Bovine cutaneous streptothricosis and demodicosis : studies on the defects and economic losses on crust leather resulting from damage caused by these diseases / Mukhtar Taha Abu-Samra in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 73 (Année 1989)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 73 (Année 1989) . - p. 74-87 Titre : Bovine cutaneous streptothricosis and demodicosis : studies on the defects and economic losses on crust leather resulting from damage caused by these diseases Type de document : texte imprimé Auteurs : Mukhtar Taha Abu-Samra, Auteur ; K. E. E. Ibrahim, Auteur Année de publication : 1989 Article en page(s) : p. 74-87 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Défauts Cuirs et peaux de bovins Démodécie Peau -- Maladies Streptothricose Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the Sudan, 16,540 cattle were surveyed for bovine cutaneous streptothricosis and 48,000 were surveyed for bovine demodicosis. The incidence of cutaneous streptothricosis ws 4.5 %, while the incidence of bovine demodicosis among the total number of the animals (48,000) surveyed was 34-3 % and its incidence among slaughtered animals (1535) was 38.8 %. These results show that slaughterhouse surveys for demodicosis are more reliable than clinical surveys because many cattle with demodectic mange might have no visible cutaneous lesions and can only be detected after careful examination, flaying of the hides or during tanning. In both cutaneous streptothricosis and demodicosis many forms of lesions, were encountered. The lesions were localised, confluent or generalised involving extensive areas or the wholehide of infested cattle. Dermatophilus congolensis was demonstrated in smears and isolated in pure culture from affected material obtained from cattle infested with cutaneous streptothricosis. Numerous demodex bovis mites were demonstrated and isolated from caseated ("cheesy") waxy material obtained from demodectic mange lesions. Severe and advanced histopathological changes were seen in skin sections from the lesions of both diseases. Leather sections from cutaneous stre ptothricosis showed a badly damaged grain surface with many scars and depressions. The fibres were distorted and had lost their contour ; the whole thickness of the crust leather was fibrosed. Leather sections from bovine demodicosis showed, at the site of lesions, a ragged cavity with no definite boundaries. The fibres round the cavity were distorted, thinner than normal and compressed. In some sections, the grain surface was found to be separated from the corium. Hides affected by cutaneous streptothricosis and demodicosis were gree-graded as rejects. During the tanning procedure, both diseases causes difficulty in soaking, plumping, splitting, scudding or shaving. At the site of lesions there was uneven distribution of chemicals leaving unsightly blemishes. Both diseases caused a marked reduction in the aesthetic appeal and cutting area of the leather. Cutaneous streptothricosis resulted in a course and rough grain surface and, in severely affected areas, the leather was pitted. Bovine demodicosis caused depressions, cavities or holes in the crust leather. Cutaneous streptothricosis and bovine demodicosis caused a marked reduction in the tensile strength, apparent density and flexing endurance. Bovine demodicosis was found to have the more deleterious effect on crust leather because the percentage decrease in tensile strength, apparent density and flex endurance in the former disease was greater. Hides affected by cutaneous streptothricosis and demodicosis were completely rejected or fetched low prices resulting in serious economic loss. En ligne : https://drive.google.com/file/d/1IvbDq-HWnYitKRRj0WlU3HiIUk9OUTj6/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8830 [article]

