Feeding co-extruded flaxseed to pigs: Effects of duration and feeding level on growth performance and backfat fatty acid composition of grower–finisher pigs

Multi-omics unveils tryptophan metabolic pathway as a key pathway influencing residual feed intake in Duroc swine

The genetic trait of residual feed intake (RFI) holds considerable importance in the swine industry. Recent research indicates that the gut microbiota of pigs plays a pivotal role in the manifestation of the RFI trait. Nevertheless, the metabolic pathways involved in the functioning of these microorganisms remain elusive. Thus, based on the ranking of the RFI trait in Duroc pigs, the present study selected the top 10 and bottom 10 pigs as the experimental subjects. The distribution and metabolite differences of cecal microbiota were analyzed using 16S rRNA gene sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. The low RFI cecal group was named LRC, and the high RFI cecal group was named HRC. The results indicate that the LRC group had lower RFI, feed conversion ratio (FCR), average daily feed intake (ADFI) (p < 0.001), and thinner backfat (p < 0.05) compared with the HRC group. We simultaneously recorded the foraging behavior as well, the LRC group had a significant increase in total time spent at the feeder per day (TPD) (p < 0.05) and a significant increase in average feed intake per mins (AFI) and the number of visits to the feeder per day (NVD) compared to the HRC group (p < 0.001). Clostridium_XVIII, Bulleidia, and Intestinimonas were significantly enriched in the LRC group (p < 0.01), while Sutterella, Fusobacterium, and Bacteroides were significantly increased in the HRC group (p < 0.01). In the metabolome, we detected 390 (248 metabolites up and 142 down in the LRC compared with HRC), and 200 (97 metabolites up and 103 down in the LRC compared with HRC) differential metabolites in positive and negative ionization modes. The comprehensive analysis found that in the LRC group, Escherichia and Eubacterium in the gut may increase serotonin content, respectively. Bacteroides may deplete serotonin. We suggest that the RFI may be partly achieved through tryptophan metabolism in gut microbes. In individuals with low RFI, gut microbes may enhance feed efficiency by enhancing host synthesis and metabolism of tryptophan-related metabolites.

Effect of the inclusion of extruded flaxseed in the diet of fattening pigs on lipid metabolism and tissue redox status

The aim of the study was to evaluate the effect of a diet containing extruded flaxseed (Linum usitatissimum L.) on the fatty acid composition of the loin, blood lipid parameters, and the redox status of tissues of finishing pigs. A total of 160 weaners (about 30-110 kg BW) were assigned to four experimental groups of 40 animals each (5 replicates with 8 individuals each). Group C (control) received a diet in which the fat source was soybean oil, while in groups 2FE, 4FE and 6FE soybean meal was replaced with extruded flaxseed in the amount of 2%, 4% or 6%, respectively. The diet containing extruded flaxseed reduced cholesterol levels in the blood plasma of pigs (grower 2FE and 6FE vs. C; finisher 2FE, 4FE and 6FE vs. C) and loin muscle (2FE, 4FE and 6FE vs. C). A decrease in the atherogenic LDL-C fraction and in the content of triacylglycerols was also noted in the blood plasma of grower and finisher pigs receiving flaxseed (2FE, 4FE and 6FE vs. C). The beneficial effects noted in the experimental pigs also included an increase in the overall content of n-3 PUFAs, especially ALA (18:3 n-3), and a reduction in the n-6/n-3 ratio. This was especially evident at 4% and 6% inclusion of flaxseed. The highest proportion of flax (6%) in the blend increased lipid peroxidation, as evidenced by the increase in the content of LOOH and MDA in the blood plasma of grower and finisher pigs. For this reason, a 4% share of flaxseed in the diet of fattening pigs seems to be optimal, while higher levels require an additional supply of exogenous antioxidants.

Effect of the inclusion of extruded flaxseed in the diet of fattening pigs on performance parameters and blood parameters

