Wool growth of pregnant Merino ewes fed to maintain maternal liveweight

1989 ◽  
Vol 29 (4) ◽  
pp. 503 ◽  
Author(s):  
AJ Williams ◽  
J Butt

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.

1995 ◽  
Vol 35 (4) ◽  
pp. 437
Author(s):  
PT Doyle ◽  
RA Love ◽  
TW Plaisted

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.


2001 ◽  
Vol 41 (5) ◽  
pp. 611 ◽  
Author(s):  
G. J. Lee ◽  
K. J. Thornberry ◽  
A. J. Williams

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.


1980 ◽  
Vol 30 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J. A. Woolliams ◽  
G. Wiener

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.


1977 ◽  
Vol 88 (3) ◽  
pp. 651-653 ◽  
Author(s):  
M. H. Fahmy ◽  
J. A. Vasely

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.


1978 ◽  
Vol 18 (90) ◽  
pp. 52 ◽  
Author(s):  
AJ Williams ◽  
RN Tyrrell ◽  
AR Gilmour

The responses in wool production of Merino ewes to abomasal supplements of casein (56 g day-1) and of a mixture of methionine and cystine were measured during late pregnancy and early lactation. The mixed supplement provided equal quantities of the sulphur amino acids as the casein. The ewes were offered sufficient quantities of a diet of sorghum grain/lucerne hay (in the ratio 7 : 3 by weight) to maintain maternal liveweight. During the final four weeks of pregnancy and the first six weeks of lactation, the cassin supplement increased wool growth (826 vs. 639 g cm-2 day-1). A similar response was observed for fibre diameter (1 9.7 vs. 18.5 pm : P < 0.05). Wool production and fibre diameter did not differ between the ewes supplemented with methionine and cystine and the control ewes during this same period. The ewes supplemented with methionine and cystine produced wool with the greatest sulphur content, and this trait was least in the wool from the control ewes (3.84 vs. 3.64 vs. 3.49: P < 0.05). We concluded that the availability of the sulphur amino acids was not primarily limiting wool production in pregnant/lactating ewes.


1996 ◽  
Vol 47 (8) ◽  
pp. 1291 ◽  
Author(s):  
DG Masters ◽  
G Mata

Responses in wool production, ewe liveweight, lamb birth weight, and growth were compared when the major source of protein in the diet was either lupin seed or canola meal. The diets were fed to ewes during the final 3 weeks of pregnancy and first 3 weeks of lactation, and for a similar period of time to a group of dry ewes. All ewes were fed to maintain conceptus-free liveweight. The diet containing canola meal increased (P < 0.001) wool growth in the reproducing ewes (50-63%) and the dry ewes (12.5-20%) during, and for 3 weeks after, the treatment period. Fibre diameter of wool grown during the treatment period was increased (P < 0.025) by 0.5-1.5 pm in the ewes fed canola meal compared with ewes fed lupins. The ewes fed canola meal gained slightly (P = 0.06) more weight during the experiment than the ewes fed lupins. Lambs from the ewes fed canola meal were lighter (P < 0.05) at birth (480 g) than lambs from ewes fed lupins. The reproducing ewes had lower fleece weights, average fibre diameters, and staple strengths and lengths than the dry ewes. These fleece characteristics were not significantly affected by diet. Canola meal is partially protected from rumen degradation and is less expensive than other sources of similar proteins and may therefore provide a practical option for commercial sheep producers.


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.


2009 ◽  
Vol 49 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Afolayan ◽  
N. M. Fogarty ◽  
A. R. Gilmour ◽  
V. M. Ingham ◽  
G. M. Gaunt ◽  
...  

Genetic correlations between reproductive and productivity traits of ewes and their early growth, wool production and worm resistance traits were estimated among 2460 crossbred ewes. The ewes were progeny of 74 maternal breed sires and mainly Merino dams. The ewes were born over 3 years and had three joinings with a total of 6824 ewe joining records. The reproductive and ewe productivity traits included: (i) fertility (ewes lambing per ewe joined); (ii) litter size (number of lambs born per ewe lambing); (iii) rearing ability or lamb survival (lambs weaned of lambs born for lambing ewes); (iv) number of lambs born (NLBj) per ewe joined; (v) number of lambs weaned (NLWj) per ewe joined; (vi) total litter weight weaned (TWWj) per ewe joined; and (vii) the component trait average lamb weaning weight in the litter (AWW). The growth traits included the weight of the ewe at birth (BWT), weaning (WWT) and postweaning (PWWT), as well as growth rate pre- and postweaning. The wool traits included greasy (GFW) and clean fleece weight (CFW), yield and average fibre diameter (FD) at their first adult shearing. Worm egg count (WEC) during their first year was also recorded. Bivariate mixed models analyses using ASReml procedures were used to estimate the genetic correlations. The genetic correlations between TWWj and growth traits were positive and moderate to high and ranged from 0.34 for BWT to 0.61 for PWWT. Those for the other composite reproductive traits were slightly lower and ranged from 0.27 to 0.54 for NLWj and from 0.07 to 0.46 for NLBj. The genetic correlations between the overall measures of reproduction (NLBj, NLWj and TWWj) and GFW, CFW and FD were negative and generally low to moderate (–0.21 to –0.52). The correlations were generally larger for NLBj than for NLWj and TWWj. The genetic correlations between the reproductive traits and WEC were close to zero, except between AWW and WEC (0.42). The phenotypic correlations between the reproductive traits and the growth, wool and WEC traits were all close to zero. The genetic correlations were generally favourable between ewe reproduction and growth, with early selection for traits such as WWT and PWWT likely to give some improvement in subsequent reproduction and ewe productivity. In contrast, there appears to be a slight antagonism between reproduction and wool production. This study provides estimates of genetic correlations from crossbred ewes that add to the limited knowledge of these parameters that will improve the accuracy of genetic evaluation and prediction of the outcomes from breeding programs for meat and wool objectives that include reproduction.


1974 ◽  
Vol 83 (1) ◽  
pp. 171-174 ◽  
Author(s):  
K. E. Ghoneim ◽  
N. T. Kazzal ◽  
R. Kh. Abdallah

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.


1992 ◽  
Vol 43 (6) ◽  
pp. 1381 ◽  
Author(s):  
RP Lewer ◽  
RR Woolaston ◽  
RR Howe

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.


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