Digestibility Of Fatty Acids Research Articles

Preparation and analysis of selenium-enriched oleogels: Preliminary evaluation of antioxidant activity and inhibition of fatty acids release

Selenium is a trace element that is crucial for maintaining human health. Supplementing selenium through safe and effective dietary methods can effectively reduce diseases caused by selenium deficiency. The purpose of this experiment is to develop a convenient and effective selenium supplement suitable for adding oily foods. Selenium polysaccharides, Tween-80 and pectin were used to prepare W/O emulsion, and then the selenium-enriched oleogels were obtained by freeze-drying. The results showed that as the pectin content increased, the particle size of the emulsion gradually decreased, whereas the oil-binding capacity of the oleogels gradually increased, the viscosity and elasticity had an increasing trend. The preparation parameters of oleogels were optimized: The optimal preparation parameters of oleogels were 6:4 for volume ratio of oil/water, 6.5% of Tween-80, and 2% of pectin. The selenium-enriched oleogels showed a strong DPPH scavenging ability (96%). Additionally, Camellia oleifera oil added with selenium-enriched oleogels demonstrated that the selenium-enriched oleogels inhibited the amount of fatty acids released of the oil during in vitro digestion, whereas increased the relative amount of unsaturated fatty acids. This study provides an effective method for the production of novel oil-based supplements and facilitates the digestion of unsaturated fatty acids.

Comparison of rumen and abomasal infusions of an exogenous emulsifier on fatty acid digestibility of lactating dairy cows

We evaluated the effects of infusing an exogenous emulsifier (polysorbates-C18:1) either into the rumen or abomasum on fatty acid (FA) digestibility and production responses of lactating dairy cows. Nine ruminally cannulated multiparous Holstein cows (170 ± 13.6 d in milk) were assigned to a treatment sequence in replicated 3 × 3 Latin squares with 18-d periods consisting of 7 d of washout and 11 d of infusion. Treatments were abomasal infusions of water carrier only into the rumen and abomasum (control, CON), 30 g/d polysorbate-C18:1 (T80) infused into the rumen (RUM), or 30 g/d T80 infused into the abomasum (ABO). Emulsifiers were dissolved in water and delivered at 6-h intervals (total daily infusion was divided into 4 equal infusions per day). Cows were fed the same diet that contained [% diet dry matter (DM)] 32.2% neutral detergent fiber (NDF), 16.1% crude protein, 26.5% starch, and 3.41% FA (including 1.96% FA from a saturated FA supplement containing 28.0% C16:0 and 54.6% C18:0). Two orthogonal contrasts were evaluated: (1) the overall effect of T80 {CON vs. average of the T80 infusions [1/2 (ABO + RUM)]}, and (2) the effect of ABO versus RUM infusion. Compared with CON, infusing T80 increased the digestibilities of NDF (2.85 percentage units), total (4.35 percentage units), 16-carbon (3.25 percentage units), and 18-carbon FA (4.60 percentage units), and tended to increase DM digestibility and total and 18-carbon FA absorption. Compared with RUM, ABO decreased the intakes of total (28 g/d), 16-carbon (7 g/d), and 18-carbon FA (19 g/d); tended to increase the digestibility of total and 18-carbon FA; and had no effect on the absorption of total, 16-carbon, or 18-carbon FA. Production responses did not change among our treatments. In conclusion, infusing 30 g/d polysorbates-C18:1 increased NDF and total, 16-carbon, and 18-carbon FA digestibility. Compared with RUM, ABO tended to increase the digestibilities of total and 18-carbon FA; however, this may be related to the fact that ABO reduced the intakes of total, 16-carbon, and 18-carbon FA, not necessarily due to better emulsifying action per se. In summary, ABO and RUM both improved FA absorption.

Altering palmitic acid and stearic acid ratios in the diet of early-lactation Holsteins under heat stress: Feed intake, digestibility, feeding behavior, milk yield and composition, and plasma metabolites