The aim of the study was to determine the effect of the inclusion of 2%, 4% and 6% extruded flaxseed in the diet of fattening pigs on their growth performance parameters, carcass parameters, and selected blood parameters. The experiment was conducted on 160 weaners (from about 30 kg to about 110 kg BW) assigned to four experimental groups of 40 animals each (5 replicates with 8 individuals each). The animals in control group received a diet in which the source of fat was soybean oil. The other groups received extruded flaxseed (FE) in place of soybean meal in the amount of 2% (group 2FE); 4% (group 4FE) and 6% (group 6FE). Soybean oil was added to the diets in the experimental treatments to obtain equal amounts of fat. The inclusion of 2% and 4% extruded flaxseed in the diet of fatteners in place of soybean meal significantly improved the digestibility of basic nutrients, i.e. ether extract (by about 5%) and dietary fibre (by more than 20%) and led to better growth performance (higher BW by about 11%; higher ADG by about 20% and lower FCR by about 12%) vs group C. In the groups with 2% and 4% extruded flaxseed there was also an increase in the lean meat content of the carcasses (by about 6%) and the thickness of the backfat (by about 6.5%) vs group C. The inclusion of extruded flaxseed did not affect the animals' condition, as indicated by the haematological and biochemical parameters of the blood, which were within reference ranges. The results for production, nutrient digestibility and carcass analysis between groups 2FE and 4FE were similar, and at this stage of research indicate that the use of 2% extruded flaxseed is economically more justified.

Uptake of Flaxseed Dietary Linusorbs Modulates Regulatory Genes Including Induction of Heat Shock Proteins and Apoptosis

Flaxseed (Linum usitatissimum L.) is gaining popularity as a superfood due to its health-promoting properties. Mature flax grain includes an array of biologically active cyclic peptides or linusorbs (LOs, also known as cyclolinopeptides) that are synthesized from three or more ribosome-derived precursors. Two flaxseed orbitides, [1-9-NαC]-linusorb B3 and [1-9-NαC]-linusorb B2, suppress immunity, induce apoptosis in a cell line derived from human epithelial cancer cells (Calu-3), and inhibit T-cell proliferation, but the mechanism of LO action is unknown. LO-induced changes in gene expression in both nematode cultures and human cancer cell lines indicate that LOs promoted apoptosis. Specific evidence of LO bioactivity included: (1) distribution of LOs throughout the organism after flaxseed consumption; (2) induction of heat shock protein (HSP) 70A, an indicator of stress; (3) induction of apoptosis in Calu-3 cells; and (4) modulation of regulatory genes (determined by microarray analysis). In specific cancer cells, LOs induced apoptosis as well as HSPs in nematodes. The uptake of LOs from dietary sources indicates that these compounds might be suitable as delivery platforms for a variety of biologically active molecules for cancer therapy.

Are n-3 PUFAs from Microalgae Incorporated into Membrane and Storage Lipids in Pig Muscle Tissues?-A Lipidomic Approach

For the study of molecular mechanisms of to lipid transport and storage in relation to dietary effects, lipidomics has been rarely used in farm animal research. A feeding study with pigs (German Landrace sows) and supplementation of microalgae (Schizochytrium sp.) was conducted. The animals were allocated to the control group (n = 15) and the microalgae group (n = 16). Shotgun lipidomics was applied. This study enabled us to identify and quantify 336 lipid species from 15 different lipid classes in pig skeletal muscle tissues. The distribution of the lipid classes was significantly altered by microalgae supplementation, and ether lipids of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidic acid (PA) were significantly decreased. The total concentration of triacylglycerides (TAGs) was not affected. TAGs with high degree of unsaturation (TAG 56:7, TAG 56:6, TAG 54:6) were increased in the microalgae group, and major abundant species like TAG 52:2 and TAG 52:1 were not affected by the diet. Our results confirmed that dietary DHA and EPA are incorporated into storage and membrane lipids of pig muscles, which further led to systemic changes in the lipidome composition.

Effect of Concentration of Flaxseed (Linum usitatissimum) and Duration of Administration on Fatty Acid Profile, and Oxidative Stability of Pork Meat

Flaxseed is a common ingredient used for livestock feed. The aim of this work was to study the effect of a diet supplemented with flaxseed at 5% and 10% concentrations in the intervals of 3 and 6 weeks prior slaughter on fatty acid profile and oxidative stability of pork meat. Meat samples were collected after slaughter from each animal (five groups, n = 6). Samples of the musculus longissimus dorsi (MLD) and the musculus gluteobiceps (MGB) were selected. Chemical composition, fatty acid profile and oxidative stability during the storage of meat under chilling conditions (4 °C, 7 days) was analyzed. The addition of flaxseed significantly affected the composition of fatty acid profile and the shelf life of the produced meat. The fat content was changed in the experimental groups with 10% flaxseed supplementation (10.84% in MGB and 9.56% MLD) versus the control group. Despite the different concentrations of flaxseed, the best EPA/AA ratio was observed in the experimental groups fed with flaxseed supplementation for 3 weeks. The worst oxidative stability of meat samples (p < 0.05) was recorded in the experimental groups with the addition of flaxseed for 6 weeks, which was related to higher PUFA content in samples of the experimental groups and higher susceptibility of PUFAs to lipid oxidation. The oxidative stability of meat in the experimental group fed 5% flaxseed supplementation for 3 weeks was not affected.

