|VAN SAMBEEK, DANA - Iowa State University|
|VAN LEEUWEN, JOHANNES - Iowa State University|
|GABLER, NICHOLAS - Iowa State University|
Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2012
Publication Date: 3/21/2012
Citation: Van Sambeek, D., Weber, T.E., Kerr, B.J., Van Leeuwen, J., Gabler, N. 2012. Evaluation of Rhizopus oligosporus in nursery pig diets on growth performance and nutrient digestibility [abstract]. Midwestern Section of the American Society of Animal Science. Journal of Animal Science 90 (Suppl. 2):129.
Technical Abstract: The thin stillage leftover from ethanol production contains biodegradable organic compounds and sufficient micronutrients that are ideal for fungal cultivation of Rhizopus oligosporus (RO). This fungus removes about 60% of the organic material, including the suspended solids and even more of some specific substances that are undesirable for recycling. The resulting fungal pellets can easily be harvested as a food-grade organism, which is rich in fat and amino acids, specifically lysine and methionine. Thus, this value added byproduct may be a suitable feed ingredient for swine. We conducted a four week growth performance experiment using 24 gilts (5.62±0.35 kg BW) allocated to one of three diets: 0% RO, 10% RO or 20% RO (n=8 pigs/trt). All diets were formulated to be isocaloric and contained the digestibility marker titanium dioxide. Pig feed intake and body weights were measured weekly, and total tract fecal samples were collected at week four. Irrespective of dietary treatment, there was no difference in pig ADFI (P=0.97), ADG (P=0.94) or G:F (P=0.55) over the four week nursery period. Proximate analysis of feed and fecal samples yielded the following apparent total tract digestibility coefficients for 0% RO, 10% RO or 20% RO, respectively: Gross Energy, 85.6, 86.7 and 81.1% (P<0.001); P, 58.0, 59.2 and 46.5% (P<0.01); and N, 86.2, 84.3 and 82.8 (P<0.05). Total tract DE was improved feeding 10% RO (4.16 Mcal/kg), but not 20% RO (3.81 Mcal/kg) versus the control treatment (4.01 Mcal/kg). Altogether, these data indicate that Rhizopus oligosporus cultivated on distillers stillage and bioproducts can be used in nursery swine diets with no negative effects on performance. However, as the inclusion rates increase, nutrient digestibility may decrease.