Seasonal fluctuations in wool growth in south Western Australia.

1961 ◽  
Vol 1 (2) ◽  
pp. 85 ◽  
Author(s):  
AM Stewart ◽  
RJ Moir ◽  
PG Schinckel

The growth rate of wool was measured at monthly intervals for a period of two years in four groups totalling forty Merino sheep, maintained under typical farm conditions in a Mediterranean climatic environment. Marked seasonal fluctuation in wool growth was found in all sheep. The highest level of clean wool production, 85 attained in the spring months, was nearly three times that of the lowest level, which occurred in the autumn. The rate of wool growth fluctuated independently of body weight. Wool growth fell steep4 while bob weight was maintained; wool growth subsequently rose sharply while body weight increased relatively slowly. The factors responsible for the observed fluctuation in the rate of wool growth are discussed and the conclusion reached that lack of useful energy and protein, in the summer and autumn grazing is probably the principal cause of the decline in rate of wool growth in these months.


1967 ◽  
Vol 20 (1) ◽  
pp. 153 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks ◽  
OB Williams ◽  
AJ Williams

The sulphur content of wool from 66 Peppin Merino wethers maintained together at pasture was measured in midside staples representing 49 weeks growth. The distribution of sulphur values was normal with a mean of 3�43 % and a range of 3�08-3�92 %. The sulphur content of the wool was inversely related to wool production among these sheep. There were no significant differences in the relationship when wool production was expressed as fleece weight index (F.W.I.), i.e. clean fleece weight/body weight (r = -0�48), as clean fleece weight (r = -0�42), or as wool growth per unit area of skin (r = - 0�37). The mean sulphur content of wool from sheep with the 10 highest values for F.W.I. was 3�27%, compared with a mean of 3 �55% sulphur for wool from sheep with the 10 lowest values for F.W.I.



1980 ◽  
Vol 31 (4) ◽  
pp. 791
Author(s):  
DA Tunks ◽  
RDG Rigby ◽  
AM Downes ◽  
JA Lamberton ◽  
BA Panaretto ◽  
...  

Merino sheep, offered feed at two levels of intake, were given an oral dose of N-[5-(4-am1nophenoxy)- pentyllphthahmide at rates varying over 100-800 mg/kg body weight. Consistent defleecing was obtained at dose rates of 400 nig/kg and above. Feed intake did not Influence defleecing activity. lntravenous infusion of smaller amounts also allowed defleecing. Wool growth rate following dosing was not affected by a dose of 100 mg/kg, but doses of 200 and 400 mg/kg caused depressions of c. 15 and c. 70% respectively in the rate of wool growth in the 2 weeks after dosing. Blindness was observed In one sheep dosed at 400 mg/kg and In all sheep dosed at higher rates



1990 ◽  
Vol 30 (4) ◽  
pp. 477
Author(s):  
RGA Stephenson ◽  
GR Suter ◽  
DA Pritchard ◽  
MDJ Martin

An analogue of DL-methionine, Alimet, was evaluated for its commercial potential for increasing wool growth in Merino sheep in pen and grazing experiments. This was done by administering Alimet as a drench, in drinking water, or via rumen or abomasal fistula, and measuring wool growth rate and plasma methionine concentrations. In vivo data indicated that significant wool growth responses (23-35%) to Alimet as a drench or in drinking water occurred at low rates (estimated 5-6 g/sheep.day) of basal wool production when sheep were fed a lucerne diet to maintain liveweight. At higher rates of clean wool growth (10-12 g/sheep.day) when sheep were eating above-maintenance diets (lucerne ration or pasture), Alimet treatment was associated with variable and reduced response. A significant (P<0.05) negative correlation (r2 = 0.699, n = 11) between wool growth responses (x � s.d. = 0.11 � 0.067) to the 3 mL dose rate of Alimet and wool growth in control treatments (y �: s.d. = 0.70 � 0.202) confirmed the above trend. Four hours after administration of Alimet via either rumen or abomasal fistula, comparative plasma concentrations of methionine, 28 and 168 �mol/L respectively, suggest that Alimet is susceptible to degradation in the rumen. The corresponding values for DL-methionine, via either rumen or abomasal fistula, were 64 and 350 �mol/L, respectively. The small rises (40%) in plasma methionine values associated with significant increases in wool production indicate that a dose of 3 mL is as effective as 4 mL of Alimet when the basal nutritional regime is limiting. While administration of Alimet in drinking water during dry seasons is possible, the profitability of supplementation would need to be tested further.



