Acid Silage Research Articles

Fatty acid concentration and proximate composition of acid silage from Nile tilapia (Oreochromis niloticus) waste, farmed in Indaiatuba – SP

This study was conducted to determine the composition and fatty acid profile of the Nile tilapia waste silage with the aim of investigating its nutritional potential. Four lots (5 kg each) of Nile tilapia waste was ground with 3% (w/w) formic acid, stored at 27°C room temperature for 90 days in polyethylene boxes with holes, through which gases went out and then the levels of moisture, protein, ash and total lipids were analyzed obtaining: 77.25, 16.31, 3.17 and 3.26% respectively. 22 types of fatty acids were identified in the range of 10 to 22 carbon atoms and the most abundant was oleic acid-18:1 (22:14%), followed by palmitic acid-16:0 (18.2%). Approximately 97% of fatty acids (FA) were identified in the silage, being 30.81% of saturated fatty acids (SFA), 38.42% of monounsaturated fatty acids (MUFA) and 27.32% of polyunsaturated fatty acids (PUFA) which characterize this product as an important source of essential fatty acids. All parameters indicate a good nutritional potential for acid silage of Nile tilapia, mainly in relation to fatty acids and protein content.

Effect of jaggery on the quality and intake levels of maize silage

Silage, which is anaerobically fermented green fodder, is valued throughout the world as a source of animal feed during lean months. Several farms in India use carbohydrate sources like jaggery or molasses at 2% for preparation of silage, and this increases cost of production. The present study was undertaken to assess the effect of jaggery on quality and intake of maize silage, with an objective to find out whether additional carbohydrate source is essential in preparation of silage using green maize. Three silage types, one without jaggery (A), the second with 1% jaggery (B), and the third with 2% jaggery (C) were prepared in cylindrical bins under similar conditions. They were compared for colour, pH, lactic acid bacteria count, lactic acid content, proximate composition and silage intake by sheep. Silage type C with 2% jaggery was significantly different from the other two types with values of 3.98 and 805.66 g for pH and mean silage intake, respectively. Even though the values of pH and dry matter intake for all three silage types were within normal levels, silage type C was significantly superior in terms of fermentation and palatability. The method of preparation followed could be ideal for small holder farmers requiring less quantity of silage.

Effect of Ensilaging and Organic Solvent Treatment on Activity of Proteases from Chicken Intestine

Studies were carried out to assess the extractability of proteins from chicken intestine and to determine the activity of proteases in crude extract. Further, the activity of proteases was evaluated in acid and fermented chicken intestinal silage as well as in organic solvent-treated intestinal samples. Extractability of proteins was in the range of 3.85–4.06 mg/ml and was not affected (p ≥ 0.05) by the four different extractants, viz., distilled water, phosphate buffer, and 1% potassium chloride with or without 0.1 M Na2EDTA. The specific activity of acidic and alkaline proteases were in the range of 4.78–7.26 and 19.31–24.07 units, respectively, and was not affected (p ≥ 0.05) by the type of extractant used. The pH profile for activity showed higher activity in the alkaline pH range. Addition of acid or ingredients for fermentation reduced the extractability of protein significantly (p ≤ 0.05). During storage of silage, the reduction in enzyme activity was higher in acid silage compared with fermented silage. Treatment of chicken intestine with organic solvents enhanced the enzyme activity and higher increase was observed with isopropyl alcohol-treated intestine. During storage of solvent-treated powders up to 3 months, the activity of proteases reduced in all the solvent-treated samples highest being in acetone-treated powder.

Silagem ácida do resíduo do camarão Litopenaeus vannamei em rações para tilápia do Nilo

Isoproteic (30% DP) and isoenergetic (3,200 kcal kg -1 ) diets were formulated using acid silage of shrimp waste as alternative protein source at five levels (0, 4, 8, 12 and 16%). Two hundred fish (7.2 ± 0.5 g) were randomly distributed in 20 tanks of 100 L at a density of 10 fish tank-1 in a closed recirculation water system. The experiment was accomplished in a completely randomized design with 5 treatments and 4 replicates. Growth performance and proximal composition parameters of the muscular tissue were evaluated to tilapia fed three times a day to satiation during sixty days. Quadratic effect (p L. vannamei waste provide better growth performance, without losses in proximate composition of the muscular tissue, with 2.75% of inclusion in fingerling Nile tilapia diets

