The development and structure of, and seasonal change in, the coat of some Wiltshire sheep

1969 ◽  
Vol 11 (4) ◽  
pp. 467-477 ◽  
Author(s):  
M. L. Ryder
Keyword(s):  
Seasonal Change ◽  
Seasonal Cycle ◽  
Follicle Development ◽  
Peak Period ◽  
Spring Equinox ◽  
Skin Samples

SUMMARYCoat and skin samples were taken monthly from three Wiltshire ewes for two years, and then fortnightly between the spring equinox and the autumn equinox of 1968.The fleece comprised kemp and wool, having a weight of 1·1 kg and a length of 50 mm. In summer all the primary fibres had a latticed medulla, and although the secondaries were smaller than the primaries, they were relatively coarse and often medullated, over one-third having a latticed medulla at the peak period. The overall mean S/P ratio was 3·5.Follicle development was studied in four lambs from birth to 84 days. Only 27% of the secondaries lacked fibres at birth, and all had fibres at 14 days. There was a trend of increasing medullation in the primary fibres. Shedding primary follicles were seen from birth onwards, and shedding secondaries from 28 days, although obvious casting of the birth coat did not begin until 84 days (at the beginning of June).There was a basic seasonal cycle of follicle activity starting in March and lasting until September; inactivity began in September, reached 100%, and continued at this level until March. Subsidiary cycles suspected from the monthly samples were confirmed by the fortnightly samples. Thus peaks of inactivity in June and August separated three cycles of growth of two months duration. Only 80% of the primaries and 50% of the secondaries became inactive in June, with 50% of the primaries and 30% of the secondaries, in August.

Post-natal follicle development and fleece changes in two selection lines of Scottish Blackface sheep

1974 ◽  
Vol 18 (2) ◽  
pp. 169-177 ◽  
Author(s):  
M. L. Ryder
Keyword(s):  
Fibre Type ◽  
The Other ◽  
Control Line ◽  
Follicle Development ◽  
Control Groups ◽  
Fine Line ◽  
And Control ◽  
Skin Samples

SUMMARYFleece and skin samples were taken at intervals from birth to 86 days from Scottish Blackface lambs born into one line selected for hairiness, another for fineness and an unselected control line. The birthcoats in the Hairy line were longer than those in the Fine line, and had a predominance of Plateauo and Pi fibre type arrays, whereas P2 and P3 arrays predominated in the Fine line. The Hairy group had significantly more halo hairs and hairy-tip curly-tip fibres, but significantly fewer histerotrichs.Most secondary follicles had fibres by 56 days, and development appeared to be faster in the Control than in the other two groups. The Hairy and Control groups had consistently high percentages of primary medullation, whereas the Fine group had a peak at 14 days. The Fine group had consistently low secondary medullation, whereas it increased in the Hairy and Control lambs, apart from a set-back at 28 days.Up to 56 days the Fine group had no fibre shedding in the skin, and the Hairy group had most, although the incidence in any sample was less than 2%. There was more follicle inactivity at 86 days, and the Fine group then had most.

Skin follicle development in Cheviot × Dorset Horn cross foetuses

1975 ◽  
Vol 84 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Marjorie B. Derbyshire
Keyword(s):  
Follicle Development ◽  
Secondary Follicle ◽  
Skin Samples

SUMMARYSkin samples were used to evaluate the developing skin follicle population of Cheviot × Dorset Horn cross foetuses. The follicle population was studied from the first appearance of skin follicles (55 days' gestation) to the end of gestation. The pattern of development of primary and secondary follicles is described, and compared with the data available for other breeds. The occurrence of secondary follicle branching, previously confirmed only in the Merino, is described, and the ‘prenatal check’, an important feature of follicle development which had not previously been investigated in prenatal studies, is briefly discussed.

Effect of egg transfer on the skin follicles and birthcoats of Finnish Landrace and Soay lambs

1974 ◽  
Vol 82 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Marca Burns ◽  
M. L. Ryder
Keyword(s):  
Fibre Type ◽  
Opposite Effect ◽  
Fibre Diameter ◽  
Follicle Development ◽  
Direct Effects ◽  
Hair Density ◽  
Maternal Environment ◽  
Secondary Follicle ◽  
Wide Range ◽  
Skin Samples

