe liveweight itself rather than feed on offer will achieve more predictable outcomes. A higher liveweight at joining resulted in a predictable improvement in ewe reproductive rate and liveweight at joining was more important than the liveweight profile leading up to joining. This paper has shown that it is possible to predict the differences in wool production and reproductive rate of flocks of Merino ewes if ewe liveweight records at key times are known.

Selection for ultrafine Merino sheep in New Zealand: heritability, phenotypic and genetic correlations of live weight, fleece weight and wool characteristics in yearlings

2001 ◽  
Vol 72 (2) ◽  
pp. 241-250 ◽  
Author(s):  
T. Wuliji ◽  
K. G. Dodds ◽  
J. T. J. Land ◽  
R. N. Andrews ◽  
P. R. Turner
Keyword(s):  
New Zealand ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Live Weight ◽  
Production Traits ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Staple Strength ◽  
Fleece Weight ◽  
Staple Length

AbstractMerino yearling records from 1988 to 1992 birth years in ultrafine wool selection and random control flocks at Tara Hills High Country Station, New Zealand were analysed for live weight, fleece weight and wool characteristics. Estimates of heritability, genetic and phenotypic correlations among traits using REML methods are presented. Heritabilities (h2) of birth, weaning, autumn, spring and summer live weights and greasy and clean fleece weights were estimated as being 0·35, 0·34, 0·44, 0·43, 0·49, 0·24 and 0·28 respectively; while h2 of yield, fibre diameter, coefficient of variation in fibre diameter, staple crimp, staple length, staple strength, position of break, resistance to compression, bulk, CIE Y and CIE Y-Z were estimated to be 0·58, 0·59, 0·60, 0·45, 0·71, 0·13, 0·18, 0·46, 0·38, 0·38 and 0·42 respectively. Genetic correlations were found to be high among the live weights but low to moderate among fleece weight and wool characteristics. Heritability estimates of fibre diameter, fibre diameter variation and staple length were found to be higher in New Zealand fine wool Merinos than most of those reported in the literature. The results indicate that selection for reduced fibre diameter will have little effect on other major production traits such as live weight and fleece weight.

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.

scholarly journals The effects of pasture inputs and intensive rotational grazing on superfine wool production, quality and income

2013 ◽  
Vol 53 (8) ◽  
pp. 750 ◽  
Author(s):  
D. Cottle ◽  
C. A. Gaden ◽  
J. Hoad ◽  
D. Lance ◽  
J. Smith ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Management Strategies ◽  
Fibre Diameter ◽  
Production Quality ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Wool Production ◽  
Staple Strength ◽  
Fleece Weight ◽  
Staple Length

A farmlet experiment was conducted between July 2000 and December 2006 as part of the Cicerone Project, which sought to enhance the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A self-replacing Merino enterprise was grazed as the dominant livestock enterprise, together with ~20% of the carrying capacity as cattle, on each of three farmlet treatments: higher levels of soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet A), moderate soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet B) and moderate soil fertility and pasture renovation with intensive rotational grazing over 37 paddocks (farmlet C). Prior to commencement of the trial, the three 53-ha farmlets were allocated equivalent areas of land based on soil type, slope and recent fertiliser history. This paper describes the effects of the three pasture and grazing management strategies on the production, quality and value of the wool produced per head, per ha and per farmlet. Up until 2001 there were no differences in wool production between farmlets. Thereafter, significant differences between farmlets emerged in greasy fleece weight per head and price received per kg of fleece wool. For example, the clean fleece value averaged over the 2003–05 shearings for all hoggets, ewes and wethers was 1531, 1584 and 1713 cents/kg for farmlets A, B and C, respectively. There were small but significant differences, which varied between sheep class and year, between the farmlets in average fibre diameter and staple length but less so with staple strength. In general, while the differences between farmlets in staple strength varied over time, farmlets A and B tended to have wool with longer staple length and broader fibre diameter than farmlet C and this affected wool value per kg. Differences in wool income per ha between farmlets grew in later years as the farmlet treatments took effect. In spite of farmlet A having a slightly lower wool value per kg, after taking into account its greater fleece weight per head and its higher stocking rate, the total wool income per ha was higher than on either farmlets B or C. The average gross wool income per ha from 2003 to 2005 was $303, $215 and $180 for farmlets A, B and C, respectively. The highest amount of greasy wool produced was in 2004 when 38.2, 26.5 and 21.5 kg/ha was harvested from farmlets A, B and C, respectively. The fibre diameter profiles of 2-year-old ewes showed similar profiles for farmlets A and B but a significantly finer fibre diameter profile for farmlet C ewes due to intensive rotational grazing. However, sheep on all three farmlets produced wool with high staple strength. Multivariate analyses revealed that greasy fleece weight, staple length and staple strength were significantly positively correlated with the proportion of the farm grazed at any one time, and with soil phosphorus, legume herbage and green digestible herbage thus highlighting the significant influence of pasture and soil inputs and of grazing management on wool production and quality.

