A series of experiments was conducted to test the overall hypothesis that reducing the omega-6 (n-6) to omega-3 (n-3) fatty acid (FA) ratio in sow diets would improve sow reproductive performance (characterized by increases in numbers and body weight of piglets born alive and weaned) and would lessen the inflammatory responses of their offspring post weaning. Diets were wheat/barley based and consisted of a control (tallow based, similar to a standard production diet), 3 diets with plant oil based n-6:n-3 ratios (9:1P, 5:1P, and 1:1P) and a 5:1 fish oil diet (5:1F). The control diet had a ratio of 8:1, but contained approximately half the polyunsaturated FA content of the other diets. Sows were randomly assigned to a treatment diet on d 80 of gestation, and remained on that treatment for three consecutive reproductive cycles (gestation/lactation 1 = P1, gestation/lactation 2 = P2, gestation/lactation 3 = P3). Experiment 1 was designed to test the hypothesis that reducing the n-6:n-3 FA ratio in sow diets would increase circulating concentrations of n-3 FA’s in sows and in their offspring, and the passive immune status of piglets would be improved. Performance data was collected throughout P1 and P2 on 150 sows (n = 30/diet). Sow and piglet serum, colostrum and milk were analyzed for FA profiles, and colostrum and piglet serum were analyzed for immunoglobulin (Ig) A and IgG. In P1, birth weights were unaffected by diet (P > 0.05). Average piglet weaning weights (P = 0.02) and ADG (P = 0.01) however, were highest for piglets born to sows consuming the 9:1P and 5:1P diets. During P2, 5:1F sows consumed 10% less feed (P = 0.04), their piglets had reduced birth weights (P = 0.05), and average weaning weight was reduced by 0.8 kg (P = 0.04) relative to control or 5:1P sows. Colostral and piglet plasma IgA and IgG were unaffected by diet (P > 0.05). Colostrum FA profile patterns were similar to that of the sow diets. Serum n-3 FA’s were greatest in sows (P < 0.01) and piglets (P < 0.01) consuming 1:1P or 5:1F diets. Serum α-linolenic acid (ALA) was highest in the 1:1P sows and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were highest in the 5:1F sows. In piglet serum obtained prior to suckling, ALA and DHA did not differ among treatments (P > 0.05) but EPA was 2.5 times greater in the 1:1P group and 4 times greater in the fish group (P < 0.01) compared to those from the control diet. In post-suckle samples, ALA was highest in serum from 1:1P diet piglets (P < 0.01), and EPA and DHA were highest in piglet serum from the 5:1F sows (P < 0.01). Omega-3 FA’s can perturb lipid metabolism, specifically increasing the lipolytic activity of adipose tissue and thus the second experiment tested the hypothesis that high producing sows, consuming reduced n-6:n-3 ratios would have increased body fat mobilization. Twenty sows per diet, farrowing ≥ 11 piglets and nursing ≥ 10 piglets during P3, were used. Performance data on sows and piglets (such as weights, numbers, backfat changes) was collected throughout lactation and milk samples obtained on d 4 and d 16 of lactation. Jugular catheters were inserted into 8 sows from each of the 9:1P and 1:1P groups on d 5 of lactation and sows were challenged with a single injection of epinephrine followed by serial blood collections. Feed intake was highest for sows consuming the control (8.4 kg/d) and 5:1P (8.2 kg/d) diets and lowest for the sows fed the 1:1P (7.4 kg/d) and 5:1F (7.7 kg/d) diets (P = 0.05). Altering the n-6:n-3 FA ratio did not affect sow BW, piglet ADG, milk DM and N content or the total output of milk (P > 0.2). Sows consuming the 1:1P diet had greater backfat thickness (P < 0.05) and numerically higher plasma NEFA at baseline compared with the 9:1P sows (240 vs 93 uM; P = 0.16). When given epinephrine, 9:1P fed sows tended to have lower net incremental area under the curve (niAUC) glucose (P = 0.08) and numerically higher niAUC NEFA (P = 0.17) and glycerol (P = 0.15). A third experiment was conducted to test the hypothesis that piglets raised by sows consuming reduced n-6:n-3 ratios would have reduced inflammatory responses post-weaning. Piglets (n = 20/diet) raised by sows consuming the treatment diets described above for 2 gestation/lactation cycles (P2) were selected at weaning. Within diet group, pigs were randomized to either a challenge control group (saline injected) or to a lipopolysaccharide (LPS) injected group (n=10/challenge•diet-1). Piglets were fed a common starter diet for 6 days followed by saline or LPS injections on d 7. Rectal temperatures were recorded for 24 hrs and blood samples were collected at 0, 2, 6 and 12 hrs post injection for pro-inflammatory cytokine and blood urea nitrogen (BUN) analysis. Injecting LPS caused decreased feed intake and reduced ADG (P < 0.01), and increased temperature and cytokine production (P < 0.05). Piglets raised by sows consuming the 1:1P diet had elevated temperatures (P = 0.01; diet x challenge P > 0.05). Overall, circulating plasma ALA and EPA were increased in sows and piglets when sows were fed a 1:1 plant based ratio compared to the control or high n-6:n-3 ratio groups. Sows fed a ratio of 1:1 mobilized more body fat relative to those consuming the 9:1 ratio; there were no treatment effects on piglet growth. Reducing maternal n-6:n-3 FA ratios below 5:1 increased piglet body temperature prior to and during an LPS induced inflammatory challenge,. Reducing the sow dietary n-6:n-3 FA ratio below 5:1 may have detrimental effects on piglets due to over-stimulation of inflammatory responses.

