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Effect of corn germ meal inclusion level on the growth performance and carcass characteristics of wean-to-finish pigs
The effect of corn germ meal (CGM) inclusion level on the growth performance and carcass characteristics of pigs reared under commercial conditions was evaluated with 2 studies. Both studies used RCBD with 2 CGM inclusion levels: 0 and 20%, and 0 and 25% for Study 1 and 2, respectively. A total of 952 (14 replicates) and 680 (10 replicates) barrows and gilts were used in Study 1 and 2, respectively, housed in mixed-sex groups of 34 pigs in Study 1, and single-sex groups of 34 pigs in Study 2. The studies were carried out from weaning (6.4 ± 0.57 and 6.6 ± 0.53 kg BW for Study 1 and 2, respectively) to a final BW of 133.3 ± 1.62 and 127.1 ± 1.71 kg, respectively. An 8-phase dietary program was used with diets formulated to the same SID-lysine to calorie (ME) ratio within each phase and to meet or exceed nutrient requirements proposed by NRC (2012). Calculated NDF levels, averaged across all phases, were 6.91 and 12.47% for 0% and 20% CGM diets, respectively, in Study 1 and 7.98 and 13.48% for 0 and 25% CGM diets, respectively, in Study 2. Pigs had ad libitum access to feed and water. At the end of each study, pigs were harvested at a commercial facility and standard carcass grading measurements were collected. The pen of pigs was the experimental unit for all measurements; data were analyzed using PROC MIXED of SAS with the model accounting for the effects of CGM level, block, and replicate. For both studies, there was no effect (P >0.05) of CGM inclusion level in the diet on overall ADG and ADFI. There was no effect of CGM on G:F in Study 1; however, in Study 2 G:F was decreased (P <0.05) for pigs fed diets with 25% compared to 0% CGM (0.414 vs. 0.428 kg:kg, respectively). Carcass yield was reduced (P <0.05) by feeding CGM (0.7 and 1.6% units in Study 1 and 2, respectively), which resulted in reductions in overall average daily carcass weight gain (2.4 and 4.7% lower in Study 1 and 2, respectively), and overall carcass weight G:F (2.3 and 6.2% for Study 1 and 2, respectively). The results of these studies suggest that inclusion levels of CGM of 20 and 25% in diets for wean-to-finish pigs reduces carcass yield and has a negative effect on growth rate and feed efficiency when measured on a carcass weight basis.
Keywords: Corn Germ Meal, Pigs, Carcass