The effect of nutrition on fibre growth in the alpaca

1997 ◽  
Vol 64 (3) ◽  
pp. 509-512 ◽  
Author(s):  
A. J. F. Russel ◽  
H. L. Redden
Keyword(s):  
Growth Rate ◽  
Adult Male ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Weight Yield ◽  
Fibre Growth ◽  
Maintenance Requirements

AbstractTwelve adult male alpacas were given either 0·67 (low) or 2·0 (high) × assumed maintenance requirements for a period of 6 weeks after which time each was transferred to the alternative level of nutrition for a further 6 weeks. Fibre samples were taken from two 10-cm2 areas on the mid-side position of each animal at 2, 6, 8 and 12 weeks, and measurements of fibre weight, yield (clean fibre weight/raw fibre weight), fibre diameter and fibre length made on the samples collected at weeks 6 and 12. The higher level of feeding resulted in higher clean fibre weight (low = 0·42 (s.e. 0·03); high = 0·53 (s.e. 0·04)mg/cm2 per day, P < 0·001) and fibre growth rate (low = 186 (s.e. 10); high = 223 (s.e. 14) yon/day, P < 0·05). Changes in yield (low = 0·917 (s.e. 0·006); high = 0·929 (s.e. 0·009)) and mean fibre diameter (low = 31·4 (s.e. 1·9); high = 32·1 (s.e. 1.6) \xm) were not statistically significant. Calculations showed that the increased weight of fibre attributed to the higher level of nutrition could be explained in terms of the observed increases in fibre-length and diameter but that, unlike the sheep in which the ratio fibre length: diameter remains relatively constant under varying nutritional regimes, the effect of nutrition in the alpaca has a proportionally larger effect on fibre length than on fibre diameter.

The effects of intradermal injections of spermidine on the growth rate of fibres and mitosis of wool follicles in Merino lambs

2002 ◽  
Vol 75 (1) ◽  
pp. 33-40 ◽  
Author(s):  
S. M. Liu ◽  
A. Murray ◽  
A. C. Schlink ◽  
G. Mata ◽  
D. G. Masters
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Cell Division ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Optimal Growth ◽  
Contralateral Side ◽  
Length Growth ◽  
Local Supply ◽  
High Doses

AbstractPolyamines (putrescine, spermidine and spermine) are required for optimal growth in all cells, and are essential for cell proliferation and growth of cultured wool follicles, with an optimal concentration of spermidine required for the fibre elongation. The effects of a local supply of exogenous spermidine on the rate of cell division in the wool follicles, the length growth rate and diameter of fibres were therefore examined in Merino lambs. Three groups of eight lambs (40 kg) were given food at 1·2 ✕ maintenance. Spermidine was injected intradermally into a small patch (3 ✕ 3 cm) on the left flank three times per day for 7 days at one of three concentrations: 1·38, 2·75 or 4·58 џmol in 0·8 ml volume. The same volume of saline was injected into the contralateral side as a control. The concentration of spermidine in the skin patch 3 h after injection on day 7 increased by proportionately 018, 0·33 or 0·41 (P < 0001) respectively. The rates of cell division in the follicle bulb 3 h after the spermidine injection were proportionately 0104, 0184 and 0·283 higher compared with the contralateral side (P = 0078 overall) for the low, medium and high doses of spermidine respectively and differed between the three doses (P < 005). The fibre length growth rate, as measured using autoradiography, was proportionately 0099, 0117 and 0156 higher than that of the contralateral side (P < 0001 overall) for the low, medium and high doses of spermidine respectively, but differences between doses were not significant (P > 005). Spermidine injection did not result in a significant change in fibre diameter during the treatment period. The ratio of fibre length growth rate to fibre diameter was increased by the injection of spermidine (P < 0001). The results suggest that injecting extra spermidine into the skin altered spermidine homeostasis in the skin, stimulated cell proliferation and resulted in increased fibre growth.

Seasonal variation in fibre diameter and length in wool of grazing Merino sheep with low or high staple strength

1999 ◽  
Vol 39 (5) ◽  
pp. 507 ◽  
Author(s):  
A. C. Schlink ◽  
G. Mata ◽  
J. M. Lea ◽  
A. J. M. Ritchie
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Subterranean Clover ◽  
Experimental Period ◽  
Strength Group ◽  
Pooled Data ◽  
Length Growth ◽  
Fibre Growth ◽  
Staple Strength ◽  
Highly Correlated