The effect of Lactobacillus buchneri 40788 or Lactobacillus plantarum MTD-1 on the fermentation and aerobic stability of corn silages ensiled at two dry matter contents

Whole-plant corn was harvested at 33 (normal) and 41% (moderately high) dry matter (DM) and ensiled in quadruplicate 20-L laboratory silos to investigate the effects of Lactobacillus buchneri 40788 (LB) or L. plantarum MTD-1 (LP) alone, or in combination, on the fermentation and aerobic stability of the resulting silage. Aerobic stability was defined as the amount of time after exposure to air for the silage temperature to reach 2°C above ambient temperature. The chopped forage was used in a 2×2×2 factorial arrangement of treatments: normal and moderately high DM contents, LB at 0 (untreated) or 4×105 cfu/g of fresh forage, and LP at 0 or 1×105 cfu/g. After 240 d of ensiling, corn silage harvested at the moderately high DM had higher pH, higher concentrations of ethanol, and more yeasts compared with the silage ensiled at the normal DM content. Inoculation with LB did not affect the concentration of lactic acid in silages with a moderately high DM, but decreased the concentration of lactic acid in the silage with normal DM. Higher concentrations of acetic acid were found in the silage treated with LB compared with those not treated with this organism. Inoculation with LP increased the concentration of lactic acid only in the silage with the normal DM content. The concentration of acetic acid was lower in silage treated with LP with a moderately high DM content, but greater in the silage treated with LP with the normal DM content when compared with silages without this inoculant. Appreciable amounts of 1,2-propanediol (average 1.65%, DM basis) were found in all silages treated with LB regardless of the DM content. The addition of L. buchneri increased the concentration of NH3-N in silages but the addition of L. plantarum decreased it. Aerobic stability was improved in all silages treated with LB, with greater aerobic stability occurring in the silage with moderately high DM compared with silage with normal DM content. Inoculation with LP had no effect on aerobic stability. There were no interactions between L. buchneri and L. plantarum for most fermentation products or aerobic stability of the silages. This study showed that inoculating whole-plant corn with L. buchneri 40788 or L. plantarum MTD-1 has different beneficial effects on the resulting silage. There appear to be no major interactions between these organisms when added together to forage. Thus, there is potential to add both organisms simultaneously to improve the fermentation and aerobic stability of corn silage.

Bacterial Inoculant Effects on Corn Silage Fermentation and Nutrient Composition

The survival and effect of three new probiotic inoculants (Lactobacillus plantarum CCM 4000, L. fermentum LF2, and Enterococcus faecium CCM 4231) on the nutritive value and fermentation parameters of corn silage was studied under laboratory conditions. Whole corn plants (288.3 g/kg DM) were cut and ensiled at 21°C for 105 days. The inoculants were applied at a concentration of 1.0×10 9 cfu/ml. Uninoculated silage was used as the control. The chopped corn was ensiled in 40 plastic jars (1 L) divided into four groups (4x10 per treatment). All corn silages had a low pH (below 3.55) and 83-85% of total silage acids comprised lactic acid after 105 days of ensiling. The probiotic inoculants in the corn silages affected corn silage characteristics in terms of significantly (p<0.05-0.001 ) higher pH, numerically lower crude protein content and ratio of lactic to acetic acid compared to control silage. However, the inoculants did not affect the concentration of total silage acids (acetic, propionic, lactic acids) as well as dry matter digestibility (IVDMD) of corn silages in vitro. In the corn silages with three probiotic inoculants, significantly (CCM 4231, CCM 4000) lower n-6/n-3 ratio of fatty acids was detected than in control silage. Significant decrease in the concentration of C 181 and significant increase in the concentration of C 182 and C 18 3 was mainly found in the corn silages inoculated with the strains E. faecium CCM 4231 and L. plantarum CCM 4000. At the end of ensiling, the inoculants were found at counts of less than 1.0 log10 cfu/g in corn silages.