Dietary flaxseed's protective effects on body tissues of mice after oral exposure to xylene

Xylene is a common pollutant in the environment that enters the body of animals and humans in various ways, but most often through the respiratory tract and adversely affects their overall health. However, xylene effects after oral exposure have not been sufficiently studied. This study aimed to investigate the effects of xylene exposure on the mouse organism and to identify possible beneficial effects of flaxseed on such exposure. Eighty mice were divided into four groups: control group C (basal diet + no xylene exposure), group X (oral exposure by 400 mg/kg/day xylene), group F (10% flaxseed supplementation of basal diet), and group XF (10% dietary flaxseed + oral exposure by xylene). Experimental trial took 14 days. Clinical examination, spectroscopic analysis of tissue aminotransferases, total lactate dehydrogenase (TLDH), and acetylcholinesterase (AchE) activities, electrophoretic analysis of LDH isoenzymes, western blot and immunohistochemical analysis of apoptosis as well as routine histology of the kidneys and jejunum, and transmission electron microscopy of the liver were performed. Marked restlessness in group X and high weight losses in mice of all groups were recorded during the experiment. Xylene promoted apoptosis (caspase-3 expression) without causing marked structural changes in the liver and jejunum, although renal cortex structure was affected adversely. In the brain, liver, and kidney of mice, xylene increased levels of liver transaminases, LDH, and decreased AchE activities, reflecting cell membrane damage. Flaxseed feeding improved animal behaviour, leakage of enzymes and prevented selected tissue toxic damage induced by xylene by protecting cell membrane integrity and fluidity and by suppressing apoptosis. These results point at the protective effect of flaxseed consumption on mice.

Effects of dietary fat saturation level on growth performance, carcass traits, blood lipid parameters, tissue fatty acid composition and meat quality of finishing pigs

Objective

The objective of this study was to investigate the effects of various dietary unsaturated to saturated fatty acids ratios (UFA to SFA ratios) on growth performance, carcass traits, blood lipid parameters, tissue fatty acid (FA) composition, and meat quality of finishing pigs.

Methods

A total of 45 crossbred pigs ([Duroc×Landrace]×Yorkshire), with an average initial body weight of 60.3±2.4 kg, were randomly allocated to three treatment groups of 1:1, 2:1, and 3:1 dietary UFA to SFA ratios.

Results

Both average daily gain and average daily feed intake of pigs were decreased linearly (p<0.05), whereas backfat thickness was decreased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Serum triglyceride and low density lipoprotein cholesterol were decreased quadratically or linearly (p<0.05) respectively, whereas high density lipoprotein cholesterol was increased quadratically (p<0.05) with increasing dietary UFA to SFA ratio. In M. longissimus thoracis, the proportion of C18:1 and monounsaturated FA was decreased linearly (p<0.05), whereas the proportion of C18:2n-6, C20:4n-6 and polyunsaturated FA (PUFA) were increased linearly (p<0.05) as dietary UFA to SFA ratio increased. In the subcutaneous adipose tissue, the proportion of SFA was decreased linearly (p<0.05), whereas the proportion of n-6 PUFA, n-3 PUFA, and the UFA to SFA ratios were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio. Meat color scores and shear force of pigs were decreased linearly (p<0.05), whereas drip loss and cooking loss were increased linearly (p<0.05) with increasing of dietary UFA to SFA ratio.

Conclusion

Appropriately boosted dietary UFA to SFA ratio could be conductive to optimize blood lipid parameters and tissue FA composition. However, when the ratio is too high or too low it tends to have negative effects on growth performance and meat quality.

Protective Effect of Flaxseed on the Health of Experimental Animals Exposed to Xylene