scholarly journals 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

2011 ◽  
Vol 51 (9) ◽  
pp. 794 ◽  
Author(s):  
A. N. Thompson ◽  
M. B. Ferguson ◽  
D. J. Gordon ◽  
G. A. Kearney ◽  
C. M. Oldham ◽  
...  
Keyword(s):  
Western Australia ◽  
Opposite Effect ◽  
Fibre Diameter ◽  
Late Pregnancy ◽  
Wool Production ◽  
Wide Range ◽  
Condition Score ◽  
Pregnancy And Lactation ◽  
Fleece Weight ◽  
Poor Nutrition

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 single-bearing 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-μm 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.

The effect of nutrition in mid pregnancy and ewe liveweight change on birth weight and management for lamb survival in highly fecund ewes

1992 ◽  
Vol 32 (1) ◽  
pp. 1 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
PJ Holst
Keyword(s):  
Birth Weight ◽  
Treatment Period ◽  
Litter Size ◽  
Late Pregnancy ◽  
Weather Conditions ◽  
Gestation Length ◽  
Nutritional Treatment ◽  
Lamb Survival ◽  
Staple Strength ◽  
Fleece Weight

The effect of moderate undernutrition in mid pregnancy on lamb birth weight and survival of single- and multiple-bearing ewes is reported. A total of 1220 ewes of 3 crossbred types with different fecundity, Booroola Merino x Dorset (BD), Trangie Fertility Merino x Dorset (TD) and Border Leicester x Merino (BLM), were examined over 2 years. The treatments were low (L) and high (H) nutrition at pasture for 4 weeks from about day 75 of pregnancy. Ewe liveweight of the L group at the end of the treatments was 5 kg lower in 1984 and 8 kg lower in 1985 (P<0.01) than the H group. The differences were smaller by late pregnancy and post-lambing. The L treatment increased (P<0.01) birth weight by 0.16 kg in 1984 but had little effect in 1985. Litter size had the greatest effect on birth weight (P<0.01). Ewe crossbred type and lamb sex effects were also significant (P<0.01), although they tended to be reduced for higher order births. Nutritional treatment had no effect on gestation length. Ewe liveweight at joining and weight gains before and after the treatment period significantly affected birth weight and accounted for the large difference in birth weight between years (0.7 kg). Ewe weight gain during the treatment period in mid pregnancy had no significant effect on lamb birth weight. Nutritional treatment in mid pregnancy had no effect on lamb survival. Litter size significantly affected lamb survival, although inclusion of birth weight in the model reduced the effect. Weather conditions, as measured by chill index, significantly (P<0.01) affected lamb survival in 1984 but accounted for less variation in 1985 (P<0.05). Lamb survival for ewes was ranked BLM > TD > BD. Maximum survival was achieved at birth weights of 4-5 kg from BD and TD ewes and 5-6 kg from BLM ewes. The L treatment reduced (P<0.01) ewe greasy fleece weight by 0.15 kg but did not affect staple strength. Plasma glucose concentration at the end of treatment was lower (P<0.01) for L ewes, but there was no difference between L and H ewes in late pregnancy. Glucose declined with increasing fetal number. Plasma B-hydroxybutyrate concentration was lower for the H group than for L, and also for BLM than TD and BD ewes (P<0.01).

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.