Effects on digestibility and growth of juvenile cobia (Rachycentron canadum) fed fish or crab silage protein

The study was conducted in Cam Ranh, Vietnam, in 1000-L tanks supplied with recirculated and biofiltered saltwater (33‰ and 28.4 °C) to evaluate the potential use of lizard fish (Saurida undosquamis) or blue crab (Portunus pelagicus) acid silage protein for juvenile cobia (23–25 g). Six isoenergetic test moist diets (4915–5125 kcal kg−1), using either raw fish diet, fish silage diet (FSD), raw crab diet, crab silage diet (CSD), mixed raw fish/raw crab diet or mixed fish/crab silage diet (MSD), as part of the protein sources in the steam-cooked diets, were fed to satiety to triplicate groups of 20 fish each for a 6-week growth trial. Y2O3 was added as an inert indicator to determine the apparent digestibility coefficients (ADC) for macro nutrients and gross energy. Weight gain (185–286%) and specific daily growth rate (2.5–3.2% per day) were significantly higher in cobia fed the raw-based diets and FSD than in fish fed CSD and MSD (34–90 and 0.7–1.5% per day). Feed conversion ratios (FCR) were significantly higher in the groups fed CSD and MSD diets (2.1–6.5) than the groups fed the other diets (1.0–1.2), resulting in significantly lower protein productive values (0.1–0.2) in the groups fed CSD and MSD than in the other groups (0.3–0.4). The FCR results were confirmed by significantly lower ADC values in fish fed CSD and MSD than those in fish fed the other diets. We thus conclude that the present raw-based diets were better utilized by juvenile cobia than silage-based diets, particularly the diet made from crab silage.

Laboratory investigations on continuous bio-methanization of energy crops as mono-substrate without supplementation

Abstract Continuous bio-methanization of an energy crop, namely the beet silage, was investigated in this laboratory-scale work as mono-substrate, using a mesophilic biogas digester controlled by a fuzzy logic control (FLC) technique and without using any supplementing or buffering agent, despite the low pH of the substrate around 3.80. The temperature, pH, redox potential (ORP), daily biogas production and composition of digester biogas were continuously measured online. During the operation, the hydraulic retention time (HRT) varied between 24.8 and 9 days, as the organic loading rate (OLR) ranged from 2.6 to 4.7 g L −1 d −1 . The average pH, specific gas production rate (spec. GPR) and volumetric gas production rate (vol. GPR) were determined to be 7.12, 0.31 L g VS −1 d −1 and 1.084 L L −1 d −1 , respectively. The average methane (CH 4 ) content of digester biogas was about 56%. The FLC technique, which was developed at HAW Hamburg for anaerobic conversion of acidic energy crops to methane, determined the daily feeding volume (∼ OLR/HRT) for the biogas digester, depending on the feedback from online pH and methane measurements, and on the calculation of the spec. GPR. The spec. GPR was calculated by the corrected daily biogas production. Through online monitoring of pH, biogas production rate and composition, and by use of the FLC technique, the acidic beet silage could continuously be converted to biogas, without using manure or any other kind of buffering or supplementing agent(s). The lab-scale anaerobic biogas digester performed stable and safe, without encountering any problems of instability, as indicated by an adequate amount of buffering capacity, a VFA content below 0.5 g L −1 and a neutral pH range throughout the study.

Cause of Damage and Failures in Silo Structures

Silos are special structures subjected to many different unconventional loading conditions, which result in unusual failure modes. Failure of a silo can be devastating as it can result in loss of the container, contamination of the material it contains, loss of material, cleanup, replacement costs, environmental damage, and possible injury or loss of life. Silo damage and failures that occurred in different regions of the world are presented in the paper using illustrative photos. Also provided are a review and discussion of the common or spectacular silo failures due to explosion and bursting, asymmetrical loads created during filling or discharging, large and nonuniform soil pressure, corrosion of metal silos, deterioration of concrete silos due to silage acids, internal structural collapse, and thermal ratcheting. Silo damage and failures from several earthquakes are also presented.