Fatty acid profiling provides information on dietary intakes and an understanding of lipid metabolism. High throughput techniques such as fingertip prick (FTP) sampling has gained popularity in recent years as a simplified method for basic research, and could be further used to assess disease risk in the population, and other similar high-throughput techniques have the potential to assist in the monitoring and labeling of fatty acids in the food supply. With the advancement of high-throughput sample analysis techniques, a more complete understanding of storage stability is required as a larger volume of samples are produced with equal amounts of time to analyze them. Energy-assisted analysis techniques have the potential to help ameliorate some of these issues. Presently, FTP blood, whole blood and salmon storage stability is assessed under various storage conditions, and both microwave-assisted direct transesterification and indirect ultrasound-assisted extraction techniques are assessed. It is determined that storage of FTP blood and whole blood samples at -20°C results in significant and nearly complete highly unsaturated fatty acid (HUFA) degradation compared to all other temperatures examined. This degradation is determined to be the result of hemolysis and subsequent iron release from erythrocytes initiating fatty acid peroxidation reactions. Direct transesterification of FTP blood is reduced from as long as three hours to one minute with microwave-assisted energy and fatty acid extraction from ground flaxseed is reduced to 40 minutes from as long as 24 hours without compromising fatty acid profiles. Results of the current study provides insight into the storage stability of food sample and blood samples collected via high-throughput techniques, and provides support for the utilization of further high-throughput energy-assisted analytical methods that can help to minimize the potentially detrimental effects that long-term storage can have on fatty acid profiles.

Revised; Originally published: 05/2008 / The article provides information about different types of dietary fats and promotes consumption of healthy fats in moderation as part of a balanced diet. The prevalence of fat-free products in grocery stores may give some health-conscious consumers the perception that all dietary fats are unhealthy. However, fats are absolutely vital for proper physiological functioning, and it is imperative that fats are included in a healthy diet. Fats are classified as saturated, monounsaturated, or polyunsaturated. Both types of unsaturated fats, when consumed in moderation, can help lower cholesterol and decrease the risk of heart disease, especially when they replace saturated and trans fats. We provide tips for selecting healthier fats, along with a guide for consuming appropriate portions of fat.

