The hair follicle and apocrine gland population of cattle skin.

Resumo -O objetivo deste trabalho foi avaliar medidas corporais associadas à tolerância ao calor em bovinos. Utilizaram-se 64 animais das raças naturalizadas Curraleiro (15), Mocho Nacional (7), Crioulo Lageano (7), Pantaneira (14) e Junqueira (11), e 26 animais de duas raças comerciais: Nelore (15) e Holandesa (11). Foram analisados dados sobre comprimento corporal, perímetro de canela, altura de cernelha, perímetro torácico, espessura da pele, espessura do pêlo, número de pêlos, comprimento de pêlos, pigmentação da epiderme e pelame. A raça Curraleiro apresentou menor perímetro torácico, tendo diferido das outras raças, principalmente da Mocho Nacional. As raças Crioulo Lageano e Pantaneira apresentaram maior espessura de pêlo; a raça Mocho Nacional apresentou maior espessura de pele. Os resultados obtidos demonstram que as raças Curraleiro e Junqueira são mais tolerantes ao calor que as demais raças naturalizadas.Termos para indexação: adaptação, bioclimatologia, medidas corporais, tolerância ao calor. Body traits associated with heat adaptation in naturalized Brazilian cattle breedsAbstract -The aim of this work was to evaluate physical aspects of heat tolerance in cattle. Sixty-four animals from five naturalized breeds were used, including Curraleiro (15 animals), Mocho Nacional (7), Crioulo Lageano (17), Pantaneira (14) and Junqueira (11), as well as twenty-six animals from two commercial breeds: Nellore (15) and Holstein (11). Measurements on shoulder height, girth, body length, cannon bone circumference, skin and hair thickness were analysed as well as hair density and hair and skin pigmentation. Girth in Curraleiro was significantly smaller than in other breeds, especially Mocho Nacional. Crioulo Lageano and Pantaneira had the thickest hair and Mocho Nacional the thickest skin. Curraleiro and Junqueira were shown to be the most heat tolerant of the naturalized breeds.

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“…A biópsia de pele foi realizada segundo a técnica descrita por Carter & Dowling (1954). Para a retirada Tabela 1.…”

Section: Methodsunclassified

Características corporais associadas com a adaptação ao calor em bovinos naturalizados brasileiros

Bianchini

McManus

Lucci

et al. 2006

Pesq. agropec. bras.

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“…The number of follicles per unit area was corrected for skin shrinkage as described by Carter and Dowling (1954). All follicles in the samples of inguinal skin (grafts and controls) were counted.…”

Section: Methodsmentioning

confidence: 99%

Effects of Grafting the Skin in Merino Sheep, With Special Reference to the Growth of Wool and Hair

Lyne¹,

Hollis²

1980

Aust. Jnl. Of Bio. Sci.

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Grafts of wool-growing trunk skin (wool grafts) and hair-growing inguinal skin (hair grafts) were studied in two black and two black and white adult Merino sheep. Skin growing black wool was transplanted to skin growing white wool and vice versa. Also, skin in both black and white regions was excised and returned to the same site. Inguinal skin was transplanted to black wool-growing skin.The areas of the grafts, which initially ranged from about 1 to 25 cm 2 , decreased to a minimum by 28 days after grafting. Most grafts then expanded slowly and returned to approximately their original size by the end of the experiment (118-194 days after grafting).Grafting caused the temporary cessation of wool and hair growth. Old fibres were shed and new fibres, usually similar in colour, appeared above the skin surface about 28 days after grafting. Each animal was given a series of injections of L-[35Sjcystine and fibres were sampled from the grafts and control regions for length and diameter measurements. The fibres on most of the grafts showed marked increases in length growth rate and diameter, resulting in large increases in volume growth rates. However, the total amount of wool produced by the grafts was usually reduced because grafting caused a loss of follicles.At the end of the experiment, skin samples were taken from the grafts and control regions for microscopic examination. The sebaceous glands were retained in the grafts except those associated with follicles that did not regenerate. The sweat glands and erector muscles were often destroyed by grafting, particularly in the wool grafts. Innervation was greatly reduced. Langerhans cells appeared to be as numerous in the grafts as in control samples. Melanocytes spread from black skin into wool and hair grafts of white skin and were most commonly seen in the epidermis, which increased in thickness. Clumps of pigment in the dermis appeared at the periphery of many of the grafts.

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“…Density estimates were made from follicle counts taken with the aid of a projection microscope and corrected for shrinkage of the section during processing (Carter and Dowling 1954). As nearly as possible, interfollicle measurements were all made at mid-sebaceous gland level.…”

Section: (C) Methods Of Describing and Measuring The Spatial Patternmentioning

confidence: 99%

The Spatial Relationships Between Central Primary Skin Follicles During their Development in Sheep

Claxton¹

1962

Aust. Jnl. Of Bio. Sci.

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SwmmaryThe spatial patterns of central primary follicles have been measured during development and compared on six body positions and hetween Romney X South. down cross and Merino shepp. The patterns are similar in both breeds on aU the body positions investigated and appear to be constant between 70 and 140 days of foetal age.The actual measurement of spatial relationships shows that the distribution of central primary follicles is highly uniform, and gives support to the idea that these follicles 'may compete for space during their initiation.The marked directional.trend of the trio groups does not appear to be associ· ated with a directional component in t,he spatial arrangement of central primary follicles.

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The hair follicle and apocrine gland population of cattle skin.

Cited by 52 publications

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Características corporais associadas com a adaptação ao calor em bovinos naturalizados brasileiros

Características corporais associadas com a adaptação ao calor em bovinos naturalizados brasileiros

Effects of Grafting the Skin in Merino Sheep, With Special Reference to the Growth of Wool and Hair

The Spatial Relationships Between Central Primary Skin Follicles During their Development in Sheep

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