n-3 fatty acid enrichment of edible tissue of poultry: a review

A food-exchange model for achieving the recommended dietary intakes for saturated fat in Irish children: analysis from the cross-sectional National Children's Food Survey II

OBJECTIVE

To identify the main foods determining SFA intakes and model the impact of food exchanges to improve compliance with dietary fat recommendations in Irish children.

DESIGN

Estimated food and nutrient intakes were obtained from a cross-sectional study, the National Children's Food Survey II. Participants were categorised into low, medium and high SFA consumers, and the contribution of food categories to SFA intakes was compared. A food-exchange model was developed, whereby a selected range of high SFA foods was exchanged with lower SFA or unsaturated fat alternatives.

SETTING

Participants were randomly selected from primary schools throughout the Republic of Ireland.

PARTICIPANTS

A representative sample of 600 Irish children (5-12 years).

RESULTS

The main determinants of low and high SFA consumers were milk, cheese and butter. These foods, including snack foods and meat and meat products, were considered exchangeable foods within the model. Compared with baseline data, modelled intakes for total fat, SFA, MUFA and trans-fat presented decreases of 3·2, 2·7, 1·6 and < 0·1 % of total energy (% TE), respectively. PUFA, n-6, n-3 and alpha-linolenic acid showed increases of 1·0, 0·8, 0·2 and 0·1 % TE, respectively. Compliance with total fat, MUFA and trans-fat recommendations remained adequate (100 %). Adherence to SFA and PUFA recommendations improved from 18 to 63 % and 80 to 100 %, respectively.

CONCLUSION

The food-exchange model decreased SFA intakes and increased PUFA intakes, suggesting modest dietary changes to children's diets can effectively improve their overall dietary fat profile.

A Comprehensive Exploration of the Fatty Acids Profile, Cholesterol, and Tocopherols Levels in Liver from Laying Hens Fed Diets Containing Nonindustrial Hemp Seed

This study investigates the impact of dietary nonindustrial Moroccan hemp seed (HS) on the fatty acid profile, cholesterol, and tocopherol levels, in the liver of 120 Lohmann brown laying hens aged 22 weeks during 12 weeks of treatment. The hens are randomly allocated into four treatment groups, each subdivided into six replicates with five birds in each replicate. The dietary treatments consist of 0% HS (control), 10% HS, 20% HS, and 30% HS. Results indicate a substantial increase (p < 0.01) in polyunsaturated fatty acids, including omega 3 (n-3) and omega 6 (n-6) types, with the inclusion of HS in the diet. The n-6/n-3 ratio is significantly reduced (p < 0.01), and there is a significant reduction (p < 0.01) in saturated fatty acids only for the 30% HS treatment, indicating a more favorable fatty acid composition. Cholesterol levels remain largely unaffected by HS inclusion, except for the 10% HS group, which shows a significant decrease (p < 0.05). Moreover, hepatic tocopherol levels are significantly elevated (p < 0.01) in subjects receiving the HS diet, with the 30% HS group exhibiting the highest tocopherol content. In summary, incorporating HS into the diet up to 30% appears to offer promising benefits for hepatic lipid composition, particularly in terms of n-3 polyunsaturated fatty acids, the n-6/n-3 ratio, and tocopherol levels, while having minimal impact on cholesterol levels.

A review of recent studies on the enrichment of eggs and poultry meat with omega-3 polyunsaturated fatty acids: novel findings and unanswered questions

Studies from our laboratory over the past decade have yielded new information with regard to the dietary enrichment of eggs and poultry meat with omega-3 (n-3) polyunsaturated fatty acids (PUFA) but have also generated a number of unanswered questions. In this review, we summarize the novel findings from this work, identify knowledge gaps, and offer possible explanations for some perplexing observations. Specifically discussed are: 1) Why feeding laying hens and broilers an oil rich in stearidonic acid (SDA; 18:4 n-3), which theoretically bypasses the putative rate-limiting step in the hepatic n-3 PUFA biosynthetic pathway, does not enrich egg yolks and tissues with very long-chain (VLC; ≥20 C) n-3 PUFA to the same degree as obtained by feeding birds oils rich in preformed VLC n-3 PUFA; 2) Why in hens fed an SDA-rich oil, SDA fails to accumulate in egg yolk but is readily incorporated into adipose tissue; 3) How oils rich in oleic acid (OA; 18:1 n-9), when co-fed with various sources of n-3 PUFA, attenuates egg and tissue n-3 PUFA contents or rescues egg production when co-fed with a level of docosahexaenoic acid (DHA; 22:6 n-3) that causes severe hypotriglyceridemia; and 4) Why the efficiency of VLC n-3 PUFA deposition into eggs and poultry meat is inversely related to the dietary content of α-linolenic acid (ALA; 18:3 n-3), SDA, or DHA.

Effects of linseed oil supplementation duration on fatty acid profile and fatty acid metabolism-related genes in the muscles of Chinese crested white ducks

Meat rich in polyunsaturated fatty acids is considered beneficial to health. Supplementing the diet with linseed oil promotes the deposition of polyunsaturated fatty acids (PUFAs) in poultry, a conclusion that has been confirmed multiple times in chicken meat. However, fewer studies have focused on the effects of dietary fatty acids on duck meat. Therefore, this study aims to evaluate the effects of the feeding time of a linseed oil diet on duck meat performance and gene expression, including meat quality performance, plasma biochemical indicators, fatty acid profile, and gene expression. For this study, we selected 168 Chinese crested ducks at 28 days old and divided them into three groups, with 56 birds in each group. The linseed oil content in the different treatment groups was as follows: the control group (0% flaxseed oil), the 14d group (2% linseed oil), and the 28d group (2% linseed oil). Ducks in the two experimental groups were fed a linseed oil diet for 28 and 14 days at 28 and 42 days of age, respectively. The results showed that linseed oil had no negative effect on duck performance (slaughter rate, breast muscle weight, and leg muscle weight) or meat quality performance (pH, meat color, drip loss, and shear force) (P > 0.05). The addition of linseed oil in the diet increased plasma total cholesterol and high-density lipoprotein cholesterol levels (P < 0.05), while decreasing triglyceride content (P < 0.05). Furthermore, the supplementation of linseed oil for four weeks affected the composition of muscle fatty acids. Specifically, levels of α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were increased (P < 0.05), while eicosatetraenoic acid content was negatively correlated with flaxseed oil intake (P < 0.05). qRT-PCR analysis further revealed that the expression of FATP1, FABP5, and ELOVL5 genes in the breast muscle, as well as FABP3 and FADS2 genes in the thigh muscle, increased after four weeks of linseed oil supplementation (P < 0.05). However, after two weeks of feeding, CPT1A gene expression inhibited fatty acid deposition, suggesting an increase in fatty acid oxidation (P < 0.05). Overall, the four-week feeding time may be a key factor in promoting the deposition of n-3 PUFAs in duck meat. However, the limitation of this study is that it remains unknown whether longer supplementation time will continue to affect the deposition of n-3 PUFAs. Further experiments are needed to explain how prolonged feeding of linseed oil will affect the meat quality traits and fatty acid profile of duck meat.

Regulation of omega-3 fatty acids production by different genes in freshwater fish species: a review

The present study aims to compare the gene expression of three different fish species (common carp, tilapia, and trout) with varying levels of fatty acids (FA). Based on transcriptome analysis and RNA sequencing, various genes and their associated metabolic pathways are identified. Pathways are categorized based on the genes they encode. Genes that were differentially expressed and their promoter's methylation patterns were revealed by RNA-seq analysis in common carp. Furthermore, fatty acid-enriched pathways, such as ARA4 and adipocytokine signaling, were also identified. Many genes and pathways may influence tilapia's growth and omega-3 content. Using the mTOR pathway, trout with differential expression were discovered to be involved in producing omega-3 fatty acids. This study revealed major pathways in fish species to produce omega-3 fatty acids.

