Submitted to: Animal Nutrition Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/5/2004
Publication Date: 5/5/2004
Citation: Cole, N.A., Greene, L.W. 2004. Nutrient management considerations for livestock feeding operations: challenges and opportunities. California Animal Nutrition Conference Proceedings. p. 82-104.
Interpretive Summary: The general public is demanding that everyone - and that includes agriculture - be held accountable for their impact on the environment. This could mean big changes for American agriculture and the livestock industries in particular. Today, and in the future, we will need to balance animal production with environmental risks. Several nutritional technologies have been proposed as methods to decrease nutrient intake and excretion by feedlot cattle. It has been suggested that dietary protein concentrations (i.e. N) can be decreased and has been termed "Precision feeding". However, factors such as variability in animal requirements, variability in feed composition, changes in the environment, and other factors limit the applicability of this technology at the present time. Phase feeding (i.e. decreasing protein concentrations late in the feeding period) has promise but logistic and possible animal health concerns limit its use at the present time. Nutritionists will need to adapt technologies to meet some new environmental regulations. In the near future "safety margins" in diet formulation may have to be decreased. At the present time, the best opportunity is probably toward the end of the feeding period - the time period when we can probably have the greatest effect on nutrient excretion and gaseous emissions. The use of many technologies such as phase feeding and precision feeding are limited at the present time. However, nutritionists and scientists need to work together to modify and develop technologies that can be used in the future to meet new regulations and to balance animal performance, risk, and environmental concerns.
Technical Abstract: Protein and phosphorus requirements and utilization by ruminants have been extensively evaluated. However, in recent years, protein and phosphorus nutrition have received additional research focus because of the potential impact of these nutrients on the environment. Excess nutrients in livestock manure can pose a threat to soil, water, and air quality. Diet composition can influence the quantity and chemical composition of manure produced, affect the composition of runoff from feedyards or fields fertilized with feedlot manure, and also affect air quality by altering the emissions of ammonia, dust, and odors from feedyards and fields. This paper discusses current nutritional and management technologies that are potentially available to decrease adverse effects of feedyards on the environment as well as their limitations and factors restricting their use by the industry. The use of many technologies such as phase feeding and precision feeding are limited at the present time because of logistic, animal health, and risk factors. But, in the future, nutritionists will need to adapt technologies to meet new environmental regulations. Nutritionists and scientists need to work together to modify and develop technologies that can be used in the future to meet new regulations and to balance animal performance, risk, and environmental concerns.