Lupinosis and reproduction reduce the wool growth of Merino ewes

1997 ◽  
Vol 37 (5) ◽  
pp. 515 ◽  
Author(s):  
A. L. Barnes ◽  
K. P. Croker ◽  
J. G. Allen ◽  
N. D. Costa

Summary. Lupinosis was induced in Merino ewes by subcutaneous injections of phomopsins. Liver damage and impairment of liver function was measured by increases in plasma activities of glutamate dehydrogenase and gamma glutamyl transferase, plasma concentrations of bilirubin, and plasma clearance of bromosulfthalein. The wool growth of the ewes during and after exposure to phomopsins at different periods relative to mating was measured, and the impact of lupinosis on annual wool production assessed. Phomopsin administration decreased the length of staple grown during, and for at least 6 weeks after, exposure to phomopsins. Mean fibre diameter of wool grown during this time was also reduced. Annual wool production of the ewes was affected by exposure to phomopsins, with effects noted on fleece weight, yield, fibre diameter, strength and position of break. These effects were minor and varied between experiments. The adverse effects of reproduction on annual wool production were more significant than those of phomopsins.

1993 ◽  
Vol 33 (4) ◽  
pp. 397 ◽  
Author(s):  
LG Butler ◽  
BJ Horton ◽  
PM Williams ◽  
RG Banks

Tasmanian Merinos and Polwarths were mated in each of 2 years to produce 2 drops of Merino, Polwarth, and F1 reciprocal cross progeny. Polwarths had weaning weights similar to Merinos but were 14% heavier as hoggets. Polwarths grew a similar amount of wool of 11% greater (P<0.001) fibre diameter; however, wool production was 9% less efficient based on metabolic weight. Polwarths displayed an advantage in resistance to footrot. There was a marked Polwarth maternal effect of about 16% on weaning weight but no elfect on hogget weight. The Polwarth maternal effect on fleece weight and efficiency was 9% (P<0.001). In a comparison with a single-born male, ewes weighed 5% less at weaning and 7% less at hogget shearing and produced about 6% less wool (P<0.001), although of comparable fibre diameter. Twins weighed 17% less at weaning, but only 3% less at hogget shearing (P<0.001). They grew about 5% less wool, which was of 2% greater fibre diameter (P<0.001) and 5% higher wool score, but efficiency was 2.5% lower. Production was generally lower (except for yield and wool score) in the 1988 drop than the 1987 drop by 3-10%. Differences in productivity between ram sources were of only slightly lesser magnitude than differences between breeds. The number of feet affected by footrot was reduced by 17% in the 1988 drop. Severe footrot affecting more than 1 foot reduced liveweight but did not significantly reduce fleece weight. There appeared to be some heterosis for weaning weight (10%) and hogget weight (6%), but little heterosis in wool growth (2-3%) or efficiency (-2%).


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.


1970 ◽  
Vol 21 (5) ◽  
pp. 815 ◽  
Author(s):  
N Jackson ◽  
EM Roberts

Samples of breeding age rams and ewes were taken from seven studs representing three strains of Australian Merino, and run in a single environment at Hay, N.S.W. Measurements taken from the ram and ewe progeny of these sheep, born at Hay in 1964 and 1965, were used for a comparative study of wool and body traits of the seven studs. The traits measured were body weight, face cover, folds, greasy fleece weight, yield, clean fleece weight, quality number, character, handle, colour, staple length, crimp frequency, fibre diameter, fibre density, two estimates of the value of wool production per head, and the value of wool production per pound. Large strain and stud within-strain effects were present for both wool and body traits. Strain x year interactions in wool values were attributed to fluctuations in the wool market. Strain x year interaction in fibre diameter reflected variation between the strains in their response to changes in environment, as did stud within-strain x year interactions in greasy fleece weight, yield. and clean fleece weight. Strain x sex interactions were interpreted in relation to a proposed new classification of interactions. The amount of migration between pairs of studs was not related to the present genetic difference between them, for any trait. Schemes for extending the present study to a large number of studs are discussed. Preliminary results of selection experiments have suggested that strains may vary in their response to equal selection pressures.


1962 ◽  
Vol 2 (6) ◽  
pp. 160 ◽  
Author(s):  
MJ Sharkey ◽  
IF Davis ◽  
PA Kenney

The effect of different planes of nutrition on the wool production of Corriedale wethers at pasture was studied between August 1959 and December 1960. The plane of nutrition was controlled by rate of stocking. The effect of previous nutritional treatment on wool production was slight. It affected wool weight and fibre length for 160 one month and fibre diameter for two months. The differences in current nutritional treatment were accompanied by large differences in wool production except during the spring months. On the highest plane of nutrition the wool production showed little seasonal variation, apart from an initial increase in production during the autumn. On the medium and low planes of nutrition wool growth declined substantially in autumn and winter and increased again in spring. The mean fibre diameter of the wool that was clipped frequently was greater than that of fleece wool obtained from the opposite midside at shearing. Further, in the groups on medium and low planes of nutrition estimates of fleece weight based on the combined weight of periodical clippings were greater than actual fleece weights. It is concluded that, in the dry Victorian summer, wool production is influenced by the plane of nutrition in the previous spring for a short period only, and that in autumn and winter it is dependant almost entirely on the feed immediately available.


