title: The effect of environmental temperature and body weight on growth rate and feed:gain of male broilers.
abstract: High environmental temperatures are detrimental to the growth and feed:gain of broilers. The objective of this research was to determine the effects of incremental differences in environmental temperature on growth and feed:gain. The data are needed for decisions about the profitability of energy inputs when managing the housing environment. In Trial 1, broiler chicks were reared as a group to 21 d on litter with constant lighting and with water and feed available for ad libitum consumption. They were then moved to 10 environmental chambers. Each chamber was set at a different temperature ranging from 21.1 C to 31.1 C in 1.11 C increments. Weight gain and feed:gain were determined when the broilers were 28, 35, and 42 d old. In Trials 2 and 3, broilers were placed in the environmental chambers, and weight gain and feed:gain were determined for the 42 to 49 d period. The data were analyzed statistically, and regression equations were obtained for growth and feed:gain. Equations were based on body weight and temperature, and the body weight equation was plotted as grams gain per bird per day. Feed:gain was plotted for that body weight and temperature. Body weight gain per day increased to a maximum with increasing weight and then declined. The body weight at the maximum rate of gain was inversely related to temperature. Feed:gain increased as body weight increased. Feed:gain was directly related to temperature at weights above 800 g and the effect of temperature increased as body weight increased. The data will be useful for the evaluation of various management scenarios to determine the inputs that are profitable.
authors.affiliation: USDA, Agricultural Research Service, South Central Poultry Research Laboratory, Mississippi State, Mississippi 39762-5367, USA. DMAY@AG.GOV
authors.forename: J D
authors.initials: JD
authors.lastname: May
authors.forename: B D
authors.initials: BD
authors.lastname: Lott
authors.forename: J D
authors.initials: JD
authors.lastname: Simmons
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000821:Animal Feed; D000818:Animals; D002645:Chickens / Q000254:growth & development*; D015331:Cohort Studies; D004435:Eating / Q000502:physiology*; D008297:Male; D013696:Temperature; D015430:Weight Gain / Q000502:physiology*