Santa Gertrudis cattle developed on perhaps the best-known ranch in the United States, Texas' King Ranch. The breed got its name from the Santa Gertrudis Creek on the enormous ranch. In 1940, the Santa Gertrudis was recognized by the United States Department of Agriculture as the first beef breed developed in this country, according to the King Ranch.
At maturity, the average Santa Gertrudis bull weighs about 2,000 pounds, but some specimens weigh as much as 2,800 pounds. The Santa Gertrudis coat is light or dark red, with white on no more than 50 percent of his underbelly. The head is broad with a straight profile and slightly drooping, medium-to-large ears. He moves freely on squarely set feet, with massive shoulders, deep quarters, a long rump and considerable bone. Although he has the humped Brahman bloodlines, there's no little or no hump on the Santa Gertrudis bull. The breed standard allows horned or polled bulls.
All Santa Gertrudis cattle descend from a bull named Monkey, named for his playful, good temperament. He passed on to his descendants not only his temperament but his rapid growth and ability to forage. The modern Santa Gertrudis bull is 5/8 shorthorn and 3/8 Brahman, as was Monkey. From the Brahman, a humped breed originating from India, the Santa Gertrudis inherits loose skin with many sweat glands. This allows him to live comfortably in hot or humid climates.
Since he is a bull, his genitals are of prime importance as a potential sire. For reproductive efficiency, the Santa Gertrudis breed standard states that the prepuce of his penis must be retracted, with the sheath at a 45 degree angle with a small orifice. His testicles should be "well developed and proportionate in size," with a minimum 12 inches in circumference at the age of 1 year. At maturity, the circumference is 15 inches or more.
Ranchers often use Santa Gertrudis for crossbreeding, as the bulls improve other breeds not just in weight gain but also in hardiness and heat tolerance. The King Ranch has developed its own cross, the Santa Cruz, now a breed. By crossing Santa Gertrudis bulls with Gelbveih and Red Angus cows, the result Santa Cruz produces more tender beef than the Santa Gertrudis, but retains that breed's weight gain and feed efficiency.