The Effects of Poultry Litter Biochar as a Viable Feed Ingredient in Poultry Diets

The Effects of Poultry Litter Biochar as a Viable Feed Ingredient in Poultry Diets

Summary

Poultry is the number one agricultural commodity in West Virginia. Decreasing diet cost and environmental impact, and improving the overall sustainability of production are a few of the most important issues currently surrounding the poultry industry in the state as well as the poultry intensive Eastern United States (US). Recent legislation surrounding agricultural run-off and the increase of phosphorus deposition in the Chesapeake Bay has promoted West Virginia broiler producers to find alternative management strategies for poultry manure. Gasification of poultry litter and feeding the resultant ash may represent a viable solution to manure application problems and provide a cost effective essential nutrient for poultry diets. This accomplishes two goals: 1) provides a source of heat for poultry houses and 2) the ash can replace part, or all, of the expensive inorganic feed phosphorus sources currently used in poultry feeds.

Our goal is to perform applied research pertaining to feed manufacture manipulations that can directly benefit the poultry industry. The long-term goal of this project is to provide the industry with a simple, viable alternative to applying litter to the land. The objective of this project is to assess the effectiveness of poultry litter biochar (PLB) as a replacement for expensive ingredients in poultry diets. Thus far, this research project has demonstrated that PLB can improve pellet quality. Differences in broiler performance were observed, however, these full effects are not yet realized because birds on the low phosphorus diet performed well under the other treatments and more statistical analysis needs to be conducted. No differences in digesta viscosity were observed and bone mineralization and amino acid digestibility are currently being analyzed.

Objectives/Performance Targets

Below are the original objectives of this research project and how or if they have been met thus far.

1. 1. Decrease heavy metal content in PLB – We were successful in obtaining a PLB product that contained a lower amount of heavy metals, specifically arsenic.

2. 2. Determine pellet quality of diets with/without PLB – Pellet quality was successfully analyzed and is listed in the table below. Diets that contained 2 or 4% PLB resulted in numerically higher pellet durability than diets not containing PLB. This data was not replicated, therefore it should be considered descriptive.

3. 3. Determine digesta viscosity (broiler chicks) – Digesta viscosity was examined and found to not differ among treatments. The table below contains P-values obtained for these data.

4. 4. Determine tibia ash content (broiler chicks) – This portion of the study is currently being analyzed and data should be available soon.

5. 5. Determine ileal amino acid digestibility (broiler chicks) – This portion of the study is also currently being analyzed and data should be available soon.

6. 6. Determine true amino acid digestibility (roosters) – This portion of the study has not yet begun. Work should begin in January 2015.

Accomplishments/Milestones

Currently, three of the objectives have been completed, data for two are currently being analyzed, and the last one is set to start in January 2015. The PLB product utilized in research was found to contain an acceptable level of arsenic compared to PLB used in past research (22 vs. 99 ppm). The PLB was analyzed for nutrient and heavy metal content and these data was used to formulate diets that contained 2 and 4% PLB. Positive and negative control diets (differing in available phosphorus) were also formulated.

These diets were pelleted using a 40-HP California Pellet Mill equipped with a 5 x 38 mm pellet die and a conditioning temperature of 82°C. During pelleting, data was collected for production rate, hot pellet temperature, and pellet durability. These data demonstrated that diets with or without PLB resulted in similar production rates and hot pellet temperatures. Pellet durability revealed that diets containing PLB resulted in higher durability compared to positive and negative control diets.

            These diets were fed to Hubbard x Cobb 500 broiler chickens from days 1-21. Data collected during this period included: starting pen weight, ending bird weight, live weight gain, feed intake, feed conversion ratio, mortality percentage. On day 21, 10 birds ± 100 grams of the mean pen weight were selected for tibia excision, total and lower ileum digesta collection. Digesta collected from the total digestive tract was utilized to determine viscosity measurements on fresh samples. These data revealed no significant differences between treatments. Digesta collected from the lower ileum and tibiae were dried and are currently being analyzed.

            Live bird performance variables (listed above) demonstrated that birds fed the negative control performed at a much lower level than the other treatments. We plan to re-analyzed these data using orthogonal contrasts, removing the negative control, and potentially revealing more subtle differences between the other treatments.

Impacts and Contributions/Outcomes

Due to the fact that all data from this project has not been completed, no impacts or contributions have yet been measured. It is expected that this project will be used to create outreach presentations for small scale and commercial poultry producers. A publication is also expected to be produced in early 2015.

Collaborators: