Better Digestion Research Articles

How Apparent Digestibility of Carotenoids, Macronutrients, and Minerals are Differently Affected by Ration Level in Atlantic Salmon, Salmo Salar

The main objective of this field experiment was to investigate whether ration level affected utilization of carotenoids, macronutrients, and minerals in 1,300 g Atlantic salmon (Salmo salar) during rapid growth. Salmon fed ration levels of either 1.2% or 0.6% of biomass of a commercial diet supplemented with astaxanthin and canthaxanthin (37 and 39 mg kg−1, respectively) in two consecutive 6-day feeding periods had carotenoid digestibility coefficients of 11.8% and 32.1% at the high and low feed rations, respectively. Thus, low carotenoid digestibility, but good macronutrient digestibility, may explain poor pigmentation and good feed conversion in rapidly growing salmon. Practical implications are illustrated.

Ontogenetic Development of Porcellio scaber: Staging Based on Microscopic Anatomy

Abstract Arthropods exhibit a vast variety of morphological forms. Developmental studies on diverse arthropod groups will help clarify how these forms evolved during arthropod evolution. The terrestrial isopod Porcellio scaber is a suitable novel animal model for developmental studies; it is well adapted to terrestrial habitats and these adaptations make the species interesting from the evolutionary perspective. Porcellio scaber is already extensively used in ecotoxicological and physiological studies and its biology is well known, but a comprehensive description of its ontogenetic development is still missing. Here, a staging system of P. scaber embryos and marsupial mancas based on morphological observations with light microscopy techniques is presented. An important adaptation of oniscids to terrestrial lifestyle is formation of specific structures in the digestive system, which enable effective water retention and good digestion of cellulose-rich plant material. Differentiation of the digestive system...

Biological evaluation of mechanically deboned chicken meat protein hydrolysate

OBJECTIVE: The objective of this study was to evaluate the biological properties of a protein hydrolysate obtained by enzymatic hydrolysis of mechanically deboned chicken meat. METHODS: Mechanically deboned chicken meat was hydrolysed using Alcalase 2.4 L FG and then dried in a spray-drier. Three groups (n=6) of male Wistar rats received diets containing casein, mechanically deboned chicken meat protein hydrolysate and a protein-free diet. The rats were randomly assigned to individual cages with controlled temperature (22ºC) for 12 days. RESULTS: The mechanically deboned chicken meat diet resulted in a good net protein utilization (3.74) and high true digestibility (96%). The amino acid composition of the hydrolysate was relatively well balanced, but the concentrations of methionine and cystine were low, making them the limiting amino acids. The proximate chemical composition of the hydrolysate showed protein content to be as high as 62%. CONCLUSION: The results obtained in this work suggest that mechanically deboned chicken meat hydrolysate can be used as a protein enhancer in food preparations such as enteral formulations, and as an edible protein enhancer in general applications.

Essential oil and by-products of distillation of bay leaves ( Laurus nobilis L.) from Argentina

Preliminary chemical studies were undertaken during one year on plant materials collected in a 40 ha field located in Henderson, Province of Buenos Aires, in order to determine the technical viability of the industrial production of essential oil from bay leaves ( Laurus nobilis L., Lauraceae) growing in Argentina. The oils were extracted at a pilot scale plant and analyzed by GC–FID-MS. The apparent density of the plant material used for the distillation ranged from 90 g L −1 to 170 g L −1, depending on the type of material. The quality of the volatile oils obtained complied with market requirements and were in agreement with values reported from other countries. No considerable variations were observed in the chemical composition of the oils throughout the year. Taking in account the composition of the sub-fractions obtained during the distillation process, the quality of the final essential oil can be adjusted by fractional distillation. The occurrence of alcohol terpenes and phenols in the condensed waters (hydrolate) makes them a possible alternative to be used in industry. Moreover, and due to the good energetic and digestibility values obtained, our results showed that the exhausted plant material obtained after distillation could be a putative fibrous feed for ruminants. Both, hydrolate and exhausted plant materials are resources that can enhance added values in new endeavours. This is the first report on bay leaves essential oil production at industrial scale in Argentina.

