Alternative feedstuffs and their effects on performance of Awassi sheep: a review.

Fat-tailed sheep (FTS) is a group of breeds characterized by large (fatty) tails that it is commonly distributed in Africa, Middle East, Pakistan, and to a lesser extent in other countries. Awassi, a common FTS breed in many Mediterranean countries, is adaptive and suitable to live in harsh conditions of the arid and semiarid areas. One of the main constraints for sheep industry in those areas is the limited supply and variable quality and quantity of feedstuffs. Using several alternative feedstuffs (AF) has been a common practice to decrease production cost of Awassi sheep industry in those areas. The appropriate AF to be used is determined by several animal and feed factors. These AF includes, but not limited to, unconventional feedstuffs, agricultural byproducts, and agro-industrial byproducts. A good body of literature about the use of AF and the effects of such use on performance of Awassi sheep is available. Some of these AF have been shown to be safely used in Awassi diets with no detrimental effects on sheep performance or health and, thus, recommended to lower the production cost. Other AF has controversial effects and recommendations. This paper reviews the effects of using AF on performance of Awassi ewes and lambs. Effects on intake, nutrient digestibilities, growth rate, and carcass characteristics of lambs and on intake, nutrient digestibilities, body weight change, milk yield, and milk composition of ewes will be emphasized. Recommendations and limitations for using AF will also be briefly discussed.