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.



1955 ◽  
Vol 6 (1) ◽  
pp. 91 ◽  
Author(s):  
FHW Morley ◽  
LW Lockart ◽  
EC Davis

The correlation between greasy wool production per unit area, obtained by clipping and measuring an area of about 100 cm² on the midside, and greasy fleece weight at shearing was about 0.58. Wool production from such an area over periods of 7½ or 3½ months was almost as useful as production for 11 months for predicting greasy fleece weight. The multiple correlation coefficient between greasy fleece weight as the dependant variable and production per unit area and 11-months' body weight was 0.79 in 66 rams and 0.71 in 82 ewes. The inclusion of fold score did not improve prediction appreciably. The equation W = P/110 + B1 /12 may be used to predict greasy fleece weight (lb), W, where P is production over 11 months of greasy wool (mg/cm²) and B1 is 11-months' body weight (Ib). A table of this function is included so that values may be read directly. The technique may be a useful aid to selection of Merino sheep if recording of actual fleece weights is difficult or impossible. Nevertheless it should not be regarded as more than a moderately accurate substitute for actual fleece-weighing.



1957 ◽  
Vol 8 (1) ◽  
pp. 75 ◽  
Author(s):  
PK Briggs ◽  
MC Franklin ◽  
GL McClymont

Dry adult Merino ewes were fed at daily or weekly intervals on oat grain at levels which provided 4.0, 3.0, or 2.0 lb starch equivalent (S.E.) per sheep per week. The experimental periods were 223, 223, and 181 days respectively. Differences between the mean body weights of the ewes a t the three levels of feeding were highly significant (P < 0.001). Body weight varied only slightly and no losses occurred in ewes fed weekly at the rate of 4.0 lb S.E. per head. Ewes fed daily a t this level had a significantly greater mean body weight (P < 0.001) a t the conclusion of the 223-day experimental period. The addition of a sodium chloride supplement did not improve the body weight or wool production of ewes fed weekly a t the level of 4.0 lb S.E. The mean body weight of ewes fed at the levels of 3.0 or 2.0 lb S.E. per head declined over the first 12 and 18 respectively and thereafter remained relatively constant. There were no significant differences at these levels of feeding between groups fed daily and weekly in respect of body weight, wool production, or survival rates. Ewes fed a t the level of 4.0 lb S.E. grew significantly more wool than those given 3.0 lb S.E. (P < 0.001). Losses were negligible in all groups except those fed a t the level of 2.0 lb S.E. In these groups there were few deaths in the first 16 weeks, but in the subsequent 10 weeks losses totalled 17.1 per cent. Ewes fed a t the level of 2.0 lb S.E. consumed their rations at a significantly slower rate (P < 0.01) than did those fed a t the level of 4.0 lb S.E.