The associations between fibre growth characteristics and wool staple strength were investigated in groups (n = 10) of Merino wethers with either low or high staple strength. Sheep grazed together on pastures based on subterranean clover and annual rye grass for about 13 months. The sheep were weighed and injected intradermally with [35 S]-cysteine at about 14-day intervals. Mid-side patches were harvested and dye bands placed in the wool at about 28-day intervals. Patch clean wool growth, pasture digestible dry matter/ha and pasture crude protein/ha had similar seasonal amplitudes of production (287, 286 and 267% of respective minimum). These were significantly higher than the seasonal amplitude in liveweight (24.5%). The seasonal amplitude in fibre diameter was significantly greater than that for rate of fibre elongation (71.4 and 41.4% respectively). This seasonality in fibre length and diameter resulted in statistically significant seasonal fluctuations in the ratio of fibre length growth to fibre diameter. Fortnightly variability in fibre diameter was not significantly related to variability in fibre length growth rate between sheep for individual time periods. However, for the pooled data over the experimental period a statistically significant relationship (R2 = 0.13, P<0.01) was improved with the addition of parameters for sampling time and staple strength group. Staple strengths for the low and high staple strength groups were 25.6 and 32.8 N/ktex respectively (P = 0.057). There were no significant differences between the staple strength groups in seasonal change in liveweight, wool production or fibre parameters measured in this study but the low staple strength group had longer fibres. Staple strength was most highly correlated with mid-side fibre diameter coefficient of variation (R2 = 0.50) followed by seasonal amplitude in liveweight.

STUDIES ON THE RELATION OF GROWTH RATE TO WOOD QUALITY IN POPULUS HYBRIDS

1942 ◽  
Vol 20c (1) ◽  
pp. 28-40 ◽  
Author(s):  
L. P. V. Johnson
Keyword(s):  
Growth Rate ◽  
Wood Quality ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Fast Growth ◽  
Annual Rings ◽  
Annual Increment ◽  
Soda Pulp ◽  
Individual Trees ◽  
Slow Growing

Experiments were conducted on the relation of growth rate to wood quality in a series of 43 hybrid and parental trees, which involved Populus alba, P. grandidentata, and P. tremuloides.Fibres in fast growth annual rings were longer on the average than those in slow growth rings from the same tree. In single annual rings, fibres of early wood were shorter and thicker than those of late wood.Average fibre diameter of individual trees was significantly correlated in a positive manner with growth rate, but the correlation between fibre length and growth rate was well below the level of significance.Short, thick habit of growth was significantly correlated with high density of wood, but correlations between growth rate (in terms of annual increment in volume) and wood density were insignificant.Experimental pulp and paper tests did not reveal any very striking differences in quality between fast growing hybrid and slow growing parental trees, although there remains some doubt as to the suitability of abnormally fast growth hybrid wood for some of the higher grades of soda pulp paper.The general, and tentative, conclusion is that the investigation revealed nothing to indicate that rapid growth is seriously detrimental to wood quality.

Effects of shearing time and time of lambing on wool growth and processing characteristics

1984 ◽  
Vol 24 (126) ◽  
pp. 337 ◽  
Author(s):  
GW Arnold ◽  
AJ Charlick ◽  
JR Eley
Keyword(s):  
Growth Rate ◽  
Seasonal Pattern ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Lower Percentage ◽  
Dominant Factor ◽  
Lower Yield ◽  
Merino Sheep ◽  
Wool Growth ◽  
Fleece Weight

Wool growth rate, seasonal pattern of fibre diameter, clean fleece weight, quality and the processing characteristics of wool were measured on medium-wool Merino sheep shorn in March (autumn) or October (spring) coupled with March or June lambing. These four management systems were compared under two nutritional regimes in the medium rainfall area of Western Australia. The sheep grazed annual pastures only, or had lupin grain and stubble during summer in addition to the pasture. The study ran for two shearing periods. Time of shearing was the dominant factor. Sheep shorn in March produced 14% more clean wool and fewer tender fleeces than sheep shorn in October. The autumn wool had a lower yield, higher fibre diameter and when processed had a higher card loss, lower percentage noil and lower top and noil yield. However, mean fibre length in the top was substantially higher and the variation in fibre length lower. Vegetable matter was higher in autumn shorn wools. There were some interacting effects of lambing time and type of feed regime. Sheep fed lupins had lower yielding wool but this effect was more pronounced in June lambings and was reflected in differences in top and noil yield. From measurements of wool growth rate, it was found that the extra wool was produced in autumn after shearing, due possibly to stimulated appetite that cannot occur after spring shearing because the sheep are too fat.

