POTENTIAL ROLE OF METHIONINE IN IMPROVING PERFORMANCE OF BROILERCHICKS UNDER HEAT STRESS

摘要

Approximately 9 billion broiler chicks were raised within the U.S. alone in 2017, which provided 55.6 billion pounds of broiler products and generated a market value of 30.2 billion dollars (USDA, 2018). The majority of the poultry production is concentrated within southern States where summer temperature is high (National Chicken Council, 2016). Thus, broilers raised in those States are likely to experience heat stress during the summer. Modern broiler houses are built to raise high density of chicks for efficient use of space. High stocking density is known as another stress factor for these animals. Both factors impair growth performance, immune responses, and health status of chicks (Dozieretal., 2005; Grashorn & Kutritz, 1991; Lara & Rostagno,2013; Shanawany, 1988; Quinteiro-Filho et al., 2010).