Biogas production from boreal herbaceous grasses – Specific methane yield and methane yield per hectare

The objective of this study was to determine the specific methane yields of four grass species (cocksfoot, tall fescue, reed canary grass and timothy) cultivated under boreal conditions as well as how harvesting time and year of cultivation affects the specific methane yields per ha. The specific methane yields of all grasses and all harvests varied from 253 to 394 Nl CH 4/kg volatile solids (VS) added. The average specific methane yield of the 1st harvest of all grasses was higher than the 2nd harvests. In this study the methane and energy yields from different harvest years were ranged from 1200 to 3600 Nm 3 CH 4/ha/a, corresponding from 12 to 36 MWh CH 4 /ha/a. The methane yield per hectare of the 1st harvest was always higher than that of the 2nd harvest per hectare because of the higher dry matter yield and specific methane yield. High biomass yield per hectare, good digestibility and regrowth ability after harvesting are important factors when choosing grass species for biogas production. If 30% of fallow and the second harvest of grassland were cultivated grasses and harvested for biogas production in Finland, the energy produced could be 4.9 TWh CH 4 .

Cellulase adsorption and relationship to features of corn stover solids produced by leading pretreatments

Although essential to enzymatic hydrolysis of cellulosic biomass to sugars for fermentation to ethanol or other products, enzyme adsorption and its relationship to substrate features has received limited attention, and little data and insight have been developed on cellulase adsorption for promising pretreatment options, with almost no data available to facilitate comparisons. Therefore, adsorption of cellulase on Avicel, and of cellulase and xylanase on corn stover solids resulting from ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid, lime, and sulfur dioxide (SO(2)) pretreatments were measured at 4 degrees C. Langmuir adsorption parameters were then estimated by non-linear regression using Polymath software, and cellulase accessibility to cellulose was estimated based on adsorption data for pretreated solids and lignin left after carbohydrate digestion. To determine the impact of delignification and deacetylation on cellulose accessibility, purified CBHI (Cel7A) adsorption at 4 degrees C and hydrolysis with whole cellulase were followed for untreated (UT) corn stover. In all cases, cellulase attained equilibrium in less than 2 h, and upon dilution, solids pretreated by controlled pH technology showed the greatest desorption followed by solids from dilute acid and SO(2) pretreatments. Surprisingly, the lowest desorption was measured for Avicel glucan followed by solids from AFEX pretreatment. The higher cellulose accessibility for AFEX and lime pretreated solids could account for the good digestion reported in the literature for these approaches. Lime pretreated solids had the greatest xylanase capacity and AFEX solids the least, showing pretreatment pH did not seem to be controlling. The 24 h glucan hydrolysis rate data had a strong relationship to cellulase adsorption capacities, while 24 h xylan hydrolysis rate data showed no relationship to xylanase adsorption capacities. Furthermore, delignification greatly enhanced enzyme effectiveness but had a limited effect on cellulose accessibility. And because delignification enhanced release of xylose more than glucose, it appears that lignin did not directly control cellulose accessibility but restricted xylan accessibility which in turn controlled access to cellulose. Reducing the acetyl content in corn stover solids significantly improved both cellulose accessibility and enzyme effectiveness.

High forage yield and quality of sudan grass ( Sorghum bicolor L.) and pearl millet ( Pennisetum glaucum L.) cultivated in calcareous soils

Sudan grass and pearl millet are major warm season dryland crops, primarily grown for grain production and used as a major source of dietary energy. Both crops are highly water use efficient and belong to the C 4 group of species with high photosynthetic efficiency and dry matter accumulation rates. Both sudan grass and pearl millet have good forage quality, with an adequate crude protein content; that of pearl millet (8.7%) is higher than that of sorghum (6.0%). Therefore, the present investigation was conducted in the Western Delta Region at El-Naubaria, 40 km south of Alexandria, over two successive seasons to evaluate the forage yield and quality of sudan grass and pearl millet. Field experiments were established on calcareous soils, with five fertilization treatments. The results indicate that pearl millet surpassed sudan grass in fresh (6.56 t/ha) and dry yield (2.91 t/ha), which was 8.89% and 5.26% more, respectively, than for sudan grass. As regards the forage quality, pearl millet had good digestibility and was lower in fibre than sudan grass.

