scholarly journals Variation in the Sulphur Content of Wool of Merino Sheep Associated with Genetic Differences in Wool-Producing Capacity

1966 ◽  
Vol 19 (6) ◽  
pp. 1179 ◽  
Author(s):  
LR Piper ◽  
CHS Dolling
Keyword(s):  
Amino Acids ◽  
Seasonal Variation ◽  
Nutritional Status ◽  
Inverse Relationship ◽  
Copper Deficiency ◽  
Sulphur Content ◽  
Merino Sheep ◽  
Wool Growth ◽  
Number Of Factors ◽  
The Relationship

The sulphur content of wool may be influenced by a number of factors. Copper deficiency has been shown to reduce sulphur content (Marston 1946), while the administration of sulphur-containing amino acids or casein directly into the abomasum has been shown to increase substantially both the sulphur content of wool and the rate of wool growth (Reis and Schinckel1961, 1963, 1964). Variation in the nutritional status of both pen-fed (Reis 1965) and grazing (Reis and Williams 1965) sheep, associated with variation in either the amount or the composition of the diet, has also been shown to influence sulphur content; wool growth and sulphur content have both increased as nutrition has been improved, and vice versa. Variation in the sulphur content of wool from grazing sheep has also been reported by Ross (1961, 1964) who suggested that there was an inverse relationship between rate of wool growth and its sulphur content. The sheep observed by Ross were Romney ewes and Reis and Williams (1965) have cast some doubt on the relationship suggested by Ross on the grounds that the seasonal variation in wool growth may have been affected by factors other than nutrition.

scholarly journals A Relationship Between Sulphur Content of Wool and Wool Production by Merino Sheep

1967 ◽  
Vol 20 (1) ◽  
pp. 153 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks ◽  
OB Williams ◽  
AJ Williams
Keyword(s):  
Body Weight ◽  
Unit Area ◽  
Sulphur Content ◽  
Merino Sheep ◽  
Wool Production ◽  
Weight Index ◽  
Wool Growth ◽  
The Mean ◽  
Fleece Weight ◽  
The Relationship

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.

Variations in the sulphur content of wool from Merino sheep on two semi-arid grasslands

1965 ◽  
Vol 16 (6) ◽  
pp. 1011 ◽  
Author(s):  
PJ Reis ◽  
OB Williams
Keyword(s):  
Growth Rate ◽  
Seasonal Variation ◽  
Seasonal Variations ◽  
Seasonal Pattern ◽  
Sulphur Content ◽  
Merino Sheep ◽  
Wool Growth ◽  
Arid Grasslands ◽  
Semi Arid

Seasonal variations in sulphur content and growth rate of wool were measured at intervals of 6 weeks over a period of 1 year on two groups, each of six Merino wethers, which grazed on two semi-arid grasslands. Each group consisted of three high-producers and three low-producers, selected on the basis of wool growth rate. There were substantial seasonal variations in sulphur content, which followed very closely the seasonal pattern of wool growth. Mean sulphur contents on the two grasslands ranged from 3.25 and 3.32% during December–April, to 3.67 and 3.79% respectively during July-October. Seasonal variations in sulphur content and growth rate of wool were related to the amount of edible forage available, and it was concluded that these seasonal variations were due mainly to variable nutrition. The range of sulphur contents was 2.93 to 3.92%, owing to seasonal nutritional variations and differences between sheep; annual mean sulphur contents of wool from individual sheep ranged from 3.22 to 3.84%. The annual mean sulphur content of the wool from high-producers (3.39%) was lower than that of wool from low-producers (3.66%). The seasonal variation in sulphur content also appeared to be greater in wool from high-producers than in wool from low-producers.

scholarly journals Effects of Growth Hormone Administration on Wool Growth in Merino Sheep

1988 ◽  
Vol 41 (2) ◽  
pp. 177 ◽  
Author(s):  
PC Wynn ◽  
ALC Wallace ◽  
AC Kirby ◽  
EF Annison
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Energy Intake ◽  
Nitrogen Balance ◽  
Daily Administration ◽  
Maintenance Energy ◽  
Merino Sheep ◽  
Growth Hormone Administration ◽  
Hormone Administration ◽  
Wool Growth

The effects of daily administration of 10 mg of highly purified ovine growth hormone (GH) for a period of 4 weeks on wool growth have been measured in 12 Merino ewes fed either a calculated maintenance energy intake or 1�6 times this amount (six on each ration). Concentrations of hormones, glucose, urea, a-amino N and amino acids in the blood were monitored and faeces and urine collected for measurement of nitrogen balance.

scholarly journals Nutritional Factors Involved in Wool Production By Merino Sheep II. The Influence of Copper Deficiency on the Rate of Wool Growth and on the Nature of the Fleece

1948 ◽  
Vol 1 (3) ◽  
pp. 376 ◽  
Author(s):  
Hedley R Marston ◽  
Hector J Lee
Keyword(s):  
Copper Deficiency ◽  
Physiological Condition ◽  
Nutritional Factors ◽  
Merino Sheep ◽  
Wool Production ◽  
Wool Growth ◽  
Normal Physiological Condition

A range of nutritional states which varied in relatively small degrees from a normal physiological condition to one of acute copper deficiency was induced in a series of evenly matched groups of Merino sheep depastured on deficient terrain by providing them with supplements of copper which extended through suboptimum: amounts to quantities in excess of their full requirements.