1974 ◽  
Vol 25 (6) ◽  
pp. 945 ◽  
Author(s):  
H Dove ◽  
GE Robards

Merino wethers received daily abomasal infusions of (a) 2.6 g DL-methionine, (b) 80 g casein protein or (c) 2.6 g DL-methionine plus 87 g maize starch, while consuming either lucerne chaff or wheaten chaff. Responses in wool growth, nitrogen metabolism and body weight were measured. Sheep fed on lucerne chaff had a higher urinary nitrogen excretion and nitrogen retention than those fed on wheaten chaff regardless of the presence or type of infusion. The infusion of methionine did not markedly alter these parameters from their original levels on either diet. On both diets, casein infusion led to increased urinary nitrogen excretion and nitrogen retention. Compared with sheep given starch plus methionine infusions, those given casein had higher urinary nitrogen excretion and nitrogen retention. Changes in fleece-free body weight gain followed a similar pattern. There were no pronounced differences in faecal nitrogen excretion. Regardless of the presence or type of infusion, sheep fed on lucerne grew more wool than those on wheaten chaff. On both diets, all infusions were accompanied by higher wool growths than on the basal diet alone. The effect of the casein infusion, compared with methionine infusion, was apparent only in sheep on wheaten chaff. Wool growth rates in sheep infused with starch plus methionine were not higher than the rates in the same sheep infused with methionine alone. The results suggest that the wool production of sheep will show a greater response to abomasal supplements of sulphur amino acids or casein if they are consuming a high quality diet such as lucerne chaff, compared with a low quality diet such as wheaten chaff. The apparent failure of starch infusion to stimulate wool growth above the level obtained with methionine infusions alone is discussed in relation to the interaction of protein and energy in the growth of wool.



1976 ◽  
Vol 16 (83) ◽  
pp. 810 ◽  
Author(s):  
BD Hill ◽  
DG Saville

A grazing experiment was conducted at Cowra, on the western slopes of New South Wales, on a pasture consisting of lucerne (Medicago sativa) and annual species including capeweed (Arctotheca calendula), barley grass (Hordeum leporinum). wimmera ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) . The performance of Border Leicesterx Merino ewes mated to Dorset Horn rams and the growth of their progeny was compared under rotational and set stocked grazing management systems, with and without a 20 per cent area of lucerne saved for grazing when additional feed was required. There was one stocking rate (8.7 ewes ha-1) in 1966 and two (8.7 ewes ha-1 and 13.0 ewes ha-1) in 1967 to 1969. Rotational grazing decreased the lamb growth rate but increased the number of lambs born. The management system did not affect the body weight or wool production of the ewes. Lucerne was quickly eliminated from the set stocked areas and was greatly reduced in the rotational systems. Capeweed became dominant in the set stocked areas. Saving increased the number of lambs born at the high stocking rate in 1967 to 1969. In 1966 saving reduced lamb growth, ewe body weight and wool growth in the rotational system. The high stocking rate increased wool production per hectare, but decreased the number of lambs born and, in 1967, the lamb growth rate.



1964 ◽  
Vol 6 (3) ◽  
pp. 309-319 ◽  
Author(s):  
S. K. Stephenson

1. Body shape and carcass composition have been measured in a dated series of Romney-Southdown cross and Australian Merino sheep foetuses.2. Large differences in shape exist between the two breed groups and these result from growth rate differences in certain components of the bone and muscle tissue.3. Carcass composition at any particular foetal weight, however, is more uniform. In relation to body weight, the Merino has a higher proportion of bone in the body but the proportion of muscle is the same in both breed groups. Nevertheless, the distribution of muscle tissue is changed as there s i a higher proportion of muscle in the hind limb of the Romney-Southdown cross.



1978 ◽  
Vol 18 (90) ◽  
pp. 58 ◽  
Author(s):  
RND Reid

Groups of Polwarth ewes which 1. were barren, 2, were pregnant but aborted with prostaglandins in early pregnancy, 3. lambed and reared a single lamb and 4. lambed but had their single lamb removed soon after birth, were used to estimate the effects of pregnancy and lactation on wool and Iiveweight. Pregnancy plus lactation reduced liveweight (17 per cent), wool growth rate (9 per cent) and clean fleece weight (11 per cent) ; pregnancy alone reduced liveweight (10 per cent), wool growth rate (7 per cent) and clean fleece weight (10 per cent) and its effects were greater than those of lactation in each of the characters studied.



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