Impact of hydrolyzed feather meal on odorous compounds in swine feces

North Carolina State University Swine Nutrient Management Research from 2002. A total of 120 pigs (BW=23.2 kg) were used to determine the impact of hydrolyzed feather meal on odorous compounds in fresh swine feces. Pigs were blocked by weight and randomly allotted, within block, to three dietary treatments (5 pigs/pen, 8 pens/treatment). Treatments consisted of corn-soybean meal-poultry fat basal diets containing 0, 4, or 8% hydrolyzed feather meal. Diets were fed in four phases (4 wk each) and were formulated to contain 1.00, 0.90, 0.75, and 0.60 apparent ileal digestible lysine for phase 1 to 4, respectively, with other amino acids provided at an ideal ratio. Available P and ME were kept constant within each phase. On wk 9 of the trial (phase 3 diets; contained 19.4, 18.9, and 21.6% CP for the 0, 4, and 8% feather meal treatments, respectively), fecal samples were obtained from at least 2 pigs per pen, pooled by pen, and analyzed for odorous compounds. Butanoic acid (19.7, 32.1, 39.6 ppm) and pentanoic acid (6.1, 8.0, 14.3 ppm) concentrations were greater (P < 0.05) in feces from pigs fed 8% feather meal compared to control pigs. The concentration of 3-methylbutanoic acid (1.6, 1.6, 4.0 ppm) was greater (P < 0.05) in feces from pigs fed 8% feather meal than feces from pigs fed 0 or 4% feather meal. Inclusion of 4% feather meal reduced (P < 0.05) the concentration of 3-methylphenol (7.6, 1.0, 2.9 ppm) compared to pigs fed control diets and inclusion of 8% feather meal reduced (P < 0.05) the concentration of 4-methylphenol (4.7, 3.5, 3.3 ppm) and decane (55.1, 39.0, 15.2 ppm) compared to control pigs. The concentration of indole (0.19, 0.07, 0.05 ppm) was reduced (P < 0.05) when 4 or 8% feather meal was included. Concentrations of other detectable compounds (acetic acid, propionic acid, 2-methylindole, 3- methylindole, nonanal, undecane, dodecane, tridecane, and tetradecane) were not affected (P > 0.11) by dietary treatments. Results clearly demonstrate that odorous compounds in feces can be affected by the inclusion of hydrolyzed feather meal in diets of growing-finishing pigs. The exact impact of these changes on odor perception remains to be elucidated.