
%0 Journal Article
%A Chen, J. 
%A Hayat, J. 
%A Huang, B. 
%A Balnave, D. 
%A Brake, J. 
%T Responses of broilers at moderate or high temperatures to dietary arginine:lysine ratio and source of supplemental methionine activity
%J Australian Journal of Agricultural Research
%D 2003/02/28
%V 54
%N 2
%P 177-181
%K Keywords: feed intake, bodyweight gain, DL-methionine, 2-hydroxy&#8211;4-(methylthio) butanoic acid, Alimet, acute heat stress.
%R https://doi.org/10.1071/AR02117
%U https://www.publish.csiro.au/paper/AR02117 
%X Recent studies have shown that the relative feed intake (FI) and bodyweight gain (BWG) responses of chronically heat-stressed broilers to equimolar additions of DL-methionine (DLM) or 2-hydroxy&#8211;4-(methylthio) butanoic acid (HMB; Alimet) can be altered by changing the arginine:lysine (arg:lys) ratio of the diet. However, no information is available concerning responses of broilers during acute heat stress. Broilers were exposed to either 22°C or 30°C during 3 consecutive 5-day experimental periods between 28 and 43 days of age. Responses to equimolar additions of the 2 sources of supplemental methionine activity were similar during exposure to 22°C at 28&#8211;33 days and 38&#8211;43 days of age. However, between 33 and 38 days of age, when the temperature was 30°C, increasing the dietary arg:lys ratio from 1.04 to 1.35 significantly improved the FI and BWG of broilers fed HMB, but not DLM. At an arg:lys ratio of 1.35, the BW gain of broilers fed HMB was significantly greater than that of broilers fed DLM. Therefore, under acute heat stress conditions the choice of a supplemental source of methionine activity should be dependent upon the dietary arg:lys ratio. 
