The use of thyroxine to reduce average fibre diameter in fleece wool when feed intake is increased

2001 ◽  
Vol 41 (5) ◽  
pp. 611 ◽  
Author(s):  
G. J. Lee ◽  
K. J. Thornberry ◽  
A. J. Williams
Keyword(s):  
Saline Solution ◽  
Daily Intake ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Treatment Groups ◽  
Average Fibre Diameter ◽  
Wool Growth ◽  
Average Fibre ◽  
Ad Libitum ◽  
The Difference

An experiment was conducted to determine whether thyroxine injections would control the increases in fibre diameter when the wool growth of Merino wethers is stimulated by an increased supply of feed. Fifty-seven sheep were allocated to 1 of 5 levels of daily intake, ranging from 0.75 maintenance to ad libitum, and injected every third day with 3 mg of L-thyroxine or a saline solution (control). Sheep treated with thyroxine had elevated plasma tri-iodothyronine (T3) levels, which were highest in sheep fed the least (P<0.01). Ad libitum intakes of sheep treated with thyroxine tended to be higher than that of control sheep, particularly in the fifth to seventh weeks of the experiment, and liveweight gain over the initial 4 weeks was significantly (P<0.001) less. Wool growth was increased by thyroxine treatment, although the difference was small in the second half of the experiment at the highest intake levels. Fibre diameter of sheep treated with thyroxine was greater at low intakes, although the difference diminished as intake increased. Fibre length in the second half of the experiment was positively related to intake, but there were no effects of thyroxine. Although the relationships of fibre diameter and length with wool growth did not differ between the treatment groups, length accounted for more of the variation in wool growth in the second half of the experiment in treated wethers than in control wethers (0.376 v. 0.182 of the variation, respectively). Thyroxine did not appreciably reduce the extent of the increase in fibre diameter associated with an increase in the availability and intake of feed.

Some wool characteristics of Karadi sheep in northern Iraq

1974 ◽  
Vol 83 (1) ◽  
pp. 171-174 ◽  
Author(s):  
K. E. Ghoneim ◽  
N. T. Kazzal ◽  
R. Kh. Abdallah
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Fibre Strength ◽  
Northern Iraq ◽  
Phenotypic Correlations ◽  
Average Fibre Diameter ◽  
Average Fibre

SUMMARYOne hundred and sixty-eight wool samples were collected from commercial flocks of Karadi sheep raised in the five provinces of northern Iraq. The wool characteristics dealt with were staple and fibre length, crimps, fibre diameter, medullation, fibre strength and elongation.The results showed that the Karadi wool is a long type of carpet fleece with average staple and fibre lengths of 19·3 and 23·5 cm, respectively. It had an average fibre diameter of 48·1 μ and contained 19·45 % medullated fibres. The number of crimps per 2 cm was 2·4. Average fibre strength and elongation were 24·8 g/5 cm and 31·8 % respectively. Phenotypic correlations between wool traits were studied.

The effects of breed, crossbreeding and other factors on variation in fleece and skin traits

1980 ◽  
Vol 30 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J. A. Woolliams ◽  
G. Wiener
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Live Weight ◽  
Strong Relationship ◽  
Average Fibre Diameter ◽  
Wide Range ◽  
Average Fibre ◽  
Fleece Weight ◽  
The Relationship

ABSTRACTBreed and crossbreeding significantly affected variation in 10 fleece, follicle density and fibre diameter traits in 12-week-old lambs. The breeds involved were the Scottish Blackface, South Country Cheviot, Welsh Mountain, Lincoln Longwool, Southdown and Tasmanian Merino, but the last only by rams.The Southdown came closest to the Merino in affecting density and diameter traits although the Merino crosses remained clearly distinguishable by their high follicle density. The Lincoln and Blackface crosses were notable for their long fibres and the Blackface crosses also had the least dense follicle and coarsest primary fibres. The coarsest secondary fibres were from Lincoln and Cheviot crosses. Heterosis estimates were obtained for crosses involving the Blackface, Cheviot, Welsh and Lincoln breeds. Significant heterosis was present in a wide range of traits but was not apparent in all crosses. Maternal differences were evident for many of the traits but with density these differences were apparently related to maternal effects on live weight of the lamb. The sex of the lamb, its birth type and rearing and its 12-week live weight significantly affected many of the traits.Among breeds and crosses a strong relationship was found between fibre density and average fibre diameter. The relationship suggested that breed variation in total fibre area per unit area of skin was small compared with the breed variation in its components. Fleece weight per unit area was most closely related to mean fibre length.

