Studies of the Energy Requirements of Chickens

Abstract

T HE energy requirement of growing chicks has been studied in two widely different ways. One method is illustrated by the studies of Mitchell, Card and Hamilton (1931) who estimated the net energy requirements for maintenance and growth from the determination of basal metabolic rate and changes in body composition. Data of this kind have been of limited usefulness because of the lack until relatively recently of net energy values for poultry feedstuffs.The other method was used by Robertson, Miller and Heuser (1948) and Panda and Combs (1950). They studied the relationship between productive (net) energy of the ration and early growth rate to determine the minimum energy level per unit weight of the ration necessary to promote the maximum rate of growth. Both of these groups concluded that the minimum productive energy level required for maximum early growth rate was approximately 800-850 Calories per pound of ration on the basis of the productive energy values of poultry feedstuffs as reported by Fraps (1946). The experiments to be described in this paper were undertaken to obtain further information on the minimum dietary energy level necessary for maximum early growth rate of chicks. EXPERIMENTAL PROCEDUREAll of the experiments to be described

Energy and lysine for broilers from 44 to 55 days of age

“…It is interesting to note that feed intake was not inversely proportional to the energy level of the diet, as opposed to Hill & Dansky (1950, 1954. Therefore, birds that were fed 3,400 kcal and 3,600 kcal ME.kg -1 had higher (p<0.05) energy intake when compared to those receiving 3,200 kcal ME.kg -1 .…”

Apparent Feed Particle Size Preference by Broilers

“…It has been suggested that chicks are capable ofregulating their feed intake according to energy level (Hill and Dansky 1954) although growth is adversely Can. J. Anim.…”

“…Sci. 682 923-930 (Sept. 1988) affected when low energy diets are used (Hill and Dansky 1954). Protein appetite is less well defined since broilers in a choice situation do not maintain their protein intake (Cowan and Michie 1977).…”

The Effect of Dietary Energy on the Protein Requirements of Growing Turkeys

“…The addition of energy to this ration improved both growth and efficiency of conversion. Hill and Dansky (1954) concluded that feed consumption was determined primarily by the energy level of the diet. Biely and March (1954) indicated that the addition of energy, in the form of added fat, may be advantageous in both chick and poult rations when relatively high levels of protein are fed.…”