Submitted to: Journal of Applied Poultry Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/15/2003
Publication Date: 12/5/2003
Citation: Kidd, M.T., Barber, S.J., Zumwalt, C.D., Branton, S.L., Hoehler, D. 2003. Dietary amino acid and sodium bicarbonate responses in broilers reared in hot environmental temperatures. Journal of Applied Poultry Research. 12:145-152. Interpretive Summary: The cost of feed constitutes approximately 70 percent of the total costs of poultry production and much of these costs are tremendously impacted by environmental conditions. The increased utilization of tunnel-ventilated houses has resulted in the occurrence of less fluctuation in chicken house environmental temperatures. While much of the feed research conducted over the past 25 years has focused on dietary needs and requirements in hot temperatures, research addressing the dietary needs of chickens in more moderate temperatures, such as those seen in tunnel ventilated houses, is lacking. Although fewer differing feed formulations are being used for growing chickens in tunnel-ventilated houses, still just a one-percent improvement in feed conversion would save producers more than $50,000,000 annually. The purpose of this study was to evaluate the performance of chickens raised in either high or moderate temperature conditions and fed diets containing higher levels of specific essential amino acids and added sodium bicarbonate. Results of this study show that dietary treatments had minimal impact on growth performance of the chickens as well as on the amount of breast meat produced. However, chickens fed diets containing lower levels of crude protein experienced less mortality in the hotter temperature environments.
Technical Abstract: Better environmentally-controlled broiler houses have resulted in many integrated broiler operations using the same dietary feed formulations in winter and summer months due to only minor differences in environmental temperature in the broiler house. Much research has addressed broiler nutrient needs in thermoneutral versus hot temperature conditions, but research evaluating nutrient needs of broilers during moderate temperature conditions (tunnel-ventilated houses during summer months) is lacking. This study evaluates the impact of increasing dietary Lys and other essential amino acids, and the addition of dietary sodium bicarbonate in high and moderate temperature conditions. Experiment 1 was conducted in batteries and evaluated broiler nutritional responses (days 20 to 40) in hot-cyclic temperature conditions (26 to 34 C). Experiment 2 was conducted in floor pens and evaluated broiler nutritional responses (Days 37 to 49) in environmental temperature ranges that mimic a tunnel-ventilated broiler house during summer months (26 to 31 C). In both experiments, dietary treatments had minimal impact on live performance and breast meat yield. Lower mortality (P < 0.006), however, was observed in broilers fed the low crude protein diet in the hot temperature environment.