Assessing Wiltshire Horn-Merino crosses. 1. Wool shedding, blowfly strike and wool production traits

1994 ◽  
Vol 34 (6) ◽  
pp. 717 ◽  
Author(s):  
KA Rathie ◽  
ML Tierney ◽  
JC Mulder

Wiltshire Horn-Merino (WH-M) crosses of 1/2, 5/8 and 3/4 Merino content were compared over 10 years for wool shedding, blowfly strike frequency and wool production traits. Merinos and 1/2 Merino WH-M were compared over 4 years. For wool production traits, 1/2 and 5/8 Merino WH-M ewes were compared to Border Leicester-Merino (BL-M) ewes over 2 years. Shedding increased with age for all WH-M genotypes, with 3/4 Merinos showing less shedding than 1/2 Merinos at all ages. At 1 and 2 years of age, 5/8 Merinos were intermediate between the other 2 WH-M genotypes, but at later ages they were similar to 1/2 Merinos. All genotypes showed less shedding at the belly site than the head, neck and breech as lambs, but not at older ages. Phenotypic correlations between sites on the same sheep were high, averaging 0.85. Repeatability estimates for each site ranged from 0.26 to 0.45. Shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Little or no shoulder and back wool was shed by most sheep. All 1/2 and 5/8 Merinos and most 3/4 Merinos had bare legs and points. Blowfly strike incidence was far higher in Merinos than 1/2 Merinos, in all years. Among WH-M, blowfly strike incidence increased as Merino content increased, in all years. All WH-M were far inferior to both Merinos and BL-M in total greasy wool weight and all its components, and also in clean fleece weight, with their level of inferiority increasing as their Merino content declined. Wool fibre diameter for all WH-M was coarser than for Merinos, but was a little finer than for BL-M. Fibre diameter increased in the WH-M as their Merino content declined. All WH-M had lower wool yields than the Merinos or BL-M. In some years the 314 Merinos had lower wool yields than the 1/2 and 5/8 Merinos, which were similar in all years. Shedding caused numerous genotype x age interactions in wool weight and its components, as Merinos and BL-M did not shed, and with the WH-M shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Due to preferential shedding from the belly and other low-value areas, the WH-M inferiority in total wool weight was less severe for fleece weight. Winter shearing succeeded in harvesting some wool from WH-M that would be shed before a summer shearing, but not enough to alter rankings among genotypes. All WH-M genotypes have wool too coarse, and not enough of it, to compete as a wool sheep with the Merino at current wool prices under usual Australian pastoral conditions. In areas where mustering is difficult or blowfly strike unusually severe, WH-M genotypes may find a niche.

1989 ◽  
Vol 40 (2) ◽  
pp. 433 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins

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.


1966 ◽  
Vol 46 (1) ◽  
pp. 9-18 ◽  
Author(s):  
J. A. Vesely ◽  
H. F. Peters ◽  
S. B. Slen

Rambouillet, Romnelet, Columbia, Targhee, and Suffolk sheep were evaluated under range conditions for the production of lamb and wool in the period 1960–1963. The production traits analyzed were: birth and weaning weight; face cover and neck wrinkling; fertility, prolificacy, weaned lamb production, and body weight of ewe; lamb survival to weaning; grease and clean fleece weight, staple length, wool grade, and percentage yield of clean wool by yearling and mature ewes.Lambs of Romnelet were lighter at birth than those of the other breeds. Targhee and Suffolk were the heaviest at birth. Romnelet and Columbia lambs were lighter at weaning than those of Rambouillet, Targhee, and Suffolk.Fertility, prolificacy, and weaned lamb production were essentially the same in the four range breeds. Suffolk produced more weaned lamb than the other four breeds. There were no breed differences in the survival of lambs.Columbia exceeded all other breeds in production of grease and clean fleece weight. Suffolk produced the smallest amount of wool. Staple length of Columbia ewes was 4.3, 7.5, 18.6, 23.7 mm longer than that of Romnelet, Targhee, Suffolk, and Rambouillet ewes.