Xylene is mainly used as a solvent in the printing, tire and leather industries. It is also used as: a facility cleaner, paint and varnish thinner, component of fuel, and chemical for the laboratory processing of histological preparations. For these reasons people are frequently exposed to xylene and the risk of intoxication is high. This study focused on the protective effect of flaxseed on mice experimentally intoxicated with xylene. The experiment lasted 14 days. The mice used in this study (n = 60) were allocated to 3 groups: the control group (C) received only the standard diet; the xylene group (X) was fed a standard diet and was administered xylene p. o. (10 µl daily); and the xylene + flaxseed group (XF) received the standard feed, crushed flaxseed and xylene at the same dose as group X. The observations involved changes in: body weight, liver enzyme levels, and caspase activity in the liver of the mice. The administration of additives resulted in significant changes in the body weight of the mice on day 7 of the experiment (P < 0.05). The highest weight gain was observed in mice from the XF group. In contrast, the body weight of the mice from group X exposed only to xylene was the lowest. The biochemical analysis of the liver cells of the xylene intoxicated mice showed elevated levels of: aspartate aminotransferase (AST), De Ritis ratio (AST/ALT ratio), and lactate dehydrogenase isoenzymes LDH-3 and LDH-5. Caspase-3, the marker of apoptosis, was increased in the XF group. Thus, the administration of flaxseed in our experiment had a beneficial effect on the clinical and metabolic parameters of mice intoxicated with xylene. Our results indicated that the administration of flaxseed, may act as a preventative measure with respect to xylene intoxication of animals; however, further analyses are needed to confirm this assumption.

Biology, strategies, and fresh meat consequences of manipulating the fatty acid composition of meat

The utility and attractiveness of adipose tissue within meat products vary based on species, cut, and consumer preference. In beef, producers are rewarded for producing carcasses with greater visual marbling at the 12th and 13th rib juncture, while pork producers are either not rewarded or penalized for producing carcasses with too much adipose tissue. Some consumers prefer to purchase leaner meat cuts, while other consumers pay premiums to consume products with elevated fat content. While no clear consumer adipose tissue preference standard exists, advances in beef and swine nutrition have enabled producers to target markets that enable them to maximize profits. One niche market that has increased in popularity over the last decade is manipulating the fatty acid profile, specifically increasing omega-3 fatty acid content, of beef and pork products to increase their appeal in a healthy diet. While much research has documented the ability of preharvest diet to alter the fatty acid profile of beef and pork, the same studies have indicated both the color and palatability of these products were negatively affected if preharvest diets were not managed properly. The following review discusses the biology of adipose tissue and lipid accumulation, altering the omega-3 fatty acid profile of beef and pork, negative fresh meat color and palatability associated with these studies, and strategies to mitigate the negative effects of increased omega-3 fatty acid content.

The effects of the LIPEX finishing diet regimen on pork quality, fatty acid profile, palatability, and color stability

The objective of this study was to determine the effects of the LIPEX finishing diet regimen on pork chop n-3 polyunsaturated fatty acid (PUFA) content and fresh meat quality. Twenty-eight finishing pigs (PIC 359 × F1 Hermitage/NGT; initial BW 81.5 ± 2.55 kg) were subjected to a 49-d feeding trial. Treatments consisted of a 2 × 2 factorial design with Sex (n = 14 barrows and gilts each) and Diet as main effects. Dietary treatments consisted of a 2-phase standard finishing diet regimen or a 2-phase LIPEX finishing diet regimen (EXL Milling, Lloydminster, SK, Canada). The LIPEX diet regimen added the EXL LIPEX.FA369 additive during phase 1 and the EXL LIPEX.FA369 and XFE Omega-3 Finishing Touch during phase 2. Five-days postmortem, whole boneless pork loins were transported to the Kansas State University Meats Laboratory, aged 14 d, and halved immediately behind the spinalis dorsi. After blooming for 30 min, chops were evaluated for Japanese color score and National Pork Producers Council (NPPC) color and marbling scores. A 2.54-cm chop was taken immediately anterior to the loin cut and was used for fatty acid and proximate composition analyses. Four 2.54-cm chops were cut from the posterior portion of the loin and were utilized for a 7-d simulated retail display analyses, Warner-Bratzler shear force (WBSF), and trained sensory panel. There were no Sex × Diet interactions for all variables measured in the study (P > 0.10). The LIPEX finishing regimen increased chop C18:3n-3, C20:5, and C22:5, which decreased the n-6:n-3 ratio (P < 0.01). There were no Diet effects on pH, Japanese and NPPC color and marbling scores, and proximate composition (P > 0.23). Diet did not affect cook loss, WBSF, and trained sensory panel scores (P > 0.012). There were no 2- or 3-way interactions between Diet, Sex, and Day, or Diet and Sex main effects for L*a* values, surface oxy- and metmyoglobin percentages, or visual panel chop redness and surface discoloration scores (P > 0.14). Feeding the LIPEX finishing diet regimen increased chop n-3 PUFA content without negatively impacting fresh chop palatability or color stability.

