Studies of the Energy Requirements of Chickens

Abstract

S TUDIES of the effects of différent dietary energy levels in the nutrition of laying hens hâve been limited. 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. Using a similar procédure, Lillie and coworkers (1952) observed a marked improvement in the efficiency of egg production from the use of lard. Singsen, Matterson and Kozeff (1952) and Gerry (1954) hâve reported higher efficiency, measured as feed requirement per dozen eggs produced, with rations high in energy value as compared with low energy rations.The studies to be reported were undertaken to détermine the quantitative relationships of dietary energy level to rate and efficiency of egg production, using various grains and grain products and inedible animal fat to formulate rations containing widely différent energy levels.

Influence of feed form and energy concentration of the rearing phase diets on productivity, digestive tract development and body measurements of brown-egg laying hens fed diets varying in energy concentration from 17 to 46 wk of age

“…The decrease in ADFI observed in hens fed the high energy diet was expected because poultry eat to satisfy their energy requirements, provided that the capacity of the GIT is not compromised (Hill et al, 1956;Leeson et al, 1997). Egg production and egg size were not affected by the energy content of the diet, consistent with data of Grobas et al (1999b) in brown hens Fig.…”

Influence of feed form and nutritional characteristics of the diets on pullet performance and egg-laying hen productivity

“…The decrease in ADFI observed in hens fed the high energy diet was expected because poultry eat to satisfy their energy requirements, provided that the capacity of the GIT is not compromised (Hill et al, 1956;Leeson et al, 1997). Egg production and egg size were not affected by the energy content of the laying diet, consistent with data of Grobas et al (1999b) in brown hens fed diets varying in AME n from 2,680 to 2,810 kcal.…”

“…The decrease in ADFI observed in pullets and hens fed the high energy diet was expected because birds regulate voluntary FI to satisfy their energy requirements. Consequently, ADFI decreased and FCR improved as the energy concentration of the diet increased (Hill et al, 1956;Leeson et al, 1997).…”

“…Birds eat to satisfy their energy requirements and therefore, voluntary FI will decrease as the energy content of the diet increases (Hill et al, 1956;Leeson et al, 1996;Veldkamp et al, 2005). However, the adjustment to regulate FI with changes in energy concentration of the diet is not perfect and pullets tend to over consume energy when fed crumbles or high energy diets (Frikha et al, 2009b;Serrano et al, 2012;Guzmán et al, 2015a).…”

Effects of Lowering the Dietary Levels of Energy, Protein and Amino Acid (Methionine and Cysteine) on the Performance of Laying Hens

“…Feed intake is higher in low energy diet and lower in high energy diet. Hens fed with 1,848 kcal productive energy consumed 9.7% more feed than the hens provided with 2,046 kcal productive energy per kg of feed (Hill et al, 1956), increased in energy from 2,680 kcal to 2,810 kcal of ME/kg, and decreased the feed intake by 4% (Grobas et al, 1999). Similarly, Harms et al (2000) concluded that the hens fed with 2,519 kcal of ME/kg consumed 8.5% more feed than the hens fed with 2,798 kcal of ME/kg diet, and hens fed with 3,078 kcal of ME/kg diet consumed 3% less feed compared to the hens fed with 2,798 kcal of ME/kg diet.…”