2018 ◽  
Vol 58 (2) ◽  
pp. 207 ◽  
Author(s):  
S. Dominik ◽  
A. A. Swan

The present study estimated phenotypic and genetic relationships between wool production, reproduction and bodyweight traits in Australian fine-wool Merino sheep. The data for the study originated from the CSIRO Fine Wool Project, Armidale, Australia. Data on wool characteristics, measured at ~10 and 22 months of age, bodyweight and several reproduction traits across consecutive lambing opportunities were analysed. The genetic correlations were moderately negative between fibre diameter measured as yearling and adult, and lamb survival (rg = –0.34 ± 0.15 and rg = –0.28 ± 0.14 respectively) and total number of lambs weaned (rg = –0.32 ± 0.21 and rg = –0.40 ± 0.21 respectively). The genetic correlations of yearling and adult greasy and clean fleece weights with number of lambs weaned and fecundity showed moderately to highly negative relationships and a moderately negative correlation with the number of fetuses at pregnancy scanning. Phenotypic correlations between reproduction and wool production traits were estimated to be zero, with the exception of bodyweight showing low to moderate positive phenotypic correlations with total number of lambs born and weaned. Genetic variances were generally low for the reproduction traits and resulted in low heritability estimates (from h2 = 0.03 ± 0.01 to h2 = 0.12 ± 0.13), with the exception of total number of lambs born (h2 = 0.25 ± 0.03). The study indicated that parameter estimation and trait definition of lifetime reproduction records require careful consideration and more work in this area is required.


1997 ◽  
Vol 37 (3) ◽  
pp. 303 ◽  
Author(s):  
F. M. Foster ◽  
R. B. Jackson ◽  
D. L. Hopkins ◽  
R. Corkrey

Summary. Male, fine wool Merino sheep which had been subjected to different methods of castration as lambs were assessed from 22 to 46 months of age for their suitability for wool production, their tolerance to posthitis and their carcass characteristics. Hemi-castrates produced significantly (P<0.001) more clean wool than induced cryptorchids of a similar fibre diameter. Induced cryptorchids and hemi-castrates were significantly (P<0.05) heavier than wethers. Partial hemi-castrates and induced cryptorchids had significantly (P<0.001) heavier and leaner carcasses (lower GR measurement) than wethers and testosterone-treated wethers. Induced cryptorchidism and hemi-castration proved to be effective means of reducing the prevalence of posthitis such that as the degree of castration decreased the proportion of animals with higher posthitis scores decreased (P<0.001). Testosterone levels in induced cryptorchids (1.01 ng/mL) and hemi-castrates with partial reduction of the parenchyma (0.83 ng/mL) were similar, whereas hemi-castrates with complete reduction of the parenchyma in the 1 remaining testicle had a significantly (P<0.001) lower level (0.32 ng/mL) and significantly (P<0.001) lighter testes. Development of horns and obvious scrotums by induced cryptorchids and hemi-castrates with partial reduction of the parenchyma in the 1 remaining testicle attracted penalty rates at shearing and slaughter. Some induced cryptorchids and hemi-castrates exhibited masculine behaviour, but they were unlikely to be fertile because although spermatozoa were present they were abnormal and/or non-motile. Hemi-castrates with full reduction of the parenchyma in the 1 remaining testicle offer significant advantages over the other groups for wool production. Severe posthitis was not observed, they were infertile, they did not attract penalty rates for shearing or slaughter and their clean fleece weight, wool quality, carcass weight and grade were comparable with or superior to wethers. To reduce dependence on synthetic hormones to control posthitis, traditional complete castration techniques could be replaced with this type of partial castration in wool-producing flocks.


2010 ◽  
Vol 50 (1) ◽  
pp. 25 ◽  
Author(s):  
S. Bolormaa ◽  
M. Olayemi ◽  
J. H. J. van der Werf ◽  
N. Baillie ◽  
F. Le Jambre ◽  
...  