Sulfur supplementation of lupin grain diets fed to young sheep

1999 ◽  
Vol 39 (6) ◽  
pp. 657
Author(s):  
P. T. Doyle ◽  
A. J. M. Ritchie ◽  
M. R. Ellis
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Fibre Diameter ◽  
Sulfur Amino Acid ◽  
Cereal Straw ◽  
Dry Matter Digestibility ◽  
Wool Growth ◽  
Limiting Nutrients ◽  
Metabolisable Energy ◽  
Maintenance Requirements

Summary. We examined the effects of supplementation of lupins with limestone or gypsum on liveweight change and wool production of young Merino wethers [age 10 months; starting liveweight (mean s.e.m.) 34.8 0.33 kg]. Lupins with the added compounds were fed in amounts estimated to provide metabolisable energy at 0.8, 1.0, 1.5 and 2.0 times maintenance requirements. The remainder of the ration was cereal straw fed at 10% of the weight of lupins given. Lupins coated with limestone or gypsum had a dry matter digestibility of 880 g/kg, and contained (g/kg DM) nitrogen 56.1 v. 57.4, sulfur 2.3 v. 4.6 and calcium 7.9 v. 5.4 respectively. As the amount of the ration fed was increased, there were linear increases (P<0.001) in liveweight gain (–9 to 226 g/day), clean wool growth rate (5.3–10.2 g/day), and fibre diameter of wool grown (18.0–21.6 m). There were no significant differences between lupins coated with limestone or gypsum in liveweight change (97 v. 105 g/day) or clean wool growth rate (7.6 v. 7.5 g/day). While the addition of sulfur to the diet reduced fibre diameter of wool grown (19.4 v. 20.0 m; P<0.01), this is not consistent with the effects of increased sulfur amino acid supply which would be expected to increase fibre diameter. It is concluded that the supply of inorganic sulfur to ruminal organisms was not limiting production responses to lupins or that there were other more limiting nutrients.

A study of some wool traits in two coarse wool breeds and their reciprocal crosses

1978 ◽  
Vol 90 (3) ◽  
pp. 495-501 ◽  
Author(s):  
R. A. Guirgis ◽  
N. T. Kazzal ◽  
M. S. Haddadine ◽  
R. K. Abdallah
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Bimodal Distribution ◽  
The Other ◽  
Maternal Influence ◽  
Reciprocal Crosses ◽  
Diameter Fibre ◽  
The Mean

SummaryIn a study of two coarse wool breeds (Awassi and Karadi) and their reciprocal crosses, data were obtained on the mean fibre length, mean fibre diameter, fibre type ratio, medullation and on the effect of some environmental factors on these traits. Reciprocal crosses showed intermediate values, in growth rate of fibres, percentages of fibre types and medullation, between those of the parental breeds. Sex exhibited a significant effect at weaning only, on fibre length. Heterosis in fibre length, at the two ages, was small and negative. Maternal influence on fibre length was small and not significant. Fibre length in Karadi sheep showed the highest frequency of bimodal distribution whereas Awassi showed the lowest. Awassi × Karadi was closer to Karadi and Karadi × Awassi had greater affinity to Awassi in the frequency of samples showing bimodal distribution.Reciprocal crosses had larger diameter, at weaning, than those of the parental breeds. At 1 year of age they assumed an intermediate position between the pure bred parents.At weaning, the two reciprocal crosses showed a highly significant heterosis in fibre diameter; its value decreased with advancing age and it showed no significant effect at 1 year of age.Maternal influence on fibre diameter was very small and not significant.Karadi × Awassi and Karadi samples had the highest percentage of samples showing bimodal distribution of fibre diameter.Samples with bimodal distribution of both length and diameter, indicating two coats, had the highest frequency in Karadi followed by Karadi × Awassi; Awassi showed the lowest value.Percentages of fine, coarse and kemp fibres were significantly affected by breed and age of dam. Type of birth showed a significant effect only on percentage of coarse fibres.Karadi wool might be more suitable for carpet manufacturing. It excelled the other groups in the bimodal distribution of both length and diameter as well as in medullation. Cross-breeding increased the bimodality of fibre distribution.

THE EFFECTS OF PROLONGED ADMINISTRATION OF CORTISOL ON THE SKIN OF SHEEP ON DIFFERENT PLANES OF NUTRITION

1970 ◽  
Vol 48 (4) ◽  
pp. 649-NP ◽  
Author(s):  
R. E. CHAPMAN ◽  
J. M. BASSETT
Keyword(s):  
Growth Rate ◽  
Blood Glucose ◽  
Plasma Cortisol ◽  
Fibre Length ◽  
Sweat Glands ◽  
Moderate Increase ◽  
Prolonged Administration ◽  
Fibre Growth ◽  
Blood Glucose Concentrations ◽  
Different Tissues

