Coat and hair color: hair cortisol and serotonin levels in lactating Holstein cows under heat stress conditions
Published:July 28, 2017
By:Jalil Ghassemi Nejad, Byong-Wan Kim, Bae-Hun Lee and Kyung-Il Sung. / College of Animal Life Sciences, Kangwon National University, Chuncheon, South Korea.
Summary
The deleterious effects of heat stress on animal health are being increasingly recognized. This study aimed to determine hair cortisol (HC) and serotonin levels in lactating Holstein cows under heat stress conditions with different coat and hair-cut color. Forty-five multiparous lactating Holstein cows (days in milk = 130 ± 47, body weight = 753 ± 85 kg) were divided to two main groups of over 80% black coat color (BC) and over 85% white coat color (WC) visually observed based on registry certificates and subdividing to black hair sample (BH) and white hair samples (WH) in 2 × 2 factorial arrangements. Hair samples were taken from the forehead of the individuals. Higher HC levels were observed in BC than WC cows (P < 0.05). No differences were found in HC levels between BH and WH groups (P > 0.05). Serotonin levels showed no difference between BC and WC (P > 0.05). Interaction between coat color and hair color was not significant (P > 0.05). The cortisol levels in hair are not affected by pigmentation. However, pigmentation within the coat alters cortisol levels. In conclusion, white coat color retains less cortisol than the black coat. Therefore, white coats are preferable for dairy cows under heat stress conditions.
Thaks for your comment. More research on gene alteration can provide selective color of Holstein breeds or others. This color manipulate can easily progress through AI and selective color breeding along with other traits in order to maitain the production quality (meat and milk) in such a harsh (cold or hot-humid) environment.
The result of this publication is very important because it brings something new and logical. I hope it can be used practically in farms and bring new knowledge into the area.
It is a good point that mentioned here , but in my opinion genetically the cows ,dogs and horses are not the same, related to HF cows we could mention that they are more sensitive to heat stress then other breeds of cows, in tropical and sub tropical condition how to keep this bred? if we try to keep cold the cows, need more cost due electricity, in these days the trade of HF to sub tropical country e.g. Afghanistan, the heat stress is higher.
As a breeder of ingenious cattle, I look that cattle coat color, mainly in Bos indicus breed, is a means of adaptation and a response for the existing environment. Like wise, breeds in hot environment resemble to white coat color and short hairs for responding the excessive sunlight. This study seems to confirm such breeds view.
Years ago I was told that any animal that was white usually had a higher chance of cancer then those animals that had darker hair/hide.
A lot of white animals get sunburned easier than others & in horses, I am told that horses with with white around their eyes tend to get cancer or go blind than horses that have darker pigment around their eyes & if they have white hooves then they had soft hooves & tended to have more issues with them. I've never had a white faced horse so I don't know, but many I'm aware of have gone blind (but who knows if that's strictly due to them having white around their eyes. The only horse I've owned that had a white hoof, it was tougher then the black colored ones they had.
It'll be interesting to see that article updated & get more specific info on the color.
Thank you, Cedden. It has also long been the belief of some dog breeders that heat stroke is more common among white dog breeds. This is antidotal, however, and breeding many white dogs myself I cannot attest to this. It is a fact that with some breeds of dogs dermatitis is definitely seen much more regularly among white specimens of the breed than colored. This may be linked to the white coloring or it may be a result of poorly planned inline breeding of more popular white colored dogs that also happen to have dermatitis. With dogs you understand we have the issue that not nearly so much widespread professional research has been done as with livestock animals. As such many suppositions exist with only limited actual data.
White coated breeds can be more sensitive to sunstroke. In example, sunstroke sensitivity is more frequent in white coated Saanen goats. Moreover, white coated Holstein, even Simmental cows are not preferred by breeders because of their higher sensitivity to environmental factors and lower performance.
At a glance this suggests, "breed more white cows," but I wonder - apart from white coats being preferable under heat stress conditions, what else is statistically linked to white coats that may not be so preferable. For instance is there a known statistical difference in undesirable skin conditions between black and white coats? I'm a dog breeder not a cow breeder so I do not know what is perhaps the well known answer to that question. In my own field, however, that is the case, white dogs do tend to have a great many more undesirable skin conditions than dogs with colored coats.
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