Fontes de proteína e carboidratos para cães e gatos

O mercado de alimentos para cães e gatos absorve importante quantidade de proteínas e carboidratos, apesar disso poucos estudos existem sobre digestibilidade e energia metabolizável destes ingredientes. Arroz e milho têm sido considerados as melhores fontes de amido, mas demonstra-se que o sorgo é igualmente bem digerido por cães. Na interpretação dos estudos, deve-se distinguir os que empregaram farinhas ou amidos purificados dos que empregaram ingredientes moídos, como utilizado na fabricação de alimentos para animais de companhia. Além de sua digestibilidade e valor energético, amidos interferem na glicemia de cães, o que torna interessante se empregar, para animais em condições específicas, fontes de carboidrato que levem à menores respostas de glicose e insulina. Devido a elevada necessidade de proteína, ingredientes protéicos são importantes nas formulações. Proteínas de origem animal apresentam maior variação em composição química, qualidade e digestibilidade que as de origem vegetal. Farinhas de origem animal podem apresentar excesso de matéria mineral, limitando sua inclusão na fórmula, enquanto derivados protéicos vegetais apresentam diversos fatores anti-nutricionais que devem ser inativados durante seu processamento. Demonstra-se que proteínas vegetais apresentam boa digestibilidade e energia metabolizável para cães e gatos, sendo sua inclusão interessante para reduzir a matéria mineral da dieta, controlar o excesso de bases do alimento e manter adequada a digestibilidade do produto, neste sentido soja micronizada e o farelo de glúten de milho 60% se destacam em digestibilidade e teor de energia metabolizável. A farinha de vísceras de frango, dentre as proteínas de origem animal secas demonstra-se como a de melhor digestibilidade e energia metabolizável.

COMPOSIÇÃO NUTRICIONAL E DIGESTIBILIDADE APARENTE DALEVEDURA ÍNTEGRA, DA LEVEDURA AUTOLISADA E DA PAREDE CELULAR PELA TILÁPIA-DO-NILO

Nutritional composition and apparent digestibility coefficient of dry matter, crude protein, ether extract, gross energy, essential amino acids and no essential amino acids of spray dried whole yeast, autolyzed yeast and yeast cell wall were evaluated to Nile tilapia. Eighty juveniles (83.0±8.5g) were placed in eight 250L aquaria for feeding and four aquaria of the same volume for collecting faecal samples. Both sets were equipped with flow-trough recirculating system provided with mechanical and biological filter. The results were analyzed through comparative relative index and the 100% value corresponded to the whole yeast nutrients. It can be concluded that the whole yeast contains high protein level and good apparent digestibility to nutrients and amino acids; autolysis process improves the dry matter, crude protein, gross energy and the most of essential and no essential amino acids apparent digestibility. Moreover yeast cell wall must not be used as protein source but is suggested as functional foodstuff in Nile tilapia diets.KEY WORDS: Amino acids, Oreochromis niloticus, Saccharomyces cerevisiae

Alkaline preserved herring by-products in feed for Atlantic salmon ( Salmo salar L.)

The aim of the present study was to investigate the digestibility, growth and slaughter quality in Atlantic salmon ( Salmo salar L.) fed a novel type of moist feed. The moist feed was prepared from alkaline preserved (pH 11.2) herring ( Clupea harengus) filleting by-products, mixed with a crude binder based on seaweed before the feed was shaped in a pelleting process and the final structure was set immersing the pellets in an acidic bath. The feeding experiment was carried out with seawater-adapted salmon with an average initial weight of 1.7 kg. The moist feed and a control feed were fed to three groups of salmon with 190 fish per group. The coefficient of total tract apparent digestibility of fat, protein and energy in fish fed the moist feed was 0.96, 0.81 and 0.87, respectively. The weight gain for fish fed moist feed was significantly higher compared to salmon fed commercially extruded control feed. Carcass quality data showed that fish fed the moist feed had significantly higher dressing out percentage and less visceral fat compared to fish fed the control feed. It is concluded that alkaline preserved fish by-products can be efficiently utilized in a novel moist feed technology, yielding good growth and digestibility in Atlantic salmon.

