Performance and utilization of Northern European short-tailed breeds of sheep and their crosses in North America: a review

The five Northern European short-tailed sheep breeds present in North America are the Finnsheep, Romanov, Icelandic, Shetland and Gotland. The Finnsheep and Romanov were first imported in 1966 and 1986, respectively, for their high reproductive performance. The Shetland, Icelandic and Gotland breeds were first imported in 1980, 1985 and 2005, respectively, for the uniqueness of their physical appearance and their unique fleeces desired by fiber craftspeople. There have been no scientific studies conducted on the performance of the Shetland, Icelandic or Gotland breeds relative to other breeds of sheep in North America. However, the Shetland and Icelandic breeds have become very popular in the United States and ranked 9th and 18th, respectively, among 35 breeds of sheep for number of purebred animals registered in 2008. The performance of the Finnsheep breed in North America relative to domestic breeds has been thoroughly investigated. Compared to several domestic purebreds and crosses, sheep with Finnsheep breeding had a younger age at puberty, greater fertility to autumn mating, greater litter size, greater survival to weaning, similar growth rate, similar subcutaneous fat thickness, smaller loin muscle area and greater percentage of kidney and pelvic fat. Each 1% increase in Finnsheep breeding in ewes was associated with approximately 0.01 more lambs born per ewe lambing. In North American studies, Romanov ewes were superior to Finnsheep ewes for reproductive rate and lamb production per ewe under both autumn and spring mating. Lambs of the two breeds were similar for survival, growth and carcass traits. Romanov and Romanov-cross ewes produced fleeces that were heavily contaminated with medulated and colored fibers and were of very low commercial value. Three composite breeds containing 25% to 49% Finnsheep breeding (Polypay, Rideau Arcott and Outaouais Arcott) were developed in North America and are now more popular than the Finnsheep breed.

A study on some physical attributes of Naeini sheep wool for textile industry

In order to evaluate some physical and qualitative characteristics of Naeini sheep wool for using in textile industry, herds from 6 different regions of Isfahan province were chosen. Staple length from 3 different body parts (shoulder, side and britch) was measured prior to shearing. Wool samples were taken from a 100 cm2 surface on the mid-side of the Animals. Then the samples were transferred to the Laboratory of Animal Sciences for evaluations of some quality characteristics and to the Fiber Physics Laboratory for measuring tenacity, breaking strength and elongation at break of fibers. The means and standard deviations of staple length were estimated (10.8 +/- 2.36), (9.71 +/- 3.14) and (10.99 +/- 2.49) cm for shoulder, side and britch parts, respectively. The total average staple length of Naeini sheep (10.5 cm) is suitable for using in textile industry. Wool fibers of Naeini sheep have desirable tenacity and breaking strength (1.22 cN/dtex and 13.76 centi-Newton) to resist against mechanical tensions of the spinning step. However, Naeini sheep wool fibers have an adequate, but not a desirable % elongation at break (28.6%). Based on the fiber diameter mean of Naeini sheep and its variation (28.51 +/- 4.33 microm) the fleece grade of Naeini sheep was predicted 54's, which is an intermediate grade. However, by conducting breeding programs toward enhancing fleece grade, Naeini sheep wool will be simply applicable in textile industry.