Hi there, as a coincidence I actually answered quite a similar question about water in the deserts of the Middle East earlier today HERE that might be of interest.

One additional feature that's unique to armies of course, as opposed to just individual travellers or settled areas which I was discussing is the sheer volume of people and animals that need to be supported. This is interesting for a couple reasons:

1. While cities and wells would likely be sufficient to support the water needs of such armies in dry areas, grazing needs for horses would likely be the more pressing issue, and is actually one of the reasons why horse nomads are believed to have been more limited in their successes in penetrating or crossing some of the more purely desert areas, as as attacking across Iraq and into the Levant, as opposed to the more steppe-like conditions of the Iranian plateau, for instance.

2. This also places an upper limit on some of the estimates for armies involved in some of these invasions. Some of the figures thrown around for the Mongol invasions, for instance, seem highly implausible given the amount of forage that you would need for that many soldiers with a string of x3 or x4 or x5 horses per man.

I don't know about either Turkish or Arab customs, but the Mongols made use of their horses as mobile food and drink when crossing hard, especially desert, terrain. Mongol horse culture kept horses in a more natural state than their European or even Near Eastern counterparts: horses were not shod, nor fed any kind of special diet but rather allowed to forage freely, and were allowed to foal in season (usually starting in May and continuing throughout the Summer). This distinction is important: Mongol horses were sturdier and able to digest more rough forage, but were smaller, able to carry less weight and slower than European/Near Eastern horses.

The Mongols brought from 3-5 horses per horseman when going on campaign, and preferred to ride lactating mares as often as possible when on campaign - switching to larger males for battle. Supplemented by horse milk, each Mongol warrior also carried a bag of dried milk curd along with dried meats to eat on the ride, each of which could be eaten alone or mixed with water and eaten. Another Mongol custom when crossing desert terrain devoid of water was to drink the blood of their horses, or mixing it with their dried curd, when water was unavailable. The habit of bringing many horses per warrior and rotating them by day during campaign ensured that this bleeding was not too taxing on their mounts. In essence, Mongol warriors adapted themselves as well as any ever at crossing any type of terrain imaginable without much of any supply line or commissary system, and were capable - with an acceptable level of attrition - to cross areas that no other army in history at the time could have done.

Mongol and Turkish steppe culture had many similarities, so it would not be surprising if similar practices were common. However, it should be noted that dietary restrictions inherent in Islam - specifically blood taboo - would likely have eliminated the practice of drinking horse blood.