Method for the determination of wool fibre diameter by the airflow method

2015 ◽  
Keyword(s):  
Fibre Diameter ◽  
Wool Fibre

Liveweight and wool growth responses to a Mediterranean environment in three strains of Merino sheep

1998 ◽  
Vol 49 (8) ◽  
pp. 1187 ◽  
Author(s):  
N. R. Adams ◽  
J. R. Briegel
Keyword(s):  
Body Composition ◽  
Fibre Diameter ◽  
The Other ◽  
Wool Fibre ◽  
Growth Responses ◽  
Mediterranean Environment ◽  
Protein Loss ◽  
Broad Group ◽  
Wool Growth ◽  
Sources Of Variation

The present study examined changes in wool growth, liveweight, and body composition in groups of fine, medium, and broad wool Merino wethers grazed together at pasture in the highly seasonal Mediterranean environment, to determine the sources of variation in wool growth that may affect staple strength (SS). Seasonal changes in wool growth were measured using 6 dyebands placed at times of seasonal change in the nutrient supply from pasture, and liveweights were recorded fortnightly. Dilution of deuterated water was used to determine changes in body composition between the beginning of summer and the end of autumn. The sheep lost liveweight over this period, but loss of protein relative to fat over this period was unexpectedly high (7 : 1). The relative changes in liveweight, and loss of its components (fat and lean) during summer and autumn, were similar in all 3 groups, even though the Broad group was heavier than the other 2 genotypes at all times (P < 0·01). In contrast to the similar pattern of liveweight change, wool growth rates and changes in the fibre diameter were less variable throughout the year in the Broad group than the other 2 groups (P < 0·001). Stepwise regression indicated that the characteristics related to SS were standard deviation in fibre diameter (SDfd; P < 0·001), mean fibre diameter (P < 0·001), and variation in diameter within a 200-mm length of wool fibre (Sdfdwithin; P < 0·05). However, the relative importance of different factors for SS differed within each group. The most important factors were mean fibre diameter in the Fine group, the variation in fibre diameter along the staple (SDfdalong) in the Medium group, and the variation in diameter between fibres (SDfdbetween) in the Broad group. It is concluded that SS is a complex characteristic, depending on both the fibre diameter and several sources of variation in fibre diameter, all of which can differ among flocks. Protein loss made a disproportionate contribution to liveweight loss over summer and autumn, but the amino acids made available did not contribute substantially to wool growth or SS.

Assessing Wiltshire Horn-Merino crosses. 1. Wool shedding, blowfly strike and wool production traits

1994 ◽  
Vol 34 (6) ◽  
pp. 717 ◽  
Author(s):  
KA Rathie ◽  
ML Tierney ◽  
JC Mulder
Keyword(s):  
Fibre Diameter ◽  
The Other ◽  
Wool Fibre ◽  
Production Traits ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Fleece Weight ◽  
Head Neck

Wiltshire Horn-Merino (WH-M) crosses of 1/2, 5/8 and 3/4 Merino content were compared over 10 years for wool shedding, blowfly strike frequency and wool production traits. Merinos and 1/2 Merino WH-M were compared over 4 years. For wool production traits, 1/2 and 5/8 Merino WH-M ewes were compared to Border Leicester-Merino (BL-M) ewes over 2 years. Shedding increased with age for all WH-M genotypes, with 3/4 Merinos showing less shedding than 1/2 Merinos at all ages. At 1 and 2 years of age, 5/8 Merinos were intermediate between the other 2 WH-M genotypes, but at later ages they were similar to 1/2 Merinos. All genotypes showed less shedding at the belly site than the head, neck and breech as lambs, but not at older ages. Phenotypic correlations between sites on the same sheep were high, averaging 0.85. Repeatability estimates for each site ranged from 0.26 to 0.45. Shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Little or no shoulder and back wool was shed by most sheep. All 1/2 and 5/8 Merinos and most 3/4 Merinos had bare legs and points. Blowfly strike incidence was far higher in Merinos than 1/2 Merinos, in all years. Among WH-M, blowfly strike incidence increased as Merino content increased, in all years. All WH-M were far inferior to both Merinos and BL-M in total greasy wool weight and all its components, and also in clean fleece weight, with their level of inferiority increasing as their Merino content declined. Wool fibre diameter for all WH-M was coarser than for Merinos, but was a little finer than for BL-M. Fibre diameter increased in the WH-M as their Merino content declined. All WH-M had lower wool yields than the Merinos or BL-M. In some years the 314 Merinos had lower wool yields than the 1/2 and 5/8 Merinos, which were similar in all years. Shedding caused numerous genotype x age interactions in wool weight and its components, as Merinos and BL-M did not shed, and with the WH-M shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Due to preferential shedding from the belly and other low-value areas, the WH-M inferiority in total wool weight was less severe for fleece weight. Winter shearing succeeded in harvesting some wool from WH-M that would be shed before a summer shearing, but not enough to alter rankings among genotypes. All WH-M genotypes have wool too coarse, and not enough of it, to compete as a wool sheep with the Merino at current wool prices under usual Australian pastoral conditions. In areas where mustering is difficult or blowfly strike unusually severe, WH-M genotypes may find a niche.