COMPOSIÇÃO EM ÁCIDOS GRAXOS DAS SILAGENS ÁCIDA, BIOLÓGICA E ENZIMÁTICA DE PESCADO

A utilização da silagem de pescado como ingrediente em rações para organismos aquáticos constitui alternativa para solucionar os problemas de ordem sanitária e ambiental, causados pela falta de destino adequado dos resíduos gerados pela indústria do pescado. Além disso, podem diminuir os custos com alimentação e, conseqüentemente, os custos de produção do pescado, já que os gastos com a alimentação correspondem a aproximadamente 60% do custo total. O objetivo deste estudo foi avaliar a composição em ácidos graxos da silagem ácida (SA), silagem biológica (SB) e silagem enzimática (SE), produzidas a partir de descartes e resíduos do processamento da tilápia do Nilo (Oreochromis niloticus). Os valores encontrados de lipídios (base na matéria seca) foram: 12,45; 12,25 e 12,17 g.100 g-1 para SB, SA e SE, respectivamente. Os ácidos graxos predominantes na fração lipídica das silagens são os insaturados. O ácido oléico foi encontrado em maiores quantidades (30,49; 28,60 e 30,60 g 100 g-1 de lipídios para SB, SA e SE, respectivamente). Entre os ácidos graxos saturados, o palmítico e o esteárico estavam presentes em maiores quantidades. Apenas traços dos ácidos graxos poliinsaturados eicosapentaenóico (EPA) e docosahexaenóico (DHA) foram encontrados. As silagens produzidas a partir de descartes da piscicultura e resíduos do processamento da tilápia do Nilo não são boas fontes de EPA e DHA em dietas para peixes.

Desempenho produtivo e digestibilidade pela tilápia do NILO (Oreochromis niloticus Linnaeus, 1758) alimentada com dietas suplementadas com níveis crescentes de silagem ácida de pescado

Conduziram-se estes experimentos para avaliar os coeficientes de digestibilidade aparente dos nutrientes e da energia bruta da silagem ácida de resíduos da filetagem de tilápias e o desempenho produtivo da tilápia alimentada com dietas contendo (0, 10, 20, 30 e 40%) da silagem ácida em substituição à farinha de peixe. Na digestibilidade foram utilizados 200 alevinos revertidos sexualmente, com peso médio de 5,0 g e acondicionados em aquários de 40 litros. A coleta de fezes foi feita por metodologia indireta, utilizando-se 1,0% de Cr2O3 como indicador, incorporado à ração. No desempenho foram utilizados 2000 alevinos de tilápia nilótica, com peso médio inicial de 0,525g, acondicionados em hapas de 1m², dispostos em 1 viveiro escavado. As variáveis analisadas foram: ganho de peso final (GPF), consumo de ração total (CRT), conversão alimentar aparente (CAA) e acréscimo em comprimento (AC). O delineamento experimental foi o inteiramente casualizado, com cinco tratamentos e quatro repetições. Os valores de digestibilidade encontrados foram: coeficiente de digestibilidade aparente da matéria seca (CDA), 95,5%; CDA da proteína bruta, 96,7%; CDA do extrato etéreo, 97,2% e CDA da energia bruta, 95,4%. Não houve diferença significativa no consumo de ração total. Observou-se efeito quadrático para ganho de peso final, conversão alimentar aparente e acréscimo em comprimento. Conclui-se que este alimento pode ser eficientemente utilizado pela tilápia nilótica.

FERMENTATION PROCESS CHARACTERISTICS OF DIFFERENT MAIZE SILAGE HYBRIDS

The aim of this study was to detect the fermentation process differences in different hybrid maize silage. We conserved in laboratory conditions hybrids of whole maize plants with different length of the vegetative period (FAO number). Maize hybrids for silage were harvested in the vegetation stage of the milk-wax maturity of corn and the content of dry matter was from 377.7 to 422.8 g.kg-1. The highest content of dry matter was typical for silages made from the hybrids with FAO number 310 (400.0 g.kg-1) and FAO 300a (400.4 g.kg-1). The content of desirable lactic acid ranged from 23.7 g.kg-1 of dry matter (FAO 350) to 58.9 g.kg-1 of dry matter (FAO 420). We detected the occurrence of undesirable butyric acid in silages from hybrids FAO 250, 300b, 310 and 380. The highest content of total alcohols we found in silages made from hybrid with FAO number 240 (25.2 g.kg-1 of dry matter). Ammonia contents were in tested silages from 0.153 (FAO 270) to 0.223 g.kg-1 of dry matter (FAO 240). The lowest value of silage titration acidity we analyzed in silage made from hybrid FAO 420 (3.66). We observed in maize silages with different length of plant maturity tested in the experiment differences in content of lactic acid, total alcohols, titration acidity, pH and content of fermentation products.

