Use of anticoccidials in relation to global poultry production

Trend in all agricultural industries continues toward larger units, fewer farmers and corporate enterprise. The poultry industry has been a leader in this trend. In the broiler industry where chickens are raised on dirt floors, coccidiosis is a big problem. The success of coccidiosis control through extensive use of anticoccidial drugs in the feed has in part contributed to the development of the giant broiler industry in the U.S. and other key broiler producing countries. U.S. broiler production has increased from 700 million in 1950 to 5.7 billion in 1989. Broiler production of the other key broiler export countries also reached record levels. In 1989, Brazil produced 1500 million, France 640 million, Thailand 400 million and the Netherlands 300 million. Although the U.S.S.R. and Japan are importers, they produced 1300 and 990 million broilers, respectively, in 1989. Present world broiler production has exceeded 17 billion birds per year. Since the introduction of sulfonamides in the 1940's, the use of anticoccidials in broilers continues to increase as the industry rapidly expands. During the 1950's and 1960's, synthetic chemicals dominated the anticoccidial markets. Due to development of resistance, with the exception of nicarbazin, most of the chemical anticoccidials, such as amprolium, buquinolate, clopidal, zoalene, etc. had a relatively short life span of usage. With the introduction of monensin in 1971, it opened a new era of ionophore anticoccidials for the control of avian coccidiosis. Since then, new polyether ionophores such as lasalocid, narasin, salinomycin and maduramicin have been successively introduced. Due to the characteristics of slow development of occidial tolerance/resistance, the ionophore anticoccidials have dominated the past two decades of coccidiosis controls. The strengths and weaknesses of ionophore anticoccidials, as well as their application in shuttle programs, are discussed. The most popular programs are synthetic chemicals/ionophores shuttle. The need for new anticoccidial drugs or control programs will continue to exist for the next decade due to unavailability of effective and practical vaccines for control of coccidiosis in broiler chickens.