Influence of dietary intake and genetic capacity for wool growth on the composition of mid-trunk skin of Merino sheep

1994 ◽  
Vol 45 (8) ◽  
pp. 1715 ◽  
Author(s):  
AJ Williams ◽  
AJ Williams ◽  
FC Morley ◽  
FC Morley
Keyword(s):  
Unit Area ◽  
Amino Nitrogen ◽  
Unit Mass ◽  
Dry Skin ◽  
Merino Sheep ◽  
Wool Growth ◽  
Average Water ◽  
Dietary Treatments ◽  
Nitrogen Contents ◽  
Trunk Skin

Some nitrogenous constituents in the skin were examined in sheep from two flocks with different genetic capacities for wool growth and in sheep consuming different diets. In the first comparison, in which the sheep consumed a maintenance (1 x M) ration, the average water, lipid and nitrogen contents of skin were similar for the two flocks. The collagen content of skin from sheep with low wool growth (Fl-) was greater than that in skin of high producers (I?]+)-0.40 v. 0.36 g g-1 dry defatted skin (P < 0.05). The F1+ sheep also maintained lower concentrations of non-peptide cystine in plasma (51 v. 68 8mol L-l: P < 0.05) and in skin (1.1 v. 1.9 8mol g-l dry defatted skin: P < 0.05). In a second experiment, sheep bred from the two flocks (Fl+ and F1-), consumed rations providing either 0.8 x M or 2 x M (the latter diet containing 12.5% formaldehyde treated casein). Trephine-sampled skin from the high producing sheep and from the sheep with greater intake had lower concentrations of collagen per unit mass of skin (P < 0.05), but similar collagen per unit area of skin. Both diet and flock influenced the weight of skin sampled by trephine. The distribution ratios of non-peptide a-amino nitrogen and of cystine between skin and plasma were significantly greater in the F1+ derived sheep: 4.35 v. 3.1 L plasma kg-1 skin for cystine. In a third comparison, skin was sampled from sheep of an unselected flock (n = 50) after each received one of four dietary treatments ranging from 0.7 x M to 2.6 x M (ad lib.) for 60 days. As the dietary allowance increased, the weight of skin per unit area of skin increased, the quantities of total protein and of saponifiable lipid per unit mass of dry skin remained constant, but the content of hydroxyproline significantly decreased from 0.20 to 0.13 mmol g-l dry skin (P < 0.05). The quantities of non-collagenous protein solubilized by first sodium chloride (0.5 mol L-l) and then tartaric acid (0.1 mol L-l) per unit mass of collagen increased significantly with increased intake of feed.

A comparative investigation of the volumes of plasma and extracellular fluids and the renal clearances of urea and creatinine in Merino sheep from flocks with different genetic capacities for wool growth

1991 ◽  
Vol 42 (8) ◽  
pp. 1311
Author(s):  
AJ Williams ◽  
KJ Thornberry ◽  
H Nicol
Keyword(s):  
Extracellular Fluid ◽  
Comparative Investigation ◽  
Average Volume ◽  
Castrate Male ◽  
Merino Sheep ◽  
Genetic Groups ◽  
Wool Growth ◽  
Renal Clearances ◽  
Fleece Weight ◽  
Dietary Treatments

Adult castrate male Merino sheep (n = 24; average liveweight 47 kg), from two flocks, differing in their genetic capacity for wool growth as a result of selective breeding for clean fleece weight, consumed one of two diets, differing in both quality (i.e. digestibility and nitrogen content) and quantity, termed L and H. The L (low) and H (high) diets supplied 0.42 and 0.81 kg digestible dry matter day-' and 9.5 and 26.0 g nitrogen day-I respectively. We compared the volumes of plasma and extracellular fluids, as well as the concentration of urea in plasma and the rate of clearance of urea by the kidneys of sheep from these two genetic groups, consuming the different diets. The average plasma volume of these sheep, estimated from the dilution of Evan's Blue in plasma, was 2.24 L (s.e. 0.08). The average volume of extracellular fluid, estimated from the dilution of 35S-sulfate, was 10.3 L (s.e. 0.4). These distributional volumes were similar in sheep from the two genetic groups and were not influenced by the dietary treatments. The sheep consuming the H diet maintained significantly greater concentrations of urea-nitrogen in their plasma (7.2 v. 2.8 mmol L-1: s.e. 0.3) and cleared both urea (37.1 v. 16.1 mL min-I : s.e. 5.3) and creatinine (87 v. 49 mL min-1 : s.e. 11) at significantly greater rates from the plasma. The sheep from the two genetic groups had similar average values for these three traits.