Effects of long-chain fatty acid supplementation on the growth performance of grower and finisher pigs: a meta-analysis

Background

Supplementation of feed with long-chain fatty acids (LCFAs) during the grower and finisher phases has long been discussed as a growth promotion strategy in pigs, but its effects are inconsistent. The purpose of our study was to comprehensively evaluate its effects on the growth performance based on the average daily gain (ADG), average daily feed intake (ADFI) and gain: feed (G:F) ratio and to unveil the roles of the basal diet, LCFA concentration and LCFA saturation.

Results

We searched the PubMed and Web of Science databases (articles published from Jan 1^st, 2000, to Sep 30^th, 2018; restricted to English) and compared LCFA-supplemented diets with control diets. We retrieved 2346 studies, 18 of which (1314 pigs, 26 records) were eligible for our analysis. We used a random-effects model to calculate the weighted mean differences (WMDs) and 95% confidence intervals (CIs). LCFA supplementation in the grower-finisher phase improved the ADG (WMD = 41.74 g/d, 95% CI: 8.81 to 74.66, P = 0.013) and G:F ratio (WMD = 0.019, 95% CI: 0.006 to 0.032, P = 0.003). For supplementation solely in the finisher phase, we found a similar performance in the ADG (WMD = 39.93 g/d, 95% CI: 26.48 to 53.38, P < 0.001) and G:F ratio (WMD = 0.019, 95% CI: 0.006 to 0.032, P < 0.001) but a reduction in the ADFI (WMD = − 83.863 g/d, 95% CI: − 156.157 to − 11.569, P = 0.023). Specifically, approximately 5% LCFA supplementation in the finisher phase had significant effects on the ADG (WMD = 51.385 g/d, 95% CI: 35.816 to 66.954, P < 0.001), ADFI (WMD = − 102.869 g/d, 95% CI: − 189.236 to − 16.502, P = 0.02) and G:F ratio (WMD = 0.028, 95% CI: 0.018 to 0.039, P < 0.001), whereas a concentration of approximately 1% exhibited no effects.

Conclusions

Overall, regardless of the basal diet and saturation, LCFA supplementation greatly improves the growth performance of grower and finisher pigs, primarily by increasing the energy density.

Effects of feeding flaxseed on performance, carcass trait, and meat fatty acid composition of Guinea pigs (Cavia procellus) under northern Peruvian condition

A study was conducted to determine the effects of flaxseed supplementation on performance, carcass traits, and hindleg fatty acid composition of guinea pigs. Sixty male and female weaned guinea pigs (1 month old, five animals/cage) were blocked by sex and bodyweight and randomly fed 0 (control) or 100 g/kg flaxseed concentrate diets (15 g/animal) plus ad libitum fresh alfalfa for 30 days. Results showed that flaxseed supplementation had no influence on animal performance. However, final body weight (P = 0.035), total feed intake (P = 0.019), and body weight gain (P < 0.001) were higher in male than female guinea pigs. Similar results were also observed for carcass composition (i.e., hot, chilled, and reference carcass weights). Inclusion of flaxseed reduced saturated (P < 0.001), mono-unsaturated (P = 0.004), and increased (P < 0.001) polyunsaturated (PUFA) fatty acid concentrations in hindlegs. Concentrations of linolenic acid and n-3 PUFA increased (P < 0.001) by 49.7 and 37.1%, respectively as a result of flaxseed inclusion. It was concluded that feeding flaxseed to guinea pigs at 100 g/kg of the concentrate diets improves meat PUFA concentrations with no adverse effects on performance or carcass composition.

Current feeding strategies to improve pork intramuscular fat content and its nutritional quality

Pork, one of the most consumed meats worldwide, has been facing major challenges regarding its low sensory quality and unhealthy image of fat. This chapter addresses current feeding strategies to ameliorate pork sensory attributes and nutritional quality by increasing intramuscular fat deposition and improving fatty acid composition, respectively. Dietary protein reduction, alone or combined with some components, contributes to satisfy consumer requirements and enhances the competitiveness of the meat industry with higher pork quality and lower production costs. In addition, feeding sources of n-3 polyunsaturated fatty acids to pigs, mainly from marine origin (rich in eicosapentaenoic and docosahexaenoic acids), increases their content in pork, thus improving the health value of its fatty acid profile. In the near future, the inclusion of microalgae and seaweeds in feed represents a promising approach for the maintenance and development of the livestock sector, as an environmental friendly alternative to balance food and feed industries.

