Effective use of food scraps as poultry feed

Black Dirt Farm and a small group of other farms in our region have raised laying hens on a diet of discarded food in an active composting systems for over ten years, however no quantitative assessment of this feeding strategy has been conducted, and we were interested to clarify any concerns with the transmission of salmonella. To this end, this project assessed the opportunities and risks associated with feeding food scraps to laying hens. Specifically, we looked at the nutritional value and pathogenic risks associated with food scraps as a feed, egg production and quality and the economic viability of this practice for small-scale commercial production (50-2500 hens).

This has been a three-year project. During the one-year trial we operated a split flock with 55 birds in each group. Group One was fed only a food scrap-based compost mix (Compost Group), while Group Two (Grain Group) was fed strictly Organic Grain. Both groups had year-round access to equal pasture and Fertrell’s Poultry Mineral Mix. Food scraps were thoroughly sampled with a rigorous sub-sampling process, and tested for nutrient composition and Salmonella enteritis.

1. Eggs were tested for Salmonella enteritis and nutrient content, and coops were swabbed for Salmonella at our farm and a partnering farm using this practice and none was found.
2. Egg production: grain hens had 2% more eggs than compost-fed hens however at various points the Compost Group was out-producing the Grain Group by as much as 10%.  Eggs from the Grain Group were 4% heavier on average. 
3. Egg quality: Egg nutrition was similar in the Grain and Compost Groups with some surprising differences. Yoke color was much darker from the compost hens.
4. Feed costs: It is projected that a 50-75% reduction in feed costs for a flock of 2,000 birds amounts to $30-42,000/ year, and new revenue associated with compost sales.
5. Labor: The Compost Group required nearly twice the labor of the Grain Group, however the feed cost in the Grain Group represented over 85% of egg sales. 

Our trial demonstrated the viability of this practice and indicated opportunities for optimizing the system. Overall, while there were some differences, the outcomes were largely similar.  In addition to eggs, the Compost Group generated compost, of value both on the farm and in sales, and integrated with a profitable collection service. In terms of farm viability, the Compost Group was not only more profitable, it is also can be scaled more effectively. To a large extent as flock sizes increase, the feed costs follow the same trend. However, we are now managing 300 birds on the same system with the same amount of labor as we were with 50 hens, thereby spreading the same cost over six times more birds.

Based on the work in this project and other observation, we have produced Feeding-Community-Food-Scraps-to-Laying-Hens-in-an-Active-Composting-System-manual, an operator’s manual for considering and planning a compost-based feeding system.

Dr. Michael Darre, UCONN Poultry Specialist, worked with us on trial design and feed ration development. Dr. Jarra Jagne, Cornell University Poultry Pathologist, helped us assess the pathogen risk.

Introduction:

As long as humans have domesticated chickens and their predecessors, chickens have likely been consuming their discards in some capacity. In fact, fowl scavenging food in human communities may have contributed to domestication, leading to a longtime co-evolution. The practice continued and became more deliberate through the 1930s when a resource-mindful World War II-era US Government encouraged citizens to set aside food scraps from their trash for the purpose of feeding hens and pigs. In fact, the separation and collection of these materials was organized and government propaganda encouraged people to ‘Save Kitchen Scraps for the Hens! Your local council will collect’. Since that time there have been documented cases of pathogen transmission from humans to food scraps to pigs, which have brought about health concerns associated with feeding pigs food scraps. More recently we have come to understand the pathogen pathways between pigs and humans, however there has never been any documentation of this same risk with chickens. Many states regulate feeding discarded food to pigs, some banning it out- right. Some states have implemented similar measures for poultry, without precedent or scientific basis. As growers and communities throughout the world are looking for new models of agriculture and community resource management utilizing discarded food as poultry feeds is a practice attracting more interest in recent years. Further exploration of the practice will help ensure efficacy, safety and producer viability. This project has sought to contribute to that process for our own farm as we scale up our laying operation, and that of other growers.

