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United States Department of Agriculture

Agricultural Research Service

Title: Nutrient Digestibility of Common Feedstuffs in Extruded Diets for Sunshine Bass (Morone Chrysops Saxatilis).

Authors
item Rawles, Steven
item Gatlin, Delbert - TEXAS A&M UNIV

Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 23, 2000
Publication Date: December 1, 2000
Citation: RAWLES, S.D., GATLIN, D.M. NUTRIENT DIGESTIBILITY OF COMMON FEEDSTUFFS IN EXTRUDED DIETS FOR SUNSHINE BASS (MORONE CHRYSOPS SAXATILIS).. JOURNAL OF THE WORLD AQUACULTURE SOCIETY. 2000. v.31(4). p.570-579.

Interpretive Summary: Limited data is available regarding the digestibility of nutrients in feedstuffs for sunshine bass. Digestibility values are needed by producers and feed mills as well as scientists working on sunshine bass nutrition to improve diet formulations and allow cost effective substitution of feedstuffs. This study determined the digestibility of protein, fat, carbohydrate, and energy in a variety of feedstuffs in advanced sunshine bass fingerlings (1-2 oz.). The size of fish used in this study corresponds to the size commercial growers stock in grow out systems. The ingredients tested were low-temperature processed menhaden fish meal (Select ), meat and bone meal, a fish meal analog (PROPAK ), dehulled soybean meal, cottonseed meal, corn grain, sorghum, wheat flour, wheat middlings, and rice bran. The test diets were manufactured under commercial conditions to produce floating feed pellets like those used by commercial fish farmers. Feedstuffs which were high in protein and fat were better digested than feedstuffs that were high in carbohydrate or fiber. SelectTM menhaden fish meal and meat and bone meal appeared to be the best ingredients for sunshine bass diets in terms of overall nutrient content and digestibility. The fish meal analog did not perform as favorably as the other two animal products. Protein and fat of cottonseed meal were highly available at 85% and 92%, respectively. Protein digestibility was high for soybean meal (77%), whereas the digestibility of fat (54%), carbohydrate (25%) and energy (56%) in soybean meal was moderately low. Energy in wheat middlings and wheat was moderately available at 67% and 59%, respectively. Energy in sorghum and corn was much less available at 44% and 40%, respectively. Digestibility of nutrients and energy in rice bran exceeded 90%.

Technical Abstract: Limited data is available on the digestibility of nutrients in feedstuffs for sunshine bass. This data is needed to improve diet formulations and allow substitution of feedstuffs. This study determined the apparent diges- tibility coefficients (ADCs) for protein, lipid, carbohydrate,gross energy, and organic matter in ten feedstuffs in extruded diets for sunshine bass 50-75 g). Test diets consisted of a 70:30 mixture of reference diet to tes ingredient with chromic oxide (0.8%) as the inert marker. Diets were extru- ded under commercial conditions to produce a neutrally buoyant pellet (5 mm). Trials were conducted in 600-L tanks connected as a recirculating brackish (5-7 ppt) water system. Diets were randomly assigned and fed to tanks of 45-50 fish twice daily to satiation. Feedstuffs of high-protein and lipid content were better digested than feedstuffs of high carbohydrate or fiber content. Organic matter digestibility ranged from 42% for sorghum and corn to 96% and 98% for meat and bone meal and SelectTM menhaden fish meal, respectively. Menhaden fish meal and meat and bone meal were the best ingredients for sunshine bass diets in terms of nutrient profiles and digestibility. The fish meal analog did not perform as favorably as the other animal products. Protein and lipid of cottonseed meal were highly available (85% and 92%). Protein digestibility was high (77%) for soybean meal (SBM), whereas organic matter (51%), lipid (54%), carbohydrate (25%) and energy (56%) digestibilities in SBM were moderately low. Energy in wheat midds and wheat was moderately available (67% and 59%, respect- ively). Energy in sorghum and corn was much less available (44% and 40%, respectively). Digestibility of nutrients and energy in rice bran exceeded 90%.

Last Modified: 9/22/2014
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