Significance of Increasing n-3 PUFA Content in Pork on Human Health

Evidence for the health-promoting effects of food rich in n-3 polyunsaturated fatty acids (n-3 PUFA) is reviewed. Pork is an important meat source for humans. According to a report by the US Department of Agriculture ( http://www.ers.usda.gov/topics ), the pork consumption worldwide in 2011 was about 79.3 million tons, much higher than that of beef (48.2 million tons). Pork also contains high levels of unsaturated fatty acids relative to ruminant meats (Enser, M., Hallett, K., Hewett, B., Fursey, G. A. J. and Wood, J. D. (1996) . Fatty acid content and composition of English beef, lamb, and pork at retail. Meat Sci. 44:443-458). The available literature indicates that the levels of eicosatetraenoic and docosahexaenoic in pork may be increased by fish-derived or linseed products, the extent of which being dependent on the nature of the supplementation. Transgenic pigs and plants show promise with high content of n-3 PUFA and low ratio of n-6/n-3 fatty acids in their tissues. The approaches mentioned for decreasing n-6/n-3 ratios have both advantages and disadvantages. Selected articles are critically reviewed and summarized.

Effects of pork differentiation strategies in Canada on pig performance and carcass characteristics

Performance and quality traits were measured in carcasses from combinations of genotype, diet supplement, slaughter weight, and carcass chilling regime. Iberian-crossed pigs had lower live animal performance than Duroc and Lacombe. From 70 to 115 kg, Lacombe pigs grew slightly faster than Duroc. Duroc carcasses had a higher lean percentage, heavier ham and picnic primals, and lighter loins and bellies, compared with Lacombe and Iberian. Heavier carcasses had lower lean yield, except those from Iberian-crossed pigs, and bigger bellies. Meat from Duroc-crossed pigs was lighter in colour and higher in marbling, with intermediate values for fat hardness. Iberian carcasses displayed dark meat with intermediate marbling and the hardest fat. Meat from Lacombe pigs was the leanest although, like in all three breeds, marbling scores were higher in heavier carcasses. Generally, supplementing with canola and flax decreased and blast chilling increased fat hardness values. Dietary canola also seemed to affect meat colour traits, but these effects were not consistent among breeds and slaughter weights. The commercial combination of Duroc breed, control diet, and 115-kg slaughter weight showed a balance in terms of performance, carcass, and quality traits. Other combinations evaluated in this study showed potential to efficiently produce differentiated pork.

Effects of Addition of Linseed and Marine Algae to the Diet on Adipose Tissue Development, Fatty Acid Profile, Lipogenic Gene Expression, and Meat Quality in Lambs

This study examined the effect of linseed and algae on growth and carcass parameters, adipocyte cellularity, fatty acid profile and meat quality and gene expression in subcutaneous and intramuscular adipose tissues (AT) in lambs. After weaning, 33 lambs were fed three diets up to 26.7 ± 0.3 kg: Control diet (barley and soybean); L diet (barley, soybean and 10% linseed) and L-A diet (barley, soybean, 5% linseed and 3.89% algae). Lambs fed L-A diet showed lower average daily gain and greater slaughter age compared to Control and L (P < 0.001). Carcass traits were not affected by L and L-A diets, but a trend towards greater adipocyte diameter was observed in L and L-A in the subcutaneous AT (P = 0.057). Adding either linseed or linseed and algae increased α-linolenic acid and eicosapentaenoic acid contents in both AT (P < 0.001); however, docosahexaenoic acid was increased by L-A (P < 0.001). The n-6/n-3 ratio decreased in L and L-A (P < 0.001). Algae had adverse effects on meat quality, with greater lipid oxidation and reduced ratings for odor and flavor. The expression of lipogenic genes was downregulated in the subcutaneous AT (P < 0.05): acetyl-CoA carboxylase 1 (ACACA) in L and L-A and lipoprotein lipase (LPL) and stearoyl-CoA desaturase (SCD) in L-A. Fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and fatty acid elongase 5 (ELOVL5) were unaffected. In the subcutaneous AT, supplementing either L or L-A increased peroxisome proliferator-activated receptor gamma (PPARG) and CAAT-enhancer binding protein alpha (CEBPA) (P < 0.05), although it had no effect on sterol regulatory element-binding factor 1 (SREBF1). In the intramuscular AT, expression of ACACA, SCD, FADS1 and FADS2 decreased in L and L-A (P < 0.001) and LPL in L (P < 0.01), but PPARG, CEBPA and SREBF1 were unaffected.