Experiments were conducted to assess the effect of feeding diets containing ground flaxseed (FS); as a source of α-linolenic acid (18:3n-3), on whole body retention efficiency (RE) and disappearance (indirect measure of oxidation) of 18:3n-3, and apparent conversion (AC) of 18:3n-3 to n-3 highly unsaturated fatty acids (HUFA) in growing female pigs, using the mass balance approach (serial slaughter). Oxidation of 18:3n-3 was determined directly based on feeding U-13C-18:3n-3 and appearance of 13C in expired breath. Growth performance, composition of growth, body composition, and carcass and loin meat characteristics were not affected by feeding FS containing diets (P > 0.10). In selective pork cuts and the whole body, feeding FS increased (P < 0.10) the contents of 18:3n-3, eicosatrienoic acid (20:3n-3), eicosapentaenoic acid (20:5n-3), and docosapentaenoic acid (22:5n-3) but not docosahexaenoic acid (22:6n-3; P > 0.10). Expressed as a proportion of intake, RE of 18:3n-3 declined with duration of feeding FS (d 0 to 15 vs. d 15 to 30; P = 0.098; 68.4 vs. 52.8%). Similarly, the AC of 18:3n-3 to 20:3n-3 (8.87 vs. 5.53%) and 22:6n-3 (1.27 vs. 0.54%) was reduced over time (P < 0.05), whereas disappearance of 18:3n-3 increased over time (P = 0.074; 2.12 vs. 23.7%). At similar cumulative intake of 18:3n-3, stage of growth (25 to 50 vs. 85 to 110 kg BW) did not impact (P > 0.10) RE of 18:3n-3 and the sum of all n-3 polyunsaturated (PUFA; 95 vs. 110%), AC of 18:3n-3 to n-3 HUFA (19 vs. 22%), and oxidation of 18:3n-3 (7.0 vs. 5.6%); these parameters were influenced by dietary 18:3n-3 level. Pigs fed low dietary 18:3n-3 (0.8 g/kg) yielded both higher RE and AC of 18:3n-3 to n-3 HUFA than pigs on high dietary 18:3n-3 intake (15 g/kg). Oxidation of 18:3n-3 tended to increase with dietary 18:3n-3 level (P = 0.077; 7.97 vs. 4.67% for pigs on high and low dietary 18:3n-3, respectively) and was not affected by previous 18:3n-3 intake (P > 0.10). Feeding modest amounts of FS leads to a substantial and predictable enrichment of n-3 PUFA in pork without compromising carcass and meat quality. The content of n-3 PUFA appears to be independent of timing of feeding n-3 PUFA, providing flexibility as to when n-3 PUFA can be fed for generating n-3 PUFA enriched, value added pork. / Ontario Pork, Ontario Ministry of Agriculture, Food and Rural Affairs, Agricultural and Agri-Food Canada, and Natural Sciences and Engineering Research Council of Canada.

No description available.

Mice (C57BL/6J: B6) exposed to maternal dietary restriction (DR) exhibited fetal growth- restriction and as adults develop symptoms of the metabolic syndrome. We aimed to determine the impact of DR on fetal hepatic gluconeogenic pathway and insulin sensitivity in late gestation. Second, we aimed to determine whether a postweaning diet rich in omega-3 fatty acids would alter the development of glucose intolerance, insulin resistance and obesity in DR male offspring. The reduced rate of fetal glycogen synthesis by DR male offspring and altered hepatic gene expression of enzymes involved in insulin signalling and glucose metabolism suggest abnormal fetal development in response to DR that may contribute to the later development of the metabolic syndrome. The postweaning omega-3 diet improved obesity, glucose intolerance and insulin resistance in both DR and control males. These data suggest that nutrition in pregnancy and postnatal life play important roles in determining life-long metabolic health.

