Dietary Essential Fatty Acids Research Articles

Medium-short chain fatty acids cannot spare the essential fatty acids of low marine diets in golden pompano (Trachinotus ovatus)

Based on the essential fatty acids (EFA) precision nutrition, a blend oil (BO) of fish oil and terrestrial oils was developed, and applied successfully to the low marine diets of golden pompano (Trachinotus ovatus). To evaluate whether medium- and short-chain fatty acids (MCFA and SCFA), efficient energy supplements for animals, can spare the dietary EFA, four iso-proteic (48%) and iso-lipidic (11%) low fishmeal (FM) diets (D1-D4, contained 6% FM) were formulated and fed T. ovatus juveniles (initial weight ∼8.50 g) for 9 weeks in sea cages. Control diets (D1) contained 8% BO, while the BO of diets D2-D4 were replaced 50% with coconut oil, coconut oil + sodium butyrate, and coconut oil + n-3 LC-PUFA enriched oil, respectively. The results showed that compared to the D1 group, the growth performance of D2 and D3 were significantly lower, while a comparable growth was detected in the D4 group. The muscle and hepatic n-3 PUFA levels in the D2 and D3 groups were significantly low, and these fatty acid contents were modified in the D4 group. Meanwhile, the muscle textural firmness of the D2-D4 groups was decreased. Regarding the health index of fish, compared to the D1 group, high serum triglyceride (TG) contents and low HDL/LDL ratio were detected in the D2-D4 groups, and high ACP, AST, and ALT activities were observed in these groups. Meanwhile, high HSI and low hepatic enzymatic activities of CAT and ALT were measured in the D2-D3 groups. Additionally, the mRNA levels of hepatic fatty acid synthesis-related genes (fas, acc, and pparγ) were significantly increased in D2-D4 groups, and the expression levels of lipid catabolism genes (cpt-1 and lpl) showed an upward trend. Moreover, the D2 group exhibited the lowest intestinal wall thickness, the mRNA levels of intestine anti-inflammatory cytokines (il-10) were up-regulated in the D2-D4 groups, and the highest mRNA levels of pro-inflammatory cytokines (il-8) were detected in the D2 group. In conclusion, the EFA deficiency leads to a decline in the growth and muscle quality of T. ovatus fed low marine diets, which cannot be mitigated by the addition of medium-short chain fatty acids. The results indicated that MCFA and SCFA cannot spare the EFA of low marine diets in T. ovatus.

Consuming a Linoleate-Rich Diet Increases Concentrations of Tetralinoleoyl Cardiolipin in Mouse Liver and Alters Hepatic Mitochondrial Respiration

BackgroundHepatic mitochondrial dysfunction is a major cause of fat accumulation in the liver. Individuals with fatty liver conditions have hepatic mitochondrial structural abnormalities and a switch in the side chain composition of the mitochondrial phospholipid, cardiolipin, from poly- to monounsaturated fatty acids. Linoleic acid (LA), an essential dietary fatty acid, is required to remodel nascent cardiolipin (CL) to its tetralinoleoyl cardiolipin (L4CL, CL with 4 LA side chains) form, which is integral for mitochondrial membrane structure and function to promote fatty acid oxidation. It is unknown, however, whether increasing LA in the diet can increase hepatic L4CL concentrations and improve mitochondrial respiration in the liver compared with a diet rich in monounsaturated and saturated fatty acids. ObjectivesThe main aim of this study was to test the ability of a diet fortified with LA-rich safflower oil (SO), compared with the one fortified with lard (LD), to increase concentrations of L4CL and improve mitochondrial respiration in the livers of mice. MethodsTwenty-four (9-wk-old) C57 BL/J6 male mice were fed either the SO or LD diets for ∼100 d, whereas food intake and body weight, fasting glucose, and glucose tolerance tests were performed to determine any changes in glycemic control. ResultsLivers from mice fed SO diet had higher relative concentrations of hepatic L4CL species compared with LD diet-fed mice (P value = 0.004). Uncoupled mitochondria of mice fed the SO diet, compared with LD diet, had an increased baseline oxygen consumption rate (OCR) and succinate-driven respiration (P values = 0.03 and 0.01). SO diet-fed mice had increased LA content in all phospholipid classes compared with LD-fed mice (P < 0.05). ConclusionsOur findings reveal that maintaining or increasing hepatic L4CL may result in increased OCR in uncoupled hepatic mitochondria in healthy mice whereas higher oleate content of CL reduced mitochondrial function shown by lower OCR in uncoupled mitochondria.