Omega-3 enriched chick diet reduces the foraging areas of breeders in two closely related shearwaters from contrasting marine environments

Seabirds have evolved several life-history characteristics to help buffer environmental stochasticity. However, particularly during the breeding season, seabirds may be affected by reductions in prey availability and localised oceanographic conditions caused by variations in the environment. The increase in sea surface temperature, triggered by accelerated global warming, is impairing phytoplankton production of omega-3 fatty acids (FAs). Here, we assessed the ecological role of omega-3 FAs on chick development and subsequently on breeder foraging behaviour in two closely related shearwater species foraging in contrasting marine environments. We supplemented chicks with omega-3 FA pills or with control placebo pills and monitored chick growth, chick health status and breeder at-sea foraging behaviour using global positioning system devices. We found that omega-3 chick supplementation reduced the 95% kernel utilization distribution of short trips of Cape Verde shearwaters, but overall, breeders kept a similar foraging pattern between treatments, potentially influenced by predictable prey patches off the West African coast. In contrast, for Cory's shearwaters, the parents of the omega-3 group greatly reduced the foraging effort. This suggests that the proximity to productive prey patches around the colony may help birds to adjust their effort and, therefore, energy expenditure, to changes in the development of their offspring, as driven by their nutritional status. Overall, our results suggest a link between a chick diet enriched in omega-3 FAs and parental foraging effort, providing insight into their ability to cope with a changing and increasingly stochastic marine environment.

Effect of purified fish oil supplementation on growth performance, meat quality and blood profile in broilers

The present research experimented with the view of observing the effect of supplementing purified fish oil (FO) on growth performance, organ weight, meat quality, along with blood profile of broilers. The experiment was conducted upon 1600 male Ross 308, each aged 1 day, broiler strains with an average body weight of 43.15 ± 1.35 g were randomly allotted into four dietary treatment groups where CON, basal diet; TRT1, CON + 0.05% FO; TRT2, CON + 0.10% FO; and TRT3, CON + 0.15% FO respectively. Each treatment group consisted of 20 replication pens, with each pen containing 20 broiler chicks. The 4-week long experiment was divided into two phases. The first phase (Days 7-21), the second phase (Days 22-35) and the overall (Days 7-35). On Day 21, the body weight of broilers in TRT2 and TRT3 was higher than the control. Increasing doses of purified FO supplementation showed a linear (p < 0.05) increase in body weight on Day 21. At the end of Phase 1, FO supplementation improved the body weight gain (BWG) of TRT2 and TRT3 group birds compared to CON. Increasing doses of FO supplementation increased the BWG linearly in all phases. Increasing doses of FO increased chicks' breast muscle weight with the highest value in the TRT3 group. Moreover, liver weight was linearly decreased in FO supplementation groups compared to the CON group. Abdominal fat was linearly decreased in FO supplemented groups. FO supplementation caused the lowest cholesterol and triglyceride in TRT3 than the CON group with a linear reduction. Low density lipoprotein (LDL) cholesterol was reduced by FO supplemental groups. In addition, FO supplementation increased the red blood cell (RBC) in the TRT3 group compared to the CON group. In conclusion, refined FO increased BWG, breast muscle weight and RBC and reduced cholesterol, triglycerides and LDL in broilers' blood.

Effect of DHA supplementation on broilers' growth performance, meat quality and blood profile

Docosahexaenoic acid (DHA) is vital in the meat composition of broilers which is helpful to maintain a healthy diet in humans. The purpose of this study is to observe the effect of DHA from fish oil on growth performance, organ weight, and meat quality along with the blood profile of broilers. A total of 1600, 1-day old, Ross 308 broilers with an average body weight of 43.15 ± 1.35 g were used in 5 weeks trail. Birds were randomly allotted into one of four dietary treatment groups named: control (CON), basal diet; treatment (TRT)1, CON + 0.05% DHA; TRT2, CON + 0.1% DHA; TRT3, CON + 0.15% DHA. Each treatment group consisted of 20 replications with 20 broilers per pen. The experiment was divided into three phases. Phase 1 (Day 1-7), Phase 2 (Day 7-21), and overall phase (Day 21-35). During Phase 1 and 2, no significant changes were observed on body weight gain (BWG) as the DHA levels increased in the diet. However, during Phase 3, broilers fed diet supplemented with DHA at increasing levels linearly increased (p < 0.05) BWG and feed intake (FI). Also, water holding capacity was reduced and drip loss percentage on Day 7 was increased linearly (p < 0.05) with the increase in DHA supplementation. At the end of trial, pH value of the meat was increased linearly (p < 0.05) with DHA levels. Moreover, blood cholesterol level, high-density lipoprotein, low-density lipoprotein was significantly and linearly (p < 0.05) decreased in DHA supplemented groups. Broiler-fed diet with DHA supplement decreased the red blood cell linearly (p < 0.05) in blood. The results of the study indicate that DHA supplementation increased BWG with FI. Moreover, it has reduced blood lipid constituents with some adverse effect on meat quality.

A review of black soldier fly (Hermetia illucens) as a potential alternative protein source in broiler diets

Since per capita global meat utilization is predicted to increase to 40% from 2019 to 2050, global use of cultivable land in livestock, poultry, and feed production is 30%. Use of alternative protein sources as animal feed can be a solution to minimize cropland usage in conventional feed production. Commonly used protein sources in animal diets like soybean meal and fish meal are facing challenges of high demand, but the current production might not fulfill their dire need. To overcome this issue, the discovery of alternative protein sources is the need of the hour, insect meals like black soldier fly (BSF) are one of these alternative protein sources. These flies are non-infectious, bite-less, can convert the variant types of organic waste (food wastes, animal and human excreta) proficiently into rich profile biomass with reduced harmful bacteria count and do not serve as a vector in disease transmission. Based on the substrate used, the BSF larvae protein, fat and ash contents vary from 37-63%, 7-39% and 9-28% on dry matter basis, respectively. Previous studies have reported that using BSF and its byproducts as alternative protein sources in broiler diets with partial or complete replacement of conventional protein sources. In this review, a brief introduction to insect meal, BSF origin, life cycle, nutritional profile, influences on growth performance, carcass characteristics, fatty acid profile of meat, biochemical properties of blood, gut morphology and microbiota of the caecum along with its influence on laying performance of layers has been discussed in detail. Studies have concluded the partial replacement of conventional protein sources with BSF is possible, whereas complete replacement may cause poor performance due to reduced digestibility up to 62% attributable to chitin content (9.6%). Further studies to corroborate the effect of dietary BSF on growth performance, carcass characteristics, fatty acid profile of meat, and gut morphology and caecum microbiota are required to standardize the inclusion levels in feeds for higher performance of poultry.

Intake of nutrients (polyunsaturated fatty acids, tocols, and carotenes) and storage efficiency in different slow-growing chickens genotypes reared in extensive systems

An extensive rearing system (ERS) for poultry requires an outdoor run, which enhances the foraging activity of chickens. Slow-growing (SG) strains are more adapted to ERS than fast-growing (FG); and generally, have higher levels of bioactive compounds in their meat. The aim of this paper was to assess the storage efficiency of n-3 and n-6 polyunsaturated fatty acids (PUFA), tocols and carotenes in the meat of seven commercial SG genotypes (SG1-7). One hundred SG chicks/strain of both sexes were included and their walking activity (High- or Low-W) was classified: SG1-4, HW comprised more than 10% of the time budget, and SG5-7, less than 10% (LW). Chickens were reared in pens (4 pens/strain) with indoor (0.10 m2/bird) and outdoor (4 m2/bird) areas, and they were fed the same diet ad libitum (starter feed for 1-21 d, grower feed from 22 d to slaughter at 81 d). The chickens were weighed weekly; feed consumption and grass intake were also estimated. At 81 days of age, 32 chickens/genotype were selected on the basis of the average weight (1:1, M:F) and slaughtered. The breast, thigh and drumstick meat were excised from 30 carcasses/genotype, sampled and stored at -20°C until analysis. Nutrients (e.g., n-3, n-6, carotenes and tocols) of feed, grass and meat were analyzed. The storage efficiency of nutrients was estimated as the ratio between the amount deposited in the body muscles (OUT) and the dietary intake (feed and grass, IN). The genotype affected chickens foraging behavior and the intake of nutrients. For SG1, SG2 and SG3, more than 50% of the intake of n-3 came from grass, whereas in the other genotypes, less than 20%. Accordingly, chickens that foraged more showed better meat nutritional profiles (less fat, more n-3 and antioxidants), which, in ERS, was ascribed to grass ingestion. However, the storage efficiency of nutrients into meat was inversely correlated with the grass intake: strains with higher grass intake (SG1, SG2, and SG3) had lower storage rates. Several hypotheses were proposed to explain these trends.

