Each year, the American poultry industry produces roughly nine billion chickens for meat that is sold in markets in the U.S. and around the world. In 2010, the USDA reported that the total live weight of chicken processed in the U.S. was 49.3 billion pounds.
Feathers, the largest byproduct generated in the poultry industry, account for roughly 7 percent of the total live weight. This means, in 2010, the broiler industry generated roughly 3.5 billion pounds of feathers. Not included in this number is the volume of feathers generated from the turkey and egg industries.
There is a common misconception that feathers generated at a poultry processing facility are a waste product with little or no value and they end up being disposed of in a landfill.
This is far from true. Poultry feathers are made of keratin, a protein fiber similar to hair and wool. In their natural state, protein within the feathers cannot be utilized as a source of dietary protein.
However, when subjected to a series of processes that consists of cooking under pressure with steam, drying and grinding, poultry feathers are transformed into a dietary supplement with substantial value.
This process produces roughly 1.2 billion pounds of feather meal each year and has been shown to be a source of high-quality protein for ruminant and non-ruminant animals.
Realizing feather meal was not fully utilized as a protein source for dairy and beef cattle due to the lack of information regarding its nutrient content, in 2004 the U. S. Poultry & Egg Association (USPOULTRY) and the William H. Miner Agriculture Research Institute (Miner Institute) partnered to carry out a research study to develop nutrient profiles of feather meal produced in the U.S. and incorporate the nutrient composition profiles into the CPM Dairy 3.0® feed dictionary. Eighteen separate processing plants provided feather meal samples.
Feather meal samples that had been processed with and without the inclusion of poultry blood were collected from each processing plant on a daily basis for three consecutive weeks. The inclusion of poultry blood within the sample collected was recorded accordingly.
A portion of each daily sample was analyzed for dry matter, crude protein, fat and ash. The remaining portion of each daily sample was used to create a five-day (weekly) composite sample. Weekly samples were analyzed for the complete Cornell Net Carbohydrate and Protein System nutrient profile.
This includes dry matter, crude protein, soluble protein, insoluble crude protein, fat, ash, sugar, non-structural carbohydrates, total digestible nutrients, net energy lactation, net energy maintenance, net energy growth, metabolized energy, digestible energy, calcium, phosphorus, magnesium, potassium sodium, iron, zinc, copper, manganese, molybdenum, sulfur and chloride. Amino acid analyses were conducted on the crude protein as well.
The study found the crude protein levels were 87.8 percent and 87.7 percent for feather meal with no blood and with blood, respectively. When comparing amino acid profiles, the study showed feather meal with blood had higher levels of aspartate, alanine, methionine, leucine, tyrosine, phenylalanine, histidine and lysine, while feather meal without blood added had higher levels of serine, proline, glycine, arginine and tryptophan.
The study explains that the difference in the amino acid profiles become significant when you consider the dietary needs of the animal being fed. As an example, the study points out that feather meal with blood would be better suited for a dairy cow as their diets often lack adequate levels of methionine, lysine and histidine.
Following the study characterizing the nutrient profile of feather meal, USPOULTRY and the Miner Institute collaborated on a second research project to determine the ruminal and intestinal digestibility of protein and amino acids for feather meal.
Previous studies have shown the intestinal digestibility of feather meal to vary between 8.5 and 33.2 percent. Researchers used a three-step in vitro procedure to measure the ruminal and intestinal protein and amino acid digestibility of feather meal. This process closely simulates the physiological conditions of digestion in cattle.
Thirteen samples collected during the initial research study were selected for analysis. Seven samples consisted of feather meal with blood added during the production process, while six samples did not include the addition of blood.
The results of the in vitro digestibility study showed total nitrogen digestibility ranged from 66.6 percent to 57.6 percent. The variation in digestibility depended on whether blood had been added to feather meal during the manufacturing process.
Results indicated total nitrogen digestion was highest in feather meal with blood added after the hydrolysation (pressure cooking) process and the lowest where no blood was added to the feather meal. The values determined in the study are much higher than the previously reported values of 8.5 to 33.2 percent.
In situ ruminal digestion of feather meal was determined by placing bags containing five-gram samples of feather meal in the rumen of lactating cows. The results of this aspect of the study showed the mean nitrogen digestibility of the feather meal samples varied from 72.2 percent to 76 percent.
Although digestion of individual amino acids varied, the highest digestion occurred in feather meal with the greatest total nitrogen degradation. Researchers explained the study showed protein/amino acids in feather meal do not differ in their rumen solubility, which allows greater confidence in predicting the specific amino acid profile that reaches the small intestine of cattle.
The nutritional details gained from these studies provide information to assist dairy nutritionists with the formulation diets for dairy cattle. Reports from both research projects can be downloaded free of charge from the Poultry Protein & Fat Council website. PD
Paul Bredwellis withU.S. Poultry and Egg Association. Email Paul Bredwell.