REPLACEMENT OF FISH MEAL IN DIETS FOR JAPANESE SEA BASS (Lateolabrax Japonicus): I. IN VIVO AND IN VITRO APPARENT DIGESTIBILITY OF FEED INGREDIENTS


M. Xue, L.F. Qin, L. Luo, X.F. Wu, H.N. Cao, Y. Yu

In vivo apparent digestibility coefficients (ADCs) for dry matter, nitrogen, energy and in vitro ADC for nitrogen for 24 commonly used feed ingredients were determined for Japanese sea bass (Lateolabrax japonicus). Each test diets was composed of 70% reference diet and 30% test ingredient, which 0.1% of Yttrium oxide (inert marker) mixed with mineral premix. 4 batches of 28d experiment for in vivo test and a two-step in vitro experiment were conducted. ADCs for dry matter, nitrogen and energy were highest for spray dried blood meal and several fish meals except Chinese fish meal, although several other ingredients, including soybean meal, wheat gluten and fish protein concentrated had similar ADCs. Japanese sea bass were capable of digesting protein very effectively in almost all ingredients tested, but quite different for digesting energy. The regression relationship between in vitro and in vivo ADCp Of 24 ingredients is Y(in vivo)=25.20±0.70X(in vitro), r = 0.76. After eliminating the data of the water-soluble and the ingredients with factors that difficultly to be digested under in vitro condition, such as spray dried blood meal, wheat gluten, wheat and shrimp meal, the regression relationship is Y=1 1.20±0.87X, r = 0.86.

(Beijing Aquaculture Nutrition Research Center, Beijing, 100075, China)


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