Circulating levels of triacylglycerol (TG) is a recognized risk factor for developing cardiovascular disease, a leading cause of death worldwide. The Institute of Medicine and the American Heart Association both recommend the consumption of n-3 polyunsaturated fatty acids (PUFA), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), to reduce serum TG in hyperlipidemic individuals. Additionally, a number of systematic reviews have shown that individuals with any degree of dyslipidemia, elevated serum TG and/or cholesterol, may benefit from a 20-30 % reduction in serum TG after consuming n-3 PUFA derived from marine sources. Given that individuals with serum lipid levels ranging from healthy to borderline dyslipidemic constitute a large portion of the population, the focus of this review was to assess the potential for n-3 PUFA consumption to reduce serum TG in such individuals. A total of 1341 studies were retrieved and 38 clinical intervention studies, assessing 2270 individuals, were identified for inclusion in the current review. In summary, a 9-26 % reduction in circulating TG was demonstrated in studies where ≥ 4 g/day of n-3 PUFA were consumed from either marine or EPA/DHA-enriched food sources, while a 4-51 % reduction was found in studies where 1–5 g/day of EPA and/or DHA was consumed through supplements. Overall, this review summarizes the current evidence with regards to the beneficial effect of n-3 PUFA on circulating TG levels in normolipidemic to borderline hyperlipidemic, otherwise healthy, individuals. Thus demonstrating that n-3 PUFA may play an important role in the maintenance of cardiovascular health and disease prevention.

Cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD) are manifestations of the metabolic syndrome. CVD remains the number one cause of mortality in the West, while NAFLD is the most common liver disease. Growing evidence suggests that polyunsaturated fatty acids (PUFA) influence risk factors including circulating lipids and inflammation on the development of CVD and NAFLD. N - 6 and n - 3 PUFA are comprised of distinct family members, which are increasingly recognized for their individual effects. Therefore, this review examines what is currently known about the specific effects of the major n - 3 and n - 6 PUFA on CVD and NAFLD. Overall, this review supports a beneficial effect of n - 3 PUFA and highlights distinctive effects between alpha-linolenic acid found in plant oils relative to marine derived eicosapentaenoic acid and docosahexaenoic acid. This review also highlights contrasting health effects between the n - 6 PUFA, linoleic and arachidonic acid.

BackgroundBreast cancer is attributable to modifiable risk factors including the intake of dietary n-3 polyunsaturated fatty acids (PUFA). A key piece of evidence, yet to be addressed, that would demonstrate a causal relationship between n-3 PUFA and breast cancer, is a dose-dependent effect of n-3 PUFA on tumour outcomes. Thus, the objective of the present study was to determine whether n-3 PUFA reduces mammary gland tumor outcomes in a dose-dependent manner in female MMTV-neu(ndl)-YD5 transgenic mice, an aggressive model of human breast cancer.MethodsHarems were provided one of three experimental diets comprised of 0, 3 or 9% (w/w) menhaden fish oil containing n-3 PUFA. Female offspring were weaned onto the same parental diet and maintained on their respective diet for 20 weeks. Tumour onset, size and multiplicity were measured throughout the study. Fatty acid composition of mammary gland and tumours were determined by gas–liquid chromatography.ResultsTumour size was significantly (p < 0.05) reduced in a dose-dependent manner. n-3 PUFA were also incorporated in a dose-dependent manner; differential incorporation was observed for eicosapentaenoic and docosapentaenoic acids into mammary gland tissue, while docosahexaenoic acid was preferentially incorporated into tumours.ConclusionOverall, the present study provides fundamental knowledge about the dose-dependent effect of n-3 PUFA on tumour outcomes in a pre-clinical model and also sheds light on the differential role of individual n-3 PUFA on tumour outcomes.

The current research was designed to determine the effect of phytase and glucanase on the energy value of corn and soybean meal (SBM) separately for broilers at various ages. The treatments were arranged as a 2 x 2 x 2 factorial, with 0 or 500 phytase units/kg or with 0 or 500 units of glucanase/kg, supplemented to either corn or SBM, with each combination represented by 6 cages of 10 birds. Diets of pure corn and soybean meal were not supplemented with additional nutrients, and were fed for 3-d periods beginning at 7, 14, or 21 d of age, representing the immature, transitional, and mature digestive tract, respectively. Each experiment was performed on a different group of birds from the same hatch. At the end of each experimental period, the broilers were euthanized and the contents of the ileum, duodenum and jejunum (pooled), and pancreas were removed for analysis. The ileal samples were analyzed for acid-insoluble ash and gross energy to determine the ileal-digestible energy (IDE) of the feedstuffs. The pancreas and duodenal-jejunal samples were analyzed for proteolytic and amylase activity to determine the influence of practical levels of phytate on enzyme activity. Results showed that neither phytase nor glucanase influenced enzyme activity in the digesta or pancreas, suggesting that practical levels of phytate did not influence the activity of proteolytic enzymes or amylase. Phytase did not influence the IDE value of either corn or SBM, and improved DM digestibility of the feed only for corn fed at 21 to 23 d. Glucanase improved IDE in both the corn and SBM diets at all ages, and improved DM digestibility in corn diets at all ages and SBM diets fed at 14 to 16 d. The IDE and DM digestibility of corn and the digesta and pancreatic enzyme activities increased with age, whereas the IDE of SBM was similar among age groups. The relative effect of glucanase on IDE of both feedstuffs was similar among age groups.