Wool yield and characteristics of Dorset, Leicester and Sunffolk breeds and their ‘DLS’ cross

1977 ◽  
Vol 88 (3) ◽  
pp. 651-653 ◽  
Author(s):  
M. H. Fahmy ◽  
J. A. Vasely
Keyword(s):  
First Generation ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Wool Production ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
Wool Yield ◽  
Fleece Weight

SUMMARYGreasy fleece weight (12 months growth) and wool samples from hip and shoulder regions were taken on 15 Dorset, 20 Leicester, 20 Suffolk and 17 DLS ewes (a cross of ½ Dorset, ¼ Leicester, ¼ Suffolk obtained by mating DL rams to DS ewes and DS rams to DL ewes). The purpose of the study was to compare wool production and characteristics of the first generation of DLS with that of the three breeds of origin. Wool production of DLS was 3·58 kg, 8·8 and 14% higher than that of Suffolk and Dorset, but 11% lower than that of Leicester (P< 0·01). The percentage of clean wool was highest in Leicester (78·3%), followed by DLS, Dorset and Suffolk (76·1, 74·3 and 70·5%, respectively). The average fibre diameter of the DLS and Leicester was 38 /m, 4 /m thicker than that for Suffolk and Dorset (P < 0·01). Average fibre length was 15 cm in DLS and Dorset, 6 cm shorter than in Leicester, and 3 cm longer than in Suffolk (P < 0·01). The variability in fibre diameter and length was highest in Leicester, followed closely by DLS.

Birthcoat of lambs and adult fibre diameter

1956 ◽  
Vol 7 (2) ◽  
pp. 152 ◽  
Author(s):  
LW Lockart
Keyword(s):  
Fibre Diameter ◽  
Strongly Correlated ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
The Difference

Birthcoat hairiness is significantly correlated with adult fibre diameter variability, the coarser birthcoats being more variable. Birthcoat grade is not correlated with average fibre diameter, but is strongly correlated with the difference between diameters of primary and secondary fibres and with variability of primary, but not of secondary, fibres. A correlation of 0.83 was found between birthcoat grade and primary-secondary diameter difference in the adult.

Mineral supplementation and wool production of young Merino sheep on the south coast of Western Australia

1995 ◽  
Vol 35 (4) ◽  
pp. 437
Author(s):  
PT Doyle ◽  
RA Love ◽  
TW Plaisted
Keyword(s):  
Growth Rates ◽  
Fibre Diameter ◽  
Supplementary Feeding ◽  
Wool Production ◽  
Average Fibre Diameter ◽  
Mineral Supplementation ◽  
Wool Growth ◽  
Average Fibre ◽  
Staple Strength ◽  
Mineral Lick

Wool-free liveweight change (LWC), wool growth rate, annual wool production, and wool characteristics of young Merino wethers fed supplements of lupins with gypsum or a multi-element mineral lick were examined in 12 experiments at 5 farms between 1989 and 1992. The source of sheep varied between experiments; age was 4.5-6.5 months and liveweight 28-37 kg at the beginning of supplementation. Sheep were fed lupins, lupins coated with gypsum (15-20 g/kg lupins), or lupins along with access to the mineral lick (offered at 140 g/sheep.week). The amount of lupins offered in all treatments within any experiment was the same. Supplementary feeding varied between experiments from 150 to 240 days. The sheep grazed annual pastures at stocking rates of 8-1 6.7ha. Average lick intake was 12-18 g/sheep. day. During supplementary feeding, there was considerable variation in LWC (-80 to +110 g/day) and clean wool growth rates (3.8-15.1 g/day) within and between experiments. However, there was no significant positive effect of gypsum or mineral lick supplementation on LWC or clean wool growth rates during or after supplementary feeding in any experiment. There were positive (P<0.01) relationships between LWC and clean wool growth rates during supplementation. Also, for some spring-shorn sheep types, staple strength of wool was linearly related (P<0.01) to LWC in the period before the position of break in the wool staple. Annual wool production, average fibre diameter, and staple strength of midside wool were not significantly increased by supplements of gypsum or mineral lick in any experiment.