Infection, Inflammation, and Immunity in Sepsis.

Sepsis is triggered by microbial infection, injury, or even major surgery. Both innate and adaptive immune systems are involved in its pathogenesis. Cytoplasmic presence of DNA or RNA of the invading organisms or damaged nuclear material (in the form of micronucleus in the cytoplasm) in the host cell need to be eliminated by various nucleases; failure to do so leads to the triggering of inflammation by the cellular cGAS-STING system, which induces the release of IL-6, TNF-α, and IFNs. These cytokines activate phospholipase A2 (PLA2), leading to the release of polyunsaturated fatty acids (PUFAs), gamma-linolenic acid (GLA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which form precursors to various pro- and anti-inflammatory eicosanoids. On the other hand, corticosteroids inhibit PLA2 activity and, thus, suppress the release of GLA, AA, EPA, and DHA. PUFAs and their metabolites have a negative regulatory action on the cGAS-STING pathway and, thus, suppress the inflammatory process and initiate inflammation resolution. Pro-inflammatory cytokines and corticosteroids (corticosteroids > IL-6, TNF-α) suppress desaturases, which results in decreased formation of GLA, AA, and other PUFAs from the dietary essential fatty acids (EFAs). A deficiency of GLA, AA, EPA, and DHA results in decreased production of anti-inflammatory eicosanoids and failure to suppress the cGAS-STING system. This results in the continuation of the inflammatory process. Thus, altered concentrations of PUFAs and their metabolites, and failure to suppress the cGAS-STING system at an appropriate time, leads to the onset of sepsis. Similar abnormalities are also seen in radiation-induced inflammation. These results imply that timely administration of GLA, AA, EPA, and DHA, in combination with corticosteroids and anti-IL-6 and anti-TNF-α antibodies, may be of benefit in mitigating radiation-induced damage and sepsis.

P24-042-23 Association of Dietary Essential Fatty Acid Intakes During Pregnancy and Pregnancy Induced Hypertension in a Cohort of South-Indian Pregnant Women

P24-042-23 Association of Dietary Essential Fatty Acid Intakes During Pregnancy and Pregnancy Induced Hypertension in a Cohort of South-Indian Pregnant Women

Effects of n-3 HUFA-enriched Artemia on growth, biochemical response, skeletal morphology and stress resistance of Asian sea bass (Lates calcarifer) larvae reared at high temperature

Improving the growth and health status of marine fish larvae to adapt to climate change, is crucial for commercial hatchery production in tropical regions. This study evaluated the effects of dietary essential fatty acids used for Artemia enrichment on growth, biochemical responses, skeletal morphology, and stress resistance of Asian sea bass larvae, reared at high temperatures of 30 °C and 34 °C. Starting 11 days after hatch, Asian sea bass larvae, were fed Artemia, enriched with a commercial emulsion of n-3 HUFA for 14 days, at four concentrations (0, 100, 300, and 500 ppm), at two rearing temperatures (30 °C and 34 °C). The results showed that enriching Artemia with n-3 HUFA significantly improved the final weight and specific growth rate of the larvae fed n-3 HUFA enrichment at 300 ppm, at 34 °C (P < 0.05). Moreover, n-3 HUFA enriched Artemia significantly increased the essential fatty acids of the larvae in parallel with the dose of enrichment. Fish fed unenriched HUFA Artemia resulted in significantly higher ratio of skeletal deformities and lower survival rate following an air exposure test than the larvae fed the n-3 HUFA enriched diets. Overall, the findings showed that n-3 HUFA-enriched Artemia diets had benefits on body weight, specific growth rate, and stress tolerance in Asian sea bass fed HUFA enriched diets, even at high temperatures.

