Impact of Methionine Sources on Performance in Turkeys

SUMMARY Data are scarce for relative effectiveness of the liquid hydroxy analogue of Met (MHA-FA) relative to DL-Met (DLM) in turkeys. In the current paper, 2 experiments are presented in order to determine the relative effectiveness of liquid MHA-FA. In trial 1, female 1-d-old Hybrid Converter turkeys were fed 13 different corn-soy diets supplemented with graded levels of DLM, diluted DLM (65%), or liquid MHA-FA (0.07, 0.14, 0.21, 0.28%) from d 7 to 50. DLM (65%) treatments can be regarded as an internal standard for the validation of exponential regression analysis. In trial 2, male 1-d-old BUTA Big 6 turkeys were assigned to 63 battery cages for 21 d. Treatments consisted of a basal corn-soy diet and 2 series each containing graded levels of either DLM (0.100, 0.200, 0.300%) or liquid MHA-FA (0.154, 0.308, 0.462%). The ratio between both products at the 3 corresponding inclusion levels was 65% weight/weight. In both trials, basal diets were formulated to be deficient in Met + Cys but adequate in all other nutrients and energy. Exponential regression analysis revealed a relative effectiveness for weight gain and feed conversion of liquid MHA-FA of 68 and 56% vs. DLM in trial 1, respectively, and of 66 and 44% in trial 2, respectively. These findings support the hypothesis of a relative bioeffectiveness of approximately 65% of liquid MHAFA as compared with DLM.