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.

scholarly journals Metabolism of Cystine by Merino Sheep Genetically Different in Wool Production III. the Incorporation of Radioactivity Into Wool Fibres During and After Intravenous Infusions of l-[35S]Cystine and its Relationship to Wool Growth and Efficiency of Conversi

1973 ◽  
Vol 26 (2) ◽  
pp. 465 ◽  
Author(s):  
AJ Williams
Keyword(s):  
Merino Sheep ◽  
Wool Production ◽  
Wool Growth ◽  
Intravenous Infusions ◽  
Fleece Weight ◽  
Dietary Treatments

Twelve mature ewes from a flock selected for high clean fleece weight (Fleece Plus) and twelve from a flock selected for low clean fleece weight (Fleece Minus) were randomly divided between two dietary treatments: 500 or 1100 g per day of chaffed lucerne hay.

Ectopic expression of FGF5s induces wool growth in Chinese merino sheep

Gene ◽  
2017 ◽  
Vol 627 ◽  
pp. 477-483 ◽  
Author(s):  
Wen-Rong Li ◽  
San-Gang He ◽  
Chen-Xi Liu ◽  
Xue-Mei Zhang ◽  
Li-Qin Wang ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Merino Sheep ◽  
Wool Growth

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.

Studies in fleece-rot of sheep.

1953 ◽  
Vol 4 (4) ◽  
pp. 430 ◽  
Author(s):  
RH Hayman
Keyword(s):  
Microscopic Examination ◽  
Similar Condition ◽  
Unit Area ◽  
Skin Surface ◽  
Climatic Conditions ◽  
Field Station ◽  
Merino Sheep ◽  
Naturally Occurring ◽  
Sufficient Intensity ◽  
Experimentally Induced

Occasions of unduly heavy and prolonged rainfall during the period April 1946 – July 1951 resulted in the occurrence of fleece-rot in sheep of the Field Station flock in each of the six years. Data obtained from periodic examinations of the flock have been related to the nature of climatic conditions associated with outbreaks of the disease. They show that when rain occurs in falls of sufficient intensity and frequency to wet sheep to the skin for a period of a week or more, fleece-rot may be expected to develop in some of them. The longer the period for which the sheep are kept wet, the greater the number in a flock which will be affected. Fleece-rot was experimentally induced in four out of five Merino sheep known to be susceptible to the condition, whereas five animals known to be resistant were unaffected by the same treatment. Microscopic examination of skin sections taken from naturally occurring cases revealed the presence of a dermatitis. A similar condition was observed in skin sections from the animals in which fleece-rot was experimentally induced. Young sheep were found to be more susceptible than old. There was no association between degree of wrinkling and susceptibility or between 'grip' and susceptibility. When subjectively-appraised attributes of the fleece were related to the occurrence of fleece-rot, confusing results were obtained. However, when measured fleece data, obtained from a group of Merino sheep which had been under observation for four consecutive years, were considered, it was found that those for clean-scoured yield, wax and suint ratio, and density of fibre population per unit area of skin surface, were related to resistance or susceptibility. Nevertheless, a number of animals were found which were susceptible or resistant to the disease despite the nature of their fleece attributes. Differences in susceptibility were found between families of Merino sheep. These are associated with between-family differences for the fleece attributes found to be important in fleece-rot reaction.

An Ultrastructural Autoradiographic Study of the Incorporation of [35S]Cystine in the Wool Fibre Cortex

1973 ◽  
Vol 13 (3) ◽  
pp. 811-819
Author(s):  
R. E. CHAPMAN ◽  
R. T. GEMMELL
Keyword(s):  
Unit Area ◽  
Autoradiographic Study ◽  
Wool Fibre ◽  
Cross Sectional ◽  
Electron Microscope Autoradiography ◽  
Merino Sheep ◽  
Microscope Autoradiography ◽  
Cystine Content ◽  
Chemical Studies ◽  
Filament Bundle

Previous autoradiographic and chemical studies gave incompatible results as regards the incorporation of cystine into and cystine content of the 2 cortical segments of the wool fibre. In this study the incorporation of [35S]cystine into the wool fibre cortex was therefore re-examined by electron-microscope autoradiography. Skin samples were taken from a Merino sheep 1 h and 5 h after intradermal injections of L-[35S]cystine. At both times there was very little incorporation of 35S in the follicle bulbs. By 5 h incorporation occurred distally from the suprabulbar region throughout the zone of macrofibril (filament bundle) formation. More 35S was incorporated per unit area in the paracortex than in the orthocortex, and at the level of maximal uptake near the middle of this zone there was about a 2-fold difference per unit area. However, when the relative cross-sectional areas of the cortical segments were also considered, the actual amount of 35S incorporated at this level was slightly greater in the orthocortex than in the paracortex. These differences in the incorporation of [35S]cystine by the cortical segments agreed with previous results from chemical studies on cortical fractions separated from wool.