The objective of this study was to evaluate the effects of varying the ratio of dietary palmitic (C16:0; PA) and stearic (C18:0; SA) acids on nutrient digestibility, production, and blood metabolites of early-lactation Holsteins under mild-to-moderate heat stress. Eight multiparous Holsteins (body weight = 589 ± 45 kg; days in milk = 51 ± 8 d; milk production = 38.5 ± 2.4 kg/d; mean ± standard deviation) were used in a duplicated 4 × 4 Latin square design (21-d periods inclusive of 7-d data collection). The PA (88.9%)- and SA (88.5%)-enriched fat supplements, either individually or in combination, were added to diets at 2% of dry matter (DM) to formulate the following treatments: (1) 100PA:0SA (100% PA + 0% SA), (2) 66PA:34SA (66% PA + 34% SA), (3) 34PA:66SA (34% PA + 66% SA), and (4) 0PA:100SA (0% PA + 100% SA). Diets offered, in the form of total mixed rations, were formulated to be isonitrogenous (crude protein = 17.2% of DM) and isocaloric (net energy for lactation = 1.69 Mcal/kg DM), with a forage-to-concentrate ratio of 40:60. Ambient temperature-humidity index averaged 72.9 throughout the experiment, suggesting that cows were under mild-to-moderate heat stress. No differences in DM intake across treatments were detected (mean 23.5 ± 0.64 kg/d). Increasing the dietary proportion of SA resulted in a linear decrease in total-tract digestibility of total fatty acids, but organic matter, DM, neutral detergent fiber, and crude protein digestibilities were not different across treatments. Decreasing dietary PA-to-SA had no effect on the time spent eating (340 min/d), rumination (460 min/d), and chewing (808 min/d). As dietary PA-to-SA decreased, milk fat concentration and yield decreased linearly, resulting in a linear decrease of 3.5% fat-corrected milk production and milk fat-to-protein ratio. Feed efficiency expressed as kg 3.5% fat-corrected milk/kg DM intake decreased linearly with decreasing the proportion of PA-to-SA in the diet. Treatments had no effect on milk protein and lactose content. A linear increase in de novo and preformed fatty acids was identified as the ratio of PA to SA decreased, while PA and SA concentrations of milk fat decreased and increased linearly, respectively. A linear reduction in blood nonesterified fatty acids and glucose was detected as the ratio of PA to SA decreased. Insulin concentration increased linearly from 10.3 in 100PA:0SA to 13.1 µIU/mL in 0PA:100SA, whereas blood β-hydroxybutyric acid was not different across treatments. In conclusion, the heat-stressed Holsteins in early-lactation phase fed diets richer in PA versus SA produced greater fat-corrected milk and were more efficient in converting feed to fat-corrected milk.

Polyunsaturated Fatty Acids (PUFAs): Sources, Digestion, Absorption, Application and Their Potential Adjunctive Effects on Visual Fatigue.

When the eyes are exposed to the environment, they are easily affected by strong light stimulation and harmful substances. At the same time, prolonged use of the eyes or incorrect eye habits can cause visual fatigue, which mainly manifests as eye dryness, soreness, blurred vision, and various discomforts. The main reason for this is a decline in the function of the eye, especially the cornea and retina on the surface of the eye, which have the greatest impact on the normal function of the eye. Research has found that supplementation with appropriate foods or nutrients can effectively strengthen the eye against external and internal stimuli, thereby alleviating or avoiding visual fatigue. Among these, supplementation with polyunsaturated fatty acids has been found to be effective at protecting eye health and relieving visual fatigue. This article summarizes the sources of polyunsaturated fatty acids (including the main dietary sources and internal synthesis), the mechanisms of digestion and absorption of polyunsaturated fatty acids in the body and the safety of polyunsaturated fatty acid applications. It also reviews the mechanism of action of polyunsaturated fatty acids in aiding the relief of visual fatigue based on the mechanism of impaired function or structure of the ocular surface and fundus in the hope of providing some reference and insight into the development and application of polyunsaturated fatty acids in functional foods for the relief of visual fatigue.

Abomasal infusion of oleic acid and exogenous emulsifier alter fatty acid digestibility and production responses of lactating dairy cows

