Dietaryn-3 andn-6 fatty acids alter avian metabolism: metabolism and abdominal fat deposition

Antemortem Diagnosis and Successful Long-term Management of Disseminated Intracoelomic Xanthogranulomatous Disease in an Eclectus Parrot (Eclectus roratus)

A 12-year-old male eclectus parrot (Eclectus roratus) was referred for evaluation of coelomic distention. Computed tomography and blood work revealed coelomic effusion with free coelomic mineral-attenuating material and elevations in the bile acids and aspartate aminotransferase activity, respectively. Coelomic effusion was consistent with macrophagic inflammation with abundant intracellular lipids. Initial treatment with meloxicam resulted in minimal patient improvement. Disseminated xanthogranulomatous inflammation was suspected based on imaging and diagnostic laboratory results, which were consistent with those previously reported. Biopsy samples of liver tissue and intracoelomic masses confirmed this diagnosis. Treatment was initiated with prednisolone 1 mg/kg/d for 6 months, followed by 0.5 mg/kg/d for 3 months. Clinical improvement was assessed based on owner evaluation, plasma bile acid concentrations, and repeated computed tomographic scans. After 2 months of treatment, the owner reported improved behavior and appetite; this persisted throughout treatment and when the bird was reexamined 17 months following the cessation of steroid therapy. Bile acid concentrations were normal 10 months after the prednisolone therapy was discontinued. Diagnostic imaging showed minimal coelomic effusion 10 months after the last prednisolone dose was administered, with improved ventilation of the air sacs and static to improved dystrophic mineral foci. This report describes the antemortem diagnosis and treatment of disseminated coelomic xanthogranulomatous disease in a psittacine species, with an observed measurable therapeutic response.

Effect of n-6/n-3 PUFA ratio on body fat deposition, tissues fatty acid composition and key genes expression of liver lipid metabolism in silver foxes (Vulpes vulpes fulva) during the winter fur-growth period

Objective

The proportion of n-6/n-3 polyunsaturated fatty acid (PUFA) plays an important role in regulating lipid metabolism. This study aimed to investigate the effects of dietary n-6/n-3 PUFA ratios on body fat deposition, tissues fatty acid composition, and gene expression of liver lipid metabolism of silver foxes during the winter fur growth period.

Methods

Forty-eight age-matched male silver foxes with similar body weights were randomly divided into four dietary groups for 47 days, which were fed n-6/n-3 PUFA ratio with 3, 18, 41, and 136 experimental diets, respectively.

Results

Dietary n-6/n-3 PUFA ratio did not significantly influence fat deposition parameters except for hepatic fat content. The variation trend of the fatty acid composition of liver, intramuscular fat, and subcutaneous fat in silver fox was directly related to dietary fatty acid content (p < 0.05). With the dietary n-6/n-3 PUFA ratio increasing, the expression of liver fatty acid synthase (FAS) mRNA and peroxisome proliferator-activated receptor (PPAR) mRNA exhibited the trend of first decreasing and then increasing (p < 0.05), whereas L-fatty acid binding protein (L-FABP) mRNA expression showed a gradual increasing trend (p < 0.05).

Conclusion

In summary, silver foxes fed an n-6/n-3 PUFA ratio 18:1 diet (supplementing with 9.38% corn oil and 4.62% soybean oil) was more conducive to lipid decomposition, PUFA transport, and utilization of tissues, thereby meeting it for supplying energy and withstanding the cold.

Effects of a 0.3% cholesterol diet and a 20% fat diet on plasma lipids and lipoproteins in Quaker parrots (Myiopsitta monachus)

BACKGROUND

Lipid disorders are common in captive psittacine birds, but associated changes in blood lipids and lipoproteins have not been well characterized. The Quaker parrot is prone to dyslipidemia and has been extensively used as an experimental model.

OBJECTIVES

We aimed to study the effects of a 0.3% cholesterol diet and a 20% fat diet on plasma lipids and lipoproteins in Quaker parrots.

METHODS

Two crossover studies were performed with each diet. During each study, 12 parrots were divided into two groups fed the treatment or control diet for 2 weeks. After a 2-month wash-out period, the groups were reversed. At the end of each period, plasma lipidomics and lipoprotein profiling were performed. Data were analyzed by univariate tests adjusted for false discovery rates, volcano plots, and enrichment analyses.