Pork as a Source of Omega-3 (n-3) Fatty Acids

Pork is the most widely eaten meat in the world, but typical feeding practices give it a high omega-6 (n-6) to omega-3 (n-3) fatty acid ratio and make it a poor source of n-3 fatty acids. Feeding pigs n-3 fatty acids can increase their contents in pork, and in countries where label claims are permitted, claims can be met with limited feeding of n-3 fatty acid enrich feedstuffs, provided contributions of both fat and muscle are included in pork servings. Pork enriched with n-3 fatty acids is, however, not widely available. Producing and marketing n-3 fatty acid enriched pork requires regulatory approval, development costs, quality control costs, may increase production costs, and enriched pork has to be tracked to retail and sold for a premium. Mandatory labelling of the n-6/n-3 ratio and the n-3 fatty acid content of pork may help drive production of n-3 fatty acid enriched pork, and open the door to population-based disease prevention polices (i.e., food tax to provide incentives to improve production practices). A shift from the status-quo, however, will require stronger signals along the value chain indicating production of n-3 fatty acid enriched pork is an industry priority.

Effects of increasing co-product inclusion and reducing dietary protein on growth performance, carcass characteristics, and jowl fatty acid profile of growing-finishing pigs

Dietary inclusion of co-products (Co-P) provides opportunities for diversifying the feedstuff matrix by using local feedstuffs, reducing feed costs, and producing value-added pork. In 2 studies, we determined effects of Co-P (canola meal, distillers dried grains with solubles, and co-extruded oil seed and field pea) inclusion level and reduced dietary CP concentration on growth performance, carcass characteristics, and jowl fatty acid profiles of growing-finishing pigs. Pigs were fed isoenergetic and isolysinic diets over 4 growth phases with 8 pen observations per dietary regimen. At slaughter, carcasses were characterized for all pigs and jowl fat was collected from 2 pigs per pen. In Exp. 1, 1,056 pigs (initial BW, 35.3 ± 0.4 kg) were fed 3 levels of dietary Co-P (low, mid, and high) and 2 CP concentrations (low and normal). Overall (d 0 to 86), increasing Co-P inclusion from low to mid or high decreased (P < 0.001) ADFI and ADG of pigs. Low CP concentration increased (P < 0.05) ADFI and ADG compared with normal CP concentration. An interaction (P = 0.026) occurred between dietary Co-P inclusion and CP concentration for G:F; low CP reduced (P < 0.05) G:F compared with normal CP for pig fed low Co-P, but G:F did not differ between CP concentrations for pigs fed mid and high Co-P. Increasing dietary Co-P inclusion from low to high increased (P < 0.001) α-linolenic acid (ALA) in jowl fat but decreased (P < 0.001) carcass weight and loin depth. In Exp. 2, 1,008 pigs (initial BW, 30.3 ± 0.4 kg) were assigned to 5 dietary regimens with Co-P increasing from 2.0 to 50.0% or a sixth regimen with 10% extra supplemental AA for the 37.5% Co-P diet. Overall (d 0 to 97), increasing Co-P inclusion did not affect ADFI, ADG, and G:F. Increasing dietary Co-P inclusion linearly decreased (P < 0.01) carcass weight, dressing percentage, backfat thickness, and loin depth but linearly increased (P < 0.001) jowl ALA. Supplementing 10% extra AA to the 37.5% Co-P diet did not affect growth performance or dressing percentage but increased (P = 0.014) carcass leanness and decreased (P = 0.023) backfat thickness compared with the 37.5% Co-P diet, indicating that dietary AA supply did not limit BW gain. In conclusion, Co-P can be included by up to 50% in diets for growing-finishing pigs without affecting G:F. However, increasing dietary Co-P may reduce ADG, ADFI, and carcass weight even if diets are balanced for dietary NE and standardized ileal digestible AA content.

Effects of genotype and dietary oil supplementation on performance, carcass traits, pork quality and fatty acid composition of backfat and intramuscular fat

A 42-day study was conducted to evaluate the effect of genotype: terminal sire line Duroc×F1 (DC×F1); terminal sire line Embrapa MS-115×F1 (MS-115×F1); and MS-115×Moura (MS-115×MO) and three dietary oil sources: soybean; canola; and canola+flax, on performance, carcass traits, pork quality, and fatty acid composition. Genotype affected the technological quality of pork and fatty acid profile. MS-115-sired pigs had better meat color and Duroc-sired pigs had higher intramuscular fat content, more saturated fat and better omega-6/omega-3 ratio. Moura breed influenced positively meat tenderness and intramuscular fat. Diet did not affect the technological quality of the meat. Canola or canola+flax oil diet supplementations increased monounsaturated and C18:3 and decreased C18:2 fatty acids, reducing the omega-6/omega-3 ratio. The best omega-6/omega-3 ratio was obtained through supplementation with canola+flax.