Effect of fibrolytic enzymes and an inoculant on in vitro degradability and gas production of low‐dry matter alfalfa silage

AbstractBACKGROUND: The objective of this study was to investigate the effect of polysaccharide‐degrading enzymes (a cellulase and a xylanase) alone or in a combination with a bacterial inoculant on fermentation parameters and in vitro degradability and gas production of low‐dry matter (DM) alfalfa silage. First cut alfalfa (Medicago sativa L.), harvested at about 5% bloom stage [260 g kg−1 dry matter (DM)] was ensiled in laboratory‐scale silos without preservatives or preserved with formic acid, a cellulase (Cell), a xylanase, a cellulose/xylanase enzyme combination (Cell/Xyl), a lactic acid bacteria‐based inoculant (Inoc), and a mix of Inoc and Cell (Inoc/Cell). Triplicate silos were opened on days 1, 3, 7, 15 and 60.RESULTS: Silage pH and ammonia N and total free amino acids concentrations were the lowest (P &lt; 0.05) for the formic acid silage. Inoc and Inoc/Cell produced the highest (P &lt; 0.05) lactate concentration in the 60‐day silage. In vitro degradability of silage DM was not affected (P = 0.998) by treatment, but amylase‐treated neutral detergent fiber degradability was increased (P &lt; 0.05) by formic acid. Compared with the control (51.3 mL 100 mg−1 silage DM), all treatments except Cell/Xyl increased (P &lt; 0.001) the 24 h cumulative gas production.CONCLUSIONS: Overall, enzyme and lactic acid bacteria‐based preparations had minor effects on silage fermentation in this experiment. The increased cumulative gas production indicates some preservation or liberation of fermentable organic matter with most treatments tested. It is not clear, however, to what extent this effect would impact silage ruminal degradability in vivo. Copyright © 2008 Society of Chemical Industry

CARACTERÍSTICAS FERMENTATIVAS E COMPOSIÇÃO QUÍMICO-BROMATOLÓGICA DE SILAGENS DE CAPIM-ELEFANTE COM OU SEM Lactobacillusplantarum E FARELO DE TRIGO ISOLADAMENTE OU EM COMBINAÇÃO

To evaluate the addition effects of Lactobacillus plantarum or wheat meal, or both on the losses by gases, dry matter recovery, pH, N-NH3, lactic acid and chemical composition of elephant grass silages, this research was carried out. The experimental design was entirely randomised, with four treatments: Elephant grass silage; Elephant grass silage inoculated with Lactobacillus plantarum; Elephant grass silage + 10% of wheat meal in natural matter; Elephant grass silage inoculated with Lactobacillus plantarum + 10% of wheat meal in natural matter, with four replicates per treatment. The grass was ensiled in 5 liters buckets, with bunsen valve for escape of the gases. There was effect (P>0,05) of the wheat meal addition and of the inoculation on the losses by gases, dry matter (DM) recovery, pH and lactic acid of silages, and the combination of wheat meal and inoculant presented the smallest pH value, increased lactic acid content and decreased gas losses. The largest values of dry matter and smaller of NDF were observed in the silages with wheat meal, with or without inoculant. The inoculation reduced hemicellulose (HEM) content, in the silages with or without wheat meal, resulting in smaller NDF values, when compared to the non inoculated silages. Increases were fund in the protein content of the silages with the tested additives, being the highest value observed when both additives were present. One concludes that the inoculation with both Lactobacillus plantarum and wheat meal reduces dry matter losses and improve the quality of elephant grass silage, being the largest improvement observed when these addictive are combined. Key-words: Additive, inoculants, Penisetum purpureum, silage conservation.

Apparent digestibility coefficient of protein and amino acids of acid, biological and enzymatic silage for Nile tilapia (Oreochromis niloticus)

Using the fish silage to partially replace proteic feedstuff in aquafeeds is an alternative to mitigate sanitary and environmental problems caused by the lack of adequate destination for fisheries residues. It would also lower feed costs, consequently improving fish culture profitability. However, using fish silages in aquafeeds depends on determination of its apparent digestibility coefficients (ADC). This work aimed to determining the ADC of crude protein and amino acids of acid silage (AS), biological silage (BS) and enzymatic silage (ES) for juvenile Nile tilapia (94.5 ± 12.7 g). The ADCCP was: 92.0%, 89.1% and 93.7% for AS, BS and SE respectively. The average ADC of amino acids was: 91.8%, 90.8% and 94.6% for AS, BS and ES respectively. Results encourage the use of AS, BS and ES to partially replace protein sources in balanced diets for neotropical fish.