RESULTS

The cholesterol diet induced changes in many plasma lipids and lipoproteins. Total cholesterol and cholesteryl esters were significantly and markedly elevated. Ceramides were the second subclass of lipids that were elevated. Several glycerophosphocholines, sphingomyelins, and one diacylglycerol were also significantly elevated, albeit to a lesser magnitude. All lipoproteins were elevated, with the greatest increase seen in non-HDL. The fat diet mainly resulted in a decrease in plasma glycerolipids and an increase in acylcarnitines. Lipoprotein plasma levels remained unchanged.

CONCLUSIONS

Quaker parrots fed a 0.3% cholesterol diet showed profound and complex dyslipidemic changes that could be used to further study lipid disorders and their management in psittacine birds. A 20% fat diet higher in n-6 polyunsaturated fatty acids did not lead to dyslipidemia.

Effects of Dietary Thraustochytrid schizochytrium sp. and Other Omega-3 Sources on Growth Performance, Carcass Characteristics, and Meat Quality of Broilers

Simple Summary

Thraustochytrid schizochytrium is one of the promising microalgae for omega-3 production. We evaluated the possibility of schizochytrium as omega-3 source comparing with other omega-3 sources that have been used before. The main results were the increased levels of DHA in the thigh meat of broilers fed SP, while EPA and DHA were on the rise in the meat of broilers fed SO, and ALA was increased in the meat of broilers fed FO. The ω-6/ω-3 ratio of the thigh meat improved in all treatments, approaching the guideline levels without adverse effects on the productive performance, carcass traits, and thigh meat quality. Hence, our results suggest that salmon oil, flaxseed oil, and schizochytrium could be used as omega-3 fatty acids sources to improve the omega-3 level and ω-6/ω-3 balance in broiler thigh meat and to allow consumers to easily enhance their intake of these vital nutrients for health benefits.

Abstract

Background: Looking for alternative omega-3 sources in broiler nutrition, microalgae began to get attention. We suspected that schizochytrium might play a similar role as other omega-3 sources that have been used before. Methods: 20 g/kg schizochytrium powder (SP), salmon oil (SO), and flaxseed oil (FO) in each of the three treatment groups were supplemented in the basal diet (CON), and productive performance, carcass traits, and thigh meat quality of broilers were evaluated. Results: There was a significantly higher weight gain in the SP treatment compared to the other groups, but no difference was found in feed intake and feed conversion ratio. Thiobarbituric acid reactive substance values increased during storage in all the treatments but were significantly lower for SP than for SO and FO after 7 days of storage. Among the ω-3 fatty acids (FAs), α-linolenic acid increased the most in the FO treatment, eicosapentaenoic acid increased the most in the SO treatment, and docosahexaenoic acid increased the most in the SP treatment in thigh meat, reflecting the FA composition of the lipid source diets. Conclusions: We suggested that all the dietary ω-3 FA sources could improve the FA composition of chicken meat and our results indicated the possibility to supplement broiler diets with 2% level of SP, SO, and FO as ω-3 FA sources to produce meat with a good nutritional quality for consumer’s health benefits.

The effects of Cynara scolymus and Silybum marianum on growth, carcass and organ characteristics, immunity, blood constitutes, liver enzymes, jejunum morphology, and fatty acid profile of breast meat in broilers

To investigate the effects of adding Cynara scolymus (CS) and Silybum marianum (SM) dry extract to the diet of broiler chickens, a 2 × 2 factorial experiment was conducted using a completely randomized design with 4 treatments and 4 replicates. Ten one-day-old male broiler chicks of Ross 308 strain were used in each replicate. Experimental treatments included two levels of supplemental CS and MS, 250 and 500 mg/kg of dry extract of CS and SM, which were used in combination with a basal diet for 42 days. The 42-day trial was divided into 3 periods, 1-10 days, 11-24 days, and 25-42 days of age. The data were statistically analyzed using SAS software and means differences were tested for significance using Duncan's multiple-range test. The results showed that the effect of the experimental treatments was not significant on growth performance in the entire period (1-42 days), carcass characteristics, and weight of immunity organs. Feed cost per kilogram of live weight increased with supplemental of CS and SM (p < .01). Significant effects of CS and SM supplements were observed on antibody titer against influenza virus at 28 and 42 days and also on antibody titer against sheep red blood cells (SRBC) at 35 and 42 days. Feeding 500 mg/kg of both CS and SM in the diet of broilers resulted in the highest villus height and width, crypt depth, and percentage of oleic and linolenic acids. The results of the present study suggest that feeding 250 and 500 mg/kg of dry extract of CS and SM in the diet may have positive effects on the traits studied, but to save feed costs, only250 mg/kg is recommended.

