Though I'm not is a serious heat region, heat tolerance has been an area of interest of mine. Your article is in my collection – some others are below.
In hot times, cattle accumulate heat during the day and dissipate heat at night, if cool enough. They need every advantage they can get to stay ahead of the heat. Getting rid of heat takes work. Cattle don't sweat well, so rid heat by increased respiration or panting. That takes work and increases maintenance requirements, at the same time the heat causes decreased feed consumption. Roughage processed in the rumen causes heat to be produced just like a compost pile, so cattle want to eat less if hot.
Black cattle obviously absorb more solar radiation and are much more prone to heat stress. For heat tolerance, you can either add more ear and decreased performance, or you can choose light colored bos Taurus breeds, as discussed in the third article below.
I see the heat tolerance issue as the biggest problem with black cattle. The whole industry is heading in the wrong direction.
http://www2.dpi.qld.gov.au/health/3551.html
http://vetmed.iastate.edu/vdpam/extensi ... eef-cattle
http://nimss.umd.edu/homepages/home.cfm?trackID=11616
Here's the report on the feedlot death losses from a 1995 heat wave in Iowa.
http://www.iowabeefcenter.org/Cattlemen ... 0study.pdf
"Producers with the nonshaded
lots reported highest death loss in dark-hided
cattle. Thirty out of 36 producers indicated higher death
loss in black cattle and the other six producers
indicated higher death loss with red cattle and had no
black cattle on feed. One producer indicated only 20%
of the cattle in the pen were black, but 80% of the
death loss was black cattle."