147 Growth Performance of Nursery Pigs Fed Diets Supplemented with Dl-Methionine and Dl-2 Hydroxy-4-Methylthio-Butyrate Acid at a Ratio of 65:100

Abstract

Abstract The objective of the study was to determine if pigs fed diets containing eighter DL-2 hydroxy-4-methylthio-butyrate calcium salt (HMTBCa) or DL-methionine (DLM) at 65% of the HMTBCa amount have equal growth performance. A total of 1,296 nursery pigs (initial BW = 5.02 ± 0.2 kg, PIC 1050 x PIC 359) were evaluated for 49 d and allotted in groups of 27 pigs per pen. Diets were corn-soybean meal based and fed in 4 phases (5.54, 5.27, 5.18, and 4.80 g standardized ileal digestible [SID] Lys/Kcal NE for phases 1, 2, 3, and 4, respectively). Pens were assigned to 1 of 3 dietary treatments (16 pens/treatment). For each phase, a basal diet without supplementation of Met sources was formulated to achieve 70% of the optimal SID Met +Cys:Lys [Met-deficient], diet 2 consisted in the Met-deficient diet plus supplementation of HMTBCa to achieve 100% of the SID Met +Cys:Lys based on 84 % active substance of the product [HMTBCa], and diet 3 was the Met-deficient diet plus supplementation of DLM at 65% of the amount of HMTBCa used in diet 2 [65DLM]. Feed analyses confirmed that the amount of DLM to HMTBCa achieved was 66%. Pig performance data were analyzed using the PROC MIXED of SAS. Results are shown in Table 1. For the overall period (d 0 to 49), pigs fed the Met-deficient diet had decreased final BW, ADG, and G:F compared with pigs fed HMTBCa and 65DLM diets. Pigs fed HMTBCa and 65DLM diets did not differ in final BW, ADG, and G:F. No differences in ADFI and mortality were observed among treatments. Replacing 100 parts of HMTBCa with 65 parts of DLM on a product basis can be an alternative approach to determine the bioavailability of HMTBA compared with DLM.