Muscle oxidative stability, fatty acid and amino acid profiles, and carcass traits of broiler chickens in comparison to spent laying hens

This research compared muscle oxidative stability, meat composition, and carcass traits in commercial broilers and spent laying hens. At week 65 of age, 40 ISA Brown laying hens were randomly selected to create 10 replicate cages (4 birds per cage). Also, 60 day-old Ross chicks were equally divided into six replicates (10 chicks each). Broiler chickens had a higher dressing percentage than spent hens (P = 0.027), but a lower abdominal fat percentage (P = 0.009). Spent hens had higher level of malondialdehyde (MDA) in the breast muscles (P = 0.001). Meanwhile, the MDA levels in thigh muscles did not differ in both groups (P = 0.328). Broiler chickens showed greater concentrations of saturated fatty acids (palmitic and stearic) in the breast (P = 0.012 and 0.006, respectively) and thigh (P = 0.033 and 0.038, respectively) muscles as compared to spent hens. Meanwhile, broiler chickens had lower concentrations of palmitoleic, oleic and eicosapentaenoic in the breast muscles (P = 0.002, 0.004 and 0.001, respectively). Also, spent hens had greater concentrations of linoleic in the breast and thigh muscles (P = 0.018 and 0.035, respectively). When compared to broiler chickens, spent hens had greater essential amino acids (isoleucine, methionine and tyrosine) concentrations in the breast muscles (P = 0.002, 0.001 and 0.036, respectively). Finally, while broiler chickens had superior carcass traits, spent hens showed better meat composition (higher polyunsaturated fatty acids and essential amino acids). Furthermore, the oxidative stability of the breast muscles of spent hens was lower than that of broilers. Spent hens can be used as an attractive source of chicken meat if certain precautions are adopted.

Effects of different breeds/strains on fatty acid composition and lipid metabolism-related genes expression in breast muscle of ducks

Fatty acid composition contributes greatly to the nutritional value of meat, and breeds/strains are important factors affecting the composition of fatty acid. Recently, few studies have focused on the fatty acid composition in breast muscle of different duck breeds. Therefore, the objective of the present study was to compare the fatty acid composition and lipid metabolism-related genes expression in breast muscle of Jianchang duck (J), Cherry Verry duck (CV) and 3 crossbred strains (BH1, BH2 and MC♂ × (BGF2♂  × GF2♀)♀ (MBG)). Our results showed that the breast muscle of J had the highest contents of C22:1(n−9) but the lowest ratios of Ʃ-omega 6 (Ʃn−6)/Ʃ-omega 3 (Ʃn−3), Ʃ-mono-unsaturated fatty acid (ƩMUFA)/Ʃ-saturated fatty acid (ƩSFA) and Ʃ-polyunsaturated fatty acid (ƩPUFA)/ƩSFA. The ƩPUFA/ƩSFA ratio was higher in breast muscle of MBG than in that of BH2 and CV, and the contents of C22:1(n-9), ƩMUFA and ƩPUFA were higher in BH1 than in BH2 and CV. Furthermore, the mRNA levels of SCD1, FADS2, ELOVL2, and ELOVL5 were significantly higher in MBG (P < 0.05), while those of FASD1 and ACACA were significantly higher in BH1 than in BH2 and CV (P < 0.05). Principal component analysis showed that fatty acids variation exhibited extensive positive loading on principal components (PCs). Correlation analysis showed that PC1 and PC3 of BH1, as well as PC1 of MBG were correlated with the mRNA levels of ACACA and FABP3, respectively. Thus, it could be concluded that the breast muscles of MBG and BH1 have better fatty acid composition, which was closely related to the increased expression levels of SCD1, FADS2, ELOVL2, and ELOVL5 genes in MBG but FADS1 and ACACA in BH1. Moreover, these results also showed that crossbreeding could optimize the composition of fatty acid in breast muscle of ducks.

The effect of stocking rate and supplementary selenium on the fatty acid composition and subsequent peroxidisability of poultry muscle tissues

Selenium (Se) plays a crucial role in protecting biological materials from oxidative damage through the action of the selenoprotein glutathione peroxidase (GSH-Px), and the effectiveness of this protection is often dependent upon Se supply. Recent evidence has indicated that GSH-Px mRNA expression can be upregulated in response to potential oxidative damage risk, and that this upregulation is independent of Se supply. The current study aimed to determine the effect of Se supplementation, stocking rate and tissue fatty acid profile on GSH-Px activity in breast and thigh tissue of commercial broilers. A total of 168 Ross 308 broiler chicks were enrolled onto the study. Prior to enrolment, birds were brooded as a single group and received a starter diet containing no additional Se. The study was a 2 × 2 factorial design comprising of two levels of dietary Se (high Se, 0.5 mg/kg total Se, low Se background Se only), and two stocking rates (high, 30 kg/m², and low, 15 kg/m²). At 15 days of age, birds were blocked by live weight and randomly allocated to one of the four treatments, with six pen replicates per treatment. At 42 days of age, one bird was randomly selected from each pen replicate, euthanased and breast and thigh tissue harvested. GSH-Px activity, thiobarbituric acid reactive substances (TBARS), and fatty acid (FA) content of these tissues were determined. There was no effect (P > 0.05) of stocking rate on GSH-Px activity or TBARS. GSH-Px activity did not differ between tissue types but was greater in high Se birds (P < 0.001) compared to low Se. TBARS concentrations were greater in thigh tissue (P < 0.001), and these thigh concentrations were greater in high Se birds (P < 0.05). There were marked differences between breast and thigh tissue in most FAs (P < 0.001), with breast generally containing greater proportions of polyunsaturated FA, so that breast tissue had a higher (P < 0.001) peroxidisability index (PI) than thigh. A positive correlation between GSH-Px activity and PI in the thigh tissue of high Se birds (Pearson Correlation 0.668; P = 0.025) may indicate that increasing susceptibility to peroxidisation in lipid-rich tissues may also upregulate GSH-Px activity in Se-replete birds. This study suggests that ensuring adequate dietary selenium could be a useful tool to mitigate adverse effects on meat quality caused by oxidation, particularly in lipid-rich meat.

Effects of dietary palm oil on broiler chicken productive performance and carcass characteristics: a comprehensive review

Palm oil is a natural energy source ingredient in poultry diets that offers a broad range of beneficial effects on the performance of broiler chickens. This review was conducted to highlight the impact of palm oil as a feed ingredient on growth performance and carcass quality, as well as the biochemical, antioxidant activity and tissue fatty acids (FA) composition of broiler chickens. Palm oil inclusion in broiler chickens' rations contributes significantly to the high metabolisable energy (ME) of feed formulation, increases feed palatability and decreases digesta passage rate in the intestine. The reviewed literature indicated that dietary palm oil has a beneficial effect on broiler chickens' overall growth performance traits. The addition of palm oil can also improve the heat tolerance of chickens reared in high ambient temperature conditions. Regardless of breed and breeding conditions, palm oil exhibits good oxidative stability in broiler chickens due to the presence of prevalent phytonutrient elements in this oil. The inclusion of palm oil increased palmitic (C_16:0) and oleic (C_18:1) acids in tissue deposits, which improves meat stability and quality. Moreover, molecular studies have revealed that higher mRNA expression of several lipid-related hepatic genes in broiler chickens fed palm oil. Nonetheless, dietary palm oil can influence FA deposition in tissues, modulate lipoprotein and triglycerides (TG) levels, and cytokine contents in the blood serum of broiler chickens.

