A large number of works are devoted to the development of the skin and hair cover of sheep, depending on their breed affiliation, age, feeding conditions and housing. The authors point out that along with other conditions the quality of wool and wool clip is greatly influenced by the conditions of the feeding of animals. A high level of feeding increases the wool clip and improves the quality of the wool and vice versa a low level reduces, causes thinning and worsens other physical properties of the wool. As is known, one of the significant factors that determine the increase in wool clip is the size of the animal and, consequently, the total area of the skin. The purpose of the research was to investigate the morphological traits of the development of the skin and wool cover in sheep of Prikatunsky meat and wool type. The research material was wool samples from four topographic areas of the animal’s body (side/thigh/back/belly) and skin (side) of different sex and age groups, selected from the animals of the studied groups. In the course of research, the quality of wool and indicators of the histostructure of the skin of Prikatunsky meat and wool type of sheep have been investigated. In terms of thick-haired of wool, replacement rams and gimbers of Prikatunsky meat and wool type of sheep were superior by 4,82 pcs. per mm² or 19,0 % and 4,41 pcs. per mm² or 15,8 % of adult animals, respectively. Balance secondary follicles/primary follicles in young animals were higher by 10,3 and 17,3 % compared to breeding rams and ewes. The wool of the replacement young animals was thinner by 7,28 and 4,78 microns and they were more thick-haired. The obtained data will be used in the mating campaign when mating program rams in order to improve the sheep of Prikatunsky meat and wool type.
Приведены данные инструментальных исследований шерстных качеств (тонины шерсти) выставочных овец разных пород. С 2005 года тонина шерсти внесена в оценочную ведомость выставочного поголовья, представляемого на Российской выставке племенных овец. До начала выставки осуществляется объезд овцеводческих хозяйств, где проводятся научно-консультативные мероприятия и отбор образцов шерсти (бок, ляжка). Определение среднего диаметра волокон у животных осуществлялось на проекционном микроскопе (ланаметре) в лаборатории морфологии и качества продукции ВНИИОК -филиал ФГБНУ «Северо-Кавказский федеральный научный аграрный центр» согласно учебно-методическим указаниям «Метод комплексной оценки рун племенных овец тонкорунных пород» 2013 года. Результаты инструментальной оценки тонины представляются экспертной комиссии в форме сводных ведомостей и паспортов качества шерсти по разным половозрастным группам овец.Показатели тонины шерсти основных и ремонтных баранов тонкорунных пород, представленных в 2018 году на XIX Российской выставке в городе Астрахани, распределились следующим образом: по ставропольской породе (СТ) два хозяйства -в среднем 20,9 и 19,2 мкм соответственно; по манычскому мериносу (ММ) три хозяйства -21,0 и 19,9 мкм; по советскому мериносу (СМ) пять хозяйств -20,8 и 20,5 мкм; по джалгинскому мериносу (ДМ) одно хозяйство -19,9 и 19,4 мкм; по грозненской породе (ГТ) три хозяйства -20,5 и 17,9 мкм.Анализ качества шерсти выставочных овец показал, что тонина шерсти основных и ремонтных баранов тонкорунных пород стабилизируется на уровне 18,0-23,0 мкм, что соответствует данному уровню продуктивности и целенаправленной селекционно-племенной работе в тонкорунном овцеводстве России.Ключевые слова: выставка, порода, бараны, баранчики, шерсть, тонина, уравненность.In article the data of instrumental studies of wool qualities (tufts of wool) of exhibition sheep of different breeds are given. Since 2005, the fine wool has been included in the evaluation list of the exhibition stock presented at the Russian exhibition of breeding sheep. Before the beginning of the exhibition, a tour of the sheep farms is carried out, where scientific and consultative activities are conducted and wool samples (side, thigh) are selected. The determination of the average diameter of the fibers in animals was carried out on a projection microscope (lanameter) in the laboratory of morphology and quality of products of the All-Russian Research Institute of Sheep Breeding and Goat Breeding -branch FSBSI «North Caucasus Federal Scientific Agrarian Center» according to the training guidelines «The method of integrated assessment of runes of tribal sheep with fine woolen breeds», 2013. The results of the instrumental evaluation of tonin are presented to the expert commission in the form of summary sheets and quality certificates of wool for different sex-age groups of sheep.The indices of the fineness of the wool of the main and repair rams of fine-wool breeds presented in 2018 at the XIX Russian exhibition in the city of Astrakhan were distributed as fo...