The importance of essential fatty acids and their ratios in aquafeeds to enhance salmonid production, welfare, and human health

Long chain polyunsaturated fatty acids (LC-PUFA), namely those from omega-3 (n-3) and omega-6 (n-6) families, are paramount for both fish and human nutrition. Some of these biomolecules cannot be synthesized de novo and must be acquired through the diet, being termed dietary essential fatty acids (EFA). Fish requirements for EFA have traditionally been met through the incorporation of fish oil (FO) in the formulation of aquafeeds. However, with limited supply of FO the aquaculture industry is searching for additional sustainable sources of LC-PUFA. This has significantly shifted the type of ingredients used in aquafeed formulation, namely vegetable oils (VO) deficient in long-chain omega-3, often resulting in imbalanced levels and ratios of fatty acid classes. Such imbalances can negatively affect fish performance and welfare, as well as the levels of health promoting omega-3 LC-PUFA present in fish fillets. Given the relevance that salmonid aquaculture plays in global fish production (principally Atlantic salmon, Salmo salar), as well as its growing role as a source of dietary health promoting omega-3 LC-PUFA for humans, the present review summarizes the scientific knowledge available to date on the dietary requirements for LC-PUFA by salmonids and humans. We discuss the implications of using imbalanced aquafeed formulations upon fish performance and welfare, as well as the subsequent consequences for human nutrition, along with current efforts to replace FO by alternative ingredients such as algal oil (AO) that can safeguard high-quality salmonid products for human consumption.

Oxygen-induced pathological angiogenesis promotes intense lipid synthesis and remodeling in the retina

The retina is a notable tissue with high metabolic needs which relies on specialized vascular networks to protect the neural retina while maintaining constant supplies of oxygen, nutrients, and dietary essential fatty acids. Here we analyzed the lipidome of the mouse retina under healthy and pathological angiogenesis using the oxygen-induced retinopathy model. By matching lipid profiles to changes in mRNA transcriptome, we identified a lipid signature showing that pathological angiogenesis leads to intense lipid remodeling favoring pathways for neutral lipid synthesis, cholesterol import/export, and lipid droplet formation. Noteworthy, it also shows profound changes in pathways for long-chain fatty acid production, vital for retina homeostasis. The net result is accumulation of large quantities of mead acid, a marker of essential fatty acid deficiency, and a potential marker for retinopathy severity. Thus, our lipid signature might contribute to better understand diseases of the retina that lead to vision impairment or blindness.

The Impact of Linoleic Acid on Infant Health in the Absence or Presence of DHA in Infant Formulas

Both linoleic acid (LA) and α-linolenic acid (ALA) are essential dietary fatty acids, and a balanced dietary supply of these is of the utmost importance for health. In many countries across the globe, the LA level and LA/ALA ratio in breast milk (BM) are high. For infant formula (IF), the maximum LA level set by authorities (e.g., Codex or China) is 1400 mg LA/100 kcal ≈ 28% of total fatty acid (FA) ≈ 12.6% of energy. The aims of this study are: (1) to provide an overview of polyunsaturated fatty acid (PUFA) levels in BM across the world, and (2) to determine the health impact of different LA levels and LA/ALA ratios in IF by reviewing the published literature in the context of the current regulatory framework. The lipid composition of BM from mothers living in 31 different countries was determined based on a literature review. This review also includes data from infant studies (intervention/cohort) on nutritional needs regarding LA and ALA, safety, and biological effects. The impact of various LA/ALA ratios in IF on DHA status was assessed within the context of the current worldwide regulatory framework including China and the EU. Country averages of LA and ALA in BM range from 8.5–26.9% FA and 0.3–2.65% FA, respectively. The average BM LA level across the world, including mainland China, is below the maximum 28% FA, and no toxicological or long-term safety data are available on LA levels &gt; 28% FA. Although recommended IF LA/ALA ratios range from 5:1 to 15:1, ratios closer to 5:1 seem to promote a higher endogenous synthesis of DHA. However, even those infants fed IF with more optimal LA/ALA ratios do not reach the DHA levels observed in breastfed infants, and the levels of DHA present are not sufficient to have positive effects on vision. Current evidence suggests that there is no benefit to going beyond the maximum LA level of 28% FA in IF. To achieve the DHA levels found in BM, the addition of DHA to IF is necessary, which is in line with regulations in China and the EU. Virtually all intervention studies investigating LA levels and safety were conducted in Western countries in the absence of added DHA. Therefore, well-designed intervention trials in infants across the globe are required to obtain clarity about optimal and safe levels of LA and LA/ALA ratios in IF.