We evaluated the effects of abomasal infusion of cis-9 C18:1 (oleic acid) and an exogenous emulsifier (polysorbate-C18:1) on fatty acid (FA) digestibility and production responses of dairy cows. Eight rumen-cannulated multiparous cows (96 ± 23 d in milk) were assigned to a 2 × 2 factorial arrangement of treatments in 4 × 4 Latin squares with 18-d periods consisting of 7 d of washout and 11 d of infusion. Treatments were abomasal infusions of water carrier only (CON), 45 g/d oleic acid (OA), 20 g/d polysorbate-C18:1 (T80), or both 45 g/d OA and 20 g/d T80 (OA+T80). The OA treatments were dissolved in ethanol and the T80 treatments in water. To deliver the daily dose for each treatment, the infusate solution was divided into 4 equal infusions per day, occurring every 6 h. Cows were fed the same diet, which contained [% of dry matter (DM)] 30.3% neutral detergent fiber (NDF), 16.3% crude protein, 30% starch, and 3.2% FA (including 1.8% DM from a FA supplement containing 34.4% C16:0 and 47.7% C18:0). Infusion of T80 increased NDF digestibility compared with all other treatments (3.57 percentage units), whereas OA+T80 decreased NDF digestibility compared with CON (3.30 percentage units). Compared with CON, OA (4.90 percentage units) and T80 (3.40 percentage units) increased total FA digestibility, whereas OA+T80 had no effect on total FA digestibility. We did not observe differences between OA and T80 for total FA digestibility. Infusion of OA (3.90 percentage units) and T80 (2.80 percentage units) increased 16-carbon FA digestibility compared with CON. Digestibility of 16-carbon FA did not differ between OA and T80 or between CON and OA+T80. Compared with CON, OA increased (5.60 percentage units) and T80 tended to increase 18-carbon FA digestibility. Digestibility of 18-carbon FA did not differ between OA and T80 or between CON and OA+T80. Compared with CON, all treatments increased or tended to increase the absorption of total and 18-carbon FA. Infusion of OA and T80 increased the yields of milk fat (both increased 0.10 kg/d), 3.5% fat-corrected milk (1.90 and 2.50 kg/d), and energy-corrected milk (1.80 and 2.60 kg/d) compared with CON. We did not observe differences between OA and T80 or between CON and OA+T80 for yields of milk fat, 3.5% fat-corrected milk, or energy-corrected milk. Infusing OA tended to increase plasma insulin concentration compared with CON. Compared with the other treatments, OA+T80 decreased the yield of de novo milk FA (31.3 g/d). Compared with CON, OA tended to increase the yield of de novo milk FA. Compared with OA+T80, CON and OA tended to increase the yield of mixed milk FA, whereas T80 increased it (83 g/d). Compared with CON, all emulsifier treatments increased the yield of preformed milk FA (52.7 g/d). In conclusion, abomasally infusing either 45 g of OA or 20 g of T80 improved digestibility and similarly favored the production parameters of dairy cows. In contrast, providing both (45 g of OA + 20 g of T80) had no additional benefits and moderated the positive responses observed in the individual treatments with OA and T80.

Black soldier fly larvae oil as an alternative lipid source in diets for gilthead seabream (Sparus aurata) juveniles

The black soldier fly (Hermetia illucens, HI) is a promising insect species to be included in aquafeeds. HI larvae are rich in protein but also in fat, with a fatty acid profile dominated by saturated and medium-chain fatty acids. This study aimed to evaluate the replacement of vegetable oils (VO) with HI larvae oil (HIO) and its effects on growth, whole-body composition, nutrient retention, diet digestibility, and digestive enzyme activity. A control diet (HIO0, 45% crude protein, 18% lipids) was formulated to include 9.5% of a VO blend, and three other diets were formulated similar to the control but with the VO blend replaced at 42% (HIO42), 84% (HIO84), and 100% (HIO100). A growth trial was performed with triplicate groups of fish (initial body weight of 63 g) hand-fed to apparent visual satiation for 10 weeks. A digestibility trial was also performed simultaneously with triplicate groups of fish with similar initial body weights. Results indicate that the total replacement of VO mix with HIO did not affect growth performance, but feed efficiency and protein efficiency ratio linearly improved with the increase of HIO in the diets. No differences between groups were found in whole-body composition and protein and energy retention. There was a trend for protein and energy digestibility to linearly increase with dietary HIO inclusion. Lipid digestibility was not affected by diet composition, however, the apparent digestibility of saturated fatty acids increased and of unsaturated decreased with the increase of dietary HIO inclusion. Total proteases activity was higher in fish fed diet HIO84 and lipase activity followed a positive linear trend with the increase in dietary HIO content. Overall, present results indicate that gilthead seabream can effectively utilize HIO without compromising growth performance and digestibility while improving feed utilization efficiency, thus establishing its potential as an alternative lipid source for aquafeeds.

Digestibility of Conventional and Novel Dietary Lipids in Channel Catfish Ictalurus punctatus.

Lipid and fatty acid digestibility is presumably high in Channel Catfish, but data is lacking. We determined the lipid and fatty acid digestibility of traditional and alternative dietary lipids in Channel Catfish to inform lipid choice for commercial diets. Six diets contained 4% of different lipids: soybean oil (SBO), soybean oil containing conjugated linoleic acids (CLA-SBO), catfish offal oil (COO), flaxseed oil (FXO), menhaden fish oil (MFO) and poultry fat (PF). Diets were fed to Channel Catfish (150-200 g) maintained at 26.5 °C in each of six 110 L aquaria. Six hours post-prandial, feces were collected for analysis. Total lipid, crude protein and fatty acids of lyophilized feces were analyzed, and apparent digestibility coefficients (ADCs) were calculated. ADCs of lipid, saturated and monounsaturated fatty acids, linoleic acid and protein digestibility were similar among diets. CLA isomers (cis-9, trans-11 (84.1%) and trans-10, cis-12 (90%)) in the CLA-SBO diet were highly digestible. Oleic acid digestibility was highest in the PF diet. ADC was high for α-linolenic acid in the FXO diet, and for arachidonic acid and n-3 LC-PUFA in the MFO diet. Overall, total lipid digestibility was high, but ADCs of individual fatty acids differed by source.

