Relationship of scrotal surface temperature measured by infrared thermography to subcutaneous and deep testicular temperature in the ram

Abstract

The right testis of 9 anaesthetized rams was removed from the parietal tunica vaginalis and replaced by a surrogate testis (water-filled balloon) through which water of known temperature was circulated. Thermistors were inserted in the surrogate testis, between the scrotal skin and parietal tunica vaginalis on the right side, and deep within the intact left testis. Scrotal surface temperatures over the surrogate and intact testes were measured by infrared thermography. Scrotal surface temperature was correlated (P less than 0.01) with both subcutaneous (r = 0.95) and surrogate (r = 0.91) testicular temperature. The temperature differential between scrotal surface (30.1 +/- 0.1 degrees C) and deep testicular temperature over the intact side (34.9 +/- 0.09 degrees C) was 4.8 degrees C at an ambient temperature between 24.0 and 26.6 degrees C. Contact with the scrotal skin is not required to measure scrotal surface temperature by infrared thermography. This, coupled with the close association between scrotal surface temperature and that of underlying structures, will enhance our ability to understand better testicular temperature regulation and scrotal/testicular function.

Microvascularisation of the scrotal integument of Holstein-Friesian bulls

“…Moreover, for the number of spermatozoa per ejaculate and for the percentage of motile spermatozoa, plasma testosterone concentrations together with differences between top and bottom scrotal surface temperatures were significant independent variables [7]. These findings corroborate the view that the fine and dense blood vessel network of the scrotal dermis is generally involved in thermoregulation by heat emission [5,7,13]. In this context it has to be emphasized that the secretions of the apocrine tubular glands are not involved in thermoregulative activities but in antimicrobial defence to protect the skin and, here particularly the sparsely haired scrotal surface, against microbial invasion [15,18,20,21,24,25].…”

TERMORREGULAÇÃO ESCROTAL EM TOUROS NELORE (Bos taurus indicus)

“…Assim como em T1 depois -T5 depois, que observe-se o resultado de 3.95ºC. Esse resultados concordam com Coulter (1988) que em seu experimento obteve os padrões de temperatura de touros com a termorregulação escrotal normal tinham simetria da esquerda para direita e as temperaturas se mostraram cerca de 4º C mais altas no topo do que na extremidade distal do escroto. …”

“…A temperatura testicular em touros deve ser 4 a 5 0 C abaixo da temperatura corporal para que ocorra espermatogênese normal (COULTER, 1988). Segundo Kastelic et al (2001), uma moderada elevação da temperatura testicular em touros submetidos à insulação escrotal reduz drasticamente a produção espermática, a motilidade progressiva, a quantidade de espermatozóides vivos por ejaculado e aumenta a porcentagem de espermatozóides morfologicamente anormais.…”

“…Pesquisas têm mostrado que a temperatura superficial do escroto está altamente correlacionada com a temperatura interna dos testículos (COULTER et al, 1988). Não existe efeito significativo da variação diurna sobre a temperatura superficial do escroto.…”

REVIEW: Factors Affecting Decisions on When to Calve Beef Females

“…Even stress lasting no more than 12 h impairs spermatogenesis (53) and is attributed to an increase in temperature of testicular tissues (16,46). After cessation of stress, it is unfortunate that recovery time to normal sperm production lasts ca.…”