SummaryThe birthcoats of Finnish Landrace lambs showed a wide range of halo-hair grades but all had strongly checked fibre type arrays, which were either Plain or Valley. Transfer to Welsh Mountain dams reduced the effect of prenatal check, giving fewer sickle fibres and increased halo-hair and/or super sickle A percentage. Transfer to Border Leicester tended to have the opposite effect. Fibre diameter measurements made on skin samples indicated an increase in primary fibre diameter in transfers into Welsh dams, but no difference in transfers into the Border Leicester.All Soay samples had Grade VII halo-hair density and Plateau or Saddle arrays. Transfer of Soay eggs to Finnish Landrace ewes increased the percentage of sickle fibres mainly at the expense of hairy-tip curly-tips. Skin samples from the transferred Soays indicated reduced primary fibre medullation, and evidence of retarded secondary follicle development.Thus in both breeds the birthcoat changed slightly in the direction of that of the foster-dam. There was, however, no indication that increased prenatal check was associated with increased foetal size. It is therefore concluded that changes in birthcoat as a result of egg transfer are more probably due to direct effects of the maternal environment than to the effect of foetal size as previously postulated.

The Climates of the Victorian Novel: Seasonality, Weather, and Regional Fiction in Britain and Australia

PMLA ◽  
2021 ◽  
Vol 136 (3) ◽  
pp. 370-385
Author(s):  
Philip Steer
Keyword(s):  
Seasonal Change ◽  
Victorian Literature ◽  
Seasonal Cycle ◽  
Victorian Novel ◽  
Comparative Approach ◽  
Economic Systems ◽  
Climate Knowledge ◽  
Seasonal Basis ◽  
Regional Fiction

AbstractAnthropocene criticism of Victorian literature has focused more on questions of temporality and predictability than on those related to climate in the nineteenth century. Climate knowledge is central to the regional novel, which is attuned to the seasonal basis of agriculture and sociality, but the formal influence of the British climate also becomes more apparent through a consideration of the genre's adaptation to colonial conditions. Thomas Hardy's The Mayor of Casterbridge highlights how a known seasonal cycle underpins the differentiation of climate and weather and explores the role of economic systems in mediating the experience of climate. Rolf Boldrewood's The Squatter's Dream, set amid the nonannual seasonal change of Australia, demonstrates the fracturing of the regional novel form under the stress of sustained drought. Such a comparative approach highlights the importance of regular seasonality as the basis of the Victorian novel's ability to conceptualize the relation of climate, weather, and capital.

Pre- and post-natal wool follicle development and density in sheep of five genotypes

1996 ◽  
Vol 126 (3) ◽  
pp. 363-370 ◽  
Author(s):  
J. E. Hocking Edwards ◽  
M. J. Birtles ◽  
P. M. Harris ◽  
A. L. Parry ◽  
E. Paterson ◽  
...  
Keyword(s):  
New Zealand ◽  
Similar Pattern ◽  
Critical Period ◽  
The Other ◽  
Follicle Development ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Wool Follicle ◽  
Follicle Maturation ◽  
Skin Samples

SUMMARYThe pre-natal and post-natal development of wool follicles in sheep of five genotypes with contrasting wool types was examined to provide data on which to base studies of physiological factors affecting wool type via follicle development. This study was conducted following Autumn mating in 1992 at Palmerston North, New Zealand (40° S, 176° E). The rate and timing of follicle development in midside skin samples from Romney, Merino, Merino × Romney (M × R), Drysdale and Wiltshire foetuses and lambs collected at weekly intervals from days 76 to 143 of gestation and 1, 3, 7, 12 and 32 weeks after birth were examined.Primary (P) follicle density had a similar pattern of development in each of the genotypes, although the Merino had a significantly greater density of P follicles than the other genotypes. There was a difference in the rate of P follicle maturation between genotypes with the Drysdale, Wiltshire and M × R completing P follicle maturation before the other two genotypes. However, the majority of P follicles in all genotypes were producing fibres by 111 days of gestation. It was concluded that the small differences in the density and time of development of the P follicles could not cause the differences in wool type between genotypes.The pattern of development of the secondary (S) follicle population was examined by comparing S: P ratios. The initiation of S follicles began at similar ages in the five genotypes, but initiation was completed earlier in the Romney, Drysdale and Wiltshire than in the Merino and M × R, as indicated by a significant genotype by age interaction (P < 0·001). There was no difference between genotypes in S:P ratio from 90 to 104 days of gestation. The S:P ratio of the Romney, Drysdale and Wiltshire did not change significantly from 104 days of gestation until the end of the study, indicating that few S follicles were initiated in these genotypes after 104 days of gestation. The M × R data showed a significant increase in S:P ratio until 119 days of gestation and the Merino S:P ratio increased until 126 days of gestation.The period between days 90 and 125 of gestation was identified as being the critical period for the development of different follicle populations in Merino and non-Merino genotypes and it is this period which should be the focus for studies to determine physiological factors controlling secondary follicle development.

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