|The Improvement of Tropical and Subtropical Rangelands (BOSTID)|
To achieve the livestock benefits from any grazing program, a workable program of animal husbandry must be in place. This includes animal health to prevent and cure disesses and parasite problems. Many tropical and subtropical countries have national campaigns to provide inoculations for endemic diseases and to provide advice on animal husbandry to the farmers and herders.
In planning the grazing use of the rangeland, one must consider the total annual nutritional needs of the herds with respect to lambing or calving seasons if animal reproduction is attempted throughout the year. The availability of sufficient quality and quantity of feed will dictate the probable success in livestock production. In many countries, the structure of the herd includes lactating and dry females, young growing animals, and mature animals. This is a normal situation since the livestock may be the "bank," and the offtake is marketed throughout the year. A lactating animal requires
a more nutritious diet than does a dry animal. If the herd is largely in the lactation production phase or, conversely, in the maintenance phase of the animal production cycle, the needs for nutrients from rangeland can be reasonably estimated. Herds that consist of growing, dry, and lactating animals should be fed according to the needs of the growing animals, unless special supplementation can be provided to those with the greatest nutrient demand. It is generally agreed that the animals with highest nutrient demand set the base nutritional requirement of the herd. In tropical and subtropical countries, however, the demand for quantity of forage is so great that little attention is paid to quality. A range manager who can find a way to upgrade the diet quality in growing or lactating animals could greatly increase productivity.
The range probably cannot provide the quantity or balance of nutrients during the entire year. If animals are fed when rangeland forage is deficient, then a grazing program should be developed to complement the feeding period. It may be necessary to provide only a portion of the nutrients during part of the year, and feeding can be replaced with supplementation that can bring the animal's nutritional level up to minimum requirements. Supplementation will be less costly than feeding and, when correctly used, will provide for excellent livestock performance on ranges that without supplementation cannot meet the minimal needs of the livestock. Supplements can be worth many times their cost since they add what is needed to provide a correctly balanced diet, but supplementation is not a normal practice in most countries because of the comparatively high cost of desirable supplements. Furthermore, in remote areas, the cost of transportation of supplements to the herds is often prohibitive.
Since rangelands by their nature exist in areas with variable and extreme climates, a grazing program must have some plans for the expected but unpredictable droughts or storms. Forage reserves can be of utmost importance over the long term. Excellent use of shrubs and cacti is being made in many countries where the grazing demands exceed supply in extreme years. Forage reserves can prevent catastrophic losses if they are predictably planned for and used (figure 6-11). Although some use of forage reserves during normal years may be appropriate, it is critical that they be sufficient to ameliorate the forage losses that are sure to come to the semiarid and arid rangelands during drought. Many forage reserves are considered a luxury, since in many countries demand exceeds supply of forage in normal years. The hema system of North Africa and the Middle East
is a management strategy from previous centuries that still has merit for maintaining forage reserves for the expected drought years.