Partial Replacement of Animal Fat with Full-Fat Almond in Broiler Chicken Diets: Performance, Nutrient Digestibility, Blood Profile, Cecal-Fecal Microflora Composition, and Foot-Pad Dermatitis

Simple Summary

Recently, as the price of grains in feed increases worldwide, interest in new raw materials that can replace protein and fat sources is increasing. This study evaluated the effect of full-fat almonds (FFA) on broiler nutrition. In the study, the formulation of FFA as a raw material showed higher growth performance than the basic feed. This seems to be due to the high digestibility of protein and fat and the promotion of intestinal health through the reduction of harmful microorganisms in the intestine. Therefore, FFA can be used as a high-quality protein and fat substitute as a raw material for broiler feed.

Abstract

The purpose of this study was to evaluate the effect of full-fat almonds (FFA) as an alternative protein and fat source for broiler feed on broiler productivity, nutrient digestibility, blood characteristics, cecal-fecal microflora, and foot-pad dermatitis (FPD). A total of 96, one-day-old broiler chickens (Arbor Acres) with initial body weight 41.61 ± 0.36 g were placed in 16 cages. In each trial, four treatments were set up: a basal diet partially replacing animal fat with FFA 0% (Control, CON), a basal diet partially replacing animal fat with FFA 1% (T1), a basal diet partial replacing animal fat with FFA 2% (T2), a basal diet partially replacing animal fat with FFA 4% (T3). The experiment was conducted for a total of 4 weeks. Feed conversion ratio (FCR) was higher (p < 0.05) in the T3 group of broilers at weeks 0 to 1 than in the CON group of broilers. From weeks 3 to 4, and for the entire experimental period, FCR was lower (p < 0.05) in the T3 group of broilers than in the CON and T1 groups of broilers. The apparent ileal digestibility (AID) of the ether extract (EE) was higher (p < 0.05) in the T3 group than in the other treatment groups, and AID of crude protein (CP) was higher (p < 0.05) in the T3 group than in the CON group. The apparent total tract digestibility (ATTD) of EE was lower (p < 0.05) in the CON group than in the other treatment groups, and the ATTD of CP and energy was higher (p < 0.05) in the T3 group of broilers than in the CON group of broilers. The AID and ATTD of total amino acids were higher (p < 0.05) in the T3 group than in the other treatment groups. Blood cholesterol levels were lower (p < 0.05) in the T3 group of broilers than in the CON and T1 groups of broilers, and higher (p < 0.05) in the CON group of broilers than in the T2 and T3 groups of broilers. The amount of E. coli in the cecal and fecal was lower (p < 0.05) in the T3 group than in CON and T1 groups. FPD score was higher (p < 0.05) in the T3 group of broilers than in the CON group of broilers. In conclusion, replacing a partial of animal fat with at least 4% FFA in broiler diets can increase growth performance and nutrient digestibility in broiler nutrition.

Fighting Fat With Fat: n-3 Polyunsaturated Fatty Acids and Adipose Deposition in Broiler Chickens

Modern broiler chickens are incredibly efficient, but they accumulate more adipose tissue than is physiologically necessary due to inadvertent consequences of selection for rapid growth. Accumulation of excess adipose tissue wastes feed in birds raised for market, and it compromises well-being in broiler-breeders. Studies driven by the obesity epidemic in humans demonstrate that the fatty acid profile of the diet influences adipose tissue growth and metabolism in ways that can be manipulated to reduce fat accretion. Omega-3 polyunsaturated fatty acids (n-3 PUFA) can inhibit adipocyte differentiation, induce fatty acid oxidation, and enhance energy expenditure, all of which can counteract the accretion of excess adipose tissue. This mini-review summarizes efforts to counteract the tendency for fat accretion in broilers by enriching the diet in n-3 PUFA.

Effect of supplementing palmitic acid and altering the dietary ratio of n-6:n-3 fatty acids in low-fibre diets on production responses of dairy cows