The morphological and histological features of the skin and wool cover of sheep as the basis for the quality of fur sheep pelts have been studied. The most important properties of sheep pelts (uniformity, thinness and density of wool) are provide the possibility of producing high-quality fur semi-finished products from them. However, the features of the histostructure of fine-wool sheep determine the low mechanical strength of the “facial” layer of skin. As a result, the “front” layer during processing often cracks to the upper border of the reticular layer or even peels off from the latter, making the sheep pelt unsuitable for use on fur products. These defects in fur practice are called “cracking” and “peeling” of the facial layer. They are mainly peculiar to sheep pelts of fine-wooled sheep. In these animals due to the high density and tone of the coat, the roots and hair follicles, root vaginas, secretory departments, excretory ducts of the glands and other structures occupy a significant share of the volume in the thickness of the Pilar layer (up to 25–30 %). The share of fibrous structures remains less volume, and these structures themselves are relatively weakly developed, located loosely and loosely intertwined with each other. The accumulations of fat cells that occur here also cannot be attributed to skin-strengthening elements. In fine-fleece sheep the pilar layer is on average 60 % of the thickness of the dermis. Therefore, more than half of its thickness is a weakened zone. The strength of the “front” layer is not the same in different fine-wool breeds of sheep and in different animals within the breed. For example, the average breaking load for cod of the “front” layer in Soviet Merino pelts is 1,25 kg, and in Precoce is 2,49 kg.
The intensive development of genetics at the molecular level has now opened up the possibility for breeders to identify and study genes that are directly or indirectly related to desirable economically useful traits. The purpose of the research was to identify desirable genotypes in the breeding of Kazakh White-Headed cattle based on the genes-markers of meat productivity of calpain (CAPN1) and somatotropin (GH) for use in breeding to increase meat productivity and beef quality. Experimental researches have been carried out on steers of the Kazakh White-Headed breed on the basis of the APC collective farm “Gigant” in the Blagodarnensky district in the Stavropol Territory. Analysis of growth and development indicators of calves has shown that the value of live weight and average daily gains was higher in calves carrying the C allele at calpain gene locus and V allele at somatotropin gene locus. Dominant alleles C and V in the homozygous state characterize the desired genotype of calves. During weaning the studied indicators were higher with a diff erence on average up to 13,0 % in young animals of homozygous genotypes (CC and VV). The largest number of muscle fi bers has been observed in steers with the desired CC and VV genotypes. They outperformed their herdmates with GG genotype by 36,82 pcs/мм² or 19,7 % in calpain gene group (CAPN1) by 55,7 pcs/мм² or 31,4 % in somatotropin gene group (GH), respectively. The diameter of muscle fibers in carcasses with the desired genotype was less by 4,23 microns or 11,9 %, and by 6,82 microns or 16,8 %. The meat of steers with homozygous CC and VV alleles according to the studied genes differed from the meat of animals with GG and LL genotypes by 12,6 % in calpain gene (CAPN1) and 15,1 % in somatotropin gene (GH). The connective tissue content was higher in animals with the undesirable type of G and L alleles than in animals of the desired genotype, by 2,13 and 3,34 abs. percent’s. The area of the eye of loin in animals of desired VV genotype of somatotropin cluster (GH) was higher than in animals of CC genotype of calpain cluster (CAPN1) by 4,84 cм² or 10,1 %.
Increasing the production of wool and improving its quality characteristics for a number of years remains an urgent issue in breeding work with fine-fleeced sheep. In this regard the main purpose of the research was a comparative assessment of the age dynamics of the main properties of wool and the histostructure of the skin of the young ewes of Artlukh merino breed in the farm AC “Krasny Oktyabr” in the Kazbekov district in the Republic of Dagestan. It has been found that at the age of one year in the experemental young ewes the epidermis increased by 21,2 %, the pilar and reticular layers by 2,9 and 12,8 %, respectively, and the total skin thickness by 6,1 %. The biggest increase in skin thickness was due to the epidermis and the reticular layer as the number of fat cells increased. The width of the secretory parts of the sweat glands increased by 7,1 %, the sebaceous glands by 9,6 %, in this regard the amount of wool fat increased by 7,6 %. The studied parameters of the skin histostructure revealed that the number of hair follicles decreased by 6,8 % with age. This is due to the increase in the area of the skin due to the growth of the animal. The change in the basic properties of wool was as follows: the diameter of wool fibers increased by 5,6 %, the strength of wool decreased by 13,8 %. Comprehensive studies allowed us to recommend testing the main properties of wool and indicators of the histostructure of the skin of experimental animals when improving existing breeds and breeding new breeds and lines of sheep. Histological studies of the skin should be carried out at the age of 4,5 months, and the most objective indicators are the ratio of secondary and primary follicles, this will allow for early selection of lambs by wool density.
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