Apparent digestibility of selected feed ingredients in diets for juvenile hybrid tilapia, Oreochromis niloticus×Oreochromis aureus

Abstract

The apparent digestibility coe⁄cients (ADCs) of dry matter, crude protein, crude lipid, ash, phosphorus, gross energy and amino acids of 10 selected ingredients for juvenile hybrid tilapia (7.05 AE 0.09 g) were determined using 0.5% Cr 2 O 3 as an inert indicator. The feed ingredients tested in this study were corn gluten meal (CGM), corn byproduct, corn germ meal (CG), soybean meal (SBM), fermented soybean meal (FSM), soy protein concentrate (SPC), soy protein isolate, malt sprouts (MS), ¢sh meal (FM) and earthworm meal (EM). The test diets were prepared by incorporation of 30% test ingredients into the reference diet. Reference and test diets were fed to the ¢sh and the faecal samples were collected using a faecal collection column attached to the ¢sh-rearing tanks. The ADCs for dry matter, crude protein, crude lipid, ash, phosphorus and gross energy were 41.7^98.9%, 90.6^99.6%, 73.1^98.8%, 34.1^98.6%, 49.5^99.6% and 45.4^99.7% respectively. Soy protein isolate, FM and EM had higher dry matter, crude protein and gross energy ADCs. Corn byproduct and EM had higher crude lipid ADCs, and CG and EM had higher phosphorus ADCs. Corn germ meal had the highest ash ADC, while CGM had the highest value for gross energy. The lowest dry matter, crude protein, lipid and gross energy ADCs occurred in MS, while the lowest ash and phosphorus ADCs occurred in SPC. The amino acid ADCs ranged from 83.3% to 100%, exhibiting a positive correlation with crude protein digestibility for a given test ingredient. The feed ingredient digestibility of this study may provide useful information about nutrient and energy utilization to facilitate formulation of least-cost practical diets for hybrid tilapia. Ã Mineral premix (values are in g kg À 1 mineral premix): MgSO 4 Á 7H 2 O, 25.3; ZnSO 4 Á 7H 2 O, 21.5; KI, 0.20; FeSO 4 Á 7H 2 O, 73.9; CuSO 4 Á 5H 2 O, 6.3; MnSO 4 Á H 2 O, 14.8; CoCl 2 , 0.2; Na 2 SeO 3 , 0.7 and NaCl, 0.4. wVitamin premix (values are in g kg À 1 vitamin premix): retinoic acid, 50.0; vitamin D 3 , 0.025; allrac-a-tocopherol, 40.0; vitamin K 3 , 5.0; thiamin, 5.0; ribo£avin, 2.5; pyridoxine, 5.0; cyanocobalamin, 0.025; pantothenic acid, 25.0; nicotinamide, 60.0; biotin, 0.5; folic acid, 2.5 and inositol, 200.0; asorbic acid, 25.0.Aquaculture Research, 2010 Hybrid tilapia apparent digestibility X-H Dong et al.

Apparent Protein and Energy Digestibility and Amino Acid Availability of Corn and Co‐products in Extruded Diets for Nile Tilapia, Oreochromis niloticus

“…Compared to our findings, Pezzato et al () reported lower ADCDM (54.5%), ADCGE (43.7%), and ADCCP (86.8%) in corn germ meal fed to Nile tilapia; in similar studies, Dong et al () recorded higher ADCDM (64.4%) and ADCGE (71.5%) and lower ADCCP (74.6%). Pezzato et al () reported lower ADCDM (48.8%), higher ADCGE (66.8%), and similar ADCCP (89.9%) for corn gluten fed to Nile tilapia, while Dong et al () observed higher ADCDM (59.9%), ADCGE (74.1%), and ADCCP (95.1%).…”

“…In studies of Nile tilapia, the ADCDM of corn gluten meal ranged from 74.9% (Gonçalves et al ) to 93.2%, as described by Köprücü and Özdemir (); ADCGE varied from 71.2% (Pezzato et al ) to 93.5% (Meurer et al ); and ADCCP ranged from 89.0% (Köprücü and Özdemir ) to 97.6% (Meurer et al ). Dong et al () recorded lower ADCDM (77.4%) and ADCGE (86.2%) but similar ADCCP (95.4%).…”

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“…The protein quality of earthworm meal was reported to be comparable to that of fishmeal with high levels of essential amino acids for fish (Tacon et al, 1983;Tacon and Metian, 2009;Dong et al, 2010;Tuan, 2010;NRC, 2011). As in full feeds, earthworm meal was suitable as a partial replacement for fishmeal with similar or beneficial effects on fish growth (described above).…”

“…In the literature, earthworms are generally described as resources with high protein content and protein quality but these parameters have been shown to differ according to earthworm species and, to a lesser extent, the feed substrate (Tacon et al, 1983;Stafford and Tacon, 1984;Sun et al, 1997;Changguo et al, 2006;Sogbesan et al, 2007;Dong et al, 2010;Tuan, 2010). There are several reports that demonstrate the suitability of various earthworm species as components of aqua feeds while others suggest that single earthworm species can have negative effects on the growth and health of fish.…”

Replacement of animal protein sources by soy protein concentrate for juvenile Nile tilapia

“…Protein apparent digestibility coefficient (ADC) of SPC to Nile tilapia was high and similar to that reported to hybrid tilapia (Oreochromis niloticus x Oreochromis aureus), which was 98.2% (DONG et al, 2010 However, we also registered that methionine and threonine supplementation of 100% SPC diet promoted an 11% increase in tilapia weight gain and showed significant effect on protein ADC. Therefore, despite being a good alternative source for replacing animal protein, SPC supplementation with the limiting amino acids is mandatory.…”