Supplementing palmitic acid (C16 : 0) in combination with modifying the dietary n-6:n-3 fatty acid (FA) ratio may benefit energy metabolism and milk responses of dairy cows. Twelve Holstein cows (70 (sd 11) days in milk) were used in a replicated 4 × 4 Latin square and allocated to four low-fibre diets (18·5 % forage neutral-detergent fibre) supplemented with no FA (CON), or 2·4 % C16 : 0-enriched supplement (PAL), 2·4 % mixture (2:1) of C16 : 0 and n-6 FA (PW6), and mixture (2:1) of C16 : 0 and n-3 FA (PW3). The dietary ratio of n-6:n-3 was increased with PW6 (10:1) and decreased with PW3 (2·8:1), whereas PAL alone made no change in the ratio (about 7:1). Compared with CON, all FA-supplemented treatments increased milk yield. However, feed and energy intakes were higher in PAL than PW3 or PW6, resulting in greater feed efficiency for PW3 and PW6 than PAL. Dietary FA supplements decreased milk protein concentration but tended to increase protein yield. Compared with CON and FA mixtures, PAL increased milk fat content and tended to increase milk SFA and atherosclerotic index. The concentration of milk n-3 FA was similar between CON and PW3. Feeding PAL increased milk energy output and decreased energy partitioning towards body reserves (-4·2 %), while this measure was positive for other treatments. Blood TAG and NEFA concentrations, but not β-hydroxybutyrate, were increased by FA-supplemented treatments. Feeding C16 : 0 combined with either n-6 or n-3 FA enhanced feed efficiency, alleviated the negative impacts on body energy reserves, but lowering the dietary n-6:n-3 ratio improved the FA profile of milk.

Nutritional modulation of fertility in male poultry

The increased consumption of protein derived from poultry demands greater poultry production, but increased poultry production (meat and eggs) is dependent on the fertility of the parent flocks. Clearly, the fertility of poultry flocks is associated with the fertility of both males and females, but the low numbers of males used for natural or artificial insemination mean that their role is more important. Thus, enhancing the semen volume, sperm concentration, viability, forward motility, and polyunsaturated fatty acids in sperm, as well as protecting against oxidative damage, could help to optimize the sperm membrane functionality, mitochondrial activity, and sperm-egg penetration, and thus fertility. Therefore, this review summarizes the nutritional factors that could improve the fertility of poultry males as well as their associated mechanisms to allow poultry producers to overcome low-fertility problems, especially in aging poultry males, thereby obtaining beneficial impacts on the poultry production industry.

Effect of omega-3 rich diet on the response of Japanese quails (Coturnix coturnix japonica) infected with Newcastle disease virus or avian influenza virus H9N2

This study was performed to evaluate the effects of omega-3 supplementation on growth performance, clinical signs, post-mortem lesions, haemagglutination inhibition (HI) antibody titres, gene expression and histopathology in quails (Coturnix coturnix japonica) infected with Newcastle disease virus (NDV) and avian influenza virus (AIV) H9N2. One hundred, 40-day-old male quails were divided into 5 groups: G1, fed a control basal diet; G2A, infected with NDV; G2B, infected with H9N2; G3A, infected with NDV and given omega-3, and G3B, infected with H9N2 and given omega-3. The dietary omega-3 supplementation was continued for 4 weeks: two weeks before infection and two weeks after intranasal infection with virulent NDV and AIV H9N2. Our results revealed significant differences (P < 0.05) in growth performance, HI antibody titres, clinical signs, post-mortem lesions, mortality, viral shedding rates, immunological parameters, and histopathological lesions between the treated (G3A and G3B) and untreated (G2A and G2B) groups. In conclusion, dietary omega-3 supplementation for 4 weeks can improve growth performance and alleviate the deleterious immunological and pathological effects of NDV and AIV H9N2 infection in quails.

Evaluating Impacts of Different Omega-6 to Omega-3 Fatty Acid Ratios in Corn-Soybean Meal-Based Diet on Growth Performance, Nutrient Digestibility, Blood Profiles, Fecal Microbial, and Gas Emission in Growing Pigs

Simple Summary

There are two major classes of polyunsaturated fatty acids found in the diet, omega-3 and omega-6, these polyunsaturated fatty acids are essential because they cannot be synthesized by humans and animals. Also, they cannot be converted into each other in the body. Supplementation of omega-3 has been reported to improve the performance and health of pigs. However, during the past years, studies had demonstrated that animal performance could be influenced by the dietary level or the ratio of omega-6 and omega-3. A high omega-6: omega-3 ratio in diets promotes the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases. An optimal omega-6: omega-3 ratio could inhibit immune stimulation to ensure the availability of more energy and nutrients for high performance and the homeostatic pathway. The present study investigated the effects of different omega-6: omega-3 ratios (17:1, 15:1, 10:1, 5:1) on growth performance, nutrient digestibility, blood profiles, fecal microflora, and gas emission in growing pigs. The results of this study showed that reducing omega-6: omega-3 ratio from 17:1 to 5:1 by increasing omega-3 in the diet increased body weight, energy digestibility, and reduced the low-density lipoprotein concentrations of blood in growing pigs.