Metabolomic and Lipidomic Approaches to Evaluate the Effects of Eucommia ulmoides Leaves on Milk Quality and Biochemical Properties

Eucommia ulmoides leaves (EUL) contain a variety of natural bioactive compounds including chlorogenic acid, geniposide acid, and aucubin. These bioactive chemicals improve immune function and regulate lipid metabolism. The aim of this study was to investigate the effects of EUL on the biochemical properties of milk. Twenty Holstein dairy cows were randomly allocated to two groups fed a control (CTR, diet without EUL, n = 10) or EUL (diet containing 3% EUL, dry matter, n = 10) diet for 55 d. At the end of the experimental period (d 55), milk samples were collected and analyzed to determine their composition. Though levels of milk fat, protein, lactose, and total milk solids were similar between the groups, small molecules, metabolites, lipids, and cytokines differed. Compared with the CTR group, the EUL group had an improved cluster of differentiation (CD)4/CD8 ratio (P < 0.05) and lower interleukin (IL)-8 and IL-6 content (P < 0.05). Metabolomics analysis identified 14 metabolites including 7Z, 10Z, 13Z, 16Z, 19Z-docosapentaenoic acid (FC = 3.129), adrenic acid (FC = 2.830), and eicosapentaenoic acid (FC=1.685) as having significantly increased in the EUL group (P < 0.05) while 11 metabolites, including indole-2-carboxylic acid (FC = 0.636), cholic acid (FC = 0.430), and creatine (FC = 0.784) had significantly decreased (P < 0.05). Based on a constructed metabolome map, linoleic acid metabolism had the highest impact value for EUL. A total of 21 lipid classes and 1,094 lipid species were detected in the milk by lipidomic analysis, among which 40 differed significantly between the CTR and EUL groups. The present findings showed that the EUL altered milk composition. Correlation analysis showed that 7Z, 10Z, 13Z, 16Z, 19Z-docosapentaenoic acid, adrenic acid, and eicosapentaenoic acid levels were negatively correlated with those of the inflammatory factors IL-6 and IL-8 (P < 0.05), indicating that EUL improved milk quality by reducing inflammatory factors and increasing the CD4/CD8 ratio. Overall, our data demonstrate that EUL had positive effects on milk antioxidant parameters, immune indices, and micro-composition metabolism, thereby improving milk quality.

Towards an Optimized Fetal DHA Accretion: Differences on Maternal DHA Supplementation Using Phospholipids vs. Triglycerides during Pregnancy in Different Models

Docosahexaenoic acid (DHA) supplementation during pregnancy has been recommended by several health organizations due to its role in neural, visual, and cognitive development. There are several fat sources available on the market for the manufacture of these dietary supplements with DHA. These fat sources differ in the lipid structure in which DHA is esterified, mainly phospholipids (PL) and triglycerides (TG) molecules. The supplementation of DHA in the form of PL or TG during pregnancy can lead to controversial results depending on the animal model, physiological status and the fat sources utilized. The intestinal digestion, placental uptake, and fetal accretion of DHA may vary depending on the lipid source of DHA ingested by the mother. The form of DHA used in maternal supplementation that would provide an optimal DHA accretion for fetal brain development, based on the available data obtained most of them from different animal models, indicates no consistent differences in fetal accretion when DHA is provided as TG or PL. Other related lipid species are under evaluation, e.g., lyso-phospholipids, with promising results to improve DHA bioavailability although more studies are needed. In this review, the evidence on DHA bioavailability and accumulation in both maternal and fetal tissues after the administration of DHA supplementation during pregnancy in the form of PL or TG in different models is summarized.

Nutritional significance of amino acids, vitamins and minerals as nutraceuticals in poultry production and health - a comprehensive review

Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals' normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed.

Effects of dietary incorporation of linseed oil with soybean isoflavone on fatty acid profiles and lipid metabolism-related gene expression in breast muscle of chickens

The meat quality of chicken is an important factor affecting the consumer's health. It was hypothesized that n-3 polyunsaturated fatty acid (n-3 PUFA) could be effectively deposited in chicken, by incorporating antioxidation of soybean isoflavone (SI), which led to improved quality of chicken meat for good health of human beings. Effects of partial or complete dietary substitution of lard (LA) with linseed oil (LO), with or without SI on growth performance, biochemical indicators, meat quality, fatty acid profiles, lipid-related health indicators and gene expression of breast muscle were examined in chickens. A total of 900 males were fed a corn-soybean meal diet supplemented with 4% LA, 2% LA + 2% LO and 4% LO and the latter two including 30 mg SI/kg (2% LA + 2% LO + SI and 4% LO + SI) from 29 to 66 days of age; each of the five dietary treatments included six replicates of 30 birds. Compared with the 4% LA diet, dietary 4% LO significantly increased the feed efficiency and had no negative effect on objective indices related to meat quality; LO significantly decreased plasma triglycerides and total cholesterol (TCH); abdominal fat percentage was significantly decreased in birds fed the 4% LO and 4% LO + SI diets. Chickens with LO diets resulted in higher contents of α-linolenic acid (C18:3n-3), EPA (C20:5n-3) and total n-3 PUFA, together with a lower content of palmitic acid (C16:0), lignoceric acid (C24:0), saturated fatty acids and n-6:n-3 ratio in breast muscle compared to 4% LA diet (P < 0.05); they also significantly decreased atherogenic index, thrombogenic index and increased the hypocholesterolemic to hypercholesterolemic ratio. Adding SI to the LO diets enhanced the contents of EPA and DHA (C22:6n-3), plasma total superoxide dismutase, reduced glutathione (GSH)/oxidized glutathione and muscle GSH content, while decreased plasma total triglyceride and TCH and malondialdehyde content in plasma and breast muscle compared to its absence (P < 0.05). Expression in breast muscle of fatty acid desaturase 1 (FADS1), FADS2, elongase 2 (ELOVL2) and ELOVL5 genes were significantly higher with the LO diets including SI than with the 4% LA diet. Significant interactions existed between LO level and inclusion of SI on EPA and TCH contents. These findings indicate that diet supplemented with LO combined with SI is an effective alternative when optimizing the nutritional value of chicken meat for human consumers.

Profile of fatty acid lipid fractions of omega-3 fatty acid-enriched table eggs

The omega-3 fatty acid (FA) enrichment of yolk is a key means one of the main objectives to improve the nutraceutical properties of eggs. We evaluated the effect of the dietary inclusion of extruded linseed fed to laying hens on the fatty acid composition of the polar and non-polar lipid classes of the eggs. Two groups of 36 Lohmann White Leghorn layers (65 weeks old) were each fed one of two different diets for a period of 12 weeks. The two diets consisted of a conventional cereal-based diet concentrate (C) and a diet concentrate containing 5% linseed (L). The inclusion of linseed in the diet increased the content of α-linolenic (C18:3n-3), eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids in neutral lipids, while a concomitant decrease in arachidonic acid (C20:4n-6) was observed. As regards the polar fraction, the fatty acid composition was slightly affected by the dietary treatments except for C18:0 (+1.14 fold), C18:2n-6 (+1.23 fold), C18:3n-3 (+2.8 fold) and C22:6n-3 (+1.41 fold). Principal component analysis demonstrated that very long-chain FAs were more representative of polar lipids, except for C20:5n-3, while neutral lipids were characterized by dietary n-3 FA (C18:3n-3).