Effects of the infusion of amino acids into the abomasum of sheep, with emphasis on the relative value of methionine, cysteine and homocysteine for wool growth

1990 ◽  
Vol 114 (1) ◽  
pp. 59-68 ◽  
Author(s):  
P. J. Reis ◽  
D. A. Tunks ◽  
S. G. Munro
Keyword(s):  
Amino Acids ◽  
Folic Acid ◽  
Adverse Effects ◽  
Essential Amino Acids ◽  
Vitamin B ◽  
Merino Sheep ◽  
Wool Growth ◽  
Relative Value ◽  
Nonessential Amino Acids ◽  
Maintenance Ration

SUMMARYMerino sheep were given abomasal infusions of various amino acids or mixtures of amino acids. Effects on wool growth were measured using autoradiography or a clipping procedure and changes in the concentration of amino acids in plasma were measured in some experiments.Mixtures of five (28 g/day) or ten (45 g/day) essential amino acids (both mixtures containing 3 g methionine) stimulated wool growth of sheep receiving a maintenance ration; on average, the volume of wool grown increased 48% and 86%, respectively. When cysteine completely replaced methionine in these mixtures, wool growth was markedly reduced, but two-thirds of the methionine could be replaced by cysteine without affecting wool growth. Homocysteine was partially effective in replacing methionine and, when supplemented with betaine, folic acid and vitamin B12, the mixture was still significantly inferior to that containing methionine. In contrast, abomasal supplements of methionine or homocysteine alone were equivalent as supplements for wool growth. The results indicated a specific role for methionine in the control of wool growth, other than the provision of cysteine. This role was postulated to be related to some function of S-adenosylmethionine.Infusion often essential amino acids caused appreciable increases in the concentrations of cystine, methionine, cystathionine and taurine in plasma; total essential amino acids increased threefold whereas nonessential amino acids decreased in concentration. The replacement of methionine in the infusion by cysteine or homocysteine significantly altered the concentration of cystine, methionine and cystathionine in plasma.Evidence was obtained that the adverse effects on wool growth of high abomasal doses of methionine (10g/day) could not be reduced or prevented by provision of additional glycine and were not related to the supposed toxic effects of 3-methylthiopropionic acid, a metabolite of the transamination pathway.

Studies on the relationship between nutrition and wool production of Merino sheep. II. The effect of the administration of cystine, cystein, sulphur and of methionine on the growth of wool of a Merino ewe on a protein-poor ration

1935 ◽  
Vol 25 (1) ◽  
pp. 113-131 ◽  
Author(s):  
Hedley R. Marston
Keyword(s):  
Protein Diet ◽  
Low Protein Diet ◽  
Daily Ration ◽  
Merino Sheep ◽  
Wool Production ◽  
Low Protein ◽  
Wool Growth ◽  
Cent Increase ◽  
The Relationship

1. The question whether the amount of cystine in the wool grown may exceed that in the diet is discussed.2. When 1 gm. of laevo-cystine was added to the daily ration of a ewe on a low protein diet, the wool grown upon a circumscribed area was 14 per cent, more than that grown during a similar period immediately preceding. Four-fifths of the sulphur in the added cystine was absorbed, about half of which was excreted in the urine during the period the cystine was being fed.3. When 1 gm. of laevo-cystein was injected subcutaneously each day for 10 days, a 34 per cent, increase in wool growth occurred. During three succeeding periods, of 10 days each, immediately after the injections had been discontinued, the increases were 30, 18 and 7 per cent, respectively. Of the 2.6 gm. of sulphur in the cystein injected during the 10 days, 1.7 gm. was retained and could be accounted for by the extra amount of wool grown during that and the succeeding periods.