The influence of type and timing of protein supplementation on wool growth and protein synthesis in the skin of young Merino sheep

1999 ◽  
Vol 50 (4) ◽  
pp. 497 ◽  
Author(s):  
D. G. Masters ◽  
G. Mata ◽  
S. M. Liu
Keyword(s):  
Protein Synthesis ◽  
Experimental Period ◽  
Protein Supplementation ◽  
The Other ◽  
Canola Meal ◽  
Protein Supplements ◽  
Wool Growth ◽  
Low Concentrations ◽  
High Concentrations ◽  
Dietary Treatments

There is limited evidence that the response in wool growth resulting from feeding protected protein supplements continues after the feeding has stopped. Feeding such proteins, alternated with traditional supplements, may increase wool growth as much as continuous feeding but at a lower cost. This experiment aimed to determine whether the response to protected protein continued after the sheep were switched to a cereal supplement. Over a 2-month experimental period, 56 weaners (5 months old, weighing 26 kg) were used in a 2 × 2 factorial experiment. Half were fed a diet containing 25% canola meal [partially protected protein with high concentrations of sulfur amino acids (SAA)] mixed with oaten hay, urea, and minerals. The other half were fed the same diet but with lupin seed (highly degradable protein with low concentrations of SAA) replacing the canola meal. Within each of the 2 dietary treatments and in each of 2 months, half of the weaners were fed the diet continuously, the other half were fed the diet for 2 weeks followed by 2 weeks of a barley, oats, hay, urea, and minerals diet. Another group of 8 weaners was fed the oats–barley diet continuously for 2 months. All sheep were fed to lose 35 g liveweight/day. Weaners fed canola meal grew 11% more wool during the experiment and had a higher rate of protein synthesis in the skin than weaners fed lupins. The response to canola meal of wool and skin was the same whether feeding was continuous or alternated with oats–barley, indicating that the benefits from feeding partially protected proteins continues after feeding has stopped.

Sheep of divergent genetic merit for wool growth do not differ in digesta kinetics while on restricted intakes

2014 ◽  
Vol 54 (9) ◽  
pp. 1243 ◽  
Author(s):  
I. De Barbieri ◽  
R. S. Hegarty ◽  
V. H. Oddy ◽  
M. C. Barnett ◽  
L. Li ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Genetic Selection ◽  
Amino Nitrogen ◽  
Feeding Level ◽  
Wool Growth ◽  
Selection For ◽  
Fleece Weight ◽  
Estimated Breeding Values ◽  
Growth Differences ◽  
Weight Groups

Sheep selected for high wool growth were previously shown to exhibit higher microbial protein outflow from the rumen and higher uptake of amino nitrogen in portal blood than those selected for low wool growth. This suggests that genetic selection for wool growth may induce changes in foregut physiology. This study was undertaken to determine whether differences in digesta kinetics, especially mean retention mime (MRT), are associated with differences in fleece production between sheep with low or high estimated breeding values (EBVs) for fleece weight. Twenty mature Merino wethers with uniform EBVs for liveweight were allocated to two groups of 10 animals on the basis of high or low EBVs for yearling fleece weight. Five sheep with low-EBVs and five sheep with high-EBVs for fleece weight groups were allocated in a crossover design to low and high feeding-level treatments, which comprised a blended hay diet fed at maintenance or 1.5 times maintenance. All sheep were given single doses of chromium-mordanted fibre and cobalt-EDTA as inert, non-digestible markers. Digesta kinetics was determined by analysis of the faecal marker excretion patterns using a compartmental model. Higher feed intakes from animals fed 1.5 times maintenance were associated with higher rates of wool growth and higher masses of indigestible fibre in the gut, but reduced MRT of digesta. Although sheep with higher EBVs for fleece weight had higher wool growth rates, there was no indication that these wool growth differences were associated with differences in digesta kinetics. The lack of interaction between feeding level and genotype suggests that MRT did not contribute to genotype differences in wool growth in sheep fed restricted intakes. The differences in wool growth among commercial Merino sheep with divergent fleece weight EBVs achieved by multi-trait selection are not attributable to differences in digesta kinetics, at least when feed is not available ad libitum.

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