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Associate Professor and Extension Broiler Specialist

Ph.D. - University of Wisconsin, 1981

Phone: 301-405-2805
Email: nickz@umd.edu

Extension Interests:

An ongoing project is the National Poultry Infobase (NPI), a Web and CD-based collection of current, reliable, readily accessible information to aid a variety of users to make informed decisions. The NPI provides full text published articles, selected by poultry experts in numerous disciplines.

On going research on drinking water quality and its effects on performance and health of chickens. The program began as a survey of Delmarva drinking water quality and its effect on broiler performance. The program's original focus on improving production efficiency evolved and now has implications in food safety, human health, and environmental stewardship. A major finding is that any bacteria in the drinking water will impair growth performance and increase morbidity. Research on cost-effective drinker disinfection systems is ongoing.

Nutrient management on poultry farms. We are challenged to reduce soluble phosphorus in litter/manure to allow greater tonnages to be land applied and discover alternative uses. Maryland regulations require farmers to use phosphorus-based nutrient management plans instead of the voluntary nitrogen-based plans previously used. These regulations are hardships on all animal producers because the litter/manure allowed to be land applied will be reduced from 3 tons/acre to 1 ton/acre under current management methods. This reduction will create a manure surplus, require farmers to buy nitrogen fertilizer, increase the cost of production, and put the livelihood of thousands of Delmarva poultry growers at risk. Results of studies employing precision feeding show nutritionists can reduce total phosphorus in broiler diets by 13% without impairing bird health or quality of the final products. Including dietary phytase to release phytate-bound phosphorus (required in MD) further reduces the total phosphorus requirement to 30%. Other feeding methods that have potential to decrease total dietary phosphorus include addition of high potency vitamin D, vitamin C, probiotics, grains having high available phosphorus, and non-phytate phosphorus sources that are more efficiently absorbed. Litter amendments such as alum and gypsum will also reduce soluble phosphorus. Research is ongoing to refine these methods to make nitrogen and phosphorus levels in litter more closely match the agronomic needs of crops.

Awards and Honors:
- Poultry Science Graduate Student Research Manuscript Award, 1977.
- President, Sigma Xi, Tahoma Chapter, 1988, 1994.
- Chair, Environmental Quality Committee of Poultry Science Association, 1997, 1998.
- Chair, American Poultry Hall of Fame Award Committee, 1998, 2001.
- National Program Leader, National Poultry Infobase System, 1999.
- Vice President, American Poultry Historical Society, 2000.

Sources for Poultry and Supplies for Small Flocks - 2004