Red Jungle Fowl are believed to be the species from which the modern chicken has descended. These jungle birds forage from the forest floor searching out bugs, fallen fruit, plant matter and seeds. Much of their diet is derived from the decomposer system. Biomimicry is the practice of attempting to replicate certain relationships and functions present in ecosystems in a constructed environment. In agriculture a wide variety of techniques have been developed and are under development to mitigate the impacts of disturbance by adopting systems that attempt to reflect native, or more ecological, systems.

The compost-based feeding system is an attempt to realize the nutritional value from food scraps, the fallen fruit of the food system, while also mimicking the biological system of the forest oor (a decomposer system) and creating a year-round pasture environment for hens to forage. By doing so, bacteria and other microorganisms pro- liferate. It is believed that these organisms likely constitute an important component of the birds’ diet, contributing protein and other nutrients, as is seen in other carion/ detritous-eating species. While the food scraps themselves provide feed for the hens, as fallen Oil Palm fruits do their ancestors, this food also becomes a medium for growing bacteria.

In the US the average individual disposes of roughly one pound of food each week. When averaged with disposal at businesses, industries and schools, communities typically dispose of roughly 500–750 pounds of food scraps per year per capita (based on statewide estimates for Vermont). Given these volumes a significant number

of hens could be fed, and a significant number of eggs could be produced, either entirely without, or with a fraction of, the grain required for a standard grain ration, thereby mitigating energy inputs in the food system and increasing producer margins. In efforts to develop regenerative food and farming systems with balanced and internalized energy equations, local economies with maximized community-based value creation and farm viability, this is an attractive proposition.

Vermont Compost Company (VCC), owned and operated by composting leader Karl Hammer, is a composting operation specializing in compost-based potting soils in Montpelier Vermont that has pioneered this practice in the US. They have been feeding hens on food scraps and selling eggs in the community for over 15 years. They began collecting food scraps from local restaurants and schools in 1998, eventually handing off their collection program to the Central Vermont Solid Waste Management District (CVSWMD). In 2016, CVSWMD delivered over 1100 tons of food scraps to VCC. VCC has fed its ock of between 600–1400 chickens—which has fluctuated somewhat over the years—with no purchased grain. The chickens produce eggs year-round, with augmented light in the winter, and have not displayed any signs of a lack of nutrition or disease.

As homesteaders we had also utilized this practice for over 10 years with success. Upon establishing Black Dirt Farm in 2014 we were eager to bring this model to scale, but had no data. Our desired flock size was 2,000 hens. We applied for a USDA SARE Farmer Grant to better understand the practice before of scaling up. The practice fits our operation for a variety of reasons. Black Dirt’s farm model is designed to increase value within the farm system through process integration that will mitigate input costs, such as hen feed or heat for the greenhouse, reducing pressure to increase revenues. By stacking functions and dovetailing value from one enterprise into the next, we aim to keep the scale of each enterprise as contained as possible, limiting the need for growth.

Our core enterprises follow the decomposer cycle, beginning off the farm when we collect food scraps. We currently collect roughly 200 containers per week from 60 entities, mostly within a 30-mile radius, but extending as much as 50 miles in some cases. We deliver roughly 15 tons a week to a partnering farm for making compost, and bring 7–10 tons to our own farm each week. Food scraps arrive at the farm at a net pro t and reduce our need for purchased feed, immediately lowering operating costs and the scale at which we must operate to be profitable. After food scraps have been blended into a compost mix and fed, they are removed from the hens for making compost. We are in the process of establishing an Aerated Static Pile system to harvest heat from the composting process to heat our 30’x100’ greenhouse and reduce labor. The composting process yields a preconditioned feed for worms, from which we make worm castings, and compost. Our farm sits at 1500’ on Stannard Mountain in the Northeast Kingdom of Vermont in a USDA Zone 3b climate, where we also undertake a variety of farm enterprises and homestead functions included in this project.

In general, small egg operations (less than 5,000 birds) are economically challenging given the high cost of feed within current production models. Feed costs can represent as much as 70% of total production costs and 30% of the retail value of the egg.   Communities everywhere generate substantial volumes of discarded food and food processing byproducts that may be cost-effective alternative feed sources, and these materials, when integrated into a composting system, may yield additional benefits.