Responses of broilers at moderate or high temperatures to dietary arginine:lysine ratio and source of supplemental methionine activity

Abstract

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-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 28-33 days and 38-43 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 BWG 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. A R 0 2 1 1 7 R e s p o n s e o f b r o i l e r s t o a r g : l y s r a t i o J . C h e n e t a l .Additional keywords: feed intake, bodyweight gain, DL-methionine, 2-hydroxy-4-(methylthio) butanoic acid, Alimet, acute heat stress. Australian Journal of Agricultural ResearchJ. Chen et al.

Effects of methionine source, arginine: lysine ratio and sodium chloride level in the diets of grower broilers reared under high-temperature conditions

“…Similarly, the Arg:Lys ratio of 1.05 improved (p<0.05) broiler weight gain and feed conversion. Consistent results were reported in other studies, where an increase in Arg:Lys ratio improved the performance of broilers reared under high environmental temperatures (Brake et al, 1998;Balnave & Brake, 2001;Costa et al, 2001;Chen et al, 2003;Chen et al, 2005). No interaction was detected between tested factors (p>0.05) for live performance parameters.…”

“…Balnave et al (1999) observed a progressive decline in weight gain when broilers received DLM in their diet and when the Arg:Lys ratio increased from 1.03 to 1.34. Chen et al (2003) also evaluated the interaction between Met sources and Arg:Lys ratios in diets with DLM and HMTBA and observed an increase in weight gain when broilers were kept under of heat stress conditions with increasing Arg:Lys ratios (1.04-1.19 to 1.35), in the presence of HMTBA, but not of DLM. Balnave & Brake (2004), in a review on the effects of environmental temperature and dietary composition on the effectiveness of DLM and HMTBA, concluded that, in diets with low Arg:Lys ratio (1.05) and high NaCl levels, supplementation with DLM was more effective, while in diets with high Arg:Lys ratio (1.35) and low NaCl levels, performance was better when the diet was supplemented with HMTBA.…”

Effect of Methionine Source and Dietary Crude Protein Level on Growth Performance, Carcass Traits and Nutrient Retention in Chinese Color-feathered Chicks

“…Derick et al (1999) found that favorable growth responses to HMTBa were evident at higher Arg:Lys ratios (i.e., 1.20 and 1.34), whereas the growth response to DLM was optimized at a lower dietary Arg:Lys ratio (i.e., 1.03). In the experiment of Chen et al (2003), broilers exhibited increased BW gain with increasing Arg:Lys ratio from 1.04 to 1.35 in the presence of HMTBa but not DLM during acute heat stress. The Arg:Lys ratio may become a critical factor that limits growth and may obscure the difference between methionine sources at low dietary CP level.…”