Author
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LI, MENGHE - Mississippi State University |
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OBERLE, DANIEL - Mississippi State University |
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LUCAS, PENELOPE - Mississippi State University |
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/4/2011 Publication Date: 1/8/2013 Citation: Li, M.H., Oberle, D.F., Lucas, P.M. 2013. Apparent digestibility of alternative plant-protein feedstuffs for channel catfish, Ictalurus punctatus (Rafinesque). Aquaculture Research. 44:282-288. Interpretive Summary: Prices of traditional feed ingredients, such as soybean meal and corn, have increased dramatically in recent years. To reduce feed cost, more alternative feedstuffs, such as corn gluten feed (CGF), corn germ meal (CGM), and distillers dried grains with solubles (DDGS), are being used to partially replace high cost, traditional ingredients in channel catfish diets. However, little is known about the nutrient and energy digestibility of alternative feedstuffs for channel catfish. Knowing the nutrient and energy digestibility coefficients of these emerging alternative feedstuffs is essential to more precisely formulate cost-effective feeds that not only meet nutrient requirements of the fish, but also maximize feed utilization and profit. Therefore, a study was conducted to determine apparent digestibility/availability coefficients for these alternative ingredients as compared with soybean meal. Results show that apparent digestibility/availability coefficients of protein, essential amino acids and energy in alternative protein feedstuffs tested were generally lower than those in soybean meal by channel catfish. Apparent digestibility coefficients of protein ranged from 75 to 87% and those of energy ranged from 52 to 59% for alternative feedstuffs. Lysine in alternative feedstuffs was 67–79%, methionine was 69–85% and cystine was 73–82% available to channel catfish. There were no significant differences in lipid ADCs among test feedstuffs (91.9–96.8%). Results from the present study can be useful in formulating cost-effective catfish feeds using these alternative feedstuffs to ensure that all nutrient and energy requirements are met for optimum fish performance. Technical Abstract: A study was conducted with channel catfish, Ictalurus puntatus to determine apparent digestibility/availability coefficients of protein, amino acids, lipid and energy for alternative plant-protein feedstuffs: corn gluten feed, corn germ meal, distillers dried grains with solubles, and canola meal, compared with those for soybean meal. A 32%-protein, chemically defined diet containing 8% fish meal was used as the reference diet. Test diets consisted of 70:30 ratio of reference diet to test ingredient with chromic oxide (0.75% of the diet) as an inert indicator. Apparent digestibility/availability coefficients of protein, essential amino acids and energy in alternative protein feedstuffs tested were generally lower than those in soybean meal by channel catfish. Apparent digestibility coefficients of protein ranged from 75 to 87% and those of energy ranged from 52 to 59% for alternative feedstuffs. Lysine in alternative feedstuffs was 67–79%, methionine was 69–85% and cystine was 73–82% available to channel catfish. There were no significant differences in lipid ADCs among test feedstuffs (91.9–96.8%). Results from the present study can be useful in formulating cost-effective catfish feeds using these alternative feedstuffs. |