White hair coat color does not influence heat tolerance of sheep grazing under a hot arid environment

Roan (Rn) horses show a typical seasonal change of color. Their body is covered with colored and white hair. We performed a descriptive statistical analysis of breeding records of Icelandic horses to challenge the hypothesis of roan being lethal in utero under homozygous condition. The roan to non-roan ratio of foals from roan × roan matings revealed homozygous roan Icelandic horses to be viable. Even though roan is known to be inherited in a dominant mode and epistatic to other coat colors, the causative mutation is still unknown. Nevertheless, an association between roan phenotype and the KIT gene was shown for different horse breeds. In the present study, we identified KIT variants by Sanger sequencing, and show that KIT is also associated with roan in the Icelandic horse breed.

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Aneuploidy of sex chromosomes in a tortoiseshell cat – case report

Clínica Veterinária ◽

10.46958/rcv.2017.xxii.n.126.p.40-44 ◽

2017 ◽

Vol XXII (126) ◽

pp. 40-44

Author(s):

Maria Teresa Pereira Costa ◽

Richard Roberto Lobo ◽

Valquiria Santiloni ◽

Lígia Souza Lima Silveira da Mota

Keyword(s):

Case Report ◽

Coat Color ◽

Klinefelter Syndrome ◽

Companion Animals ◽

Color Pattern ◽

White Hair ◽

The Body ◽

Black Hair ◽

Livestock Species ◽

History Of

Cytogenetic analysis is an important step in the diagnosis of animals with a history of infertility or sterility. While chromosomal studies have been indicated for livestock species for years, the demand for such analyzes in companion animals has recently increased. The coat color in cats known as tortoiseshell presents predominance of black hair mixed with white and orange hair all over the body and, in the color pattern known as calico, these three colors are presented as independent spots with predominance of white hair. However, all of these patterns are limited to females due to sex-linked inheritance. Male tortoiseshell or calico cats occur rarely, due to the occurrence of chromosomal aberrations. This article reports the chromosomal analysis of a male cat with tortoiseshell pelage that presented an extra X chromosome (diploid chromosome set of 2n = 39,XXY), a condition which is similar to Klinefelter syndrome in humans.

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The Relationship Between Coat Color and Reproductive Performance of Dairy Cows in Algeria

World s Veterinary Journal ◽

10.54203/scil.2021.wvj90 ◽

2021 ◽

Vol 11 (4) ◽

pp. 713-717

Author(s):

Sara Lamari ◽

Youcef Saber

Keyword(s):

Dairy Cows ◽

Coat Color ◽

Reproductive Efficiency ◽

Hair Coat ◽

Temperature Regulator ◽

Semi Arid Region ◽

The Relationship ◽

Efficiency Of Reproduction ◽

Semi Arid ◽

Reproduction Efficiency

The objective of the current study was to analyze the reproduction parameters of 48 dairy cows (29 Montbeliardes and 19 Normandes) and their relationship to coat color. Cows were imported from European countries and raised in the semi-arid region of Sétif in Algeria. The findings showed that the cows of the Montbéliarde breed were more fertile and of greater reproduction efficiency, compared to Normandes. Regarding the Montbéliarde breed, the intervals between calving and calving to conception were respectively 378.34 and 98.65 days, which were shorter than those of the Normandes breed (67 and 22 days, respectively). Normandes cows registered a higher number of services per conception (1.54 ± 0.9), compared to Montbeliarde cows (1.34 ± 0.55). Calving to the first service interval of the Normandes (76 days) was longer by 5 days than that of the Montbéliarde breed. The coats of Montbéliarde cows (51%) were whiter than those of Normandes (48%). A darker hair coat probably assured protectivity against thermal stress and greater efficiency of reproduction. The interval between calving in Montbéliarde cows was significantly affected by coat color; the interval between calving of cows with a colored coat was shorter (358 days) than whiter cows (400 days). For Normandes, cows with a colorful coat required fewer services per conception number (1.44). Hair works as a temperature regulator and may affect reproduction performances. The results of the current study suggest the possibility of integrating coat color into animal selection. It can be assumed that colored coats for Montbéliarde and Normande breeds appear to be related to their reproductive efficiency (interval between calving and number of services per conception, respectively).

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The medullation characteristic of the hair coat as a factor in heat tolerance of cattle

Australian Journal of Agricultural Research ◽

10.1071/ar9590736 ◽

1959 ◽

Vol 10 (5) ◽

pp. 736 ◽

Cited By ~ 11

Author(s):

DF Dowling

Keyword(s):

Seasonal Variation ◽

Thermal Effect ◽

Heat Tolerance ◽

Rectal Temperature ◽

Structural Component ◽

Heat Dissipation ◽

Unit Area ◽

Hair Coat ◽

Critical Characteristic ◽

Hair Fibre

Measurements of the hair fibres of the cattle coat show, besides considerable seasonal variation in the length, diameter, and weight of hair per unit area, marked changes in the incidence and degree of medullation, which may account for the required variation in the thermal effect of piliary development associated with seasonal conditions. The medulla, a structural component of the hair fibre, may be a critical characteristic of the coat in the regulation of heat dissipation by the animal. The correlation between the incidence of medullation and the animal's ability to regulate the rectal temperature was 0.95.

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