Genetic parameters for liveweight (LWT), greasy fleece weight (GFW), mean fibre diameter (MFD), standard deviation of MFD (MFD-s.d.), mean fibre curvature (CURVE) percentage of medullated (%MED) and kemp (%KEMP) fibres, faecal worm egg count (WEC), packed cell volume (PCV), mean corpuscular volume (MCV) mean corpuscular haemoglobin content (MCHC), circulating anti-nematode IgG (IgG) and counts of circulating eosinophils (EOS), lymphocytes (LYM), neutrophils (NEU), basophils (BASO) and monocytes (MONO) up to 18 months of age were estimated in Australian Angora goats (608 animals, 14 sires 3 years of birth). Measurements were made during a period of natural parasite challenge up to 5 months of age, or following artificial challenge with 10 000 infective larvae of Trichostrongylus colubriformis at 5.25 months of age. Year of birth had a significant impact on production and parasite-associated traits at all ages studied. Sex had a marked effect on production and erythrocyte traits. Birth type had no effect on any traits in animals older than 6 months. Maternal effects were not significant except for LWT at 3, 5 and 6 months and for IgG at 3 months. Most production traits were highly (LWT, GFW, MFD, %MED) or moderately (CURVE, MFD-s.d.) heritable (range 0.17–0.59) with only %KEMP having a low heritability (0.02–0.14). The heritability estimates (±s.e.) for CURVE are novel for goats and ranged from 0.18 ± 0.09 at first shearing to 0.44 ± 0.14 at third shearing. Heritability estimates were low for WEC (0.02–0.16) and for specific IgG during natural infection (0.14–0.15) but higher for IgG following artificial challenge with T. colubriformis (0.42 ± 0.13). Of the haematological variables NEU and all red cell traits were highly heritable (0.45–0.71), LYM and MONO were moderately to highly heritable (0.31–0.55), and EOS was weakly to moderately heritable (0.06–0.28). Strong phenotypic correlations existed between production traits. MFD was positively correlated with GFW and negatively correlated with CURVE, indicating that finer fibres have a higher crimp or wave count. WEC had consistent negative phenotypic correlations with PCV, LYM and EOS, and positive correlations with NEU. Correlations with IgG were positive up to 5 months and negative thereafter. Phenotypic correlations between WEC and LWT as well as with GFW and MFD were negative. Heritability estimates for production traits were generally consistent with other studies. Haematological and fibre curvature findings are completely novel for Angora goats. Estimates of heritability for WEC fell in mid range of published findings for other goat breeds, and these results suggest that there is some scope for breeding for worm resistance in Angoras but the response is likely to be slow.


1993 ◽  
Vol 44 (7) ◽  
pp. 1523 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins

Components of the fleece and wool quality traits were measured or assessed 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 recorded were face cover score (FC), leg cover score (LC), neck fold score (NF), body fold score (BF), wax content (W), suint content (S), vegetable matter content (VM), dust penetration (D), follicle density (N) and follicle ratio (RA). Genetic differences within and between flocks of Merino sheep were examined for the traits, and estimates of heritability and within-flock genetic and phenotypic correlations and between-flock genetic correlations among the traits were obtained. Genetic and phenotypic correlations were also estimated between these traits and the major wool production traits: greasy fleece weight (GFW), clean fleece weight (CFW), fibre diameter (FD), body weight (BWT) and staple length (SL). Significant strain. flock within strain and flock effects were wresent for all traits. The influence of environmental effects (birth-rearing type, age at measurement and age of dam) on the traits was estimated, with the birth-rearing type being significant and the largest effect for most traits. Paternal half-sib heritability estimates were 0.44� 0.06 for FC, 0.35� 0.06 for LC, 0.24�0.05 for NF, 0.23�0.05 for BF, 0.38�0.07 for W, 0.42�0.07 for S, 0.06�0.04 for VM, 0.22�0.06 for D, 0.20� 0.07 for N and 0.21�0.07 for RA. Estimates of within-flock phenotypic and genetic correlations were in broad agreement with available published estimates. The implications of the results for Merino breeding programs are discussed.


1988 ◽  
Vol 28 (6) ◽  
pp. 707 ◽  
Author(s):  
DJ Cottle

Ten groups, each of 6 superfine Merino wethers were individually penned indoors and hand-fed at maintenance level a ration of 70% oats and 30% chopped lucerne hay (w/w). The groups of sheep were fed 3 different supplementary pellets rotationally during three 9-week periods. Each group received 3 of the following 7 pellets: (1) control, (2) cottonseed meal (CSM), (3) CSM plus hydroxymethyl-methionine (MEP), (4) CSM plus methionine hydroxy analogue (MHA), (5) CSM plus avoparcin (AV), (6) CSM plus MEP plus AV, and (7) CSM plus MHA plus AV. The rations were offered 3 times a week. Half of the sheep had no rumen ciliate protozoa. Wool production was measured during the 7-month period. Defaunation resulted in a 6.9% increase in greasy fleece weight and a 7.7% increase in clean wool production. Average wool fibre diameter increased by 0.6 pm in defaunated sheep. The clean wool growth responses compared with sheep fed the control pellets were 4, 5, 12, 0, 3 and 9% respectively for sheep fed pellets 2-7. The most cost-effective supplement was the CSM plus MHA pellet, which increased clean wool production by 0.5 glday compared with sheep fed the CSM pellet but did not significantly affect wool quality. It was concluded that supplements containing MHA could be economically fed to housed superfine Merino wethers ('Sharlea'), but MHA appears to be relatively inefficient in supplying methionine to the intestines.