Formulation of a nutritional cassava (Manihot esculentaCrantz) starch-based beverage

Cassava ( Manihot esculenta Crantz) starch-based vegetable beverage (cassava milk) was formulated to get a composition close to that of cow’s milk with 3% cassava starch, 4% soybean proteins, 3% soybean oil and 0.3% calcium citrate. Heat treatment of the dry starch at 110 °C for 6 h was done prior to the addition of other components to stabilise milk and to avoid gelatinisation. The most stable form of cassava milk that did not separate into two phases for 10 days was obtained by homogenisation at high pressure 12,000 psi/5 min. Milk with starch particle size of 10 μm was found to have sensory qualities close to that of cow’s milk with white colour and viscosity of 7.8 cP. Cassava milk homogenised at 12,000 psi/5 min with cow’s milk (50%) and aromatised with 1% chocolate flavour was given the highest score by 20 sensory panellists. The final product was a white milky solution with good taste, good digestibility, homogeneous, physically and microbiologically stable, and had a nutritional composition similar to that of cow’s milk.

Bagaço de mandioca na ensilagem do capim-elefante: qualidade das silagens e digestibilidade dos nutrientes

Utilizaram-se 16 novilhas ¾ Holandês-Zebu com idade média de 15 meses e peso médio inicial de 144kg, para avaliar o efeito da adição de diferentes níveis (5; 10; 15 e 20%) de bagaço de mandioca na ensilagem do capim-elefante (Pennisetum purpureum, Schum) sobre a qualidade e a digestibilidade dos nutrientes da dieta. Os tratamentos consistiram de quatro dietas contendo, como volumoso, silagem de capim-elefante com quatro diferentes níveis de bagaço de mandioca, mais concentrado balanceado, com quatro repetições por tratamento. Avaliou-se a qualidade das silagens, os consumos de nutrientes das dietas e as digestibilidades dos nutrientes das silagens e das dietas totais. O bagaço de mandioca elevou o teor de matéria seca (MS) da silagem, preservando-a com o pH que variou de 3,85 a 4,07 e a relação N-NH3/NT de 6,2 a 7,85. Os consumos médios diários de MS e proteína bruta (PB) não diferiram entre os tratamentos (P>0,05). Os consumos médios de fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) apresentaram comportamento linear decrescente (P<0,05) com o aumento dos níveis de bagaço de mandioca. Não foi detectada diferença entre os tratamentos (P>0,05) na digestibilidade da MS (DMS), da FDN (DFDN) e da FDA (DFDA) das silagens. Os nutrientes digestíveis totais (NDT) das silagens foram semelhantes em todos os tratamentos. A digestibilidade da PB (DPB), do extrato etéreo (DEE) e dos carboidratos não-fibrosos (DCNF) das silagens decresceu linearmente (P<0,05) com o aumento do nível do bagaço de mandioca nas silagens. Constatou-se que não houve diferença (P>0,05) na DMS, DPB, DFDN, DFDA, DEE, DCNF e NDT entre as dietas experimentais. O nível de adição de 5% de bagaço de mandioca à silagem de capim-elefante é satisfatório para sua preservação, propiciando boa digestibilidade.

Apparent Digestibility of Different Ingredients in Diets for Bullfrog Rana catesbeiana Tadpoles

The objective of this study was to determine apparent digestibility of protein and energy of ingredients commonly present in rations fed to bullfrog tadpoles Rana catesbeiana such as corn, soybean meal, wheat meal, rice bran, poultry by-product meal, blood meal, fish meal, corn starch and soybean oil. A completely randomized design was used to test ten experimental diets with four replicates. About 30% of the reference diet was replaced by the test ingredients, except for soybean oil that was used at 10% ratio and 0.5% of chromium oxide as inert marker. The values of apparent digestibility coefficient of crude protein (ADCCP) and gross energy (ADCGE) of the protein ingredients were, respectively: fish meal, 81 and 95%; poultry byproduct meal, 82 and 87%; blood meal, 64 and 53%; and soybean meal, 93 and 90%. While for the energetic ingredients, ADCCP and ADCGE, were, respectively: wheat meal, 100 and 72%; rice bran, 57 and 24%; and corn, 84 and 92%. Soybean oil and cornstarch ADCGE values were 70 and 96%, respectively; cornstarch digestibility is highly dependent on feed processing technique. The results showed that the ingredients of plant origin, except for rice bran, had good digestibility, thus indicating that tadpoles can effectively use plant protein. In this trial, the least digestible ingredients were blood meal and rice bran, thus indicating that the use of such ingredients in bullfrog tadpole diets should be limited.

