The Effect of Different Dietary Protein Levels on Laying Hens

Many studies have been conducted on hens' protein requirements. These include amounts of protein, types of protein, ratio to other feed ingredients and the age of the hen when the diet was instituted. Factors considered are amount of egg production, quality of the eggs, age at which egg production began, and effect on the health of the hen.

  1. Effect on the Health of the Hens

    • Laying hens use protein for growth, egg production and energy. This affects their weight along with other factors. When a hen's oviduct does not retract after egg laying it is called prolapse. Overweight, underweight and insufficient calcium can be factors in causing prolapse. Adjusting the feed balance and restricting the feed intake are two suggested methods for preventing prolapse. Other diet-related health concerns are soft shells and weak bones.

    Effect on the Growth of the Hen

    • Young hens need protein to grow.

      A study published by J. D. Summers and S. Leeson of the Department of Animal and Poultry Science, University of Guelph, Ontario, Canada indicated that pullets fed between 17 percent and 20 percent protein had higher body weight at 16 weeks, and subsequently laid larger eggs, than pullets fed 11 percent to 17 percent protein in their diet.

    Effect on Egg Production

    • Protein levels can affect the size of eggs.

      O. C. Onwudike conducted research at the Department of Animal Science, University of Nigeria, which determined that a protein level of 18 percent was optimal to egg production, egg weight and feed efficiency in a tropical environment. This is consistent with other findings worldwide. Lower levels reduced egg production. Higher levels reduced feed efficiency.

    Effect on Egg Quality

    • Triticale can affect the yolk color.

      In studies that compared triticale-barley-soybean and triticale-barley-corn-soybean mixtures to a control diet of corn-soybean, triticale, which is a high protein grain, had little effect except that the egg yolks appeared paler. When chickens are fed protein that contains all the needed amino acids, the protein level in the diet does not have a great effect upon egg quality. Supplements, and the type of protein fed, had a greater effect.

    Effects of Different Proteins

    • The type of protein, and the level of different types of protein, are also a factor. This can be species specific. Research published by A. K. Ward, H. L. Classen and F. C. Buchanan of the Department of Animal and Poultry Science, University of Saskatchewan, Canada, determined that when hens who produce brown shelled eggs are fed canola meal at levels from 12 percent to 24 percent, the eggs have a fishy taint caused by an accumulation of trimethylamine (TMA) in the yolk. This is recessively inherited and caused because these hens cannot process TMA into the nonodorous TMA N-oxide.

    Effects of Supplements on Protein Balance and Diets

    • Chickens require more than just a balanced protein level. They require other supplements as well. New supplements are being tested to maximize hen performance. In a study at the University of Saskatchewan, Canada, A. L. Hughes, J. P. Dahiya, C. L. Wyatt and H. L. Classen determined that supplementing a corn and soybean-meal diet with E. coli 6-phytase (Quantum), can be used to reduce the hen's need for inorganic phosphorous. Another study determined that supplementing a low protein diet with essential amino acids did not compromise the hens' performance as compared to a control group.