Chinese mass media recently featured pictures of Chinese soldiers mounted on yaks. These mounted combat troops were shown patrolling mountainous portions of the border with India. This is not unusual because yaks are the only breed of cattle with long hair and adapted to living at high altitudes (Tibet and adjacent highlands). Domesticated males weigh about half a ton (wild yaks weigh twice as much) and have long been used for carrying cargo, or riders. While not as fast as a horse yaks are more surefooted in ice, snow and rocky areas. Soldiers have been riding yaks in this area for over a thousand years.
Many countries still use four-footed transport (mainly horses and mules) for soldiers and police working in remote and difficult terrain. Some countries, like the United States, maintain small forces of experts capable of handling horses and mules in military situations. This is especially true for special operations forces. For example in 2013 the U.S. Marine Corps special operations troops (MARSOC) followed the example of the army and established a training program for managing and caring for pack animals. The course is run by the U.S. Marine Corps MWTC (Mountain Warfare Training Center) in California. The marines have had such training programs before and have long maintained a small herd of pack animals (and a sergeant designated as a “mule skinner”) at MWTC and organized training programs as needed. The army has done the same and U.S. SOCOM (Special Operations Command) helped by issuing an updated 255 page training manual on this subject in 2004 (Field Manual FM 3-05.213).
World War II was the last time the United States made widespread use of mules and horses, but continued to maintain capabilities in this area after the war. During World War II even the U.S. Navy used mounted troops, raising a regiment of cavalry from local manpower in Inner Mongolia, as a security force for Navy weather stations, while the Coast Guard had mounted beach patrols along the East Coast of the United States in order to prevent German submarines from landing intelligence agents and saboteurs. Mules were used by American troops in mountainous areas of Italy and France.
The reason for maintaining this capability is quite practical. In many parts of the world the easiest way to move goods, including food and ammo for troops, is via pack animal. Depending on what part of world the troops are in, the animal can be a dog, elephant, llama, camel, horse, ox, donkey, mule, or reindeer. In many areas you can hire local animals and people to handle the animals. But in some situations you have to bring in your own animals and handlers. The training courses show troops how to care for the animals and how to load (“pack”) cargo on each species. Usually a pack animal can carry about a quarter of its own weight as cargo and the most common ones encountered are horses, donkeys, and mules. The need for these training courses is one reason why the military still recruits large-animal veterinarians.
While the American military use of pack animals doesn’t get much media coverage they continue to be needed despite all the mechanization and use of parachute drops and helicopters to move supplies in the last half century. For example during the 1980s the United States supplied the Afghan rebels (fighting the Russian invaders) with some 700 mules as these were the most efficient mode of transport for those (like the rebels) who were not able to use the few roads (which the Russians controlled). Earlier in the 80s, when the British were fighting in the Falklands Islands to expel the Argentine invaders, they purchased local pack animals to help move supplies over terrain that did not tolerate wheeled or tracked vehicles very well.
Some European countries recognized the continuing importance of pack animals and even have a special breed of horse (the Freiberger) bred over the centuries to work in hills and mountains carrying people or cargo. Starting during the Cold War the Swiss government paid some Swiss farmers an annual stipend for each mule and horse maintained on their farms and ready to be taken over by the military in the event of war. The animals had long since ceased to be efficient for farm work. Yet the Swiss Army found them useful for reconnaissance and for moving supplies in many parts of mountainous Switzerland and needed to assure a reasonable supply on hand in the event of war. Without the government payments (plus a bit of nostalgia and patriotism) farmers would have gotten rid of nearly all these animals.
There is one aspect of military animals that won’t return, even though it would, in theory, speed up the movement of armies on the march. That’s because despite the introduction of all those trucks and armored vehicles, which can move at better than 60 kilometers an hour, the daily combat rates of advance are not that impressive. The fastest sustained daily advance rate by an army is still that of the Mongol horse archers 700 years ago, who regularly maintained over 20 kilometers a day for extended periods.
Rarely has a 20th century mechanized army managed a sustained rate of 20 kilometers a day. In fact, one of the fastest moving armies in this century was the 1950 Chinese Army in Korea. It did better than 10 kilometers a day on foot for several weeks. Mechanized armies have not done as well. In World War II the German Blitzkrieg, at its best, sustained only 5 kilometers a day in Russia (1941), 10 kilometers day in France (1940), and 17 kilometers a day in North Africa (1941). The Arab-Israeli Wars of 1956 and 1967 did scarcely better and contemporary exercises show advance rates of under 10 kilometers a day.
The critical factor here is sustained rate of advance, the rate at which the entire army moves forward, regardless of what individual units may do, which may greatly exceed the average. Then there are the supply problems. Horses can live on grass for a while and troops can live off the land up to a point. Mechanized armies changed that and must generally stick to the roads and need an enormous fuel and maintenance system to keep moving and dragging all their gear along, which slows them down, even though most vehicles can zip along at sustained rates of over 50 kilometers an hour, and smaller individual units may average 100 kilometers in 24 hours. Thus military horses will never return in a big way but until someone comes up with a robotic replacement that can equal all the capabilities of horses and mules you will always have to be prepared to use these animals in situations where hooves outperform machines.