Use of soybean meal and phytase for partial replacement of fish meal in the diet of red sea bream, Pagrus major

This study was designed to determine the optimum dosage of phytase in soybean meal diets for red sea bream to produce good growth performance, digestibility and retention efficiencies of nutrients and energy, and to reduce phosphorus discharge of effluent rearing waters. Six isoenergetic diets were formulated: fish meal 65% (F), fish meal 40% + soybean meal 30% (S), and S supplemented with phytase at 1000, 2000, 3000 and 4000 phytase activity units (FTU) kg − 1 (SP 1000, SP 2000, SP 3000 and SP 4000, respectively). Twenty fish (initial mean weight ca. 24 g) were stocked into each of twelve 300-l tanks and two tanks were assigned randomly to each diet. Fish were fed their respective diets for 6 weeks, twice daily until satiation to investigate the growth performance. Fish were then transferred into separate fecal collection columns to investigate digestibility. This experiment was run for another 4 weeks with a similar feeding protocol and 0.5% chromic oxide (Cr 2O 3) was included as an inert marker. The partial replacement of fish meal by soybean meal in diet S resulted in reduced weight gain, specific growth rate (SGR), digestibility and retention efficiencies of nutrients and energy; however, all parameters were increased significantly in fish fed diet SP 2000 ( P < 0.05). Phosphorus discharge was also significantly reduced in fish fed diet SP 2000 compared to the fish fed diets F and S. The growth performance in fish fed diet SP 2000 was as good as those fed diet F. Phytase dosage higher than 2000 FTU kg − 1 , however, did not further improve growth performance. This suggests that the optimum dosage of phytase in the diet including 40% fish meal and 30% soybean meal was approximately 2000 FTU kg − 1 for red sea bream.

Dietary oligochitosan supplementation enhances immune status of broilers

AbstractOligochitosan (COS) is a type of prebiotic, which favourably alters the intestinal microflora balance, inhibits the growth of harmful bacteria, promotes good digestion and boosts immune function. The effect of dietary COS supplementation on immune function in broilers was assessed by feeding graded levels (0, 50, 100, 150 mg kg−1) of COS. Two thousand four hundred male commercial Avian® broilers (1 day old) were assigned randomly to five dietary treatment groups (60 birds/pen with eight pens per treatment). Diet A was a typical maize‐ and soybean meal‐based diet supplemented with 6 mg kg−1 antibiotics of flavomycin (positive control). Diet B was the basal diet without any supplement. Diets C, D and E were formulated by addition of 50, 100, 150 mg kg−1 of COS to the basal diet, respectively. On the morning of days 21 and 42, a total of 64 (eight birds/pen with eight pens per treatment) of the growth experimental birds were killed by cervical dislocation, respectively for determination of serum concentrations of IgG, IgA and IgM, and weights of spleen, bursa and thymus. Compared with broilers fed the control and the positive control diets, dietary supplementation with COS increased (P &lt; 0.001) serum concentrations of IgG, IgA, and IgM, with the greatest response for the 100 mg kg−1COS supplementation. Chitosan oligosaccharides supplementation also enhanced the immune organ development. Results suggest COS can improve immune response in birds. Through positive modulation of the immune response, COS has great potential as an effective, antibiotic‐like growth promoter for poultry. Copyright © 2006 Society of Chemical Industry

Nutritive Value of Mulberry (Morus Spp.) Leaves in the Growing Rabbits in Nigeria

