Digestibility Coefficients Of Lipid Research Articles

Mechanical processing of Phaeodactylum tricornutum and Tetraselmis chui biomass affects phenolic and antioxidant compound availability, nutrient digestibility and deposition of carotenoids in Atlantic salmon

Cell walls of microalgae differ both in terms of chemical composition and architecture. Certain characteristics of cell walls limit both the effectiveness of extraction of valuable constituents and nutrient bioavailability and bioaccessibility in fish. We first investigated the potential of bead milling to disrupt cell walls to improve extractability of bioactive compounds from Phaeodactylum tricornutum and Tetraselmis chui. We also evaluated the effect of the mechanical treatment on i) digestibility of nutrients in the two microalgae and ii) fatty acid and pigment content of fillet of Atlantic salmon fed the algae diets.Cell wall disruption facilitated efficient release of total phenolic compounds (TPC), chlorophyll A, chlorophyll B and total carotenoids from both microalgae species, but increased only the total antioxidant capacity (TAC) of T. chuii. The polyphenol profile varied between the two species; we identified 2 and 6 polyphenols from P. tricornutum and T. chui, respectively.For the feeding experiment, microalgae biomass, intact or cell wall disrupted (90.7 and 76.4% disruption degree for T. chui and P. tricornutum, respectively), were mixed with the other feed ingredients. Atlantic salmon (315 g start weight / 55 fish per tank) were fed one of the five extruded experimental diets (a fishmeal-based reference diet and four feeds with 30% of the whole or broken microalgae biomass added to the reference diet). The digestibility of protein in the P. tricornutum was significantly higher compared to that of T. chui. Breaking the cell walls by bead milling caused a significant improvement in digestibility of protein in T. chui. The apparent digestibility coefficient of lipid was higher in P. tricornutum and bead milling improved the digestibility of the two algae. However, bead milling did not favourably change the fatty acid profile of Atlantic salmon. At the end of the feeding trial, P. tricornutum-fed fish had significantly improved pigmentation, probably due to the higher content of fucoxanthin and fucoxanthinol compared to the fish fed the reference diet. The main conclusion from the mechanical processing of the microalgae is that bead milling can increase i) the extractability of polyphenols and pigments, ii) the digestibility of lipid in both algae while the effect on protein was improved only for T. chui. Furthermore, P. tricornutum can be considered a natural pigment source in the feeds of Atlantic salmon.

Dietary guanosine‐monophosphate improves growth performance, feed utilization and intestinal morphology of whiteleg shrimp ( Litopenaeus vannamei ) maintained on soybean meal‐based diets

The present study evaluated the effects of dietary supplementation of individual or a combination of nucleotides in soya bean meal‐based diet on growth, survival, apparent digestibility and intestinal condition of whiteleg shrimp, Litopenaeus vannamei. The experimental protocol comprised a control set, and four test diets that were separately supplemented with 0.1% inosine monophosphate (IMP, D + I), 0.1% guanosine monophosphate (GMP, D + G), 0.1% mixture of IMP and GMP (D + IG) and 0.1% mixture of IMP, GMP, cytidine monophosphate (CMP) and uridine monophosphate (UMP) (D + IGCU). Triplicate groups of the shrimp (initial body weight = 0.99 ± 0.01 g) were fed four times daily for 8 weeks. Results demonstrated that D + G significantly enhanced body weight gain and specific growth rate in the shrimp compared with control and other dietary treatments with the various combinations of nucleotides (p 0.05). Shrimp fed D + G showed significantly higher feed intake and apparent net protein utilization compared with D + IGCU and, control and D + IG (p < 0.05) respectively. Nucleotide supplementation did not significantly improve the crude protein and lipid digestibility coefficients. This was evident when the data on these parameters were compared with those of the control. Shrimp fed D + G showed significantly improved intestinal villus height and body crude protein content (p < 0.05). In conclusion, GMP supplementation in soya bean meal‐based diet enhanced the growth, feed intake, protein utilization and villus height of L. vannamei.