Abstract

This study was conducted to evaluate the effect of different omega-6: omega-3 fatty acid (FA) ratios in a corn–soybean meal-based diet in growing pigs. A total of 140 [Duroc × (Landrace × Yorkshire)] growing pigs with an average body weight (BW) of 24.75 ± 1.43 kg were used in a 6-week trial. Pigs were allocated randomly into one of four treatments according to sex and BW (seven replications with five pigs per pen). The treatment groups consisted of 4 diets with omega-6:omega-3 FA ratios of 17:1, 15:1, 10:1, and 5:1. In the current study, the energy digestibility, BW, and average daily gain (ADG) increased (p < 0.05) in pigs provided with the 5:1 diet compared to pigs fed the 17:1 diet in the sixth week. The low-density lipoprotein (LDL) concentrations of blood were lower (p < 0.05) in pigs fed the 5:1 diet compared to the 17:1 and 15:1 diet. However, the fecal microflora and fecal gas emissions were unaffected (p > 0.05) by the different omega-6: omega-3 FA ratios in diets. In conclusion, reducing omega-6: omega-3 ratio by increasing omega-3 in diet improved BW, ADG, and gross energy digestibility, and reduced the LDL concentrations of blood in growing pigs.

Effect of dietary fat level and source on performance and immune system response of turkeys

An experiment was conducted to determine effects of different levels and sources of fats in diets on growth performance, carcass characteristics and immune response of turkeys during four periods (0-21, 22 to 42, 43 to 63 and 64 to 70 days of age). A completely randomized design with five treatments, six replicates and eight B.U.T.6 turkey chickens per replicate was used. Treatments included: Control diet, diet containing 2.5% of soybean oil, diet containing 2.5% fat supplement, diet containing 5% soybean oil, diet containing 5% fat supplement. The results showed that using 5% of soybean oil increased average daily gain of turkeys (89.04 g) throughout the experimental period (0-70 days) compared with the control group (81.11 g; p < 0.05). Treatments containing 2.5 and 5% soybean oil improved feed conversion ratio compared to control group (p < 0.05). Soybean oil at the levels of 2.5 and 5% was led to higher spleen and bursa percentages compared to other treatments, respectively (p < 0.05). The level and source of dietary fat had not significant effect on antibody titer against Newcastle virus vaccine on 42 and 70 days of age (p > 0.05). It can be concluded that supplementing diet with 5% soybean oil improved the performance of turkeys.

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.

Supplemental Docosahexaenoic-Acid-Enriched Microalgae Affected Fatty Acid and Metabolic Profiles and Related Gene Expression in Several Tissues of Broiler Chicks

This experiment was to enrich docosahexaenoic acid (DHA) in broiler tissues through feeding a DHA-rich microalgal biomass and to explore the underlying metabolic and molecular mechanisms. Hatchling Cornish male broilers (total = 192) were fed a corn-soybean meal basal diet containing a full-fatted microalgae ( Aurantiochytrium) at 0%, 1%, 2%, and 4% for 6 weeks ( n = 6 cages/treatment, 8 birds/cage). The inclusion of microalgae led to dose-dependent ( P < 0.01) enrichments of DHA and decreases ( P < 0.01) of n-6/n-3 fatty acids (FAs) in plasma, liver, muscle, and adipose tissue. The microalgae supplementation also lowered ( P < 0.05-0.1) nonesterified FAs concentrations in the plasma, liver and adipose tissue. The mRNA abundances of most assayed genes involved in lipid metabolism were decreased ( P < 0.05) in the liver but elevated ( P < 0.05) in the adipose in response to the biomass supplementation. In conclusion, the biomass-resultant DHA enrichments in the broiler tissues were associated with a distinctive difference in the expression of lipid metabolism-controlling genes between the liver and adipose tissue.

Inclusion of Dietary Defatted Microalgae Dose-Dependently Enriches ω-3 Fatty Acids in Egg Yolk and Tissues of Laying Hens

BACKGROUND

The potential for dietary microalgae to enrich eggs of laying hens with ω-3 (n-3) fatty acids, and the mechanisms involved, are unclear.

OBJECTIVES

The aim of this study was to determine the effects and molecular regulation of a defatted Nannochloropsis oceanica microalgae (DNOM) biomass on the enrichment of the eggs and tissues of laying hens with ω-3 fatty acids.