Determination of dietary essential fatty acids in a deep-sea fish, the splendid alfonsino Beryx splendens: functional characterization of enzymes involved in long-chain polyunsaturated fatty acid biosynthesis

The splendid alfonsino Beryx splendens is a commercially important deep-sea fish in East Asian countries. Because the wild stock of this species has been declining, there is an urgent need to develop aquaculture systems. In the present study, we investigated the long-chain polyunsaturated fatty acid (LC-PUFA) requirements of B. splendens, which are known as essential dietary components in many carnivorous marine fish species. The fatty acid profiles of the muscles, liver, and stomach contents of B. splendens suggested that it acquires substantial levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from its natural diet. The functional characterization of a fatty acid desaturase (Fads2) and three elongases (Elovl5, Elovl4a, and Elovl4b) from B. splendens confirmed their enzymatic capabilities in LC-PUFA biosynthesis. Fads2 showed Δ6 and Δ8 bifunctional desaturase activities. Elovl5 showed preferential elongase activities toward C18 and C20 PUFA substrates, whereas Elovl4a and Elovl4b showed activities toward various C18-22 substrates. Given that Fads2 showed no Δ5 desaturase activity and no other fads-like sequence was found in the B. splendens genome, EPA and arachidonic acid cannot be synthesized from C18 precursors; hence, they can be categorized as dietary essential fatty acids in B. splendens. EPA can be converted into DHA in B. splendens via the so-called Sprecher pathway. However, given that fads2 is only expressed in the brain, it is unlikely that the capacity of B. splendens to biosynthesize DHA from EPA can fulfill its physiological requirements. These results will be useful to researchers developing B. splendens aquaculture methods.

The effects of dietary essential fatty acid ratios and linoleic acid level in grow-finish pigs.

The objective of this study was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (LA:ALA) on the growth performance, expression of genes associated with lipid metabolism, and inflammatory status of grow-finish pigs. A total of 300 growing pigs (body weight [BW] = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) dietary linoleic acid level with a high (23:1; HR), moderate (13:1; MR) or low (4:1; LR) dietary LA:ALA in a 2 × 3 factorial design. Diets were fed across three 28-d phases and were balanced for dietary metabolizable energy. Pigs were housed five pigs per pen in single-sex pens. Blood samples were collected on days 0, 21, 42, and 84, and synovial fluid was collected from the hock joint on days 0 and 84 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial BW as a covariate, pen as the experimental unit, and LA level, LA:ALA, sex, phases, and their interactions as fixed effects. Compared to HLA, LLA pigs tended to have increased BW at days 56 and 84 (P = 0.088). There was no effect of LA × LA:ALA for growth performance. For the overall days 0 to 84 growth period, pigs fed HR had increased ADG compared to MR, with pigs receiving LR performing intermediate of MR and HR. Gilts receiving HR diets had increased day 84 BW compared to gilts receiving the low and moderate LA:ALA (P = 0.006), which was a result of improved overall days 0 to 84 ADG compared to gilts receiving the MR diets (P = 0.023). Barrows fed LR had improved BW on day 56 compared to MR and HR and higher final BW compared to HR, with MR performing intermediately (P = 0.006). This was a result of greater days 0 to 84 ADG (P = 0.023). Overall, C-reactive protein (CRP), tumor necrosis factor-α (TNFα), and interleukin-6 were reduced in the plasma of pigs over time (P ≤ 0.037). Across all treatments, CRP and TNFα were reduced in the hock and carpus synovial fluid on day 84 vs. day 0 (P ≤ 0.049). In conclusion, LA:ALA ratios utilized in this study can be fed at varying linoleic acid levels without impacting growth or inflammation. Additionally, LA:ALA ratios can differentially impact the growth of gilts and barrows.

The effects of dietary essential fatty acid ratios and energy level on growth performance, lipid metabolism, and inflammation in grow-finish pigs.