Lipid Assessment, Cholesterol and Fatty Acid Profile of meat from broilers raised in four different rearing systems

Evaluated lipid and cholesterol concentration and fatty acid profile of raw breast, thigh and drumstick meat from broilers raised in different rearing systems. Were used 200 male broiler carcasses from four different rearing systems (n=50 from conventional intensive; n=50 from organic; n=50 from free-range; and n=50 from antibiotic-free) distributed in a completely randomized design with four rearing systems and 50 replications (carcasses). Breast meat from conventional broilers showed higher lipid (1.47) and cholesterol (34.13) concentration. Thigh and drumstick meat from free-range broilers had higher lipid (7.53/4.73) and cholesterol (45.55/53.65) concentration. Fat contained in breast, thigh and drumstick meat from free-range broilers showed higher levels of polyunsaturated fatty acids. Fat from breast and thigh meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Fat from thigh meat from organic broilers showed higher levels of EPA (C20:5n3) and DHA (C22:6n3). Fat from drumstick meat from free-range broilers showed higher total concentration of ω3 and ω6 fatty acids. Meat from chickens raised in alternative rearing systems offers less risk to cardiovascular health because it presents lower concentrations of lipids and cholesterol, greater amounts of polyunsaturated fatty acids, which are beneficial for human health.

Linseed oil supplementation affects fatty acid desaturase 2, peroxisome proliferator activated receptor gamma, and insulin-like growth factor 1 gene expression in turkeys (Meleagris gallopavo)

Objective

Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated.

Methods

The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction.

Results

The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control.

Conclusion

Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

Energy metabolism and sources of oxidative stress in wooden breast - a review

Modern broilers show dramatic growth over a short interval and contribute directly to the success of the poultry meat industry. The growth performance of commercial broilers is a result of genetic selection for "performance traits", such as body size, meat yield, and feed conversion rate. However, due to the rapid growth rate of modern commercial broilers, several growth-related conditions have arisen, increasing economic losses and consumer concerns. Among the most economically consequential is the muscle disorder called wooden breast. Together with associated myopathies such as white striping and spaghetti meat, wooden breast is causing losses of $200 million a year in the U.S. alone and occurs worldwide. No causative factors are known for wooden breast to date. Wooden breast can affect over 80% of broilers in a flock, yet no methods of amelioration are currently available. Overall, the evidence suggests that wooden breast is a genetic, age-dependent condition associated with fast growth rate. The primary features of wooden breast are muscle degeneration and fibrosis, high levels of oxidative stress, hypoxia, and altered energy metabolism. Recent work has also implicated reduced pectoral vessel density in the pathogenesis of wooden breast. This review examines the history of myopathies in commercial broilers and the relationship of myopathies to metabolism and oxidative performance. This review summarizes the foundational knowledge of wooden breast and provides a platform for further investigation of wooden breast.

Effects of feeding broiler breeder hens a coextruded full-fat flaxseed and pulses mixture without or with multienzyme supplement

The effects of coextruded full-fat flaxseed and pulses (FFF; 1:1 wt/wt) mixture on n-3 polyunsaturated fatty acids (PUFA) enrichment in egg yolk, hepatic attributes, apparent retention (AR) of components, and ceca metabolites were evaluated in broiler breeder hens. The diets were as follows: 1) corn–soybean control, 2) control diet plus 18% FFF (FFF−), and 3) FFF plus enzyme supplement (FFF+) containing galactanase, protease, mannanase, glucanase, xylanase, amylase, and cellulase activities. Twenty-six-week-old Cobb 500 broiler breeder hens were allocated to 30 identical cages (2 hens/cage) and given 1-week adaptation period. The 3 diets were assigned to 10 replicate cages based on postadaptation BW and fed based on breeder curve for 30 D. Excreta samples were collected from day 24 to 27 for determination of AR of components, and eggs were collected from day 28 to 30 for yolk polyunsaturated fatty acids analyses. On day 30, birds were weighed, killed via cervical dislocation, liver weighed, and stored for fat analyses. Ceca digesta samples were taken for concentration of short-chain fatty acids. Liver and yolk weights as well as total yolk FA were not influenced by diets (P > 0.05). Control birds had lower yolk concentration of α-linolenic acid than birds fed either FFF− or FFF+ (P < 0.01) corresponding to 7.5, 36.8, and 37.3 mg/g for the control, FFF−, and FFF+, respectively. Control birds also exhibited lower yolk concentration of docosahexaenoic acid (P < 0.01). Control birds had higher hepatic concentration of crude fat and apparent retention of dry matter and crude protein compared with either the FFF− or FFF+ birds (P < 0.05). Birds fed FFF- diet had lower ceca digesta concentration of lactic acid than control and FFF+ (P < 0.05) birds. Results showed broiler breeder hens enriched egg yolk with n-3 polyunsaturated fatty acids without effects on the liver while the supplemental enzyme did not improve the utilization of FFF.

Independent and combined effects of Satureja khuzistanica essential oils and dietary acetic acid on fatty acid profile in thigh meat in male broiler chicken

A 2 × 6 factorial experiment was conducted to evaluate the effect of Satureja khuzistanica essential oils (SkEO; 0, 200, 300, 400, 500, and 600 mg/bird/day) administered via oral gavage and dietary acetic acid (AA; 0 and 20 g/1 kg) on fatty acids (FA) composition in thigh meat of Ross 308 broiler chickens at days 34, 38, and 42 of age. Dietary AA reduced DWG, DFI, and European economic efficiency index, and increased FCR compared with the nonacidified diet. In day 34 of age, saturated FA (SFA) percentage reduced and polyunsaturated FA (PUFA), n-3, and n-6 percentages increased in the birds that received 400 mg SkEO. Mean monounsaturated FA (MUFA) percentage was greater, whereas PUFA, n-3, n-6, and total FA (TFA) percentages were lesser in the birds fed on the acidified diet. In day 38 of age, mean PUFA, TFA, n-3, and n-6 percentages were greater while MUFA and cis FA (CFA) concentrations were lesser in the thigh muscle of the birds that received 400 mg SkEO. Mean MUFA, PUFA, n-3, n-6, CFA, and TFA percentages were lower in the birds maintained on the acidified diet. In day 42 of age, mean SFA percentage reduced in the birds given 300 mg SkEO, while TFA percentage lowered in the birds that received 200 and 600 mg SkEO. The acidified diet decreased MUFA, TFA, and CFA percentage and increased SFA and the n-6 to n-3 fatty acids ratio of thigh meat in chicken. The results led to the conclusion that the daily enteral administration of SkEO through oral gavage may feasibly modify the fatty acids profile of thigh meat in favor of increased PUFA. Dietary AA and its interaction with SkEO inconsistently modified concentration of certain classes of fatty acids in broiler thigh meat, particularly in advanced ages. Almost all alterations induced by AA-involving treatments in fatty acids composition of thigh meat were on the contrary to the SkEO influences as they were in favor of an increased SFA proportion.

Comparison of different dietary sources of n-3 polyunsaturated fatty acids on immune response in broiler chickens

The study aims to research the effects of varied dietary sources of n-3 polyunsaturated fatty acids (PUFA) on the immune response in broiler chickens with stress on natural killer (NK) cell activity. Diets supplemented with one of the four sources of n-3 PUFA: linseed oil-, echium oil-, fish oil (FO) or algal biomass-enriched diets at levels of 18, 18, 50 and 15 g/kg fresh weight, were provided for one-d-old male Ross 308 broilers, totaling 340 in number, until they were slaughtered. The analyses included total lipid profile using gas chromatography (GC) for plasma, spleen, thymus, and blood. Additionally, NK cell activity and cell proliferation were investigated for thymocytes and splenocytes. The results indicated that the source of n-3 PUFA had a strong influence on fatty acid composition across all tissues. NK activity was highest in splenocytes and PBMCs from broilers fed linseed oil, followed by those fed algal biomass or echium oil, and lowest for those from broilers fed FO. The proliferative response of lymphocytes from algal biomass-fed chickens tended to be the highest, followed by those fed linseed oil in most cases. Lymphocytes from chickens fed fish oil showed the lowest proliferative response. These results could mean that a docosahexaenoic acid (DHA)-rich algal product might enrich chicken meat with n-3 PUFA without significant damaging effects on chicken immunity.