SUMMARY The effects of prolonged administration of cortisol on epithelial and dermal tissues were examined in three groups of non-pregnant ewes with different food intakes. The changes observed depended on the degree of increase in plasma cortisol and in some instances on the amount of food eaten. Successive increases in plasma cortisol up to about 3 μg/100 ml progressively inhibited the tissues in the skin of sheep on restricted food intakes, but not those in the skin of sheep which increased their intakes. In the latter, a slight increase in plasma cortisol to about 1 μg/100 ml stimulated wool production and fibre-length growth rate. Moderate increase to about 2 μg/100 ml produced temporary enlargement of sweat glands, dilatation of capillaries and an increase in the number of dermal mast cells. Regardless of the amount of food eaten, retrogression of all epithelial and dermal components was maximal when plasma cortisol remained above about 3 μg/100 ml. Follicle inactivation and cessation of fibre-growth occurred with the formation of brush-ends on the fibres. The retrogression of the tissues occurred in spite of increased blood glucose concentrations, indicating that cortisol depressed the utilization of glucose by the skin. Keratinization of the epidermis was altered and was possibly hastened. The rates of recovery of the different tissues after cessation of cortisol administration were variable. Follicle regeneration and commencement of fibre regrowth were the slowest. The epidermis of the sheep on restricted food intake showed an unusual thickening. Cortisol acetate applied topically to the skin of other sheep produced changes consistent with those induced by injected cortisol.

A comparative study of fleece growth in Tasmanian Fine Merino and Wiltshire Horn ewes

1961 ◽  
Vol 57 (1) ◽  
pp. 11-19 ◽  
Author(s):  
J. Slee ◽  
H. B. Carter
Keyword(s):  
Growth Rate ◽  
Fibre Diameter ◽  
The Body ◽  
Back Side ◽  
Body Regions ◽  
Wide Range ◽  
Diameter Fibre ◽  
Fibre Growth ◽  
Skin Biopsies ◽  
Three Body

1. From repeated fibre samplings and several skin biopsies on six Tasmanian Fine Merinos and eight Wiltshire Horn adult ewes variations in fibre diameter, fibre growth rate, and fibre regeneration or shedding frequency were measured over a period of 15 months. Slight differences were present in the treatment of the two breeds, but from the combined evidence of the live weights and fibre diameters maintained, it was concluded that these were negligible, that both breeds were under closely comparable conditions, and that their performance was at a moderately high and typical level for each breed.2. In the Merinos fibre diameter (ca. 20 µ) fluctuated little during the period of observation, whereas in the Wiltshires it varied over a wide range from less than 40µ in winter to more than 80µ in summer. There were negligible differences between the three body regions, back, side, and belly, in the Merinos, but in the Wiltshires the belly grew markedly coarser fibres than the other two regions.3. The fibre growth rate in the Merinos did not vary greatly from 7 to 8 mm. per 28 days throughout the period of observation or between the body regions. In the Wiltshires, fibre growth rate showed extreme variations from a minimum of about 3 mm. during the winter to a maximum of about 12 mm. per 28 days at the end of summer, with significant differences between the three body regions. However, in spite of these differences in the mode of growth, the total length of fibre grown per annum at the midside was approximately the same (10 cm.). Thus, were it not for fibre shedding, the Wiltshire Horn breed would grow a short-wool fleece.

Maternal and genetic influences on follicle and fleece development in Lincoln and Welsh Mountain sheep—a study involving egg transfer

1965 ◽  
Vol 7 (3) ◽  
pp. 333-345 ◽  
Author(s):  
G. Wiener ◽  
J. Slee
Keyword(s):  
Post Partum ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Maternal Environment ◽  
Maternal Influences ◽  
Wool Production ◽  
Secondary Follicle ◽  
Specific Effects ◽  
Fibre Growth ◽  
General Average

SUMMARYBy mean of egg transfer, lambs of a large breed of sheep (Lincoln) were born out of dams of a small breed (Welsh Mountain) and vice versa. One breed was approximately twice the weight of the other. The effects of this contrast in maternal environment upon the development of the wool follicles and upon subsequent wool production are described in this paper. These effects are compared with differences between singles and twins.Data were obtained from skin and wool samples taken at birth and at 84 days post-partum.Genetic differences were the largest single source of variation for most of the component characters of the skin and fleece.Strong maternal influences were in evidence. These were shown to have affected both Lincoln and Welsh lambs in a general (average) way and also to have had different, specific effects on each genotype as shown by genotype-environment interactions. Differences in maternal environment following egg transfer, clearly affected follicle density, primary/secondary follicle ratio, fibre medullation, fibre diameter and fibre length. Wool production was not affected, apparently because reduced follicle density was associated with increased fibre length.In the comparison between singles and twins the latter appeared to suffer a post-natal rather than a pre-natal restriction of secondary follicle development, and in the absence of extra fibre growth there was reduced wool production at 84 days.

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.

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