Different dietary protein and PUFA interventions alter the fatty acid concentrations, but not the meat quality, of porcine muscle

The present study investigated the effect of a reduced protein diet in combination with different vegetable oils (sunflower seed oil or linseed oil) on carcass traits, meat quality and fatty acid profile in porcine muscle. Forty male Landrace pigs were allocated into four experimental groups (each n = 8) and one control group (n = 8) at a live weight of approximately 60 kg. The pigs were fed ad libitum from 60 kg to 100 kg live weight and restricted to 2.8 kg/day until they reached 120 kg. In contrast to other studies, the intramuscular fat content (IMF) did not increase in animals of groups fed a reduced protein diet and vegetable oils. The IMF ranged between 1.2% and 1.4%. The growth performance and meat quality of the longissimus muscle was not affected by the diet, but the average daily gain (ADG) and drip loss were affected. The muscle fatty acid concentrations were significantly affected by the diet, resulting in higher n-3 FA concentrations up to 113 mg/100 g muscle and lower n-6/n-3 PUFA ratio for pigs fed linseed oil-containing high- and reduced protein diets, compared to sunflower seed oil-containing diets.

Increased EPA levels in serum phospholipids of humans after four weeks daily ingestion of one portion chicken fed linseed and rapeseed oil

Since the amounts of arachidonic acid (AA) and EPA in food may have implications for human health, we investigated whether a small change in chicken feed influenced the blood lipid concentration in humans ingesting the chicken. Forty-six young healthy volunteers (age 20-29) were randomly allocated into two groups in a double-blind dietary intervention trial, involving ingestion of about 160 g chicken meat per day for 4 weeks. The ingested meat was either from chickens given a feed concentrate resembling the commercial chicken feed, containing 4% soybean oil (SO), or the meat was from chickens given a feed where the soybean oil had been replaced by 2% rapeseed oil plus 2% linseed oil (RLO).Serum total cholesterol, LDL and HDL cholesterol, triacylglycerols, serum phospholipid fatty acid concentration, blood pressure, body weight and C-reactive protein were determined at baseline and post-intervention. In subjects consuming chicken meat from the RLO group there was a significantly (p < 0.001) increased concentration of EPA in serum phospholipids, and a reduced ratio between AA and EPA. The participants that had a low% of EPA + DHA in serum phospholipids (less than 4.6%), all increased their% of EPA + DHA after the four week intervention period when consuming the RLO chicken. No significant response differences in cholesterol, triacylglycerol, C-reactive protein, body weight or blood pressure were observed between the groups. This trial demonstrates that a simple change in chicken feed can have beneficial effects on amount of EPA and the AA/EPA ratio in human serum phospholipids.

Oxidative stability in grinds from omega-3 enhanced pork

Juárez, M., Dugan, M. E. R., Larsen, I. L., Thacker, R., Rolland, D. C. and Aalhus, J. L. 2011. Oxidative stability in grinds from omega-3 enhanced pork. Can. J. Anim. Sci. 91: 623–634. In order to investigate the effect of enhancing n-3 fatty acid levels in carcasses on the retail and sensory characteristics of pork grinds, as well as the ability of increasing dietary levels of vitamin E to stabilize the increase in PUFA levels from flaxseed supplementation, 81 pigs were used in a 3×3 factorial experiment. Dietary treatments included three lengths of time (0, 3 and 6 wk) of flaxseed supplementation and three levels of vitamin E (40, 200 and 400 mg kg feed−1). α-Tocopherol tissue levels increased with dietary vitamin E supplementation (P<0.001), and fat softness (P=0.018) and total PUFA and n-3 fatty acids (P<0.001) increased with flaxseed supplementation. Most other animal performance, carcass and lean pork quality traits were not affected (P>0.05) by dietary treatments. In ground pork, the increase in TBARS after 6 d in retail was lower (P<0.001) with increasing dietary vitamin E levels. However, vitamin E had no effect (P>0.05) on the higher (P<0.001) TBARS levels observed in grinds from flaxseed fed pigs. The dietary addition of flaxseed negatively modified (P<0.05) all the sensory attributes of both cooked and reheated products. Increasing the fat content of the grinds up to 30% seemed to counteract (P>0.05) the negative effects of feeding flaxseed for 3 wk. Feeding vitamin E was not able to prevent negative effects (P<0.05) observed during retail display in grinds with either increasing fat content or higher n-3 fatty acids from dietary flaxseed. However, increasing dietary vitamin E only showed a protective effect (P<0.05) on retail appearance after long periods of ageing.