Effect of Diet on Efficiency of Egg Production

Thyroprotein and Fat in Laying Diets

“…The price of crude tallow at this writing is 6ff per pound and that of soybean oil is 10.5 ff per pound. The validity of a ratio at least as great as * Bird and Whitson (1946). 2| is supported by the results of these experiments. According to this ratio a diet with 8 percent of added fat replacing an equal quantity of corn would be approximately 11 percent more efficient than the counterpart group without added fat.…”

“…The feed efficiency index was expressed in terms of a modification of the formula of Byerly (1941), as reported by Bird and Whitson (1946).…”

The Effect of Dietary Fat, Caloric Intake and Protein Level on Caged Layers

“…production compared to similar rations of high fiber content. Bird and Whitson (1946) have shown that the productive efficiency of laying rations was related inversely to fiber content. Following the work of Scott et al (1947) it was demonstrated that high energy rations tended to promote more rapid growth and better feed conversion in broilers.…”

Studies of the Energy Requirements of Chickens

“…Heuser and coworkers (1945) were among the first to show that rations low in fiber content supported a higher rate of egg production than similar rations high in fiber content. Bird and Whitson (1946) studied layer rations of high and low fiber content with respect to productive efficiency and showed that efficiency was related inversely to fiber content. They were the first to use the Byerly (1941) partition équation to calculate expected feed requirement as a basis for estimating the relative efficiency of rations.…”