The objective of this study was to investigate the effects of dietary metabolizable energy (ME) level and the ratio of linoleic acid:α-linolenic acid (LA:ALA) on the growth performance, lipid metabolism, circulatory and joint inflammatory status, and synovial fluid proteome of grow-finish pigs. A total of 224 pigs (BW = 41.5 ± 6.1 kg; PIC Genus 337 × 1050, Hendersonville, TN) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) ME dietary treatment with a high (23:1) or low (12:1) LA:ALA in a 2 × 2 factorial arrangement. Diets were fed across three 28-d phases. Pigs were housed either four barrows or four gilts per pen. Blood samples were collected on days 0, 21, 42, and 84. Synovial fluid was collected from the hock and carpus joints on days 0 and 84. Liver and adipose tissue samples were collected on day 84. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with pen as the experimental unit and energy level, essential fatty acid ratio, sex, phase, and their interactions as fixed effects. Compared to LE, HE increased days 28, 56, and 84 body weight (BW; P = 0.005). For the overall period, HE increased average daily gain (ADG) compared to LE (P < 0.001) and improved feed efficiency (P = 0.001), while LE increased feed intake compared to HE (P < 0.001). Gilts receiving diets with low LA:ALA had similar final BW to barrows receiving a low LA:ALA at days 28, 56, and 84 (P = 0.024), resulting from improved overall days 0-84 ADG compared to gilts receiving the high LA:ALA (P = 0.031). In the liver, HE decreased the mRNA abundance of acetyl CoA carboxylase (ACACA; P = 0.004), cluster of differentiation 36 (P = 0.034), and tended to decrease fatty acid synthase (FASN; P = 0.056). In adipose tissue, HE decreased ACACA (P = 0.001) and FASN (P = 0.017). Plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNFα) were reduced on day 84 compared to day 0 (P ≤ 0.014). In the hock and carpus synovial fluid, LE tended to reduce CRP and TNFα (P ≤ 0.096). Hock and carpus synovial fluid CRP were also reduced on day 84 compared to day 0 (P = 0.001). Age of the pig impacted serum and hock synovial fluid protein abundance, but not energy level, LA:ALA, or their interactions (P < 0.05). To conclude, the high and low LA:ALA ratios utilized in this study can be fed at varying energy levels without impacting growth. Additionally, LA:ALA ratios can differentially impact the growth of barrows and gilts.

Pentadecanoylcarnitine is a newly discovered endocannabinoid with pleiotropic activities relevant to supporting physical and mental health

As an emerging dietary essential fatty acid, pentadecanoic acid (C15:0) is expected to have bioactive metabolites with broad health benefits. Here, we evaluated pentadecanoylcarnitine, an endogenous C15:0 metabolite, for dose dependent cell-based activities, including measurement of its effects on 148 clinically relevant biomarkers across twelve primary human cell systems mimicking various disease states. Mechanisms of action for pentadecanoylcarnitine were also assessed across 78 cell-based target assays. Pentadecanoylcarnitine had dose-dependent anti-inflammatory activities, including lower IL-1α, ITAC, MCP-1, and IP-10, across five cell systems relevant to treating cardiovascular, immune, neoplastic, pulmonary, and skin diseases. Targeted assays showed pentadecanoylcarnitine as a full-acting cannabinoid 1 and 2 receptor agonist (EC50 3.7 and 3.2 µM, 111% and 106% maximum activity compared to the positive control, respectively). Pentadecanoylcarnitine also had 5-HT1A and 5-HT1B receptor agonist and histamine H1 and H2 receptor antagonist activities. In summary, pentadecanoylcarnitine, a second discovered full-acting endocannabinoid, had broad pleiotropic activities relevant to regulating inflammation, pain, mood, and sleep. This study’s findings further the need to evaluate the potential health impacts of C15:0 nutritional deficiencies caused by population-wide avoidance of all dietary saturated fats, including C15:0.

Evaluation of essential fatty acids in lactating sow diets on sow reproductive performance, colostrum and milk composition, and piglet survivability.