METHODS

Fifty Shaver-White Leghorn hens (46 wk of age, body weight: 1.70 ± 0.27 kg) were individually caged (n = 10) and fed a corn-soy-based diet supplemented with DNOM at 0% (control), 2.86%, 5.75%, 11.5%, and 23% for 6 wk. Fatty acid profiles, health status, and related gene expression in eggs, blood, and tissues were performed at weeks 0, 2, 4, and 6. Data were analyzed by a combination of 1-factor ANOVA and correlation between DNOM doses and measures.

RESULTS

The DNOM produced linear (P < 0.01) enrichments of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total ω-3 fatty acids in the egg yolk (R2 > 0.9) and of DHA in the liver, breast, and thigh (R2 = 0.66-0.82). Concentrations of EPA + DHA in the egg yolk and these 3 tissues of hens fed 11.5% and 23% DNOM were 1.4-2.1, 0.6-1, 3.3-5.3, and 6-7 times greater (P < 0.001) than those in the controls, respectively. The DNOM caused dose-dependent elevations (P < 0.01) of malic enzyme and elongases 3, 4, and 5 mRNA levels (R2 = 0.97, 0.78, 0.97, and 0.86, respectively), along with increased (P < 0.01) Δ5- and Δ6-desaturases and decreased (P < 0.01) Δ9-desaturase and acyl-coenzyme A thioesterase 4 mRNA levels in the liver.

CONCLUSIONS

Feeding DNOM to laying hens produced dose-dependent enrichments of DHA in their eggs, liver, and muscles by regulating key genes involved in the elongation and desaturation of polyunsaturated fatty acids. Our findings will help produce DHA-enriched eggs.

Flaxseed and Carbohydrase Enzyme Supplementation Alters Hepatic n-3 Polyunsaturated Fatty Acid Molecular Species and Expression of Genes Associated with Lipid Metabolism in Broiler Chickens

Flaxseed is rich in α-linolenic acid and is used in broiler chicken diets to enrich tissues with n-3 fatty acids (FA). However, non-starch polysaccharides (NSP) in flaxseed decreases nutrient digestibility and limits the availability of n-3 FA. Addition of carbohydrase enzymes to flaxseed-based diets can decrease the anti-nutritive effects of NSP. We hypothesized that flaxseed and enzyme supplementation affect lipid content and alter expression of genes related to lipid metabolism in broiler liver. Five day-old broiler chicks were fed a corn-soybean basal diet with 0% flaxseed, a basal diet with 10% of flaxseed, or 10% flaxseed + 0.05% enzyme diet up to day 42 of growth. Total lipids, including long-chain (≥20C) n-3 FA and monounsaturated FA, were increased in flax-fed broiler livers. Enzyme addition reduced arachidonic acid and total long chain n-6 FA. These changes were similarly reflected in phosphatidylcholine lipid species. Dietary flax and enzyme treatments up-regulated PPARα target genes CPT1A and ACOX1 while reducing expression of de novo FA synthesis-related genes. This study concludes that flaxseed and enzyme supplementation in broiler diets enhances LC n-3 FA species, while reducing n-6 FA species in hepatic phospholipids (PL). Flaxseed-based diets changes the expression of genes involved in FA lipid metabolism without affecting growth or production performance in broilers.

Diet and ambient temperature interact to shape plasma fatty acid composition, basal metabolic rate and oxidative stress in great tits

Diet and ambient temperature affect animal physiology, survival and reproductive success. However, knowledge of how these environmental factors interact to shape physiological processes and life-history traits of birds and other animals is largely lacking. By exposing adult great tits (Parus major) to two contrasting diets (saturated or unsaturated fatty acids; SFAs and UFAs, respectively) and ambient temperatures (3°C versus 20°C) that the birds encounter in nature, we investigated the effects of these two factors on several physiological parameters. Our results show that diet and ambient temperature interact to affect the composition of plasma fatty acids, basal metabolic rate (BMR) and oxidative stress, which are thought to affect the life-history and survival of individuals. Specifically, birds provided the SFA-rich diet had higher mass-specific BMR and oxidative stress (levels of lipid peroxidation) after exposure to low compared with high ambient temperature, whereas the opposite pattern was evident for birds with a UFA-rich diet. Surprisingly, birds on the SFA diet had higher relative levels of monounsaturated fatty acids compared with the UFA-fed birds at low ambient temperature, whereas the opposite, and expected, pattern was found at the high temperature. Although the present study focuses on the physiological implications of the diet×temperature interaction, our results might also be important for the leading theories of ageing, which currently do not take interactions between environmental factors into account. In addition, the present results are important for wildlife management, especially with regards to anthropogenic feeding of wild animals across variable and changing climatic conditions.