The potential of mulberry leaves in rabbit production was investigated in a 12-week long experiment where feed intake, weight gain and nutrient digestibility of the rabbits were monitored. Thirty weaner rabbits (19 females and 11 males; mean weight = 450 ± 0.05 g) of mixed breeds were sorted by weight and randomly allocated to five experimental diets. The percentage of concentrate in the rations was incrementally replaced with mulberry leaves: 100:0, 75:25, 50:50, 25:75, 0:100 and were fed in a completely randomized design. Total dry matter (DM) intake of the concentrate: mulberry diet remained at the level of that of the all-concentrate ration (~38 g/d) until mulberry leaves comprised >50% of the ration before it declined significantly. The intakes of crude protein (CP) and crude fiber (CF) increased significantly while those of ether extract (EE), ash and nitrogen free extract (NFE) decreased significantly with increasing level of mulberry leaves in the diets, following the trends of the concentrations of the nutrients in the materials. The nutrient digestibilities of the diets were high and there were no significant differences among the means for DM (75.67 82.33%), organic matter (OM: 77.33 86.67%), CP (76.33 84.00%), CF (79.67 88.67%), and ash (52.00 62.67%). Digestibility of EE (55.65 86.00%) and NFE (76.00 87.33%) significantly declined with increasing level of mulberry leaves in the rations. Weight gain of rabbits on diets containing 25 and 50% mulberry leaves (5.14 and 4.72 g/d, respectively) was not significantly different (P=0.05) from that of the allconcentrate ration (5.72 g/d), but these were significantly higher than those of 25:75 and 0:100 concentrate: mulberry diets (3.43 and 2.27 g/d, respectively). Thus, mulberry leaves can support good feed intake, digestibility and satisfactory weight gain in rabbits, and could reduce reliance on and cost of expensive concentrate diets. However, some level of concentrate feeding is necessary to reach potential weight gains.

In vivo dry matter and protein digestibility of three plant-derived and four animal-derived feedstuffs and diets for juvenile Australian redclaw, Cherax quadricarinatus

Dry matter and protein digestibility of three plant-derived and four animal-derived feedstuffs and diets in which they were included were evaluated for juvenile Australian redclaw. The ingredients evaluated were: soy paste, textured wheat, sorghum meal, two sardine meals (67% and 58% crude protein), squid meal, and red crab meal. A reference diet was formulated and produced in the CIBNOR nutrition laboratory. Seven experimental diets were then made including 15% of each ingredient in the reference diet. The experiment consists of a single-factor, completely randomized design with five replicates per treatment. Digestibility was measured indirectly, using chromic oxide as a marker. Plant-derived ingredients and the corresponding diets had, in general, a higher digestibility than animal ingredients. Soy paste and sorghum meals, and the diets in which they were included, showed an excellent dry matter (over 87%) and protein (approximately 90%) digestibility. Some of the animal ingredients such as sardine meal 67% CP and squid meal had a good dry matter digestibility (over 80%), but were significantly lower than plant-derived ingredients. The lowest dry matter and protein digestibility was recorded for sardine meal 58% CP and red crab meal. It is concluded that juvenile redclaw are omnivorous and able to efficiently consume diets containing plant- and animal-derived ingredients, but they can digest plant-derived ingredients more efficiently.

Avaliação do desempenho do reator anaeróbio de manta de lodo (uasb) em escala laboratorial na remoção da carga orgânica de águas residuárias da suinocultura

Objetivou-se com o presente trabalho avaliar o desempenho do reator anaeróbio de manta de lodo (UASB-Upflow Anaerobic Sludge Blanket) construído em escala laboratorial na redução da carga orgânica poluidora dos despejos suinícolas brutos. O sistema completo foi composto de um tanque de acidificação e equalização, reator UASB e lagoa aerada facultativa. O tempo de detenção hidráulica (TDH) e temperatura adotada para o reator UASB foram de 30 horas e 30 ºC, respectivamente. Os valores médios afluentes de DQO T, ST e SVT foram de 1806, 1810 e 1240 mg.L-1. As eficiências de remoção de DQO T, ST e SVT foram de 84, 58 e 73%, respectivamente. O sistema se apresentou-se estável, com boas condições de tamponamento, retenção e digestibilidade de sólidos, demonstrando que os critérios adotados foram adequados, principalmente aqueles referentes ao TDH, carga orgânica volumétrica (COV) e temperatura.