The form more than the fatty acid profile of fat supplements influences digestibility but not necessarily the production performance of dairy cows

The form of a lipid supplement, its degree of saturation, and its fatty acid (FA) profile greatly influence digestibility and cow productive response. The objective in this study was to examine the effect of fat supplements that differ in their form or FA profile on nutrient digestibility and cow performance. Forty-two mid-lactation cows (128 ± 53 d) were assigned to 3 treatment groups according to milk yield, days in milk, and body weight. For 13 wk, the cows were fed rations that contained (on a dry matter basis) (1) 2.4% of calcium salts of fatty acids (CSFA) consisting of 45% palmitic acid (PA) and 35% oleic acid (OA; CS45:35); (2) 2.4% of CSFA consisting of 80% PA and 10% OA (CS80:10); or (3) 2.0% of free FA consisting of 80% PA and 10% OA (FF80:10). Rumen samples were taken to measure the ammonia and volatile FA concentrations, and fecal samples were taken to measure the digestibility. Preplanned comparisons were CS45:35 versus CS80:10 to assess 2 CSFA supplements with different FA profiles, and CS80:10 versus FF80:10 to assess similar FA profiles in different forms. Compared with CS45:35, CS80:10 decreased the milk yields, increased the fat percentage, and tended to increase the energy-corrected milk (ECM) yields. The fat percentage of milk was highest in the FF80:10 cows (4.02%), intermediate in the CS80:10 cows (3.89%), and lowest in the CS45:35 cows (3.75%). Compared with CS80:10, FF80:10 increased milk yields (50.1 vs. 49.4 kg/d, respectively), tended to increase fat percentage, and increased 4% fat-corrected milk (4% FCM; 49.1 vs. 47.7 kg/d, respectively) and ECM yields (49.5 vs. 48.2 kg/d, respectively). Treatment had no effect on dry matter intake (DMI), and compared with CS80:10 cows, the calculated energy balance was lower in the FF80:10 cows. The 4% FCM/DMI and ECM/DMI ratios were higher in the FF80:10 group compared with the CS80:10 group. Compared with the CS80:10 cows, the FF80:10 cows had a lower rumen pH, higher propionate, lower acetate/propionate ratio, and higher total VFA. Compared with CS45:35 cows, the apparent total-tract digestibilities of neutral detergent fiber and acid detergent fiber were higher in CS80:10 cows; whereas, the apparent total-tract digestibilities of dry matter, organic matter, protein, neutral detergent fiber, and acid detergent fiber were higher in the CS80:10 cows compared with the FF80:10 cows. Compared with the CS80:10 group, the apparent digestibility of total FA was 13.0 percentage points lower in the FF80:10 cows (79.1 vs. 66.1%, respectively), and similarly, the digestibilities of 16-carbon and 18-carbon FA were lower in the FF80:10 cows than in the CS80:10 cows. In conclusion, the form, more than the FA profile of fat supplements, influenced digestibility. Further, the CSFA supplements were more digestible than the free fatty acids, regardless of the FA profile. However, energy partitioning toward production appeared to be higher in the FF80:10 cows, although the digestibility of nutrients was lower than in the CSFA product with a similar FA profile.

Wet-food diet promotes the recovery from surgery of castration and control of body weight in adult young cats.

Inappropriate dietary management may lead to delayed recovery from castration surgery and significant weight gain in cats after castration. Wet canned food often exhibits more advantageous characteristics than dry food (e.g., higher palatability and digestibility, and lower energy density). This study compared the effects of canned and dry food on surgical recovery and weight management in cats after castration. Eighteen healthy cats (weighed 4.33 ± 1.04 kg and aged 18-months old) were allocated to one of the two dietary treatments (N = 9/group), dry (CON) and canned food (CAN) balanced for sex and initial BW. Cats were fed ad libitum for 7 weeks, including one week before surgery (week 0) and 6 weeks after surgery (week 1-6). Daily dry matter intake (DMI), and weekly body weight (BW) and body condition score (BCS) was obtained. Feces were collected for measuring nutrient digestibility and concentrations of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA). Physical pain and wound surface assessment were performed at week 1. Blood was also collected intermittently for measuring biochemical indices and untargeted metabolomics analysis. Results indicated that BW, BCS and daily DMI in CON group increased (P < 0.05) over time after castration, but were maintained relatively stable in CAN group. Cats in CAN group exhibited less pain-related behavior as reflected by lower score of comfort (P < 0.05) and vocalization (P < 0.10), improved wound surface assessment (P < 0.10), lower level of lipase (P < 0.10) and ratio of blood urea nitrogen/serum creatinine (BUN/SC; P < 0.05), and higher level of superoxide dismutase (SOD; P < 0.05) in week 1 than CON cats. Meanwhile, the CAN group had significantly higher concentration of immunoglobulin G (IgG) on days 5 and 7, and higher level of high-density lipoprotein cholesterol (HDL-C; P < 0.10) but lower triglyceride (TG; P < 0.05) than CON group on day 20 and 48. Fecal total and most individual SCFA increased significantly from week 1 to week 6 regardless of diet, but the increase of butyric acid over time only occurred in CON group (P < 0.05). Also, serum metabolomic analysis revealed differential metabolic pathways between the two groups. Overall, compared with the dry food, the canned food tested in our study promoted cat wound recovery by reducing pain and increasing immune and antioxidative capacity after sterilizing surgery, and helped to maintain healthy body condition in cats after castration.