Effects of abomasal protein and energy supply on wool growth in Merino sheep

1992 ◽  
Vol 43 (6) ◽  
pp. 1353 ◽  
Author(s):  
PJ Reis ◽  
DA Tunks ◽  
SG Munro
Keyword(s):  
Amino Acids ◽  
Energy Supply ◽  
Essential Amino Acids ◽  
Merino Sheep ◽  
Lattice Design ◽  
Wool Growth ◽  
Extra Energy ◽  
Whole Milk ◽  
Wool Proteins ◽  
Protein Supply

The relative importance for wool growth of energy-yielding nutrients compared with amino acids required for incorporation into wool proteins was assessed in an experiment in which most nutrients were supplied via the abomasum. Nine nutritional treatments, providing three levels of protein (53, 99 and 145 g/day) to the intestines at three levels of energy (5.2, 7.5 and 9.7 MJ/day), were given to 12 Merino sheep during three consecutive periods of 3 weeks in a balanced lattice design. Abomasal nutrients consisted of varying proportions of casein, whole milk, glucose and glycerol. There was a large effect of protein supply on all components of wool growth, but there was no significant effect of energy. There was a significant interaction between the effects of protein and energy supply on diameter, length growth rate and volume of wool, but it was small relative to the main effect of protein. Extra energy appeared to enhance wool growth at the highest level of protein but reduce it at the lowest level of protein. The concentration of urea, cystine, methionine and other essential amino acids in plasma increased with protein level. Increasing energy supply reduced the concentration of urea and essential amino acids in plasma but not that of cystine or methionine. The experiment confirmed the major role of amino acid supply in controlling wool growth but indicated that there may be a small interaction with energy supply.

The influence of season and nutrition on the sulphur content of wool from Merino and Cheviot sheep

1968 ◽  
Vol 70 (2) ◽  
pp. 111-116 ◽  
Author(s):  
J. M. Doney ◽  
C. C. Evans
Keyword(s):  
Growth Rate ◽  
Nutrient Intake ◽  
Sulphur Content ◽  
Nutrient Cycle ◽  
Wool Growth ◽  
Seasonal Depression ◽  
The Difference ◽  
Cycle Group ◽  
The Relationship ◽  
Annual Amount

SUMMARYSulphur content, expressed as a percentage of clean dry wool weight, was measured at monthly intervals in two breeds of sheep, Cheviot and Merino x Cheviot backcross (¾ Merino, ¼ Cheviot), offered an equivalent annual amount of feed in three ways—constant level, natural grazing cycle and reversed grazing cycle. The relationships between S content and wool growth rate or nutrient intake differed with both breed and nutrient cycle, but all the results could be explained satisfactorily on the basis of a constant optimum composition for each individual with sulphur impoverishment related to lack of balance between follicle activity rate and high-S substrate availability.The difference in mean maximum S content between breeds (3·87% and 3·81% for Cheviot and ‘Merino’ respectively) was much smaller than the difference between individuals within the breeds (4·05·3·72% and 3·92·3·66%). The seasonal depression within individuals varied with nutrition and wool growth rate, Cheviot sheep showing the greatest depression and lowest values (2·89 and 3·28% for Cheviot and 'Merino, respectively in the reversed cycle group). There was no consistent seasonal trend in the relationship between clean and unscoured wool weight.

Seasonality in wool growth under semi-arid conditions

1974 ◽  
Vol 83 (3) ◽  
pp. 443-446 ◽  
Author(s):  
A. A. Elsherbiny ◽  
B. Markotić
Keyword(s):  
Seasonal Variation ◽  
Genetic Effects ◽  
Genotype X Environment Interaction ◽  
Environment Interaction ◽  
Merino Sheep ◽  
Genotype X Environment ◽  
Arid Conditions ◽  
Wool Growth ◽  
Time Of Year ◽  
Semi Arid

SummaryWool samples from 49 ewes representing four breeds of sheep, Ossimi, Rahmani, Barki and Merino were used to study the seasonal variation in wool growth. The first three breeds are of the local carpet-wool types of Egypt.Consistent differences were found between breeds in diameter and length of fibres (i.e. genetic effects). These effects were not modified by the environment (i.e. time of year) although the latter had different effects on diameter than on length. Medullation, however, was not consistent from breed to breed in all seasons (i.e. there was genotype x environment interaction). It is concluded that seasonality in wool growth exists under the semi-arid conditions of Egypt in local breeds but to a lesser extent in imported Merino sheep.

scholarly journals Effects of Intravenous Infusion of Mimosine on Wool Growth of Merino Sheep

1975 ◽  
Vol 28 (6) ◽  
pp. 483 ◽  
Author(s):  
PJ Reis
Keyword(s):  
Amino Acids ◽  
Intravenous Infusion ◽  
Merino Sheep ◽  
Wool Growth ◽  
Intravenous Infusions

Merino sheep were given continuous intravenous infusions of L-mimosine for periods of It, 2 or 21 days; efficacy as a defleecing procedure and effects on subsequent wool growth were measured. In addition, the amino acids tyrosine, phenylalanine and cystine were investigated as antagonists to the effects of mimosine.

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