Plant Products Affect Growth and Digestive Efficiency of Cultured Florida Pompano (Trachinotus carolinus) Fed Compounded Diets

Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25–30 percent SBM in combination with 43–39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient

Apparent availability of amino acids, by type, in ingredients fed to Florida pompano.

<p>Values are mean percentage availability ± SD.</p>1<p>Acidic: aspartic acid, glutamic acid; Basic: arginine, histidine, lysine; Non-polar: alanine, isoleucine, leucine, methionine, phenylalanine, proline, valine; Uncharged polar: cysteine, glycine, serine, threonine, tyrosine.</p>2<p>Canola meal.</p>3<p>Corn gluten meal.</p>4<p>Distillers dried grains with solubles.</p

Ingredient composition of the reference diet and test diets as fed (g/kg).

1<p>Carboxymethylcellulose, sodium salt.</p>2<p>Per kg diet: vitamin A, 6000 IU; vitamin D, 1000 IU; vitamin E, 0.1 g; biotin, 0.2 g; folic acid, 9 mg; niacin, 0.2 g; pantothenic acid, 0.1 g; vitamin B-6, 25 mg; riboflavin, 40 mg; thiamin, 40 mg; vitamin B-12, 20 mg.</p>3<p>Per kg diet: iron, 0.1 g; manganese, 25 mg; copper, 10 mg; zinc, 0.1 g; iodine, 4.5 mg; cobalt, 50 mcg; selenium, 0.5 mg.</p>4<p>Stay-C stabilized vitamin C (L-ascorbyl-2-polyphosphate), 35% ascorbic acid activity.</p>5<p>Canola meal, corn gluten meal, or distillers dried grains with solubles.</p

Influence of carbohydrate and fiber on digestibility.

<p>Simple linear regression demonstrates the negative relationship between apparent crude protein digestibility (ACPD) and nitrogen-free extract (NFE) (plot A; <i>r</i> = −0.91), and apparent energy digestibility (AED) and fiber (plot B; <i>r</i> = −0.97) among the three ingredients tested. NFE is primarily starches and other carbohydrates; fiber is mostly cellulose. As concentrations of NFE or fiber increase, Florida pompano digest protein and energy in the feedstuffs less efficiently.</p

Apparent availability coefficients of dietary essential and non-essential amino acids (AA) in ingredients fed to Florida pompano.

<p>Mean values ± SD (n = 3), values in each row with different letters are significantly different (<i>P</i><0.05).</p>1<p>Canola meal.</p>2<p>Corn gluten meal.</p>3<p>Distillers dried grains with solubles.</p

Apparent digestibility coefficients of crude protein (ACPD) and energy (AED) in ingredients fed to Florida pompano.

<p>Mean values ± SE (n = 3), values in each column with different letters are significantly different (<i>P</i><0.05).</p

Quantities of dietary essential amino acids, expressed in proportion to lysine¹, in the whole-body of pompano and in the experimental diets.

<p>M = soybean meal; C = soy protein concentrate.</p>1<p> </p>2<p>Whole-body pompano.</p

Whole-body composition of Florida pompano fed the experimental diets.

<p>Mean values ± SE (n = 3), values in each column with different letters are significantly different (<i>P</i><0.05). Initial body composition prior to treatment (g/100 g): moisture, 68.9; crude protein, 14.9; lipid, 10.5; ash, 3.0; GE, 6.1.</p><p>M = soybean meal; C = soy protein concentrate.</p>1<p>Crude protein = percentage nitrogen×6.25.</p>2<p>Gross energy as determined by bomb calorimetry.</p

Chemical composition of the diets and test ingredients as fed (%).

<p>Values determined by analysis.</p>1<p>Canola meal.</p>2<p>Corn gluten meal.</p>3<p>Distillers dried grains with solubles.</p>4<p>Gross energy.</p>5<p>Nitrogen-free extract = dry matter−(crude protein+lipid+ash+fiber).</p

Epitope dampening monotypic measles virus hemagglutinin glycoprotein results in resistance to cocktail of monoclonal antibodies.

International audienceThe measles virus (MV) is serologically monotypic. Life-long immunity is conferred by a single attack of measles or following vaccination with the MV vaccine. This is contrary to viruses such as influenza, which readily develop resistance to the immune system and recur. A better understanding of factors that restrain MV to one serotype may allow us to predict if MV will remain monotypic in the future and influence the design of novel MV vaccines and therapeutics. MV hemagglutinin (H) glycoprotein, binds to cellular receptors and subsequently triggers the fusion (F) glycoprotein to fuse the virus into the cell. H is also the major target for neutralizing antibodies. To explore if MV remains monotypic due to a lack of plasticity of the H glycoprotein, we used the technology of Immune Dampening to generate viruses with rationally designed N-linked glycosylation sites and mutations in different epitopes and screened for viruses that escaped monoclonal antibodies (mAbs). We then combined rationally designed mutations with naturally selected mutations to generate a virus resistant to a cocktail of neutralizing mAbs targeting four different epitopes simultaneously. Two epitopes were protected by engineered N-linked glycosylations and two epitopes acquired escape mutations via two consecutive rounds of artificial selection in the presence of mAbs. Three of these epitopes were targeted by mAbs known to interfere with receptor binding. Results demonstrate that, within the epitopes analyzed, H can tolerate mutations in different residues and additional N-linked glycosylations to escape mAbs. Understanding the degree of change that H can tolerate is important as we follow its evolution in a host whose immunity is vaccine induced by genotype A strains instead of multiple genetically distinct wild-type MVs