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn-soybean meal-wheat-based lactation diets that contained 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low LA and ALA in diets with CWG or high LA and ALA in diets that included soybean oil. Sows received their assigned EFA treatments until weaning and were then fed a common gestation and lactation diet in the subsequent reproductive cycle. Average daily feed intake during the lactation period increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. However, daily LA and ALA intakes of sows fed the Combination and SO diets were still greater (P < 0.05) than those of sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P < 0.05) piglet weaning weights and greater (P < 0.05) litter ADG when compared with litters from sows fed diets with CWG that provided low EFA. Despite advantages in growth performance, there was no impact of sow EFA intake on piglet survivability (P > 0.10). Additionally, lactation diet EFA composition did not influence sow colostrum or milk dry matter, crude protein, or crude fat content (P > 0.10). However, LA and ALA content in colostrum and milk increased (P < 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P > 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by soybean oil during lactation increased overall litter growth and pig weaning weights, reduced sow ADFI, but did not affect piglet survivability or subsequent performance of sows.

PSVII-8 The Impact of Dietary Essential Fatty Acids Ratios and Unsaturated:Saturated Ratio on Growth Performance of Grow-Finish Pigs

Abstract The objective was to investigate the effects of dietary unsaturated:saturated fat ratio (U:S) and the fatty acid ratio of linoleic acid:linolenic acid (n6:n3) on growth performance of grow-finish pigs. A total of 240 pigs with initial body weight (BW) 54.4±5.5kg were randomly assigned to a high (&amp;gt; 1.8; HUS) or low (&amp;lt; 1.0; LUS) U:S ratio with a high (20:1), moderate (12:1) or low (4:1) n6:n3 in a 3×2 factorial design (n = 10). Diets were fed across 3 phases and balanced for energy and linoleic acid. Pigs were housed 4 pigs per pen and separated by sex. Data were analyzed as repeated measures using SAS (9.4) with pen as the experimental unit and U:S ratio, n6:n3 ratio, sex, and their interactions as fixed effects. Initial BW was fit as a covariate. Within each phase, there were no differences in BW, daily gain (ADG), feed intake (ADFI) or feed efficiency (G:F) for U:S, n6:n3, or their interaction (P &amp;gt; 0.10). For the overall period, there was a U:S×n6:n3 interaction for ADG (P &amp;lt; 0.05) with pigs receiving LUS×12:1 (1.19kg/d) having increased ADG compared with pigs receiving HUS×12:1 (1.12kg/d). There was no effect of sex (P &amp;gt; 0.10) for G:F within each phase; however, overall, gilts had improved G:F compared with barrows (P &amp;lt; 0.05). Compared with HUS, gilts receiving LUS had greater ADFI overall (P &amp;lt; 0.05; 2.84 vs. 2.70kg), which translated into improved G:F for HUS gilts (P &amp;lt; 0.05; 0.40 vs 0.39). Overall, gilts receiving the 20:1 diet tended to have improved G:F compared with 12:1 (P &amp;lt; 0.10; 0.40 vs 0.39). The dietary U:S ratio impacted overall ADG of pigs fed the 12:1 ratio when averaged across sex; however, there was no significant sex × U:S × n6:n3 interaction. A low U:S ratio can also increase feed intake of gilts; however, this did not result in improved ADG.

65 Evaluation of Essential Fatty Acids in Lactating Sow Diets on Sow Reproductive Performance, Colostrum and Milk Composition, and Pre-Weaning Litter Growth and Survivability

Abstract Mixed parity sows (n = 3,451; PIC, Hendersonville, TN) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. At approximately d 112 of gestation, sows were randomly assigned to 1 of 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low EFA [linoleic acid (LA) and α-linolenic acid (ALA)] in diets with CWG or high EFA in diets with SO. Lactation ADFI increased (P &amp;lt; 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. Daily LA and ALA intake of sows fed the Combination and SO diets were greater (P &amp;lt; 0.05) than sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P &amp;lt; 0.05) piglet weaning weights and greater (P &amp;lt; 0.05) litter ADG when compared with litters from sows fed diets with low EFA provided through CWG. There was no effect of sow EFA intake on piglet survivability (P &amp;gt; 0.10). Lactation diet EFA concentration did not influence colostrum or milk dry matter, crude protein, or crude fat content (P&amp;gt;0.10). However, LA and ALA content in colostrum and milk at weaning increased (P &amp;lt; 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P &amp;gt; 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and pig weaning weights but did not affect piglet survivability or subsequent performance.