Feed processing effects on digestibility, palatability, excreta fermentation products and blood parameters in blue-fronted amazon parrots (Amazona aestiva)†

Captive parrots show a high incidence of obesity and other metabolic disorders due to the consumption of unbalanced diets. Therefore, this study evaluated the digestibility and metabolic effects of transitioning blue-fronted amazons from a high fat diet (sunflower seeds) to processed diets with three degrees of starch gelatinization (SG). The same feed formulation was processed to obtain pelletized feed (PEL) at 27.1% SG; low-cooked extruded feed (EXT_L ) at 81.6% SG; and high-cooked extruded feed (EXT_H ) at 98.5% SG. Thirty adult parrots were fed sunflower seeds for 90 days, then were distributed in a completely randomized design with 10 repetitions per treatment, and fed one of the three prepared diets for 160 days. Feed palatability, apparent digestibility, excreta concentrations of volatile fatty acids, lactate and ammonia, initial and final radiographic examinations, blood cell counts and glucose, triglycerides, cholesterol, total protein, albumin, aspartate aminotransferase (AST) and uric acid levels were evaluated. The data were analysed by an analysis of variance and compared by Tukey's test (p < 0.05). Sunflower seed was more digestible than processed feeds (p < 0.05). Diet processing interfered with fat and starch digestibility (p < 0.001), being higher in the PEL than in the EXT_H and EXT_L respectively. Transitioning from sunflower seeds to balanced diets reduced serum glucose, triglycerides, cholesterol and AST (p < 0.05) and increased red blood cell, haemoglobin, lymphocyte, monocyte and leucocyte counts (p < 0.01). Radiographs indicated a decreased hourglass (p = 0.015) and a reduced heart-liver ratio after ingesting the processed feeds (p < 0.05). Feed processing did not affect blood cell counts, serum biochemistry or radiographic examinations. In conclusion, parrots preferred the extruded diet and did not require an extensive SG to properly digest the feed. Consuming the processed diets improved the birds' metabolism and health.

On growth performance, nutrient digestibility, blood T lymphocyte subsets, and cardiac antioxidant status of broilers

Different lipid sources differ in the fatty acid profiles and differently affect growth performance as well as immune function of broilers. The influences of different dietary lipid sources on growth performance, nutrient digestibility, blood T lymphocyte population, and cardiac antioxidant status were investigated of broilers. A total of 360 one-day-old male broilers (BW = 44 ± 3 g) were randomized into 3 treatment groups, consisting of 6 replicates with 20 birds in each group. Broilers received standard diets supplemented with 5% (wt/wt) of lard (LD, as a control diet), sesame oil (SO), or flaxseed oil (FO). Broilers in both SO and FO treatment groups had lower (P < 0.05) feed conversion ratios from 22 to 42 d and during the overall phase compared to those in LD treatment group. Meanwhile, the apparent total tract nutrient digestibility of crude fat in SO and FO treatment groups was higher than that in LD treatment group. Both FO and SO treatments decreased (P < 0.05) abdominal fat percentage compared to LD treatment. Total triglycerides and total cholesterol in chicken blood were decreased (P < 0.05) by SO and FO treatments compared to LD treatment. Feeding broilers with FO and SO led to a decrease (P < 0.05) in blood CD4⁺ T lymphocyte count and in CD4⁺:CD8⁺ ratio compared to LD treatment. Sesame oil and FO treatments increased cardiac glutathione peroxidase (P < 0.05) compared to LD treatment. It is concluded that addition of 5% SO and FO to the standard corn-soybean meal diet improved feed efficiency, increased the activities of cardiac glutathione peroxidase, and affected the T lymphocytes ratio of fast growing broilers.

Is dietary macronutrient composition during pregnancy associated with offspring birth weight? An observational study

