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.

Wool follicle development in the New Zealand Romney and N type sheep. V. The pre-natal relationships between growth, skin expansion, and primary follicle number

1959 ◽  
Vol 10 (3) ◽  
pp. 453 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Surface Area ◽  
Linear Growth ◽  
The Body ◽  
Follicle Development ◽  
Competition Effect ◽  
Primary Follicle ◽  
Skin Expansion ◽  
Wool Follicle

A method is presented for estimating changes in primary follicle number on different regions of the body of the sheep foetus from linear growth measurements and primary follicle density determinations. The major factor controlling the initiation of new primary follicle anlagen on different regions is shown to be rate of skin expansion, and therefore it appears probable that there is a competition effect between anlagen during this phase of development. After allowance is made for area increases, there are still real differences between regions in the rates of initiation of primary anlagen. There is also evidence that, during the period of primary anlagen initiation, foetuses with a greater surface area have a greater total number of primary anlagen.

Some factors affecting the rate of adoption of new herbage cultivars

1985 ◽  
Vol 3 ◽  
pp. 79-87
Author(s):  
J.A. Lancashire
Keyword(s):  
New Zealand ◽  
Similar Pattern ◽  
High Rate ◽  
Factors Affecting ◽  
New Cultivars

Between 1973 and 1983 the number of certified grasses and legumes (excluding lucerne) available to the New Zealand farmer increased from 21 to 37 (Table 11 .l), with a further 5 added to the New Zealand National List during 1984/85. Clearly the high rate at which new cultivars are being released is continuing. Lucerne has followed a similar pattern with 10 cultivars now available compared with only 3 in 1970.

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.

Wool follicle development in the New Zealand Romney and N type sheep. I. The relationships of development to age in the New Zealand Romney and N type sheep foetuses and a comparison with results obtained from the Merino

1957 ◽  
Vol 8 (4) ◽  
pp. 371 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Least Squares ◽  
Linear Relationship ◽  
Population Studies ◽  
Regression Line ◽  
The Body ◽  
Follicle Development ◽  
Method Of Least Squares ◽  
Rate Of Development ◽  
Wool Follicle

The development of the follicle population in New Zealand Romney and N-type sheep foetuses has been studied by comparing stages of development at different ages, using the method developed by Carter and Hardy (1947) and Hardy and Lyne (1956). Their scale has been altered so as to give a linear relationship with age, and a regression line has been fitted to the data by the method of least squares. Analysis of the N-type and New Zealand Romney mating groups and a comparison with the Merino data given by Carter and Hardy (1947) show that no marked or consistent differences occur in the age at which different stages of follicle development are completed or in the rate of development of the follicle population. Studies of different positions on the body agree with the findings of other workers that development begins first on the head and limbs and later over the trunk. Between positions the correlation between the age at which follicle development begins and the rate of development after initiation is not significant.

Wool follicle development in New Zealand Romney and N-type sheep. 3. Diameters of follicles and fibres

1959 ◽  
Vol 10 (1) ◽  
pp. 108 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Pleiotropic Effect ◽  
Primary Effect ◽  
N Gene ◽  
Follicle Development ◽  
Primary Follicle ◽  
Fibre Size ◽  
Wool Follicle ◽  
Follicle Size

The diameters of the primary and secondary follicles hare been measured in N type and New Zealand Romney foetuses. It is shown that the primary effect of the N gene is on the primary follicle papilla and fibre size, not on overall follicle size A secondary pleiotropic effect is on the primary follicles, which Increase in diameter as a result of growing large fibres There do not appear to be any other effects of the dominant N gene up to 126 days after conception, either on the follicle population or on the growth of the foetus.

Sectarian struggle in the Middle East and the new Alliances

2019 ◽  
pp. 337
Author(s):  
Harith Qahtan Abdullah
Keyword(s):  
Middle East ◽  
Critical Period ◽  
The Other ◽  
New Era ◽  
Islamic World ◽  
The World ◽  
Gulf States ◽  
Other World ◽  
Islamic Civilization ◽  
New Formation

Our Islamic world passes a critical period representing on factional, racial and sectarian struggle especially in the Middle East, which affects the Islamic identification union. The world passes a new era of civilization formation, and what these a new formation which affects to the Islamic civilization especially in Syria, Iraq, Yemen, and Lebanon. The sectarian struggle led to heavy sectarian alliances from Arab Gulf states and Turkey from one side and Iran states and its alliances in the other side. The Sunni and Shia struggle are weaken the World Islamic civilization and it is competitive among other world civilization.

Multicultural and Transnational Novels

2018 ◽  
Author(s):  
James Meffan
Keyword(s):  
National Identity ◽  
New Zealand ◽  
The Other ◽  
Colonial History ◽  
History Of ◽  
Return Home ◽  
Access Rights ◽  
The One

This chapter discusses the history of multicultural and transnational novels in New Zealand. A novel set in New Zealand will have to deal with questions about cultural access rights on the one hand and cultural coverage on the other. The term ‘transnational novel’ gains its relevance from questions about cultural and national identity, questions that have particularly exercised nations formed from colonial history. The chapter considers novels that demonstrate and respond to perceived deficiencies in wider discourses of cultural and national identity by way of comparison between New Zealand and somewhere else. These include Amelia Batistich's Another Mountain, Another Song (1981), Albert Wendt's Sons for the Return Home (1973) and Black Rainbow (1992), James McNeish's Penelope's Island (1990), Stephanie Johnson's The Heart's Wild Surf (2003), and Lloyd Jones's Mister Pip (2006).

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