Mice (C57BL/6J: B6) exposed to maternal dietary restriction (DR) exhibited fetal growth- restriction and as adults develop symptoms of the metabolic syndrome. We aimed to determine the impact of DR on fetal hepatic gluconeogenic pathway and insulin sensitivity in late gestation. Second, we aimed to determine whether a postweaning diet rich in omega-3 fatty acids would alter the development of glucose intolerance, insulin resistance and obesity in DR male offspring. The reduced rate of fetal glycogen synthesis by DR male offspring and altered hepatic gene expression of enzymes involved in insulin signalling and glucose metabolism suggest abnormal fetal development in response to DR that may contribute to the later development of the metabolic syndrome. The postweaning omega-3 diet improved obesity, glucose intolerance and insulin resistance in both DR and control males. These data suggest that nutrition in pregnancy and postnatal life play important roles in determining life-long metabolic health.

Fatty acid profiling provides information on dietary intakes and an understanding of lipid metabolism. High throughput techniques such as fingertip prick (FTP) sampling has gained popularity in recent years as a simplified method for basic research, and could be further used to assess disease risk in the population, and other similar high-throughput techniques have the potential to assist in the monitoring and labeling of fatty acids in the food supply. With the advancement of high-throughput sample analysis techniques, a more complete understanding of storage stability is required as a larger volume of samples are produced with equal amounts of time to analyze them. Energy-assisted analysis techniques have the potential to help ameliorate some of these issues. Presently, FTP blood, whole blood and salmon storage stability is assessed under various storage conditions, and both microwave-assisted direct transesterification and indirect ultrasound-assisted extraction techniques are assessed. It is determined that storage of FTP blood and whole blood samples at -20°C results in significant and nearly complete highly unsaturated fatty acid (HUFA) degradation compared to all other temperatures examined. This degradation is determined to be the result of hemolysis and subsequent iron release from erythrocytes initiating fatty acid peroxidation reactions. Direct transesterification of FTP blood is reduced from as long as three hours to one minute with microwave-assisted energy and fatty acid extraction from ground flaxseed is reduced to 40 minutes from as long as 24 hours without compromising fatty acid profiles. Results of the current study provides insight into the storage stability of food sample and blood samples collected via high-throughput techniques, and provides support for the utilization of further high-throughput energy-assisted analytical methods that can help to minimize the potentially detrimental effects that long-term storage can have on fatty acid profiles.

Omega-3 fatty acids are increasingly recognised as playing an important role in human brain development and mental health. The polyunsaturated fatty acids (PUFAs) include omega-3 and omega-6 fats which are essential fatty acids (EFAs), consumed via the diet. Omega-3 fatty acids are particularly abundant in fish oils. The omega-3 fatty acids are being focused on for their role in depression, the main types being docosahexaenoic acid (DHA), which is abundant in neural tissue, and also eicosapentaenoic acid (EPA) which is biologically very active. There is an emerging literature in relation to omega-3 fatty acid blood levels in depression and the effects of treatment with omega-3. Strong epidemiological evidence has also been published indicating an association between a population's fish intake and depression rates. A specific research focus on omega-3 as a treatment for depression in the perinatal period is also starting to emerge. The importance of this particular area is enhanced by the knowledge that omega-3 depletion occurs during the perinatal period due to fetal diversion for neurodevelopment. In view of the lay public promotion of omega-3 and its appeal to women as a 'natural therapy', there is a need to scientifically evaluate its effectiveness to treat depression in the perinatal period. It is also important to investigate omega-3 as an alternative to antidepressants given the ongoing uncertainties regarding their safety in pregnancy. In this thesis a literature review presents current research relating to this field. This is followed by a description of the methodology and results for the two trials conducted. The results of the double-blind randomised placebo controlled trial of omega-3 as a treatment for depression in the perinatal period were essentially negative. However this result is limited by the small sample size in the study and therefore it may be unwise to interpret the result as conclusive. The case-control study confirmed the hypothesis that omega-3 levels were more depleted in depressed women compared to non-depressed women. A discussion of the results and trial limitations then follows in the thesis. It is concluded that further larger studies are warranted in this area.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vii, 44 p. : ill. Includes abstract. Includes bibliographical references (p. 30-33).