Preparation of silage from Spanish mackerel ( Scomberomorus maculatus) and its evaluation in broiler diets

The aim of the present study was to prepare silage from whole Spanish mackerel, which is one of the cheapest commercial fish, and an under-utilized species found on both the Pacific and Gulf of Mexico coasts. Chemical and biochemical changes during the silage process: pH, total nitrogen (TN), non-protein nitrogen (NPN), lipid oxidation, and trimethylamine (TMA) generated were monitored. The effect of ter-butylhydroquinone (TBHQ) as antioxidant under mechanical stirring and stabilized temperature was also observed. The liquid silage obtained was mixed with sorghum (1:2 w/w), and dried in the sun. This silage-sorghum flour was used to prepare five diets with different silage-sorghum mix inclusions, and evaluated in a 21 d feeding trial with broilers. During the silage process the NPN increased significantly by 85% from the original total nitrogen at 96 h. The protein content in the dried silage and in the silage-sorghum mix was 653 and 169 g kg −1 on a dry matter basis, respectively. Minerals were found in high concentration in both fishmeal and silage, since the whole fish with bones and scales was used to prepare the silage, being Ca and P, which were at a higher concentration. Trp was the AA most affected by the silage process. Its concentration in the silage was decreased by 54% compared to that of fishmeal. However, the addition of sorghum supplemented the deficiency of this amino acid in silage. Most of the fatty acids were protected by the antioxidant and the ratio PUFA (poly unsaturated fatty acid) n-3/ n-6 in fishmeal and silage was 4.7 and 4.9, respectively. In the feeding trial, no differences were found between the weight gain and feed conversion of the control diet and the four diets prepared with increasing amounts of silage-sorghum mix ( P<0.05). It can be concluded that silage-sorghum mix is a good alternative to use as fish wastes or undesirable marine species in poultry feeding. The process does not require sophisticated equipment and the environment is protected.

Effects of plant species, stage of maturity and additive on the feeding value of whole‐crop cereal silage

AbstractThis experiment aimed to study the effects of plant species, stage of maturity, additive and their interactions on yield, chemical composition and fermentation characteristics of whole‐crop cereal silage. Barley, triticale, oats and spring wheat were harvested at the early milk stage or at the early dough stage of maturity in 2002 and 2003 with three field replicates of the plant species within each year. Proens™ (Perstorp Inc, Perstorp, Sweden), which contained 2/3 formic acid and 1/3 propionic acid, was applied at 4 L tonne−1 herbage and Lactisil 200® NB (Medipharm Inc, Kågeröd, Sweden), which contained Lactobacillus plantarum, Enterococcus faecium, Pediococcus acidilactici, Lactococcus lactis, cellulase and sodium benzoate, was applied at 200 000 colony‐forming units g−1 herbage, and both applications were compared to untreated silage. Unwilted herbage, chopped at 12 mm length, was ensiled in 4‐L laboratory silos for 90 days. Barley had more starch whereas triticale had more sugar and crude protein but less neutral detergent fibre than other species (P &lt; 0.001). Barley and triticale had less acid detergent fibre and lignin but greater in vitro organic matter (OM) digestibility than oats and spring wheat (P &lt; 0.0001). Averaged over maturity stages, wheat had a greater yield of digestible OM than barley and oats (P &lt; 0.0001). Yield of digestible OM and concentration of starch increased whereas sugar concentration decreased with later maturity stage (P &lt; 0.0001). Late harvest increased the risks for high levels of butyric acid in silage when no additives were used (P = 0.002). Additives resulted in increased lactic:acetic acid ratios but decreased protein degradation and DM losses (P &lt; 0.0001). Acid treatment was more effective than inoculation to degrade starch and to decrease protein degradation and DM losses during ensiling (P &lt; 0.0001). Harvest at the early milk stage of maturity resulted in more lactic acid and a lower pH than harvest at the early dough stage of maturity (P &lt; 0.0001). When considering both maximal yield of digestible organic matter and good silage quality, triticale, wheat or barley silage harvested at the early dough stage of maturity and ensiled with acid or inoculant is suggested. Copyright © 2007 Society of Chemical Industry

