Animal nutrition technologies to reduce environmental pollution caused by livestock production

A major issue facing the animal industry is the impact of modern production on the environment. Nitrogen, phosphorus, copper, and zinc from animal wastes have been of most concern relative to their accumulation in the soil and water; methane and odor because of implication to global warming and air pollution. Dietary management is considered the best available technology for the purpose of reducing pollutant at source. The formulation of low pollution diets is based on the concept of environmental nutrition whereby animals are fed to meet their minimum nutrient needs for acceptable performance, reproduction and carcass quality with mineral nutrient wastage. Feeding measures to alleviate manure problem has focused mainly on reducing the dietary input of nutrients (nitrogen, phosphorous, copper and zinc) and/or their more efficient utilization. The nutritional strategies to conserve and reduce nitrogen and phosphorous excretions include the use of scientific diet formulations aimed at supplying the precise nutrient requirement of the animal by (multi) phase feeding and split sex feeding; net energy system to provide more accurate estimate of the true' energy utilized; low protein diet supplemented with synthetic amino acid to reduce dietary nitrogen; more digestible, good quality feedstuff to increase nutrient digestibility; and the inclusion of pronutrient feed additives (feed enzymes, organic acids, pro biotics, prebiotic; conjugated linoleic acid, antimicrobial agents, direct fed microbials and herbals) to increase feed efficiency. Phosphorous excretion can be reduced by 20 to 30% by using microbial phytase vitamin D isomers to enhance phytase activity; use of phosphate sources with high biological value; phase feeding and formulation based on available phosphorous content. Copper and zinc excretions can be reduced by 83 and 65% with the use of organic or chelated minerals which are considered more bio-available than the inorganic sources. Reduction of ammonia emission by 28 to 79% by feeding involves the use of low protein diets; inclusion of addition of acidifying calcium salts in the diet. Dietary management to reduce odors from manure involves increasing the nutrient utilization of the diet while reducing nutrient excretion; manipulating the diet to alter microbial fermentation in the lower gastrointestinal tract and reduce odor causing compounds excreted; and altering the physical environment of urine and feces to suppress odor emissions. These nutritional strategies coupled with the use of genetically superior breeds of animals given optimal management, housing and health considerations will help address the pollution problem of the livestock industry.