Effects of dietary oil sources and fat extraction methods on apparent and standardized ileal digestibility of fat and fatty acids in growing pigs

BackgroundThere is a lack of data for the standardized ileal digestibility (SID) of fat and fatty acids in national feed databases. In addition, it is important to specify the procedures used for fat analyses. Therefore, an experiment was conducted to 1) determine the apparent ileal digestibility (AID) and SID of fat and fatty acids in ten different oil sources for growing pigs and to develop prediction equations for SID of fat based on fatty acid composition; and 2) compare the effect of the fat extraction methods on the calculated values for endogenous loss and digestibility of fat.MethodsTwenty-two barrows (initial body weight: 32.1 ± 2.3 kg) were surgically fitted with a T-cannula in the distal ileum, and allotted to 1 of 11 experimental diets in a 4-period Youden Square design. A fat-free diet was formulated using cornstarch, soy protein isolate and sucrose. Ten oil-added diets were formulated by adding 6% of dietary oil sources to the fat-free diet at the expense of cornstarch. All diets contained 26% sugar beet pulp and 0.40% chromic oxide.ResultsThe endogenous loss of ether extract (EE) was lower than that of acid-hydrolyzed fat (AEE; P < 0.01). There were significant differences in the AID and SID of fat and saturated fatty acids across the dietary oil sources (P < 0.05). The SID of AEE for palm oil was lower than that of sunflower oil, corn oil, canola oil, rice oil and flaxseed oil (P < 0.01). The AID and SID of fat ranged from 79.65% to 86.97% and from 91.14% to 99.18%. Although the AID of EE was greater than that of AEE (P < 0.01), there was no significant difference in SID of EE and AEE except for palm oil. The ratio of unsaturated to saturated fatty acids (U/S) had a positive correlation with SID of fat (P < 0.05), whereas C16:0 and long chain saturated fatty acids (LSFA) were significant negatively correlated with SID of fat (P < 0.01). The best-fit equation to predict SID of fat was SID AEE = 102.75 − 0.15 × LSFA − 0.74 × C18:0 − 0.03 × C18:1 (Adjusted coefficient of determination = 0.88, P < 0.01).ConclusionsWhen calculating the SID of fat, the EE content of the samples can be analyzed using the direct extraction method, whereas the acid hydrolysis procedure should be used to determine the AID of fat. Fat digestibility of dietary oils was affected by their fatty acid composition, especially by the contents of C16:0, LSFA and U/S.

Evaluating the in vitro digestion of lipids rich in medium-chain fatty acids (MCFAs) using dynamic and static protocols

Investigating the digestion of lipids is paramount for developing new lipid-based products. This work evaluated the gastrointestinal (GI) digestion of medium-chain fatty acids (MCFAs) rich lipids. The dynamic GI in vitro system was used to simulate gastric, duodenal, jejunal, and ileal GI tract portions. Results from the dynamic protocol were compared against static in vitro assays and GC analyses were conducted to assess the FA profile of FFA released during digestion. Caprylic and capric acids released during the gastric digestion of MCT oil varied from 61–63% and 36–38% of total esterified FA, respectively. Lauric acid was the most representative FFA released (31–54%) during the gastric digestion of coconut oil samples. It was observed that the gastric digestion phase plays a crucial role in the MCFA lipolysis and the lipase activity restricted the amount of free MCFA liberated during the GI digestion, resulting in incomplete lipids hydrolysis.

Enhanced direct interspecies electron transfer and methane production during anaerobic digestion of fat, oil, and grease by coupling carbon-based conductive materials and exogenous hydrogen

To investigate the combination of carbon-based conductive materials and exogenous hydrogen (EH2) on methane recovery from fat, oil, and grease (FOG), granular activated carbon (GAC) and carbon cloth (CC) were chosen to collaborate with EH2, resulting in increased methane production by 59 % and 84 %, respectively. Further digestion of long chain fatty acids (LCFAs) confirms that enhanced direct interspecies electron transfer (DIET) was achieved in the reactors with GAC/CC + EH2 than those with GAC/CC only. Other evidences (such as increased microbial population and rapid degradation of volatile fatty acids) were found to support the role of GAC/CC + EH2 in promotion of DIET. Significant change of microbial community was observed using GAC/CC + EH2, which was mainly attributed to the enrichment of electrogenic species (such as Spirochaetaceae, Syntrophomonas palmitatica, and Methanosaeta), leading to some changes in metabolic pathways during acidogenesis and methanogenesis. Together, enhanced DIET was achieved by GAC/CC + EH2, thus improving the methane recovery from FOG.