1994 ◽  
Vol 34 (3) ◽  
pp. 311 ◽  
Author(s):  
LG Butler ◽  
GM Head

Twelve wethers of each of the Merino and Polwarth breeds and their reciprocal crosses were fed at1 of 2 levels in individual pens for 14 months. Periodic clean wool weight, yield, fibre diameter, and the coefficient of variation (CV%) for fibre diameter were measured from midside patches harvested every6 weeks.There was a significant effect of time of wool harvest on clean wool weight per cm2, yield, fibre diameter(all P<0.01), and its CV% (P<0.05). A trough in wool production occurred about August-September and a peak in January. The amplitude of the photoperiodic rhythm of wool growth (difference between maximum and minimum wool growth per cm2 per 42 days as a percentage of the average) was 40%. Yield also displayed a substantial photoperiodic rhythm, but that of fibre diameter was less pronounced. Mean staple strength was 32.3 N/ktex, the mean break occurring at a distance of 60% of the staple length from the tip; there was no effect of genotype or level of feeding. From comparison with published Tasmanian field data, the seasonal wool growth pattern of sheep at pasture appears similar to the photoperiodic rhythm but occurs about a month earlier. It was concluded that the photoperiodic rhythm of wool production of Tasmanian Merino-based breeds should not be a barrier to manipulation of wool quality (staple strength and fibre diameter) by nutritional management.


2020 ◽  
Vol 106 (1) ◽  
pp. 174-187
Author(s):  
Rowan S Hardy ◽  
Hannah Botfield ◽  
Keira Markey ◽  
James L Mitchell ◽  
Zerin Alimajstorovic ◽  
...  

Abstract Background The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) determines prereceptor metabolism and activation of glucocorticoids within peripheral tissues. Its dysregulation has been implicated in a wide array of metabolic diseases, leading to the development of selective 11β-HSD1 inhibitors. We examined the impact of the reversible competitive 11β-HSD1 inhibitor, AZD4017, on the metabolic profile in an overweight female cohort with idiopathic intracranial hypertension (IIH). Methods We conducted a UK multicenter phase II randomized, double-blind, placebo-controlled trial of 12-week treatment with AZD4017. Serum markers of glucose homeostasis, lipid metabolism, renal and hepatic function, inflammation and androgen profiles were determined and examined in relation to changes in fat and lean mass by dual-energy X-ray absorptiometry. Results Patients receiving AZD4017 showed significant improvements in lipid profiles (decreased cholesterol, increased high-density lipoprotein [HDL] and cholesterol/HDL ratio), markers of hepatic function (decreased alkaline phosphatase and gamma-glutamyl transferase), and increased lean muscle mass (1.8%, P &lt; .001). No changes in body mass index, fat mass, and markers of glucose metabolism or inflammation were observed. Patients receiving AZD4017 demonstrated increased levels of circulating androgens, positively correlated with changes in total lean muscle mass. Conclusions These beneficial metabolic changes represent a reduction in risk factors associated with raised intracranial pressure and represent further beneficial therapeutic outcomes of 11β-HSD1 inhibition by AZD4017 in this overweight IIH cohort. In particular, beneficial changes in lean muscle mass associated with AZD4017 may reflect new applications for this nature of inhibitor in the management of conditions such as sarcopenia.


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.


2009 ◽  
Vol 49 (12) ◽  
pp. 1100
Author(s):  
B. J. McGuirk

Early work in the 1950s on the wool growth response of sheep from diverse genotypes for wool production in response to varying planes of nutrition at pasture did not show the significant genotype × environment interactions exhibited in later pen studies with the same or very similar genotypes. However, this early study used a log-transformation on all traits to adjust nutritional effects for scale. Re-analysis of the original (i.e. untransformed) data shows that superior genetic merit for clean fleece weight, different sire progeny groups or selection flocks is more apparent when hogget ewes are fed a high plane of nutrition at pasture. However, only in the case of flocks was the interaction statistically significant, and this interaction was insignificant when data were either log-transformed, or when an appropriate test that accounts for scale-type effects was applied. When left untransformed, the data are, thus, in agreement with the subsequent pen studies that examined data on untransformed clean wool production.


1964 ◽  
Vol 15 (4) ◽  
pp. 657 ◽  
Author(s):  
LJ Lambourne

Groups of 20 and 30 fine-wool Merino wethers were treated with L-thyroxine and their subsequent liveweight changes and wool production studied under a variety of grazing conditions for a year. Treatments comprised : (1) Single implantations of 60 mg in autumn, winter, spring, or summer. (2) Repeated implantations at all four seasons of 30, 60, or 90 mg. (3) Weekly subcutaneous injection of 7 mg in aqueous solution. These groups were grazed with untreated wethers on improved native pastures at one to two sheep per acre. (4) Repeated 60 mg implantations at four seasons in wethers grazed on native pasture providing a lower level of nutrition. (5) Repeated 60 mg implantations at four seasons in wethers grazed on sown pasture providing a higher level of nutrition. After every implantation there was a loss of 5–10 lb liveweight — more pronounced and more prolonged in the wethers given greater amounts of thyroxine, and more prolonged in those at lower levels of nutrition. Deaths occurred in several groups, increasing with dose rate or with poorer nutrition up to 30–50% of the group. Wool growth was not increased significantly by repeated 60 mg implants at the lowest level of nutrition, nor by the single 60 mg implant in late spring. Increases of 34% in annual fleece weight resulted from 60 mg implants in autumn and summer. Repeated implantation of 30, 60, and 90 mg in groups on a medium or high plane of nutrition increased annual fleece weight by 8, 14, and 19%, and 7 mg injected weekly by 11%. Increases in fleece weight were due partly to increased fibre length, and partly to an increase in grease and suint which reduced the clean scoured yield by 1–2%. It is concluded that line-wool Merinos, despite their lower body weight and greater specialization for wool production, react to thyroxine treatment in the same way as has been established for "dual-purpose" sheep. The safe maximum dose rate is critically dependent on the current level of nutrition, particularly for young sheep. Repeated implantations without adequate opportunity for recovery of catabolized body tissues may produce no increase in wool growth and may cause death.


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.


Sign in / Sign up

Export Citation Format

Share Document