Performance of Commercial Laying Hens Fed Diets with Various Levels of Methionine

Two experiments were conducted to evaluate the Met requirement of Hy-Line W36 laying hens. In experiment 1 the temperature decreased to 26.7°C at night and reached 29.4°C during the day. In experiment 2 the temperature reached 29.4°C during the day and was not allowed to go below 28.6°C at night. Tunnel ventilation with no evaporative cooling was used in both houses. The Met requirement for egg production was obtained with 260.2 ± 4.0 and 239.4 ± 8.0 mg/d for 47.17 and 37.86 g egg content, for hens in experiments 1 and 2, respectively. There was a quadratic response for increased Met in both experiments. Maximum energy consumption was 271 and 225 kcal/d for hens in experiments 1 and 2, respectively. It is suggested that the lack of energy consumption was the cause of the low EP in experiment 2. The Met content greater than 0.30% in the diet in experiment 2 resulted in a decrease of 2.4% in egg production, 0.3 g in egg weight, and 1.6 g in egg content. This finding indicated that methionine was not the factor limiting performance.