Dietary chia (Salvia hispanica L.) improves the nutritional quality of broiler meat

OBJECTIVE

The current study was conducted to evaluate the quality and profile of fatty acid in the breast and thigh, and the performance of broilers fed diets containing seed or oil of chia (Salvia hispanica L.) as a replacement for soybean, in the rearing period from 29 to 42 days of age.

METHODS

On the 29th day of age, 120 broilers were distributed in four treatments evaluated in five replicates of six birds. The grain or oil of soybean was respectively replaced on a weightto-weight basis in the formulation by the seed or oil of chia, constituting the experimental diets. The roasted whole soybean and chia seed were included in the feed at 16.4%, whereas the soybean and chia oils were included at 2.5%.

RESULTS

The dietary chia oil increased the lipid peroxidation in the thigh meat, and the dietary chia seed increased the cooking loss of the thigh. However, for the other physicochemical parameters evaluated and for the proximate composition of the breast and thigh, in general, the inclusion of chia seed or oil in the diet provided similar or better results than those observed when the diets contained soybean oil or roasted whole soybean. With regard to the fatty acid profile and associated parameters, dietary chia increased the concentrations of α-linolenic, eicosapentaenoic, and docosahexaenoic acids and reduced the Σω-6:Σω-3 ratio and the atherogenicity and thrombogenicity indices of the broiler meat. However, the dietary chia seed worsened the feed conversion ratio.

CONCLUSION

Diet containing 2.5% chia oil supplied to broilers during the period from 29 to 42 days of age improves the feed conversion ratio, increases the deposition of the ω-3 fatty acids in the breast and thigh, in addition to reducing the Σω-6:Σω-3 ratio and the atherogenicity and thrombogenicity indices, thereby resulting in meat with higher nutritional quality.

Effects of chlorogenic acid-enriched extract from Eucommia ulmoides leaf on performance, meat quality, oxidative stability, and fatty acid profile of meat in heat-stressed broilers

To investigate the effects of chlorogenic acid-enriched extract (CGAE) from Eucommia ulmoides leaf on performance, meat quality, oxidative stability, and fatty acid profile of breast meat in heat-stressed broilers, 400 28-day-old male Ross 308 broilers were randomly assigned into 4 groups with 10 replicates per group (10 broilers per replicate). Broilers in the normal group (NOR) were kept at 22 ± 2°C (24 h/D) and fed the basal diet, and the other 3 groups were treated with cyclic heat (34 ± 2°C from 08:00 to 18:00 and 22 ± 2°C from 18:00 to 08:00) and fed the basal diet supplemented with 0 (HT), 500 (CGAE500), and 1,000 mg (CGAE1000) mg of CGAE/kg of diet. The experiment lasted for 14 D. Compared with the HT group, broilers in the NOR and CGAE1000 groups had a higher average daily gain and a lower feed conversion ratio (P < 0.05). CGAE supplementation at 1,000 mg/kg increased pH24 value, a* value and total superoxide dismutase activity and reduced drip loss, cooking loss, L* value and the contents of malondialdehyde and carbonyl in breast meat of heat-stressed broilers (P < 0.05). Broilers in the HT group showed lower mRNA levels of nuclear factor erythroid 2-related factor 2 (P < 0.001), superoxide dismutase (P = 0.004), and catalase (P < 0.001) in breast meat compared with the other groups. CGAE supplementation at 1,000 mg/kg reduced the stearic acid and saturated fatty acids (SFA) contents and increased the dihomo-γ-linolenic acid, linoleic acid, linolenic acid, eicosapentaenoic acid, polyunsaturated fatty acids (PUFA), and n-6 PUFA contents and PUFA:SFA ratio in breast meat of heat-stressed broilers (P < 0.05). In conclusion, CGAE supplementation at 1,000 mg/kg could alleviate the adverse effects of heat stress on growth performance and meat quality and improve oxidative stability and fatty acid profile of breast meat in heat-stressed broilers.

Omega-3 and Omega-6 Fatty Acids in Poultry Nutrition: Effect on Production Performance and Health

Omega-3 (ω-3) and omega-6 (ω-6) fatty acids are important components of cell membranes. They are essential for health and normal physiological functioning of humans. Not all fatty acids can be produced endogenously owing to the absence of certain desaturases; however, they are required in a ratio that is not naturally achieved by the standard diet of industrialized nations. Poultry products have become the primary source of long-chain polyunsaturated fatty acids (LC-PUFA), with one of the most effective solutions being to increase the accretion of PUFAs in chicken products via the adjustment of fatty acids in poultry diets. Several studies have reported the favorable effects of ω-3 PUFA on bone strength, bone mineral content and density, and semen quality. However, other studies concluded negative effects of LC-PUFA on meat quality and palatability, and acceptability by consumers. The present review discussed the practical application of ω-3 and ω-6 fatty acids in poultry diets, and studied the critical effects of these fatty acids on productive performance, blood biochemistry, immunity, carcass traits, bone traits, egg and meat quality, and semen quality in poultry. Future studies are required to determine how poultry products can be produced with higher contents of PUFAs and favorable fatty acid composition, at low cost and without negative effects on palatability and quality.

Influence of storage and packaging method on chicken breast meat chemical composition and fat oxidation

The aim of this study was to determine the influence of storage conditions and packaging methods on chicken breast meat chemical composition and fat oxidation. In this study, chicken breasts available in retail sale were used for evaluation. The meat packed by three different methods (air packaging-AP, modified atmosphere packaging-MAP, and vacuum packaging-VP) was stored in a cooling room or a commercial display case for 9 D and tested for basic chemical composition, lipid oxidation (TBARS), and fatty acid composition. Meat in MAP during storage in the cooling room was characterized by higher (P ≤ 0.05) TBARS values as compared to meat packaged in AP and VP, respectively. The highest share in the fatty acid profile in chicken breasts was demonstrated by monounsaturated fatty acid, including cis C18:1 (n9 + n11) acid in the range from 31.86 to 34.66%. A high share of polyunsaturated acids was observed, including linoleic (C18:2 cis, cis) acid from 24.50 to 31.22% of all fatty acids. The simple relationship between the changes in the profile of fatty acids in meat packaged using different methods and in storage time was not determined, likely due to the variability of the composition of fatty acids in chicken breasts depending on the sample and the general low level of fat found in the meat.