Maximising sustainable nutrient production from coupled fisheries-aquaculture systems

Aquaculture expansion is expected to meet growing demand for sustainable animal-source foods. Yet marine-fed species already require millions of tonnes of wild-caught fish for feed, over 90% of which are nutritious food-grade species. Allocating feed fish for human consumption could reduce pressure on marine resources while increasing seafood production. We examine micronutrient flows (the transfer of micronutrients from feed to fish) in Scotland’s farmed salmon industry, which is particularly reliant on marine feeds, to show that 1–49% of essential dietary minerals and fatty acids available in wild fish are retained in farmed salmon. Using three alternative production scenarios we show that reducing marine feeds in salmon production and allocating wild-caught feed fish for human consumption could produce more nutritious seafood and leave 66–82% of feed fish in the sea. Using global data on marine-fed aquaculture production, we show that removing wild-caught fish from salmonid production could leave 3.7 Mt fish in the sea while increasing global seafood production by 6.1 Mt.

Efficiency of fatty acid-enriched dipteran-based meal on husbandry, digestive activity and immunological responses of Nile tilapia Oreochromis niloticus juveniles

This study aimed to compare the enrichment capacity of polyunsaturated fatty acids (PUFA) and the long chain polyunsaturated fatty acids (LC-PUFA) of two dipteran species, Hermetia illucens - black soldier fly (BSF) - and a blowfly, Chrysomya putoria (CP), and to test its influence on growth, digestive activities and immune responses of Nile tilapia. Two types of enriched insect larval meal were produced using larvae cultured either on vegetable substrates (VGS) to formulate two diets rich in linolenic acid (ALA) (BSF/VGD and CP/VGD), or on fish offal substrates (FOS), in order to produce two diets rich in ALA and eicosapentaenoic acid (EPA) (BSF/FOD) or in ALA + EPA and docosahexaenoic acid (DHA) (CP/FOD). These four insect-based diets containing only palm oil as a lipid source were compared to a control diet based on fish meal (FM) and fish oil (FO). After 60 days of feeding, ALA or DHA muscle content of fish fed BSF/VGD or CP/FOD diet was comparable to that of the FMFO diet, and all insect diets increased the EPA muscle levels, except for a reduction by the BSF/VGD one. The CP/FOD diet induced similar fish growth, feed efficiency and protein efficiency ratio compared to the control FMFO diet, while a decrease was observed in fish fed other insect diets. Only BSF/VGD led to a decrease in protein and lipid digestibility. CP or BSF larval meal significantly increased alkaline phosphatase activity regardless of fatty acid (FA) enrichment. The expression level of fads2, fads6 and elovl5 was significantly higher in fish fed the BSF/VGD diet compared to fish fed the FMFO diet. FA-enriched insect diets increased some immune variables such as lysozyme, peroxidase and ACH50 values of fish fed CP/FOD, CP/VGD or BSF/VGD diets. Moreover, the expression level of β-defensin-1 and mhcII genes were significantly higher in fish fed the BSF/FOD diet than the FMFO diet. Also, the expression of the pro-inflammatory gene il-1-β was significantly higher in fish fed FMFO diet than in those fed CP/FOD diet, but comparable to fish fed all other diets. No significant effects were observed for the other tested genes. The results showed a better efficiency in LC-PUFA enrichment of the CP larvae compared to BSF ones, resulting in a higher stimulation of the fish nutrient utilization processes and therefore, a higher growth capacity. Nonetheless, all dipteran larval meal stimulated the immune status whatever the insect species or dietary essential fatty acids.

Climate change‐induced deprivation of dietary essential fatty acids can reduce growth and mitochondrial efficiency of wild juvenile salmon

