Todd J. Applegate - Poultry Nutritional Physiology Laboratory

 

Welcome, Welcome, Bienvenidos, Willkommen, Bienvenue, Bem-vindo

Todd Applegate

Welcome to the Applegate Poultry Nutritional Physiology Laboratory. Our laboratory began in 2000 with the simple purpose in being responsive to the ever changing needs of poultry production. Since that time, we have had the good fortune to be host to numerous graduate students, post-doctoral researchers, and visiting scientists. As Indiana's poultry industry is very diverse with considerable production of broilers, ducks, laying hens, and turkeys, our lab conducts research across all of these birds. The range of research techniques across these different studies have enabled us to make unique comparisons across these different poultry species.

Our lab's research focus has centered around two themes:

  1. Environmental Nutrition - Strategies to maximize nutrient use and retention by the bird to ultimately reduce environmental impact (a specific focus on mineral and amino acid utilization)
  2. Intestinal Responses - Response of the intestine to different factors (pathogens, stressors, different feedstuffs, stage of growth) in terms of barrier functionality and maintenance "cost"
     

Environmental Nutrition

The two predominant nutrients our lab focuses on are nitrogen and phosphorus. Strategies we have investigated include:

  1. Evaluation and refinement of phosphorus and amino acid requirements for poultry to lower the amount of phosphorus and nitrogen being fed
  2. Development and implementation of diet formulation based on ingredient amino acid digestibility to lower nitrogen excretion
  3. Quantification of the synergy between different feed additives on phosphorus utilization by the animal
  4. Quantification of ammonia emissions and dietary approaches for their reduction (sequestering, pH modifiers, probiotics, fibrous feedstuffs)
  5. Determination of phosphorus form and eutrophication potential of poultry manure after different feeding strategies and manure storage.
  6. Quantification of mineral interactions with phosphorus and resulting use by poultry
     

Intestinal Responses

The gastro-intestinal tract is an amazing organ system that is a crucial nutrient supply organ as well as a vital barrier to the outside world. Our work in this area has been very broad, wherein we have studied at how different nutrients, growth factors, microflora, feed ingredients, pathogens, and stressors influence the intestine as a barrier, as well as endogenous maintenance functions of the intestine. Numerous studies have been conducted, including:

  1. Feed withdrawal and delayed access to feed by hatchlings
  2. Pathogen attachment with various stressors
  3. Probiotics, plant extracts, ionic compounds, micro-minerals, and yeast derivatives
  4. Growth factors
     

Various laboratory techniques have been utilized for these studies, and generally have allowed for measurement of:

  1. Apparent and standardized nutrient retention and/or digestibility
  2. Manure storage nutrient loss
  3. Intestinal morphology, including intestinal turnover (replenishment)
  4. Impact of innate immune challenges on feed intake responses (short-term and long-term)
  5. Intestinal functionality (active nutrient uptake through Ussing chamber studies)
  6. Immune cell functionality (e.g. phagocytic capability)
  7. Gene responsiveness (cytokines, transporters, mucins, etc.)
  8. Specific endogenous losses, including mucin quantification and characterization
     

Much of our research has been in collaboration with other scientists domestically and abroad (Lab collaborations).