Interactive Effects of Kemtrace Cr and Micro-Aid on Finishing Pig Growth Performance and Carcass Characteristics

A study was conducted to determine the interactive effects of Cr (KemTRACE Chromium propionate, Kemin Industries Inc., Des Moines, IA) and Micro-Aid (Yucca schidigera-based product supplied by Distributors Processing Inc., Porterville, Ca) on growth carcass performance of finishing pigs housed in a commercial environment. There were 1,188 pigs (PIC 337×1050; initial BW=27.3 kg) with 27 pigs/pen and 11 pens/treatment. Pigs were split by gender upon arrival at the facility, with 5 blocks of each gender and a final mixed gender block. Gender blocks were randomly allotted to groups of 4 pen locations within the barn. Block was included in the statistical model as a random effect and accounted for gender, initial BW, and barn location. Diets were corn-soybean meal-dried distillers grains with solubles-based and were fed in 5 phases. Diets were formulated to meet or exceed NRC (2012) requirement estimates. Treatments were arranged as a 2×2 factorial with main effects of Cr (0 or 200 µg/kg) or Micro-Aid (0 or 62.5 mg/kg). No Cr × Micro-Aid interactions were observed. Overall, ADG and G:F were not influenced by treatment. Adding Micro-Aid tended to increase (P=0.077) and adding Cr increased (P=0.049) ADFI. For carcass characteristics, HCW, loin depth, and carcass yield percentage were not influenced by treatment. Backfat depth tended to increase (P=0.055) and lean percentage was decreased (P=0.014) when Cr was included in the diets. In summary, no synergistic effects were observed from feeding Cr and Micro-Aid in diets fed to finishing pigs housed in a commercial environment. Only marginal differences in ADFI were observed from adding either Cr or Micro-Aid. Finally, diets containing Cr were associated with carcasses having more backfat and less lean.

Table 1. Interactive effects of Cr and Micro-Aid on finishing pig growth and carcass performance.
Added Cr, µg/kg	0	200	0	200	Probability, P<
Micro-Aid, mg/kg	0	0	62.5	62.5	Cr	Micro-Aid
ADG, kg	0.87	0.87	0.87	0.88	0.446	0.490
ADFI, kg	2.22	2.26	2.26	2.30	0.049	0.077
G:F	0.39	0.39	0.39	0.38	0.115	0.178
BF, mm	16.97	17.69	17.26	17.54	0.055	0.787
Lean, %	56.89	55.92	56.83	56.54	0.014	0.261
Yield, %	74.51	75.23	75.27	75.44	0.302	0.254
SEM=ADG (0.009), ADFI(0.047), G:F(0.006), BF(0.639), lean%(0.408), and yield%(0.456)