Fibre diameter and staple strength of sheep selected for divergent clean fleece weight when subjected to an increase in intake or an increase in intake and diet change

2005 ◽  
Vol 56 (2) ◽  
pp. 195 ◽  
Author(s):  
M. A. Friend ◽  
G. E. Robards
Keyword(s):  
Growth Rate ◽  
Stepwise Regression ◽  
Fibre Diameter ◽  
Dietary Treatment ◽  
Diet Change ◽  
Wool Growth ◽  
Ad Libitum ◽  
Staple Strength ◽  
Fleece Weight ◽  
Ad Libitum Feeding

Merino wethers with a high (fleece plus, Fl+) or low (fleece minus, Fl–) potential for wool growth were offered a restricted intake of either oat grain or lucerne chaff for 8 weeks followed by ad libitum lucerne chaff for 4 weeks. The Fl– sheep that were fed oats then lucerne had a lower (P < 0.05) intake during the first 2 weeks of ad libitum feeding than all other groups. Staple strength of Fl+ sheep (37.5 ± 2.2 N/ktex) was less (P < 0.05) than that of Fl– sheep (44.5 ± 2.4 N/ktex), and dietary treatment did not significantly affect staple strength. Wool growth rate was unaffected by dietary treatment, but was greater (P < 0.001) for Fl+ (6.4 ± 0.2 µg/mm2.day) than for Fl– (4.0 ± 0.2 µg/mm2.day) sheep. Along-fibre variation in diameter was greater (P < 0.001) in Fl+ (15.6 ± 0.5%) than in Fl– (9.9 ± 0.5%) sheep. Between-fibre variation in diameter was greater (P < 0.001) in Fl+ (16.5 ± 0.5%) than in Fl– (13.2 ± 0.5%) sheep, and between-fibre variation in diameter was affected (P < 0.05) by dietary treatment in Fl+ sheep. Staple strength was significantly correlated (P < 0.05) with along-fibre variation in diameter (r = –0.48), and stepwise regression analysis indicated that along-fibre variation in diameter, wool growth rate during early restricted feeding, and minimum fibre diameter explained 63% of the variance in staple strength. The results are discussed in relation to the lower staple strength of Fl+ sheep.

Effect of stocking rate on fleece measurements and their relationships in merino sheep

1976 ◽  
Vol 27 (1) ◽  
pp. 163 ◽  
Author(s):  
DH White ◽  
BJ McConchie
Keyword(s):  
Fibre Diameter ◽  
Major Determinant ◽  
Stocking Rate ◽  
Merino Sheep ◽  
Wool Production ◽  
Rate Experiment ◽  
Fleece Weight ◽  
One Year ◽  
Staple Length

The wool characteristics of Merino wethers were measured for 6 years in a stocking rate experiment. The decline in fleece weight due to increasing stocking rate from 4.9 to 12.4 sheep per hectare was usually accompanied by a reduction in fibre diameter and staple length and an increase in staple crimp frequency. The magnitude of these responses differed considerably between years; in one year clean fleece weight was reduced by 50%, with an associated reduction of 5 µm in mean fibre diameter and one of 2 cm in staple length. In four of the six years of the experiment, variation in fibre diameter accounted for at least 50% of the variation in wool production between stocking rate treatments. The relationships between clean fleece weight and fibre diameter were similar between years, mean fibre diameter being reduced by about 1.8 �m for each kilogram reduction in clean fleece weight. Fibre diameter is the major determinant of wool price, and this information should improve the prediction of economic responses to changes in stocking rate.

A note on the effect of the F gene on wool production and live weight of Booroola × South Australian Merino rams

1985 ◽  
Vol 40 (2) ◽  
pp. 367-369 ◽  
Author(s):  
R. W. Ponzoni ◽  
M. R. Fleet ◽  
J. R. W. Walkley ◽  
S. K. Walker
Keyword(s):  
Birth Weight ◽  
Fibre Diameter ◽  
Live Weight ◽  
Pleiotropic Effects ◽  
High Fecundity ◽  
Wool Production ◽  
F Gene ◽  
Fleece Weight ◽  
Australian Merino ◽  
Staple Length

ABSTRACTThe effect of the high fecundity Booroola Merino gene (F) on wool production and live weight of Booroola x South Australian Merino rams classified as being offspring of FF, F+ or ++ Booroola sires was investigated. The characters studied were: greasy fleece weight in lambs, hogget (approx. 15 months old) greasy fleece weight and the associated scouring yield, clean fleece weight, fibre diameter, staple length and wool style; birth weight and live weight gains from birth to weaning in September (3 months of age), from September to the following March, and from March to September. There were no significant differences among sire genotypes in the characters studied. The results suggest that the F gene had no undesirable pleiotropic effects on wool and live-weight traits.

Sign in / Sign up

Export Citation Format

Share Document