Wool growth of pregnant Merino ewes fed to maintain maternal liveweight

1989 ◽  
Vol 29 (4) ◽  
pp. 503 ◽  
Author(s):  
AJ Williams ◽  
J Butt
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Nutritional Management ◽  
Wool Production ◽  
Average Fibre Diameter ◽  
Wool Growth ◽  
Average Fibre ◽  
Pregnant Ewe ◽  
Sorghum Grain

The wool production at the midside of 15 non-mated Merino ewes was compared with that of their monoctocous (n = 20) and dioctocous (n = 13) flockmates during the second half of pregnancy. The ewes were compared under experimentally controlled feeding conditions designed to maintain the liveweight of each ewe, exclusive of the weights of fleece and conceptus, by progressively increasing the quantities of a sorghum grain and lucerne chaff diet (1:1 by weight) offered to the pregnant ewes. During the latter half of pregnancy, each non-mated ewe consumed 42.1 kg of the diet. The single- and twinbearing ewes consumed 27 and 44% more of the diet than did the non-mated ewes. The adjusted liveweight of the non-pregnant ewes increased by 0.03 kg/week, while those of the monoctocous and dioctocous ewes changed by 0.11 and -0.05 kg/week (s.e.= � 0.04). These changes in liveweight were small but differed between the ewe classes (P<0.05). The rate of wool production per unit area of skin at the midside was 411 �g/cm2.day, with no significant differences between the ewe classes, and with no interactions between ewe classes and period of measurement. The wool produced on the midside had an average fibre diameter of 19.0 �m, again with no significant differences between ewe classes or periods. The length of fibre grown during the latter half of pregnancy was 26.1 mm, with no difference between the ewe classes. We conclude that a loss of wool production is not an obligate consequence of pregnancy, but can be prevented by nutritional management that recognises the additional requirements of the pregnant ewe for nutrients.

The influence of selection and plane of nutrition on the components of fleece weight in Merino sheep

1958 ◽  
Vol 9 (6) ◽  
pp. 802 ◽  
Author(s):  
RB Dun
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Small Contribution ◽  
Cross Sectional ◽  
Single Character ◽  
The Mean ◽  
Low Levels ◽  
The Difference ◽  
Fleece Weight ◽  
High Level

The components of clean fleece weight were examined in five experimental flocks of medium-wool Peppin Merinos. Four single-character selection groups – clean fleece weight plus, clean fleece weight minus, crimps per inch plus, and crimps per inch minus – were examined by measuring fleece production in 18-month-old ewe progeny. Measurements were also made on progeny from the "nucleus" flock, which was selected for clean fleece weight with subsidiary selection for crimps per inch and against fold score. Data were collected in 1952 and 1954. The 1954 figures were obtained from a nutrition experiment in which sheep mere grown from weaning to 18 months on a high and on a low plane of nutrition. The mean measurements of the components of clean fleece weight (W) were compared between flocks using the "percentage deviation" technique. Four comparisons were made: (1) Nucleus/Fleece minus; (2) Fleece plus/Fleece minus; (3) Crimps minus/Crimps plus; (4) high nutritional plane/low nutritional plane. In comparisons (1) , (2), and (3), difference in weight of wool per unit area of skin (w) accounted for nearly all the difference in W. Body weight (S) made a small contribution while difference in fold score (R) was negligible. Fibre density (N) accounted for +86 per cent., and fibre cross-sectional area (A) for –28 per cent., of the difference in W in comparison (1). In comparison (2) the figures were N +47 per cent., A +21 per cent., while the figures for comparison (3) were N –26 per cent., A +121 per cent. The increase in fleece weight was invariably accompanied by a decrease in crimps per inch. In all three comparisons primary density (P) was the major cause of change in N. Fibre length (L) made a uniform contribution of approximately +15 per cent. in the three comparisons.The relative importance of the components of fleece weight was similar at both high and low levels of nutrition.The effect of a high level of nutrition was to produce large increases in A, L, and S. The increase in S was compensated by an equal decrease in P. The increase in fibre diameter was not associated with any change in crimps per inch.