Sublethal exposure to corynetoxins affects production of grazing sheep

1996 ◽  
Vol 36 (6) ◽  
pp. 649 ◽  
Author(s):  
SC Davies ◽  
CL White ◽  
IH Williams ◽  
JG Allen ◽  
KP Croker
Keyword(s):  
Birth Weight ◽  
Liver Damage ◽  
Fibre Diameter ◽  
Clinical Signs ◽  
Wool Fibre ◽  
Embryo Survival ◽  
Weaning Weight ◽  
Wool Growth ◽  
Low Levels ◽  
Production Losses

This paper reports the production losses resulting from treating sheep with sublethal doses of corynetoxins, the causal agent of annual ryegrass toxicity. Merino ewes were given 3 levels of corynetoxins twice weekly for 11 weeks from 26 days before the start of joining to day 51 of pregnancy, giving a cumulative dose of 0 , 0.4 or 0.8 mg/kg liveweight. The effect on ovulation, pregnancy, lamb birth weight, lamb survival and weaning weight were measured along with the liveweight and wool growth of the ewes. Corynetoxin treatment depressed (P<0.005) the activity of uridine diphospho-N-acetylglucosamine: dolichol-phosphate N-acetylglucosamine-1-phosphate transferase and liver damage was detected in ewes on the high toxin treatment (P<0.05). Ewe liveweight was unaffected by treatment but wool growth and wool fibre diameter were reduced by 10 and 7%, respectively (P<0.05). Corynetoxin treatment appeared to increase ovulation (P<0.05) and, as there was no effect on conception and embryo survival, this resulted in a 30-35% increase in the number of lambs weaned. Lamb birth weight and survival were not affected by treatment but weaning weight of the low toxin group was depressed (P<0.05). While reproduction was not adversely affected, the sheep in this trial were exposed to extremely low levels of corynetoxins which did not accumulate to levels capable of causing detectable liver damage until 23 days after joining. Even at these levels of intake, well below those required to show clinical signs (3-5 mg/kg liveweight), wool growth was reduced, suggesting that sheep grazed on mildly toxic pasture experience wool production losses in the absence of signs of the clinical disease.

scholarly journals Lingrong Bai 1,†, Jing Wang 2,†, Huitong Zhou 3, Hua Gong 3, Jinzhong Tao 1,* and Jon G. H. Hickford 3,*

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 142 ◽  
Author(s):  
Lingrong Bai ◽  
Jing Wang ◽  
Huitong Zhou ◽  
Hua Gong ◽  
Jinzhong Tao ◽  
...  
Keyword(s):  
Chromosome Region ◽  
Mammalian Species ◽  
Fibre Diameter ◽  
Start Codon ◽  
Wool Fibre ◽  
Gene Marker ◽  
Nucleotide Polymorphisms ◽  
Repeat Polymorphism ◽  
Reading Frame ◽  
Associated Proteins

Keratin-associated proteins (KAPs) are a diverse group of proteins and form a matrix that cross-links keratin intermediate filaments in hair and wool fibres. From over 100 KAP genes (KRTAPs) identified in mammalian species, KRTAP25-1 is a high sulphur (HS)-KAP gene, which has recently been described in humans. Here, we report the absence of KRTAP25-1 in sheep, and describe a new HS-KRTAP (named KRTAP28-1) in the chromosome region where KRTAP25-1 was expected to be found. Six variants (A−F) of KRTAP28-1 containing eight single nucleotide polymorphisms (SNPs) and a TG repeat polymorphism were detected. One was positioned 30 bp upstream of the transcription start codon and all the others were non-synonymous SNPs, including a nonsense SNP. The TG repeat polymorphism would lead to a reading frame shift at the carboxyl-terminal end. The effect of KRTAP28-1 on wool traits was investigated with 383 Southdown × Merino-cross lambs from seven sire lines. Of the four genotypes with a frequency of over 5%, lambs of genotypes AB and BD produced wool of a smaller MFD than lambs of genotype BC. This shows that KRTAP28-1 is associated with wool fibre diameter, and that variation in this gene might have potential for use as a gene marker for reducing wool fibre diameter.

Effect of defaunation on body conformation changes, wool yield and fibre characteristics of growing lambs in a hot semiarid environment

2007 ◽  
Vol 47 (7) ◽  
pp. 789 ◽  
Author(s):  
A. Santra ◽  
S. Parthasarathy ◽  
S. A. Karim
Keyword(s):  
Conversion Efficiency ◽  
Dry Matter ◽  
Body Height ◽  
Fibre Diameter ◽  
Dry Matter Intake ◽  
Wool Fibre ◽  
Feed Conversion ◽  
Feed Conversion Efficiency ◽  
Wool Yield ◽  
Fibre Characteristics

The efficacy of sodium laurel sulfate as a defaunating agent, as well as effect of defaunation on body confirmation changes, wool yield and fibre characteristics, were evaluated in growing lambs in a 90-day feeding experiment. Forty-five Malpura male weaner (90-day old) lambs were divided into three equal groups: defaunated, refaunated and faunated. The lambs of defaunated and refaunated groups were defaunated by oral administration of sodium laurel sulfate at the rate of 8 g/100 kg liveweight as a 10% aqueous solution. Six days after defaunation, all the lambs of the refaunated group were refaunated by inoculation of 100 mL rumen content per lamb drawn from a normal faunated sheep. All the experimental lambs were maintained under stall feeding on a complete feed containing 50 : 50 Pala (Ziziphus nummularia) leaf and concentrate. Treatments did not differ in intake of dry matter, digestible crude protein or digestible energy. Body height and paunch girth were greater (P < 0.01) in defaunated compared to refaunated and faunated lambs. With similar dry matter intake in the three experimental groups, liveweight gain, feed conversion efficiency and wool yield were higher (P < 0.01) in defaunated lambs. The wool fibre diameter and medullation percentage were higher (P < 0.01) in defaunated than refaunated and faunated lambs. It was concluded from the study that, with similar dry matter intake and plane of nutrition, the growth rate, feed conversion efficiency and wool yield were higher in defaunated lambs, as compared to refaunated and faunated lambs. Higher paunch girth in defaunated lambs resulted in a pot-bellied appearance of the animals.

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