Influence of Low Proteins Fed to Laying Hens

Importance of Protein

• Laying hens and the eggs they produce are largely composed of protein. This essential nutrient provides the building blocks for the formation of animal tissue through amino acids. The simple act of laying an egg depletes the chicken of necessary protein that must be replaced through the diet. Commercially prepared laying rations feature a range of 14 to 17 percent protein.

  There appears to be a slight window for the reduction of protein in the diet of laying hens. A study by Hank Classen from the University of Saskatchewan in 1999 revealed that hens can be reduced to a 14 percent crude protein diet without significant production loss, according to a Manitoba Agriculture, Food and Rural Initiatives report.

Production Rates

• The reduction of protein for laying hens negatively impacts the egg production rate of the flock. A study on the "Further Evaluation of Nonfeed Removal Methods for Molting Programs" by the University of Illinois, published in Poultry Science in 2004, looked at the results of forced molting methods for laying hens. Forced molting is the practice of forcing a hen into a molting period by the removal of feed or protein. The removal or reduction of protein from the diet of laying hens significantly reduced the number of eggs laid. After return to a 16 percent crude protein diet, chickens that had lost little body weight quickly resumed their previous laying rates. The layers that lost significant weight throughout the study took longer to recover to a pre-study laying rate.

  Additional research by the department of animal and poultry sciences at Virginia Tech, published in Zootecnica in 2008, indicates that lowering crude protein 2 to 3 percentage points below recommended levels will result in production loss and hen weight loss. Despite the supplementation of amino acids, low protein levels led to lower egg production.

Quality of Eggs

• The quality of eggs often deteriorates as the protein levels provided for laying hens are decreased. A study conducted on the effects of ambient temperature and methionine, a key amino acid in protein formation, supplementation of a low-protein diet on the performance of laying hens by the department of animal science at the National Chung-Hsing University in Taiwan, published in the Animal Feed Science and Technology journal in 1998, concluded that laying hens on a low-protein diet produced the same number of eggs as hens on a high-protein diet. However, the low protein diet hens laid eggs that were significantly lighter in higher ambient temperature situations (or hotter weather conditions). The addition of a methionine supplement did not mitigate the damage created by lower protein levels.

Animal Well-Being

• Low-protein diets are generally known to cause a reduction in feed intake by laying hens. Through the reduction of feed, there is a reduction of egg production, egg weight and hen body weight. The study conducted by Virginia Tech and published by Zootecnica in 2008 concludes that hens fed a low- protein diet showed a reduction in feed consumption, a negative body weight gain for the tested animals and a lower production and egg weight. The decreased egg production and weights were suggested to be caused by nutrients being shunted from the eggs in order to meet the needs of the animal.

  According to an article in the World's Poultry Science Journal in 2005, severe feather pecking in laying hens is exhibited by hens on a low-protein diet. University of Kentucky Cooperative Extension Service fact sheets show that an omission of protein from the diet can result in flock nervousness, increased mortality, cannibalism, poor egg albumen quality and feather eating.

Calculating the Protein

• The misappropriation of protein levels is often found in a small laying flock when a producer decided to provide a self-mixed ration to the layers. According to a 1995 University of Minnesota Extension fact sheet for horse rations, it is simple to calculate the amount of protein in a mixed ration. First, identify the protein level of the grain. Multiply how many parts by the amount of protein for each grain. Add all of the protein levels, then divide by the total number of parts. For example, a mix is comprised of 3 parts wheat, 1 part corn and 1 part oats. The wheat has a protein level of 12.5 percent. Multiply by 3 for a total of 37.5. Corn has a protein level of 9 percent, and oats has a level of 12 percent. The total added percentage is 58.5 percent. Divide by 5 for a total of 11.7 percent protein for the mix. Additional protein concentrate may be needed to meet the recommended protein requirements for laying hens.