Possibility of Using By-Products with High NDF Content to Alter the Fecal Short Chain Fatty Acid Profiles, Bacterial Community, and Digestibility of Lactating Dairy Cows.

This study aimed to investigate whether agricultural by-products with a high NDF content and small-particle-size substitute for forage could cause hindgut acidosis and dysbacteriosis in lactating dairy cows. We investigated the impact of soybean hull and beet pulp on the fecal fermentation, bacterial community, and digestibility of cows. Sixteen lactating Holstein cows were treated as follows (% of dry matter (DM)): amount of by-product added was 0 (control, CON), 1.67% (low by-products, LB), 3.33% (medium by-products, MB), and 5% (high by-products, HB). The results showed the fecal pH of cows to be 7.23–7.29, implying no hindgut acidosis. With increased inclusion of by-products in the diets, the proportion of fecal propionate; relative abundance of the phylum Bacteroidetes, the family Lachnospiraceae, and genera unclassified_f_Lachnospiraceae, Acetitomaculum, and Prevotella; and the DM and NDF digestibility of cows all increased linearly. Meanwhile, the fecal genera Turicibacter and Clostridium_sensu_stricto_1 decreased linearly. By-products promoted the abundance of fecal bacteria genes related to energy metabolism, glycolysis/gluconeogenesis, and propanoate metabolism; and correlations between fecal short chain fatty acids, digestibility, and the bacteria genera were seen. Overall, our study suggested that adding 5% by-products could be a viable dietary formulation strategy that promotes digestibility and makes positive changes in hindgut fermentation and bacteria.

Olive pomace oil and acid oil as alternative fat sources in growing-finishing broiler chicken diets

The aim of the present study was to investigate the effect of dietary supplementation of olive pomace oil and olive pomace acid oil, which are rich in monounsaturated fatty acids (FA) but differ in free FA content, on growth performance, digestibility and FA profile of abdominal fat and breast meat. A total of 3,048 one-day-old mixed-sex broiler chickens (Ross 308) were randomly distributed into 24 pens and 3 dietary treatments (8 replicates per treatment). Experimental diets were administered for growing (from 22 to 29 d) and finishing (from 30 to 39 d) periods, consisting of a basal diet supplemented with 6% (as-fed basis) palm oil (PO), olive pomace oil (O), or olive pomace acid oil (OA). Animals fed O achieved the lowest feed conversion ratio (P < 0.01), together with the highest AME value (P = 0.003), but no differences were observed between OA and PO. Regarding FA digestibility, O and OA showed higher values than PO for all FA in both apparent ileal digestibility (AID) and apparent total tract digestibility. Comparing the AID between O and OA, no differences were observed for total FA, monounsaturated FA, or polyunsaturated FA, but animals fed OA showed lower AID values for saturated FA than those fed O (P < 0.001). The FA profile of abdominal fat and breast meat reflected that of the diet, with higher monounsaturated FA and lower saturated FA in animals fed O and OA compared to those fed PO. In sum, the inclusion of both olive pomace oil and acid oil in growing-finishing broiler chicken diets led to great performance parameters and high FA digestibility values, together with an enrichment with monounsaturated FA in abdominal fat and breast meat compared to the use of palm oil. However, a better AID of saturated FA and feed conversion ratio is achieved with O compared to OA.

A Screening Study on Effects Varying Dietary Macronutrient Composition on Gut Functions in Lumpfish (Cyclopterus lumpus)

Cultivation of lumpfish (Cyclopterus lumpus) as lice cleaner fish for salmon is now expanding. For successful cultivation of a new species, understanding the basic biology of digestive functions is vital to facilitate and optimize diet formulation. This paper presents results from two experiments conducted to deepen our knowledge on lumpfish intestine physiology. Experiment 1 was a 42-day feeding trial in which lumpfish were fed twelve different diets in the following ranges of macronutrients: Protein 43-68%, lipid 4-17%, and carbohydrate 6-17%. Intestinal tissue, gut content and liver were sampled from 6 fish per tank. The results showed that with increasing lipid level and corresponding decrease in protein level, there was a linear decrease in several of the observed biomarkers, including activity of brush border membrane digestive enzymes, expression of genes related to nutrient digestion and transport, ion exchange, immune regulation, and cell remodeling. Increased intracellular accumulation of lipid (steatosis) was observed in gut and liver with increasing dietary lipid level. Fewer effects were observed for increased dietary carbohydrate and corresponding decreased protein level. Experiment 2 was a two-week feeding trial for estimation of macronutrient digestibility in which lumpfish were fed three diets, all containing 55% crude protein, with lipid to carbohydrate ratio of the low lipid diet of 7.5%/18.3%, the medium lipid diet of 13.8%/14.6%, and high lipid diet of 18.1%/9.5%. Fecal samples were collected as pooled samples per tank. These results showed that fatty acid digestibility’s increased as dietary lipid level increased. Of note, starch digestibility decreased greatly as starch level increased, whereas protein digestibility did not change as lipid or starch level varied. Taken together, the present studies indicated that increasing lipid level in the diet with corresponding decrease in protein level affects digestion, absorption, and immune responses in the lumpfish intestine. Variation in dietary carbohydrate to protein level showed less effects, possibly due to low starch digestibility which makes the variation in available carbohydrates much less than the variation in the analysed level of dietary carbohydrates.