Studies on Western Australian Merino sheep. 1. Stud, strain and environmental effects on hogget performance

1992 ◽  
Vol 43 (6) ◽  
pp. 1381 ◽  
Author(s):  
RP Lewer ◽  
RR Woolaston ◽  
RR Howe
Keyword(s):  
Fibre Diameter ◽  
Strain Differences ◽  
Average Fibre Diameter ◽  
Weaning Age ◽  
Average Fibre ◽  
Males And Females ◽  
Wool Yield ◽  
Fleece Weight ◽  
Western Australian ◽  
Australian Merino

A 6 year study is reported of Merino studs and strains (Peppin, Collinsville and Bungaree) in Western Australia. Wool and body traits of males and females were measured, with additional subjective traits assessed on females. The effects of strain, stud (within strain), birth year, dam age, birth rearing rank, weaning age and their interactions were estimated using least squares procedures. When tested against studs, strain differences were significant for fibre diameter (both sexes), clean wool yield and about half of the subjective traits (females) but for none of the liveweights. Stud and year effects were significant for all traits, as was their interaction for most traits. Some studs were more stable between years than others in both clean fleece weight and average fibre diameter. Of the remaining effects, birth rearing rank influenced the greatest number of traits, while dam age only affected yield in ewes and some early liveweights. Peppins produced wool 2.0-2.3 microns finer than Bungarees, but not significantly different from Collinsvilles. Peppins also had the best subjective wool scores, but had the highest wrinkle scores and scored poorly on other subjective body traits. Twin-born hoggets produced 0.05-0.15 kg less clean wool than their single-born contemporaries, and their fleeces were about 0.4 microns coarser with poorer subjective qualities. Twins were also lighter from birth (by 23%) up to 17 months (by 5%) in females. Late-born lambs had higher birth weights, but lower subsequent weights, persisting until 12 months in females.

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.

Anatomy of Acacia Mangium Grown in Malaysia

IAWA Journal ◽  
1993 ◽  
Vol 14 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Mohd. Hamami Sahri ◽  
Faridah Hanum Ibrahim ◽  
Nor Aini Ab. Shukor
Keyword(s):  
Age Groups ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Acacia Mangium ◽  
Tropical Species ◽  
Average Percentage ◽  
Plantation Forests ◽  
Diameter Fibre ◽  
Average Fibre ◽  
Two Age Groups

A study on the tissue proportions and fibre dimensions of plantation-grown Acacia mangium was carried out. Ten selected trees from two age groups (4- and 8-year-old) were obtained from plantation forests in Selangor. Disks were taken from four sampling heights. Acacia mangium wood is diffuse-porous with mostly solitary vessels. The rays are uniseriate. The average percentage of fibres, vessels and rays of 4-year-old and 8-year-old samples are 85.8%, 9.1%, 5.2% and 84.8%, 9.8%, 5.3%, respectively. Acacia is a shortfibred tropical species. The average fibre length, fibre diameter, fibre lumen diameter and fibre wall thickness are 934, 24, 17 and 3.3 µm for 4-year-old samples and 1017,20, 12 and 4.3 µm for 8-year-old sampies, respectively. The sampies near the pith have the shortest fibres and the length increases toward the bark. Fibre length also tends to decrease with height. The vessel percentage decreases with increasing height.

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