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Determination of the bicarbonate retention factor (BRF) is an important step during development of the indicator amino acid oxidation technique for use in a new model. A series of 4-h oxidation experiments were performed to determine the BRF of broilers aged 7, 14, 21, 28, 35, and 42 d using 4 birds per age group. A priming dose of 1.2 microCi of NaH(14)CO(3), followed by eight half-hourly doses of 1 microCi of NaH(14)CO(3) were given orally to each of 4 birds per age. The percentage of (14)C dose expired by the bird at a steady state was measured. These birds, as well as 12 additional birds matched for age and BW, were killed, and femur bone mineral density was measured by quantitative computed tomography to determine the relationship between bone development and bicarbonate retention at each age. There was a correlation (r = 0.50; P < 0.05) between total cross-sectional femur bone mineral density and bicarbonate retention at each age. A prediction equation (Y = 6.95 x 10(-2)X - 3.51 x 10(-5)X(2) + 27.58; P < 0.0001, R(2) = 0.79) where Y = bicarbonate retention and X = BW was generated to predict Y as a function of X. Bicarbonate retention values peaked at 28 d, during the stage of the most rapid bone deposition and the highest growth rate. A constant BRF was found from 1,900 to 2,700 g of BW of 35.15 +/- 1.095% (mean +/- SEM). This retention factor will allow the accurate correction of oxidation of (14)C-labeled substrates in broilers of different ages and BW in future indicator amino acid oxidation studies.

The indicator amino acid oxidation (IAAO) method allows the determination of amino acid requirements under conditions of low growth rate as found in pre-laying broiler breeder pullets. Cobb 500 breeder pullets (20 wk old; 2290 +/- 280 g, n = 4) were adapted (6 d) to a pelleted, purified control diet containing all nutrients at >or=110% of NRC recommendations. After recovery from surgery for implantation of a jugular catheter, each bird was fed, in random order, test diets containing one of nine levels of lysine (0.48, 0.96, 1.92, 2.88, 3.84, 4.80, 7.68, 9.60 and 14.40 g/kg of diet). Indicator oxidation was determined during 4-h primed (74 kBq/kg body), constant infusions (44 kBq x h(-1). kg body(-1)) of L-[1-(14)C]phenylalanine. Using the breakpoint of a one-slope broken-line model, the lysine requirement was determined to be 4.88 +/- 0.96 g/kg of diet or 366 +/- 72 mg x hen(-1) x d(-1) with an upper 95% CI of 6.40 g/kg of diet or 480 mg x hen(-1) x d(-1). IAAO allows determination of individual bird amino acid requirements for specific ages and types of birds over short periods of time and enables more accurate broiler breeder pullet diet formulation.

A, 2001. Measurements of enzyme response with hulless barley-based diets full-fed to Leghorn and broiler chicks or restricted-fed broiler chicks. Can J. Anim. Sci. 81: 403-410. Broiler chicks fed diets high in soluble non-starch polysaccharides (NSP; e.g., wheat-and/or barley-based diets) have a higher capacity to ingest, digest and absorb nutrients when diets are supplemented with appropriate NSP enzymes. However, this same enzyme response is typically reduced or non-significant in older birds, Leghorn chicks and turkey poults. We hypothesise that the enzyme response in the latter classes of poultry is reduced because feed intake is lower in comparison to feed intake by broilers. In the present study, the hypothesis that restricted feeding of broilers would reduce the enzyme response typically observed in full-fed broilers was tested.Two experiments were conducted to determine the feeding value of hulless barley supplemented or not supplemented with enzyme (Avizyme 1100, Finnfeeds Int, UK). In Study 1, eight sources of hulless barley were included at 80% in each diet and fed to four groups of six male broilers or Leghorn chicks from 4 to 17 d of age. The response to enzyme in hulless barley-based diets by broilers was approximately twofold that of Leghorns for growth and feed intake. The Leghorns had higher digesta viscosity than broilers, although the relative drop in digesta viscosity with enzyme supplementation was equal.In a second study (Study 2) broiler chicks were fed one of four diets (two hulless barley cultivars with or without enzyme) at three feed allotment levels (ad libitum, R1 and R2) from 4 to 21 d of age. The R1 and R2 feed allotments were pre-determined fixed daily feed amounts. Actual feed restriction in the R1 group was only achieved for diets with, but not without, an enzyme. At the lowest feed allotment (R2) actual feed intake of diets with or without enzyme were lower than that recorded for ad libitum fed birds. Study 2 demonstrated that restricted-fed broilers had a lower growth response to enzyme supplementation compared to birds allowed ad libitum intake, in part due to improved retention of energy, either directly in response to feed restriction or because digesta viscosity in diets without enzyme was lowered. Although digesta viscosity of restricted-fed birds was lower, it is still high enough to be considered problematic. In determining feeding value of cereal grains or supplements such as enzymes, especially those directed for use with broilers, it is imperative that a broiler chick bioassay be used and that they have ad libitum access to the diets. Les poussins de chair qui reçoivent une ration riche en polysaccharides solubles autres que l'amidon (par ex., une ration à base de blé et/ou d'orge) ingèrent, digèrent et assimilent mieux les éléments nutritifs quand on ajoute les enzymes appropriés à la nourriture. Toutefois, l'activité des enzymes diminue ou devient insignifiante chez les oiseaux plus âgés, chez les poussins Leghorn et chez les dindonneaux. Les auteurs présument que...