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

The apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in local fish meal (LFM), Peruvian fish meal (PFM), poultry by-product meal (PMM), meat and bone meal (MBM), tilapia by-product meal (TM), fermented soybean meal (FSBM), soybean meal (SBM), peanut meal, canola meal (CM), cottonseed meal (CSM) and de-gossypoled cottonseed meal were determined for juvenile hybrid tilapia (7.18 ± 0.2 g, mean ± SD). A reference diet (RF) and test diets (consisting of 70% RF and 30% of the feedstuff) were used with 0.5% chromic oxide as an external digestibility marker. The juvenile hybrid tilapias were stocked in 500-L fibreglass tanks at a density of 20 fish per tank. Faeces were collected from triplicate groups of fish using a faecal collection column attached to the fish-rearing tank. The results indicated that the ADCs of dry matter for juvenile hybrid tilapia ranged 71.88–89.53% for animal products and 65.89–79.98% for plant products. For crude protein, apparent digestibility coefficients of protein (ADCp) exceeding 90% were observed for FSBM, SBM and PFM, and ADCp of MBM was the lowest among all the treatments. Apparent digestibility coefficients of lipid in all the treatments were above 90%; the results indicate that lipids from both animal and plant sources were well digested by hybrid tilapia. The ADCs of phosphorus of animal and plant feedstuffs ranged between 58.04–74.44% and 52.65–64.23% respectively. The lowest ADC of phosphorus was observed in CSM among plant ingredients and in MBM among animal ingredients. The ADCs of energy were similar to those of dry matter and protein; the highest and lowest ADCs of energy were found in PFM and CM respectively. In general, the amino acid availability coefficients tended to reflect the ADCp among highly digestible ingredients. For the animal products, the availabilities of amino acids in PFM, LFM and PMM were generally higher than that in TM and MBM; among all the plant products, the availabilities of amino acids in FSBM and SBM were higher than in CM. These results indicated that juvenile hybrid tilapia is able to utilize different feedstuffs efficiently.

Effect of dietary n-3 HUFA on growth performance and tissue fatty acid composition of gibel carp Carassius auratus gibelio

A 12-week growth trial was conducted with gibel carp Carassius auratus gibelio (initial weight: 2.69 g) to evaluate the effects of dietary n-3 highly unsaturated fatty acids (n-3 HUFA) on growth performance and tissue fatty acid composition. Five diets of different n-3 HUFA levels from 0 to 17 g kg(-1) diet were supplemented at 80 g kg(-1) dietary lipid by including fish oil (FO) at 0, 25, 50, 75 and 100% of supplemental lipid. The remainder was coconut oil. The results showed that fish fed FO25 and FO50 obtained highest specific growth rate and lowest with FO0. Feed efficiency was highest at FO100 and lowest at FO0. Apparent digestibility coefficient of lipid increased with increasing dietary n-3 HUFA. The fish fed FO0 diet had the lowest thiobarbituric acid reactive substance in serum and muscle and highest moisture and lowest lipid content in viscera. Fatty acid compositions of muscle and liver were correlated with dietary fatty acids. Fish muscle concentration of 20:5n-3 increased with increasing dietary n-3 HUFA while the concentration of 22:6n-3 was distinctly reduced in FO0 group. It suggested that 4 g kg(-1) n-3 HUFA in diet could permit gibel carp normal growth performance and provide considerable n-3 HUFA in fish muscle. Excessive n-3 HUFA showed impact on growth performance of gibel carp.

Effect of dietary probiotics on apparent digestibility coefficients of nutrients of white shrimp Litopenaeus vannamei Boone

Apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), lipid, phosphorus (P), essential amino acids (EAA), non-essential amino acids (NEAA) and fatty acids were determined for white shrimp (Litopenaeus vannamei). A probiotic (Bacillus sp.) was used at 0% (diet 1), 0.5% (diet 2), 1.0% (diet 3), 3.0% (diet 4) and 5.0% (diet 5) inclusion rates in experiment diets. Apparent digestibility coefficients was determined using 0.01% Y2O3 as an indicator. A total of 300 shrimp (initial mean body weight 11.5±0.6 g) were randomly stocked into fifteen 500-L outdoor concrete tanks. Faeces were collected from three replicate groups of shrimp three times a day. The ADCs of five diets were: DM, 66.1–69.6%; CP, 80.4–84.7%; lipid, 82.2–84.9%; P, 25.4–28.5%; EAA, 82.0–85.4%; NEAA, 81.5–85.1%; saturated fatty acids (SFA), 79.6–82.4%; monounsaturates (MUFA), 81.6–84.2% and polyunsaturates (PUFA)+highly unsaturates (HUFA), 83.4–86.6%. Apparent digestibility coefficients of DM, CP, lipid, P, amino acids and fatty acids in diet 1 were significantly lower than in other diets (P<0.05). Apparent digestibility coefficient of P in diets increased as probiotic increased. Apparent digestibility coefficient of lipid in diet 3 was the highest, but the difference was not significant among diets. In general, ADCs of most amino acids and fatty acids were over 80% in all diets, and PUFA+HUFA>MUFA>SFA. The results showed that ADCs of diets supplemented with 10, 30 and 50 g probiotic kg−1 basal diet were higher than in other diets except lipid, and the difference was significant.