Effect of dietary inclusion of camelina or chia oil on fatty acid digestibility, histology, blood biochemistry and molecular biomarkers in juvenile gilthead sea bream (Sparus aurata, L.)

The present study evaluated fatty acid digestibility, histology, blood biochemistry and gene expression in the gut of juvenile gilthead sea bream, Sparus aurata (initial mean weight, 60.4 ± 4.9 g) fed with iso-proteic (48%) and iso-lipidic (20.7%) diets in which fish oil was partially (60%) or totally (100%) replaced with either camelina or chia oil. Each of the experimental diets was fed to triplicate groups of fish stocked at 10 fish/tank in 150 L tanks for 90 days. Although inclusion of camelina or chia oil altered dietary fatty acid (FA) profile, major differences in digestibility in the individual FAs were not observed. Total replacement of fish oil with camelina or chia oil did not have any effect on blood glucose levels, whereas cholesterol and triglyceride levels were reduced. Results of messenger ribonucleic acid (mRNA) transcription showed elevated levels in the expression of the elongases and desaturases in gilthead seabream fed with diets devoid of fish oil. Fish fed with camelina or chia oil based diets had increased expression in lipolytic and lipogenic genes, resulting in accumulation of lipid droplets in the gut of fish. Histological examination revealed no pathological disorders in the guts of the fish.

Combination of emulsifier and xylanase in wheat diets of broiler chickens

The present study was conducted to investigate the effect of emulsifier, xylanase, and a combination of both on the digestibility of nutrients and growth performance of broiler chickens. A total of 480 1-day-old male broiler chickens (Ross 308) were randomly assigned to four dietary treatment groups (15 replicate pens with 8 birds each): control (CON), control plus xylanase (XYL), control plus emulsifier (EMU), and control plus xylanase and emulsifier (XYL+EMU). The experiment was conducted for a period of 42 days, and the diets were based mainly on wheat, soybean meal, tallow, and rapeseed oil. The addition of emulsifiers to the diet showed a significant effect on body weight gain (BWG) (P < 0.001) and feed conversion ratio (FCR) of the chickens during the grower period (P < 0.001) and on the overall FCR (P < 0.001). The analysis of the digestibility of fatty acids on day 35 of the study indicated a positive influence of emulsifier addition, with the highest increase recorded for polyunsaturated fatty acids (P < 0.001). No significant differences in gene expression were noted on the 35th day of birds’ life, but an increase in the expression of some proteins encoding membrane transporters was observed (P < 0.05). The combined use of xylanase and emulsifier resulted in more than a threefold increase in the degradation of neutral detergent fiber (P < 0.05). In conclusion, the combined use of emulsifier and xylanase in wheat–soy-based diets for poultry improves apparent prececal digestibility of fatty acids, and crude protein, apparent metabolizable energy corrected to N equilibrium, and total tract neutral detergent fiber degradation, resulting in better BWG and FCR values. However, the use of emulsifier and xylanase combination showed no additive effect on the investigated variables. The results obtained in the current study indicate that supplementation with a combination of emulsifier and xylanase can be an effective feeding strategy to improve poultry production and nutrient utilization. Future studies are warranted to investigate the effect of emulsifier and xylanase combination on amylase secretion, as well as on the digestibility of other nutrients (crude protein).