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Sarcoptic mange in goats and sheep : studies on the defects and economic losses resulting from damage caused by the disease on crust leather / K. E. E. Ibrahim in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 72 (Année 1988)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 72 (Année 1988) . - p. 135-144 Titre : Sarcoptic mange in goats and sheep : studies on the defects and economic losses resulting from damage caused by the disease on crust leather Type de document : texte imprimé Auteurs : K. E. E. Ibrahim, Auteur ; Mukhtar Taha Abu-Samra, Auteur Année de publication : 1988 Article en page(s) : p. 135-144 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Défauts Cuirs et peaux de chèvres Parasitoses Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A survey of 5250 goats and 4220 sheep in the Sudan for sarcoptic mange revealed an incidence of 5,5 % (290) in the former and 5,2 % (221) in the latter species, respectively. Severe and localised or generalised lesions were seen in the infested animals. Skin scrapings from infested animals revealed numerous specimens of sarcoptes scabiei, showing that the animals were heavily infested. Severe histopathological changes were seen in skin sections. These changes mainly comprised : hyperkeratosis, acanthosis ans scab formation, beneath which numerous mites were seen. Severe cellular infiltration, micro-abscessation, degenerative and necrotic changes and marked proliferation of connective tissue also occured. Infested skins were green graded as "rejects" and the prepared crust leather was graded as "rejects" or "double rejects". Infested skins were difficult to finish into crust leather. The disease caused a marked reduction in the aesthetic appeal and cutting area of the leather. The crust leather prepared from infected skins was unsightly, hard, and fibrosed, with many tunnellings. The grain surface was coarse, rough and the fibres were loose and had a fluffy appearance. In severely infested areas, numerous holes were seen and, in some cases, the leather was completely damaged. Leather sections from infested areas showed great distortion and disintegration of the fibres with large areas of micro-abscessation. Towards the grain surface, the fibres along the tunnels of the mite were eaten away, became thin, loose and had a fluffy appearance beneath which many empty spaces and areas of fibrosis were seen. The disease caused a marked reduction in the tensile strength and apparent density of crust leather. In severely infested animals,the leather specimens were cut before the machine could even give a reading, showing complete loss of durability. The disease caused a false increase in the mean thickness and volume but brought about a marked reduction in the weight of the infested specimens. Skins so affected were completelyrejected or fetched very low prices resulting in serious economic losses. Goats were experimentally infested with sarcoptes scabiei mites. The results obtained from the clinical picture of the lesions produced, the grading of skins, the examination of histological and leather sections and physical testing of the crust leather produced, confirmed the results obtained from the survey. Treatment of the experimental lesions led to improvement of the quality of the leather eventually produced, showing that recovery from the damage could be obtained, providing that infested animals are (a) treated in the early stages of the disease and (b) ample time is given before the animals are slaughtered, in order to allow for proper restoration of the skin. En ligne : https://drive.google.com/file/d/1FMSFaYkUa5yy9034OWxCR5Vv3oVyZ3ha/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9104 [article]

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Studies on the defects and the economic losses on crust leather resulting from physical damage / K. E. E. Ibrahim in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. N° 71 (Année 1987)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. N° 71 (Année 1987) . - p. 68-74 Titre : Studies on the defects and the economic losses on crust leather resulting from physical damage Type de document : texte imprimé Auteurs : K. E. E. Ibrahim, Auteur ; Mukhtar Taha Abu-Samra, Auteur Année de publication : 1987 Article en page(s) : p. 68-74 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the Sudan, 26 010 cattle, goats and sheep were surveyed for physical defects on hides and skins. Among 16540 cattle surveyed, the incidence of physical defects was 78,2 %. Branding and cauterisation were encountered among 77,4 % of the cattle surveyed. The damage caused by horn rake and scratches by thorns and barbed wire was low in incidence (0.8 %). Among 5250 goats and 4220 sheep surveyed, the incidence of physical damage was low 3,6 % in the former and 2,1 % in the latter species, most of the physical defects being due to scratches caused by thorns and barbed wire. Branded and cauterised hides were green-graded as rejects. The damage produced was deep and visible even on the flesh side. Such hides were difficult to finish. Moreover, branding and cauterisation caused hardening, reduction in the cutting area and the grain surface of the leather was coarse and showed visible cracks. Histological sections prepared from branded or cauterised areas showed marked degenerative changes, sloughing of the epidermis and/or scab formation ; the hair follicles were destroyed. There were petechial haemorrhages in the papillary layer and in the dermis. Both the epidermis and dermis showed scar tissue formation. Leather sections showed distortion and disintegration of both transverse and longitudinal fibres. The fibres towards the grain surface were fluffy and without contours while the fibres beneath were stuck together and stouter than normal. Leather sections showed distortion and disintegration of both transverse and longitudinal fibres. The fibres towards the grain surface were fluffy and without contours while the fibres beneath were stuck together and stouter than normal. Leather specimens from branded and cauterised areas lost their durability and could not withstand physical testing. Rejected hides of this type fetched very low pricees resulting in serious economic losses. An experiment was conducted on the effect of cauterisation on goat skins. The results obtained showed that the damage produced was irreparable through treatment. The data obtained from grading, examination of histological and leather sections and physical testing of the leather from the experimental goats, confirmed the data obtained from the survey. Cauterisation was shown to cause a marked reduction in thickness, weight, durability and apparent density. It was suggested that animal owners and breeders should be taught to brand their animals on areas which would not affect the value of the hides ans skins and that the faulty practice of cauterisation should be prohibited completely. En ligne : https://drive.google.com/file/d/1klz0oUD6UR5Gbe_4UQ6CYrU_z5K2PkLI/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9156 [article]

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