Apparent Digestible Energy and Nutrient Digestibility Coefficients of Diet Ingredients for Pacu Piaractus brachypomus

AbstractThe digestible energy and apparent nutrient digestibility coefficients of common diet ingredients were determined for pacu Piaractus brachypomus (370.21 ± 17.56 g). Fish were fed with pelleted practical diets to apparent satiation and the feces were collected by siphoning. The digestibility value for each ingredient was determined by comparison of the digestibility of a test diet with a reference diet (24.5% crude protein and 1% chromic oxide). The digestible energy values of soybean meal (SBM), fish meal (FM), corn (CN), and wheat bran (WB) were 2382. 3826, 3353, and 1784 kcal/kg, respectively. The apparent dry matter digestibility coefficients were 83.72, 90.14, 89.13, and 82.05% for SBM, FM, CN, and WB, respectively. The apparent crude protein digestibility coefficients were 75.88, 90.49, 85.06, and 61.62% for SBM. FM, CN, and WB, respectively. The apparent lipid digestibility coefficients were 63.03, 77.00, 83.01, and 82.45% for SBM, FM, CN, and WB, respectively. The digestibility of protein, lipid, and energy from SBM were somewhat low compared to values for other warmwater omnivorous fishes, but similar to values reported for pacu‐caranha P. mesopotamicus. Otherwise, the nutrient and energy availability of the ingredients to P. brachypomus was similar to that of other fish. This information will be useful in formulating nutritious, economical diets for pacus.

Determination of digestibility coefficients of various feedstuffs for red drum ( Sciaenops ocellatus)

The availability of nutrients and energy in feedstuffs to fish may vary considerably, depending on a variety of factors including fish species, ingredient quality and processing conditions. The red drum is an emerging aquaculture species for which information concerning nutrient and energy availability is needed to more precisely formulate diets to meet their requirements and to enable effective substitution of ingredients. This study was conducted with red drum to determine apparent organic matter, protein, lipid, and gross energy digestibility coefficients and apparent phosphorus availability of the following ingredients: select (low temperature) menhaden fish meal; regular-quality menhaden fish meal, poultry by-product meal, meat and bone meal, dehulled soybean meal, cottonseed meal, and wheat. Test diets consisting of a 70:30 mixture of reference diet to test ingredient were utilized with chromic oxide as the non-digestible marker. Organic matter digestibility of ingredients generally decreased as the nitrogen-free extract fraction increased, ranging between 94% for select menhaden fish meal to 47% for wheat. Crude protein digestibility was high for most ingredients, ranging from 77% for regular menhaden fish meal to 97% for wheat, with the exception of poultry by-product meal which was 49%. Lipid digestibility coefficients ranged from 59% for poultry by-product meal to 88% for wheat. Digestible energy coefficients were generally high for the animal meals, ranging from 72% for poultry by-product meal to 95% for select menhaden fish meal however, digestible energy coefficients for plant feedstuffs were considerably lower, from 62% for wheat to 70% for cottonseed meal. Phosphorus availability from animal products was variable, with a low of 27% for poultry by-product meal and a high of 66% for meat and bone meal. Phosphorus availability from soybean meal and cottonseed meal was 47% and 40%, respectively. Wheat had the highest phosphorus availability at 79%. Data from this study indicate red drum can digest and absorb the nutrients in animal products more completely than those from plant products. This difference presumably reflects their inability to effectively digest the nitrogen-free extract portion of plant products. These data provide more precise information concerning nutrient and energy utilization of red drum and will allow ingredient substitutions in practical diet formulations based on levels of available nutrients.

The influence of proanthocyanidin-rich bean hulls and level of dietary protein on energy metabolizability and nutrient digestibility by adult cockerels.

Cotyledons and hulls were prepared from twelve varieties of field beans (Vicia faba L.). Adult cockerels were tube-fed either beans, cotyledons or hull diets containing high or low levels of protein. Metabolizable energy coefficients and starch digestibility coefficients were determined for beans, cotyledons and hull diets. Lipid digestibility coefficients from hull diets were also determined. When cotyledons were fed there were no significant differences in the way in which adult cockerels metabolized energy or digested starch from the proanthocyanidin-free and proanthocyanidin-rich varieties (0.780, 0.908, 0.775 and 0.918 respectively). When beans were fed, however, both energy metabolizability and starch digestibility decreased due to the presence of hulls, with proanthocyanidin-rich hulls decreasing values the most to 0.660 and 0.819 respectively, and proanthocyanidin-free hulls decreasing values to a lesser extent to 0.709 and 0.886 respectively. Diets composed of proanthocyanidin-rich hulls depressed metabolizable energy and maize starch digestibility. Their effect on maize starch digestibility, however, was considerably less than that on bean starch. Lipid digestibility was enhanced by proanthocyanidins but only when the protein content of the diet was high. There was a significant correlation (P < 0.05) between the vanillin and anthocyanidin formation methods for the estimation of proanthocyanidins (r 0.779). There was also a highly significant regression of bean starch digestibility v. proanthocyanidin content of coloured-flowered bean hulls (P < 0.001). The regression of maize starch digestibility v. hull proanthocyanidins was also significant at P < 0.005.