A comparative evaluation on the energetic values and digestibility of fatty acids in rice bran oil and palm oil for broilers

The objective of this study was to compare the digestibility of energy and fatty acids (FA) in rice bran oil (RBO) and palm oil (PO) fed to growing Arbor Acre (AA) broilers. A corn-soybean meal basal diet and the basal diet supplemented with 8% RBO or PO were evaluated. A total of 72 AA male broilers (initial BW = 1,173 ± 6 g; age = 22 d) were randomly divided to 3 dietary treatments with 6 replicates of 4 broilers in each. The growth performance and the ME and FA digestibility in oils were compared with a balance experiment of broilers from d 22 to 28. The ME of the RBO diet was greater (P < 0.05) than PO diet and basal diet, and the ME of the PO diet was greater (P < 0.05) than basal diet. However, no statistical difference was observed in the ME intake of broilers fed basal, RBO, and PO diets. To maintain daily ME intake, broilers ingested more basal diet relative to other diets, resulting in increased CP intake (P < 0.01) and retention (P < 0.01) than broilers fed diets supplemented with RBO and PO. This finding resulted in greater (P < 0.01) BWG and ADG from d 22 to 28 for broilers fed the basal diet relative to other diets, but there was no difference for BWG and ADG across oil sources. However, broilers fed RBO had numerically greater BWD and ADG than those fed PO, likely because the RBO provided greater AME, AMEn, AME/GE, AMEn/GE (P < 0.01) as well as ether extract (EE) digestibility (P = 0.0536) relative to PO. The digestibility of palmitic (C16:0), stearic (C18:0), oleic (C18:1), and linoleic (C18:2) were greater (P < 0.01) in RBO than PO, which positively influenced the energy values for RBO. These results indicate RBO has greater ME and digestibility of EE and FA, which positively influenced the growth performance of AA broilers. Therefore, RBO can be used to replace PO in broiler diets.

Olive Pomace and Soybean-Sunflower Acid Oils as Alternative Fat Sources in European Seabass (Dicentrarchus labrax) Diets: Effects on Performance, Digestibility and Flesh Fatty Acid Composition and Quality Parameters.

Simple SummaryAcid oils, by-products of edible oil refining, are potentially interesting fat sources for farmed fish diets because of their high energy content and usually competitive price. Their use and revaluation may contribute to more efficient and sustainable fish production. They are characterised by presenting a similar fatty acid profile to their respective crude oils, but with a high content of free fatty acids. The present study aimed to investigate the effects of including soybean-sunflower and olive pomace acid oils in European seabass diets, as a preliminary step to determine whether they might be suitable energy sources for fish diets. The results showed that growth was only impaired in animals fed the diet containing olive pomace acid oil, which had the highest moisture, impurities and unsaponifiable matter. They also suggest that dietary free fatty acid content affects digestibility, but not the fatty acid profile of flesh and perivisceral fat. Notwithstanding, further studies assessing the effects of the inclusion of these oils are needed before recommending their use.The effects of dietary inclusion of soybean-sunflower and olive pomace acid oils on growth, digestibility and flesh composition were studied in European seabass. Eight diets were fed for 100 days (101.37 ± 0.33 g initial weight, mean ± SD), differing in the added fat source (25% fish oil, 75% experimental oil): S (crude soybean oil), SA (soybean-sunflower acid oil), O (crude olive pomace oil) or OA (olive pomace acid oil); 3 blends: S-O, S-OA, SA-OA at a 1:1 ratio; and a diet containing only fish oil (F) as a control. Animals fed OA showed the worst performance among dietary treatments, with the lowest weight, specific growth ratio, average daily gain and the highest feed conversion ratio (p < 0.01). In contrast, other diets including acid oils did not impair performance. Acid oil diets did not affect the apparent digestibility of dry matter, crude protein or total fatty acids (p > 0.05), but a lower digestibility of lipids and saturated fatty acids was observed (p < 0.001). Flesh composition and fatty acid profile were not affected by the high dietary free FA content (p > 0.05). Hence the results suggest that the studied acid oils may potentially be used in fish diets although further studies are needed.

Impact of different dietary regimens on the lipidomic profile of mare’s milk

Despite mare’s milk being highly nutritious and beneficial to human health, the effects of different dietary regimens on the lipid profile of mare’s milk remain to be completely understood. Herein we employed targeted multiple reaction monitoring-based lipidomics with ultra-high performance liquid chromatography–quadrupole time-of-flight–mass spectrometry to compare the milk lipid profiles of mares fed: pasture grass (P), corn stover and concentrate (H), or cornsilage and concentrate (S). Overall, 461 lipids belonging to 17 subclasses were identified; 261 significantly different lipids were identified on applying the following criteria: false discovery rate-adjusted P < 0.05, variable importance in projection ≥ 1.0, and fold change ≥ 2.0 or ≤ 0.5. The number of significantly different lipids decreased in the order of P > S > H. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis using differential lipids led to the identification of 34, 32, and 31 metabolic pathways on pairwise comparisons between the P and H, P and S, and S and H groups, respectively. The milk of mares in the P group showed significantly higher levels of specific lipids, including triacylglycerols, phosphatidylcholines, and phosphatidylserines, which are known to participate in polyunsaturated fatty acid and lipid digestion and absorption-related metabolic pathways. Altogether, our data provide comprehensive insights into the correlations between feeding systems and quality of mare’s milk in terms of bioactive profile.