Egg quality, fatty-acid composition and gastrointestinal morphology of layer hens fed whole flaxseed with enzyme supplementation

1. Flaxseed is a rich source of α-linolenic acid (ALA, 18:3 n-3). Feeding flaxseed to hens can increase n-3 fatty acids (FA) in eggs. However, non-starch polysaccharides (NSP) in flaxseed decrease nutrient digestibility and can have a negative impact on egg n-3 FA incorporation. Addition of carbohydrase enzymes to flaxseed-based diets can decrease the anti-nutritive effects of NSP. 2. An experiment was conducted to investigate the effect of enzyme supplementation on FA composition and gastrointestinal morphology in hens fed flaxseed. A total of seventy-two, 51-week old brown layer hens were randomly assigned to one of the four dietary treatments (six replicates with three hens per replicate): corn-soybean based diet containing 0% flax (Control), 10% flax (Flax), Flax+0.05% enzyme (Flax+E1), or Flax+0.1% enzyme (Flax+E2) in a 120-day feeding trial. 3. Egg weight was highest in hens fed Flax+E1 (P < 0.05). Yolk weight was higher in Flax+E1 compared with the control and Flax+E2 and was not different from Flax treatment. ALA and total n-3 FA was highest in eggs from Flax+E2 hens (P < 0.05). Addition of enzyme has no effect of on docosahexaenoic acid (DHA), total long chain (>20-C FA), or n-6:n-3 FA ratio in eggs from hens fed flaxseed-based diets (P > 0.05). Over nine-fold increase in hepatic ALA was observed in the liver of hens fed flaxseed-based diets when compared with the control diet (P < 0.0001). No effect of enzyme supplementation was observed on liver ALA, DHA or long chain n-3 FA (P > 0.05). Enzyme supplementation reduced arachidonic acid, total n-6 and LC n-6 FA in liver tissue from hens fed flaxseed-based diets (P > 0.05). 4. Villi height and width was higher in the duodenum and jejunum of hens fed flax-based diets compared to the control (P < 0.05). Enzyme supplementation led to an increase in villi width in jejunum (P < 0.05) in hens fed Flax+E2 (P < 0.05). No effect of diet was observed in the crypt depth and villi height:crypt depth ratio in the jejunum (P > 0.05). 5. It was concluded that enzyme supplementation enhanced total n-3 FA deposition in eggs and liver and influence gastrointestinal morphology in layer hens fed flaxseed.

Black soldier fly defatted meal as a dietary protein source for broiler chickens: effects on carcass traits, breast meat quality and safety

Finding insect meals as alternative sources of poultry feedstuffs is a recent research topic; therefore, the present study aimed to evaluate the effects of defatted black soldier fly (Hermetia illucens L., HI) larvae meal in broiler chicken diets on the carcass characteristics and meat quality parameters, proximate composition, fatty acid profile and the heavy metal content of the breast meat. Four dietary treatments were designed: a control diet (HI0) and three experimental diets (HI5, HI10 and HI15), corresponding to 50, 100 and 150 g/kg HI inclusion levels, respectively. The inclusion of 50, 100 and 150 g HI meal per kg feed supply 16.56%, 33.01% and 49.63% of required crude protein. The broilers were slaughtered at day 35, the carcasses were weighed and the breast muscles were excised from 16 birds per each feeding group (two birds per replicate pens) and used for meat quality evaluation. Linear and quadratic responses were observed, for increasing HI meal levels, in the live and carcass weights (maximum for HI10). As far as the colour of the breast meat is concerned, redness (a*) showed a linear response, while yellowness (b*) linearly decreased with increasing HI meal levels (minimum for HI15). As the HI larvae meal increased in the diets, the moisture content linearly decreased and the protein content increased. The total saturated fatty acid and total monounsaturated fatty acid proportions rose to the detriment of the polyunsaturated fatty acid fraction. The HI larvae meal, used in the current study, represents a valuable protein source for broiler chickens when included by up to 100 g/kg in their diets, as an improved slaughtering performance was observed without any detrimental effects on meat quality parameters or heavy metal residues in the meat.

Insect Oil as An Alternative to Palm Oil and Poultry Fat in Broiler Chicken Nutrition

Simple Summary

Recently, there has been increasing interest in the use of insects as an alternative sustainable source of protein and fat in animal feed to improve animal production and maintain ecological sustainability. Palm oil is commonly used in broiler chicken nutrition; however, due to the environmental footprint, consumers have formed negative opinions regarding its applications. Therefore, alternatives to palm oil are urgently needed. The present study was conducted to evaluate the effects of Tenebrio molitor oil as a total replacement for palm oil and poultry fat in broiler chicken diets on chicken performance, nutrient digestibility, pancreatic enzyme activity, various blood parameters and lipid fatty acid compositions of liver and breast muscle tissues. Based on the obtained results, T. molitor oil did not show any adverse impacts on performance and improved the fatty acid profiles of liver and breast muscle tissues. In conclusion, T. molitor oil may be a sustainable alternative to palm oil in broiler chicken nutrition.

Abstract

This study was conducted to evaluate the effects of Tenebrio molitor (TM) oil as a total replacement for palm oil and poultry fat in broiler chicken diets on growth performance, nutrient digestibility, pancreatic enzyme activity, selected blood parameters and the lipid fatty acid compositions of liver and breast muscle tissues. A total of 72 seven-day-old female Ross 308 broiler chickens were used. The birds were randomly distributed into three groups with 12 replicates each, using two birds per replicate for 30 days in metabolic cages. The basal diet was supplemented with 5% palm oil, poultry fat or TM oil. There was no effect (p > 0.05) caused by the dietary oil replacement on the birds’ performance and apparent nutrient digestibility. Liver size (p = 0.033), the concentration of hepatic triglycerides (p = 0.049) and total cholesterol (p = 0.048) were reduced by TM oil supplementation. Furthermore, TM oil supplementation increased n-3 and n-6 fatty acids (p = 0.006; p < 0.001, respectively) in breast muscle tissue. In conclusion, the use of TM oil in broiler chickens’ diets did not show any adverse effects on performance, nutrient digestibility and blood biochemical parameters. Moreover, TM oil supplementation improved the fatty acid profiles of liver and breast muscle tissues.

Genomic, Transcriptomic, and Epigenomic Features Differentiate Genes That Are Relevant for Muscular Polyunsaturated Fatty Acids in the Common Carp

Polyunsaturated fatty acids (PUFAs) are a set of important nutrients that mainly include arachidonic acid (ARA4), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and α-linolenic acid (ALA). Recently, fish-derived PUFAs have been associated with cardiovascular health, fetal development, and improvement of brain functions. Studies have shown that fish muscular tissues are rich in PUFAs, which are influenced by various factors, including genetic variations, regulatory profiles, and methylation status of desaturase genes during fatty acid desaturation and elongation processes. However, the genetic mechanism and the pathways involved in fatty acid metabolism in fishes remain unclear. The overall aim of this study was to assess differences in gene expression responses among fishes with different fatty acid levels. To achieve this goal, we conducted genome-wide association analysis (GWAS) using a 250K SNP array in a population of 203 samples of common carp (Cyprinus carpio) and identified nine SNPs and 15 genes associated with muscular PUFA content. Then, RNA-Seq and whole genome bisulfite sequencing (WGBS) of different groups with high and low EPA, DHA, ARA4, and ALA contents in muscle, liver and brain tissues were conducted, resulting in 6,750 differentially expressed genes and 5,631 genes with differentially methylated promoters. Gene ontology and KEGG pathway enrichment analyses of RNA-Seq and WGBS results identified enriched pathways for fatty acid metabolism, which included the adipocytokine signaling pathway, ARA4 and linoleic acid metabolism pathway, and insulin signaling pathway. Integrated analysis indicated significant correlations between gene expression and methylation status among groups with high and low PUFA contents in muscular tissues. Taken together, these multi-level results uncovered candidate genes and pathways that are associated with fatty acid metabolism and paved the way for further genomic selection and carp breeding for PUFA traits.

Refined cottonseed oil as a replacement for soybean oil in broiler diet

With the shortage of common vegetable fat sources, such as soybean oil (SBO), it is urgent to find alternative oil sources for broiler producers. The objective of this study was to evaluate the potential of refined cottonseed oil (CSO) as a replacement for SBO in broiler diets. A total of 180 chickens at 1 d of age were randomly assigned to five treatments of six replicates. One treatment was the basal diet (control), and the other four experimental diets were formulated from the basal diet by replacing (w/w) 25%, 50%, 75%, and 100% of the SBO with refined CSO (only containing 0.2% cyclopropenoid fatty acids, and no free gossypol was detected). At the end of week 6, blood samples were obtained from the jugular vein and the breast muscle was aseptically isolated from two birds per replicate. The results showed that substitution of CSO for low-level SBO had no significant effect (p > 0.05) on broiler performance during the starter period (week 1-3), while 50% level of CSO inclusion significantly increased (p < 0.05) ADG and improved FCR compared with the control group during the finisher period (week 4-6). Broilers fed 100% CSO diets had lower (p < 0.05) levels of serum total protein (TP), albumin (ALB), cholesterol (CHO) concentrations, and serum alkaline phosphatase (AKP) activity than that of the control broilers. Furthermore, the serum antioxidant status appeared to be enhanced by CSO. Additionally, high levels of CSO (75 and 100%) significantly increased the proportions of C14:0 and C18:0 but decreased the proportions of C18:1n9t, C18:2n6c, and ∑ n-6 polyunsaturated fatty acids in breast muscles of broilers. Overall, the SBO could be replaced with refined CSO up to 50% in diets for broilers without adversely affecting the performance, liver functions, and breast muscle fatty acid composition of these broilers.