Dietary lipid sources for seabream and seabass: growth performance, tissue composition and flesh quality

Due to its traditionally good availability, digestibility and high content of n − 3 HUFA, fish oil is the main lipid source in fish feeds. However, world demand for this product has grown significantly in recent years, whereas its production, based on fisheries landings, is static. The purpose of the present study was to assess the effect of partial replacement of fish oil in compound diets for gilthead seabream and seabass, by several vegetable oil sources, on growth, dietary fatty acid utilization and flesh quality. Five iso-energetic and isoproteic experimental diets were formulated (25% lipid content). Fish oil was the only added lipid source in the control (FO) diet, and it was included in the other experimental diets at a level high enough (40% of FO diet) to keep the n − 3 HUFA levels well over 3% in order to cover the essential fatty acid requirements of these species. Fish oil was replaced by soyabean oil (SO), rapeseed oil (RO) and linseed oil (LO) or a mixture (Mix) of them. Feed intake in all dietary groups was in the range of results obtained for commercial diets in both species, and growth and feed utilization were very good. The results show that, providing a minimum content of essential fatty acids in the diet, it is possible to replace up to 60% of the fish oil by SO, LO and RO or a mixture of them in diets for seabream and seabass, without compromising fish growth. Fatty acid composition of liver and muscle reflected that of the diet, but utilization of dietary lipids differed between these two tissues and was also different for the different fatty acids. Despite reduction in dietary saturated fatty acids by the inclusion of vegetable oils, their levels in fish liver were as high as in fish fed the fish oil diet, whereas, in muscle, levels were reduced according to that in the diet. Linoleic and linolenic acids were accumulated in the liver proportionally to their levels in the diet, suggesting a lower oxidation of these fatty acids in comparison to other 18C fatty acids. Regarding eicosapentaenoic acid (20 : 5n − 3; EPA), docosahexaenoic acid (22 : 6n − 3; DHA) and arachidonic acid (20 : 4n − 6; ARA), these essential fatty acids were reduced in the liver at a similar rate, whereas DHA was preferentially retained in the muscle in comparison with the other fatty acids, denoting a higher oxidation particularly of EPA, in the muscle. Some other PUFA increased despite their low dietary levels in seabream fed LO diets and in seabass fed SO diet, suggesting the stimulation of delta-6 and delta-5 desaturase activity in marine fish. Despite differences in fatty acid composition, fillet of fish fed vegetable oils was very well accepted by trained judges when assessed cooked.

The Indian Club Exercise

INDIAN CLUB SWINGING became widely popular as a form of physical exercise after the Civil War. This image comes from S. D. Kehoe’s book The Indian Club Exercise (1866); the practice of club swinging was said to produce the ideal, lean male body, exercising both mind and body. Indian clubs were so named because the soldiers of the British army in India had adopted and adapted a native exercise and brought it back to England in the middle decades of the 19th century.1 In the United States, baseball teams soon practiced with the clubs, as did the crew teams of Harvard and Yale. Indian clubs, along with other forms of rhythmic gymnastic exercises, were associated with “muscular Christianity,” a social gospel that affirmed the importance of physical fitness for mental and moral improvement. Proper physical exercise built bodily strength and, with it, character and righteousness—shaping young men for God’s work, and for the nation’s.2 Gymnastic exercises—ideally, ones that exercised all the muscles in a balanced fashion and combined all ranges of motion—were said to counteract the dangerous tendencies toward nervous exhaustion, moral dissipation, and spiritual decadence associated with modern life in the big cities. Moses Coit Tyler, who would become the first professor of history in the United States, explained (in the words of the fictional Judge Fairplay of Brawnville): “It is as truly a man’s moral duty to have a good digestion, and sweet breath, and strong arms, and stalwart legs, and an erect bearing, as it is to read his Bible, or say his prayers, or love his neighbor as himself.”3 In 1861, Amherst College was the first to introduce physical culture and gymnastics—including exercises with Indian clubs—as a required subject at the collegiate level.4 Physical exercise came to be regarded as a mark of manliness and a religious and patriotic duty. By 1901, 270 colleges offered physical education, 300 city school systems required physical exercises, 500 Young Men’s Christian Association (YMCA) gymnasiums had 80 000 members, and more than 100 gymnasiums were associated with athletic clubs, military bases, and other institutions.