2011 ◽  
Vol 51 (9) ◽  
pp. 794 ◽  
Author(s):  
A. N. Thompson ◽  
M. B. Ferguson ◽  
D. J. Gordon ◽  
G. A. Kearney ◽  
C. M. Oldham ◽  
...  

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.


1998 ◽  
Vol 49 (8) ◽  
pp. 1187 ◽  
Author(s):  
N. R. Adams ◽  
J. R. Briegel

The present study examined changes in wool growth, liveweight, and body composition in groups of fine, medium, and broad wool Merino wethers grazed together at pasture in the highly seasonal Mediterranean environment, to determine the sources of variation in wool growth that may affect staple strength (SS). Seasonal changes in wool growth were measured using 6 dyebands placed at times of seasonal change in the nutrient supply from pasture, and liveweights were recorded fortnightly. Dilution of deuterated water was used to determine changes in body composition between the beginning of summer and the end of autumn. The sheep lost liveweight over this period, but loss of protein relative to fat over this period was unexpectedly high (7 : 1). The relative changes in liveweight, and loss of its components (fat and lean) during summer and autumn, were similar in all 3 groups, even though the Broad group was heavier than the other 2 genotypes at all times (P < 0·01). In contrast to the similar pattern of liveweight change, wool growth rates and changes in the fibre diameter were less variable throughout the year in the Broad group than the other 2 groups (P < 0·001). Stepwise regression indicated that the characteristics related to SS were standard deviation in fibre diameter (SDfd; P < 0·001), mean fibre diameter (P < 0·001), and variation in diameter within a 200-mm length of wool fibre (Sdfdwithin; P < 0·05). However, the relative importance of different factors for SS differed within each group. The most important factors were mean fibre diameter in the Fine group, the variation in fibre diameter along the staple (SDfdalong) in the Medium group, and the variation in diameter between fibres (SDfdbetween) in the Broad group. It is concluded that SS is a complex characteristic, depending on both the fibre diameter and several sources of variation in fibre diameter, all of which can differ among flocks. Protein loss made a disproportionate contribution to liveweight loss over summer and autumn, but the amino acids made available did not contribute substantially to wool growth or SS.


1975 ◽  
Vol 15 (73) ◽  
pp. 159 ◽  
Author(s):  
PA Kenney ◽  
IF Davis

A study was made during a three year period (1 968-1 970) of wool production by a flock of 540 ewes grazing annual pasture at Werribee, Victoria. The ewes were stocked at three rates (5, 7 1/2 and 10 ewes ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Fibre diameter and length of wool samples were measured in 1968, 1969 and 1970 ; in 1970 growth of greasy wool was calculated from staples of dye-banded wool. Wool growth was reduced in all ewes during late pregnancy and early lactation but was not affected during late lactation in ewes lambing in September. The proportion of tender fleeces from all ewes was greater in 1970 and the weight of fleeces from only those ewes bearing single lambs was less in all years for ewes lambing in July than for ewes lambing in September. More ewes were barren and fewer ewes had twins in July and consequently the mean fleece weights of all ewes from both groups were similar. Fleeces from ewes stocked at 10 ha-1 were lighter, shorter and finer than fleeces from ewes stocked at 5 and 7 1/2 ha-1, but the proportion of tender fleeces did not differ between the groups. Wool production of ewes stocked at 5 and 7 1/2 ha-1 increased from 1968 to 1970, whereas that of ewes at 10 ha-1 did not. This was associated with differences in pasture availability and composition. At 10 ewes ha-1 less pasture was present in winter and spring in 1970 than in 1968, whereas at the other stocking rates it was greater. In 1970 the density of weeds in autumn was greater and in spring more silver grass (Vulpia spp.) and less brome grass (Bromus spp.) was available at the high stocking rate.


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