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) - without supplementation; group II (positive control) - without supplementation; group III - supplementation with 100 mg vitamin E/kg; group IV - 200 mg vitamin E/kg; group V - 100 mg vitamin E/kg and 100 mg PP/kg; group VI - 200 mg PP/kg. In groups II-VI, broiler chickens aged 21-35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature.

Effect of fungal gamma-linolenic acid and beta-carotene containing prefermented feed on immunity and gut of broiler chicken

Gamma-linolenic acid (GLA) is a fatty acid from the ω-6 family. It is able to deliver a wide range of health benefits arising from its anti-inflammatory effects. An insufficient supply of GLA from agricultural and animal sources resulted in the development of a fermentation technique using lower filamentous fungi, which have the ability to accumulate high concentrations of GLA and beta-carotene during solid-state fermentation of cereals. The goal of this study was to observe the influence of the addition of prefermented cereal product, containing high amounts of GLA and beta-carotene, into the feed of broiler chickens on their immune status, and also the number of lactic acid bacteria and enterobacteria in gut content, which has never been studied before. Immunostimulation in the GLA group was manifested by a significant increase in the oxidative burst of phagocytes, CD4+CD8- lymphocytes in blood, and the CD4: CD8 ratio. Upregulation of gene expression for IgA in the GLA group indicates that the B-lymphocytes were stimulated at a local gut level. In the caecum, increased mRNA expression for mucin-2 and insulin-like growth factor was observed in the GLA group, which could contribute mainly to the protection of the intestinal mucosa and to better growth and regeneration of skeletal muscles. Improved immune activation and protection of the intestinal mucosa were subsequently reflected in a change of the microbial composition in gut contents; a significant reduction of enterobacteria occurred after GLA administration. We can conclude that prefermented cereals containing fungal GLA and beta-carotene represent a low-cost supplement for broiler diet having a beneficial health effect.

Omega-3 Long-Chain Polyunsaturated Fatty Acids, EPA and DHA: Bridging the Gap between Supply and Demand

The omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic (DHA, 22:6n-3) acids, are well accepted as being essential components of a healthy, balanced diet, having beneficial effects on development and in mitigating a range of pathological conditions. However, their global supply from all the traditional sources of these nutrients is insufficient to satisfy human nutritional requirements. For two decades there has been considerable research carried out into all possible alternatives to the main sources of n-3 LC-PUFA, marine fish oil and fishmeal, driven largely by the aquaculture sector, as both the major user and provider of EPA and DHA. In the last few years these efforts have focused increasingly on the development of entirely new supplies of n-3 LC-PUFA produced de novo. Recently, this has resulted in various new sources of EPA and/or DHA that are already available or likely to available in the near future. In this short review, we briefly summaries the current gap between supply and demand of EPA and DHA for human requirements, the role of aquaculture in providing n-3 LC-PUFA to human consumers, the range of potential novel sources, and suggest how these new products could be used effectively. We conclude that all the new sources have potentially important roles to play in increasing the supply of n-3 LC-PUFA so that they are available more widely and in higher concentrations providing more options and opportunities for human consumers to obtain sufficient EPA and DHA to support more healthy, balanced diets.

Effect of Soybean or Linseed Oil With RRR-D-α-Tocopherol or Dl-α-Tocopherol Acetate on Quality Characteristics and Fatty Acid Profile of Turkey Meat

In this study, the effect of the halved dosage of RRR-d-α-tocopherol (with respect to dl-α-to-copherol acetate) in diets containing oil rich in linoleic or α-linolenic acid (soybean or linseed oil, respectively) on the quality characteristics and fatty acid (FA) profile of turkey meat was studied. The experiment was conducted using 480 one-week-old turkey hens Big 6 line reared until the 16th week of life. The hens in Groups I and II received soybean oil added to their feed mixture, in Groups III and IV linseed oil was the source of supplementary fat. Turkeys in Groups I and III received dl-α-tocopherol acetate, whereas those in Groups II and IV RRR-d-α-tocopherol. No influence of dietary manipulation was observed on the chemical composition of turkey meat. The combined effect of the type of dietary fat and vitamin E source added to the feed was assessed using the color parameters. The addition of natural vitamin E to the feed mixture with linseed oil significantly increased the proportion of PUFA in breast muscle lipids compared with the group receiving soybean oil with this form of vitamin E. The inclusion of linseed oil increased the content of α-linolenic acid and total n-3 FA concentration in both muscles, compared with the diet that contained soybean oil. This modification of FA composition led to lower n-6/n-3 ratio in both the breast and thigh muscles regardless of the dietary vitamin E source. The use of natural form of tocopherol in diets containing linseed oil may help to improve the nutritional quality of turkey meat, especially by enhancing n-3 PUFA levels with no detrimental effect of lipid addition on the chemical composition and quality of meat.

Tolerance of Broilers to Dietary Supplementation with High Levels of the DHA-Rich Microalga, Aurantiochytrium Limacinum: Effects on Health and Productivity

It is well established that the docosahexaenoic acid (DHA) content of commonly consumed meats, such as chicken, can be increased through dietary supplementation with DHA-rich ingredients. The purpose of this study was to investigate the tolerance of broilers to dietary supplementation with the unextracted biomass of a DHA-rich microalgae Aurantiochytrium limacinum, so as to ensure its safety, since it is accumulated in broiler meat. Healthy day-old male Ross 308 chicks (n = 1120) were evenly distributed to 32 pens (35 chicks per pen), with pens randomly allocated to one of four dietary treatments, each having eight replicates. The dietary groups included one untreated control and three treatments corresponding to three inclusion levels (0.5, 2.5, and 5.0%) of All-G-Rich®, with the birds receiving the experimental diets ad libitum during the study (day 0⁻42). Bird survival, blood parameters, productivity, and breast and thigh DHA content were determined after 42 days of feeding. Supplementation at up to 10 times the intended use level had no negative effects on the mortality, blood parameters or productivity of the birds, while significant increases in the meat DHA content were observed. These results indicate that supplementation with Aurantiochytrium limacinum is a safe and effective way to increase broiler tissue DHA content.

Framework for life cycle assessment of livestock production systems to account for the nutritional quality of final products

Life cycle assessment (LCA) is widely regarded as a useful tool for comparing the environmental impacts of multiple livestock production systems. While LCA results are typically communicated in the form of environmental burdens per mass unit of the end product, it is increasingly becoming recognized that the product quality also needs to be accounted for to truly understand the value of a farming system to society. To date, a number of studies have examined environmental consequences of different food consumption patterns at the diet level; however, few have addressed nutritional variations of a single commodity attributable to production systems, leaving limited insight into how on-farm practices can be improved to better balance environment and human nutrition. Using data from seven livestock production systems encompassing cattle, sheep, pigs, and poultry, this paper proposes a novel framework to incorporate nutritional value of meat products into livestock LCA. The results of quantitative case studies demonstrate that relative emissions intensities associated with different systems can be dramatically altered when the nutrient content of meat replaces the mass of meat as the functional unit, with cattle systems outperforming pig and poultry systems in some cases. This finding suggests that the performance of livestock systems should be evaluated under a whole supply chain approach, whereby end products originating from different farm management strategies are treated as competing but separate commodities.