Effects of different dietary levels of fish protein hydrolysates on growth, digestive enzymes, gut microbiota, and resistance to Vibrio anguillarum in European sea bass (Dicentrarchus labrax) larvae

Two fish protein hydrolysates (FPH) were incorporated into four diets prepared for start-feeding sea bass larvae, at two different levels (10% and 19% of total ingredients): a commercial FPH, CPSP, in which the molecular mass of the main fraction of soluble peptides (51%) was between 500-2500 Da, and an experimental FPH obtained by acidic silage of sardine offal, SH, with a main portion of soluble peptides (54%) ranging from 200 to 500 Da. The diet with 10% of the commercial FPH gave the best results in terms of growth, survival and intestinal development, as evaluated by the early activity of digestive enzymes in the brush border membrane (alkaline phosphatase and aminopeptidase N). This was related to the low level of Vibrio spp. counted in the larvae of group C10. The high dose of FPH, especially in the experimental preparation rich in short peptides, seemed to favour the dominance of Vibrio sp. TYH3, which behaved opportunistically. The effect of the experimental FPH was ambiguous, since early larvae challenged with Vibrio anguillarum were more resistant to the pathogen, especially at high FPH dose (group S19). This might be due either to direct antagonism between V. anguillarum and Vibrio sp. TYH3, or to the stimulation of the immune response in the larvae. These results indicate that different molecular weight fractions and concentrations of feed-soluble peptides may affect the growth performance and immunological status of sea bass larvae. Consequently, a low dose of commercial FPH seems advisable, both for larval development and for the bacterial environment, although further research is required to determine and characterize peptide fractions that may have a beneficial effect on growth and immune response, and to determine their optimal inclusion levels in diets for sea bass larvae.

Dry Matter Intake of &quot;Acetic Acid Silage&quot; Made from Guineagrass (Panicum maximum Jacq.) by Breeding Japanese Black Cattle

Dry Matter Intake of &quot;Acetic Acid Silage&quot; Made from Guineagrass (Panicum maximum Jacq.) by Breeding Japanese Black Cattle

Digestibilidade e desempenho de alevinos de tilápia do nilo (Oreochromis Niloticus) alimentados com dietas contendo diferentes níveis de silagem ácida de pescado

Os experimentos foram conduzidos para avaliar os coeficientes de digestibilidade aparente dos nutrientes e da energia bruta da silagem ácida de resíduos da filetagem de tilápia do Nilo (Oreochromis niloticus) para alevinos de tilápia nilótica e o desempenho dos alevinos recebendo níveis crescentes (0, 10, 20, 30, 40 %) da silagem ácida em substituição à farinha de peixe na ração. Na digestibilidade foram utilizados 200 alevinos revertidos sexualmente, com peso médio de 2,0 g e acondicionados em aquários de 40 litros. A coleta de fezes foi feita durante 7 dias seguintes e a determinação dos coeficientes de digestibilidade aparente e energia metabolizável aparente foi feita por metodologia indireta, tendo sido utilizado 1% de Cr2O3 como indicador incorporado à ração. No desempenho, foram utilizados 2000 alevinos revertidos sexualmente com peso médio de 0,45 g, acondicionados em "hapas" de 1m², dispostos em um viveiro escavado. As variáveis analisadas foram: ganho de peso final (GPF), consumo de ração total (CRT), conversão alimentar aparente (CAA), acréscimo em altura (AA) e em comprimento (AC). O delineamento utilizado foi o inteiramente casualizado, com 5 tratamentos e 4 repetições. Os valores de digestibilidade encontrados foram: coeficiente de digestibilidade aparente da matéria seca, 95,49%; coeficiente de digestibilidade aparente da proteína bruta, 96,66%; coeficiente de digestibilidade aparente do extrato etéreo, 97,18%; coeficiente de digestibilidade aparente da energia bruta, 95,44%, e energia digestível aparente 2.880,02 kcal/kg. Não houve diferença significativa (P&gt; 0,05) para ganho de peso final, consumo de ração total, conversão e acréscimo em altura. Observou-se aumento linear (P&lt;0,01) para o comprimento. Conclui-se que este alimento pode ser eficientemente utilizado pela tilápia nilótica.