PSIII-6 Effects of L-Carnitine Supplemented Throughout Grow-Finish or Only in Late Finishing on Growth Performance and Carcass Characteristics of Pigs

Abstract L-Carnitine is a feed additive involved in the transport of fatty acids into the mitochondria to produce energy. With this mechanism, L-Carnitine can enhance the ability to use fat for energy. The objective of this study was to determine the effects of adding L-Carnitine throughout the entire grow-finishing period or just 28 d before marketing on growth performance and carcass characteristics. A total of 1,833 mixed-sex growing-finishing pigs (PIC 337 × 1050; initially 26.5 ± 0.33 kg) were used in a 112-d growth trial to determine the effects of adding L-Carnitine throughout the entire grow-finishing period or just the last 28 d before marketing. There were 26 replicate pens per treatment and 20 (group 1) or 27 (group 2) pigs per pen in a completely randomized design. There were three treatment diets: 1) control with no added L-Carnitine; 2) diets containing 50 ppm of L-Carnitine for the entire trial; or 3) control diet until d 84 and then a diet containing 50 ppm of L-Carnitine. On day 84, one-half of the control pens were randomly assigned to the diet containing 50 ppm of L-Carnitine. The experimental diets were corn-soybean meal-DDGS-based and were fed in 4 phases. From d 0 to 84, statistical analyses compared the 52 pens of pigs fed the control diets with the 26 pens of pigs that were fed diets with L-Carnitine. From d 85 until market, comparisons were made using all 3 treatments. In the first 28 d, pigs fed L-Carnitine had greater (P < 0.002) BW, ADG, and ADFI and similar G:F (P = 0.459) as those fed the control diet (Table 1). From d 0 to 84, pigs fed L-Carnitine had a tendency (P = 0.052) for greater ADFI, but there was no evidence (P > 0.14) of differences for ADG, G:F, removals, and mortalities. From d 85 to market and overall, there was no evidence of differences (P > 0.22) for ADG, ADFI, G:F, or removals and mortalities. For carcass traits, no difference (P > 0.54) in HCW, yield, backfat, lean, and loin depth were detected between treatments. In conclusion, added L-Carnitine improved performance in the early grow-finishing phase compared with control. However, this effect was not detectable at market, with no impact on overall growth performance, removals and mortalities, or carcass characteristics when added for the entire grow-finishing period or just the 28 d before marketing.