AbstractOmega‐3 long‐chain polyunsaturated fatty acids (n − 3 LC‐PUFA) are essential micronutrients for optimal functioning of cellular metabolism and for somatic growth of all vertebrates including fishes. In addition,n − 3 LC‐PUFA could also play a key role in response of fishes and other ectothermic vertebrates to changing temperatures.An important, but largely overlooked, consequence of climate change is the reduced availability of dietaryn − 3 LC‐PUFA in aquatic food webs. Changes in availability of dietaryn − 3 LC‐PUFA have recently been proposed as a major driver of novel adaptations and diversification of consumers. Yet, there is only limited knowledge about hown − 3 LC‐PUFA depletion in aquatic food webs will affect the performance of wild fishes.Here we combine biochemistry and physiology at the cellular level with physiological and cognitive processes at the whole‐animal level to test how ecologically relevant deprivation ofn − 3 LC‐PUFA affects performance of wild juvenile Atlantic salmonSalmo salar.We found that juvenile salmon had a limited capacity to maintain the fatty acid profile of both muscle and brain under ann − 3 LC‐PUFA‐deficient diet. Despite these findings, brain tissues showed remarkable functional stability in mitochondrial metabolism, and we found no effect of diet on learning ability. However, we found that mitochondrial efficiency in muscles and the somatic growth were reduced under ann − 3 LC‐PUFA‐deficient diet. Importantly, we discovered that the somatic growth of juvenile salmon within both treatments decreased with increasing rate of DHA synthesis and retention.Since DHA is essential for functioning of cellular metabolism, which together with body size are traits closely related to fitness of wild fishes, we suggest that the trade‐off between growth rate and accumulation of DHA could play a critical role in resilience of juvenile salmon to the ongoing rapid environmental change.A freePlain Language Summarycan be found within the Supporting Information of this article.

206 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Energy Level on Growth Performance, Inflammation, and Joint Health of Grow-finish Pigs

Abstract The objective of this study was to investigate the effects of dietary metabolizable energy level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 240 growing pigs (BW = 41.5 ± 6.1 kg) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) energy dietary treatment with a high (23:1) or low (12:1) n6:n3 in a 2 x 2 factorial design (n = 16). Diets were fed across three 28-day phases and were balanced for linoleic acid inclusion. Pigs were housed 4 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12 of the study. Synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. The pen was the experimental unit and data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with energy, ratio, and the interaction as fixed effects. Compared to LE, pigs receiving HE had increased BW (P &amp;lt; 0.05) at d28 (73.0 vs. 69.9kg), d56 (105.0 vs. 100.7kg), and d84 (135.3 vs. 129.9kg). For the overall period, HE had increased ADG compared to LE (1.10 vs. 1.06kg; P &amp;lt; 0.05) and improved G:F (0.41 vs. 0.37; P &amp;lt; 0.05), while LE increased ADFI compared to HE (2.88 vs. 2.72kg; P &amp;lt; 0.05). There was no effect of ratio or energy ratio interaction for growth performance. C-reactive protein tended to be reduced in hock synovial fluid of pigs receiving LE (1854.3 vs. 2277.3ng/mL; P &amp;lt; 0.10). Across all treatments, CRP was reduced in the synovial fluid and plasma in week 12 compared to week 1 (P &amp;lt; 0.05). In conclusion, dietary n6:n3 ratio did not impact growth performance or CRP response regardless of energy level.

204 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Linoleic Acid Level on Growth Performance and Inflammation of Grow-finish Pigs

Abstract The objective was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 300 growing pigs (BW = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) linoleic acid level with a high (20:1; HR), moderate (12:1; MR) or low (4:1; LR) n6:n3 in a 2 x 3 factorial design. Diets were fed across three 28-day phases and were balanced for dietary metabolizable energy. Pigs were housed 5 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12, and synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial body weight as a covariate, pen as the experimental unit, and linoleic acid level, ratio, and their interaction as fixed effects. Compared to HLA, LLA pigs had increased BW (P &amp;lt; 0.05) at d56 (103.2 vs. 101.3kg) and tended to have increased BW at d84 (P &amp;lt; 0.10; 129.1 vs. 127.8kg). Pigs receiving LR tended to have higher d84 BW compared to MR (P &amp;lt; 0.10; 129.1 vs. 127.3kg). There was no effect of linoleic acid ratio interaction for growth performance. In phase 2, pigs receiving LR had higher feed intake (P &amp;lt; 0.05) compared to MR. Pigs receiving HR performed intermediate of LR and MR. Overall, C-reactive protein was reduced in the plasma of pigs receiving HLA (P &amp;lt; 0.05; 19.3 vs. 26.2mg/mL). Across all treatments, CRP was reduced in synovial fluid and plasma in week 12 vs. week 1 (P &amp;lt; 0.05). In conclusion, LLA and a low ratio of n6:n3 improved final pig BW, and HLA is potentially beneficial in improving inflammation.