There is lack of evidence on the differential impact of maternal macronutrient consumption: carbohydrates (CHO), fats and protein on birth weight. We investigated the association between maternal dietary macronutrient intakes and their sub-components such as saccharides and fatty acids and birth weight. This analyses included 1,196 women with singleton pregnancies who were part of the CAffeine and REproductive health study in Leeds, UK between 2003 and 2006. Women were interviewed in each trimester. Dietary information was collected twice using a 24-h dietary recall about 8–12 weeks and 13–27 weeks of gestation. Multiple linear regression models adjusted for alcohol and smoking in trimester 1, showed that each additional 10 g/d CHO consumption was associated with an increase of 4 g (95 % CI 1, 7;P=0·003) in birth weight. Conversely, an additional 10 g/d fat intake was associated with a lower birth weight of 8 g (95 % CI 0, 16;P=0·04) when we accounted for energy contributing macronutrients in each model, and maternal height, weight, parity, ethnicity, gestational age at delivery and sex of the baby. There was no evidence of an association between protein intake and birth weight. Maternal diet in trimester 2 suggested that higher intakes of glucose (10 g/d) and lactose (1 g/d) were both associated with higher birth weight of 52 g (95 % CI 4, 100;P=0·03) and 5 g (95 % CI 2, 7;P<0·001) respectively. These results show that dietary macronutrient composition during pregnancy is associated with birth weight outcomes. An appropriately balanced intake of dietary CHO and fat during pregnancy could support optimum birth weight.

Relationship between the fatty acid composition of uropygial gland secretion and blood of meat chickens receiving different dietary fats

Manipulation of the fatty acid composition of chicken feed has been shown to be effective for improving the nutritional value of chicken products. Currently, however, evaluation of the effectiveness of this approach requires invasive blood sampling or post mortem tissue sampling of the birds. Preen oil can be collected non-invasively from live birds. So this study aimed to test the hypothesis that the fatty acid composition of preen oil reflects that of the blood. Male and female meat chickens (Cobb 500) were fed a diet supplemented with 4% (w/w) flaxseed oil (high n-3 polyunsaturates) or beef tallow (mostly monounsaturates and saturates) for 6 weeks. Preen oil and whole blood samples (n = 9 birds per sex/diet treatment group) were collected freshly post mortem for fatty acid analysis. Preen oil analysis showed that ~97% of fatty acids were saturates, with a small percentage of n-6 polyunsaturates and traces of other types. There were negligible n-3 polyunsaturates in preen oil. Proportions of some saturated fatty acids were slightly, but significantly, affected by diet (C16:0 (P < 0.05) and C17:0 (P < 0.01)) or by gender (C10:0 and C18:0) (P < 0.05). Some fatty acids with odd numbers of carbon atoms (e.g. C17:0 and C19:0) were found in relatively high concentrations in preen oil, despite not being detectable in either the diet or blood. In conclusion, the fatty acid composition of preen oil does not accurately reflect the fatty acid profile of the blood; it is not, therefore, a suitable alternative for determining fatty acid status of meat chickens.

Evaluation of fatty acid metabolism and innate immunity interactions between commercial broiler, F1 layer × broiler cross and commercial layer strains selected for different growth potentials

Background

The broiler industry has undergone intense genetic selection over the past 50 yr. resulting in improvements for growth and feed efficiency, however, significant variation remains for performance and growth traits. Production improvements have been coupled with unfavourable metabolic consequences, including immunological trade-offs for growth, and excess fat deposition. To determine whether interactions between fatty acid (FA) metabolism and innate immunity may be associated with performance variations commonly seen within commercial broiler flocks, total carcass lipid %, carcass and blood FA composition, as well as genes involved with FA metabolism, immunity and cellular stress were investigated in male birds of a broiler strain, layer strain and F1 layer × broiler cross at d 14 post hatch. Heterophil: lymphocyte ratios, relative organ weights and bodyweight data were also compared.

Results

Broiler bodyweight (n = 12) was four times that of layers (n = 12) by d 14 and had significantly higher carcass fat percentage compared to the cross (n = 6; P = 0.002) and layers (P = 0.017) which were not significantly different from each other (P = 0.523). The carcass and whole blood FA analysis revealed differences in the FA composition between the three groups indicating altered FA metabolism, despite all being raised on the same diet. Genes associated with FA synthesis and β-oxidation were upregulated in the broilers compared to the layers indicating a net overall increase in FA metabolism, which may be driven by the larger relative liver size as a percentage of bodyweight in the broilers. Genes involved in innate immunity such as TLR2 and TLR4, as well as organelle stress indicators ERN1 and XBP1 were found to be non-significant, with the exception of high expression levels of XBP1 in layers compared to the cross and broilers. Additionally there was no difference in heterophil: lymphocytes between any of the birds.

Conclusions

The results provide evidence that genetic selection may be associated with altered metabolic processes between broilers, layers and their F1 cross. Whilst there is no evidence of interactions between FA metabolism, innate immunity or cellular stress, further investigations at later time points as growth and fat deposition increase would provide useful information as to the effects of divergent selection on key metabolic and immunological processes.

Oil content and fatty acid composition of eggs cooked in drying oven, microwave and pan

In this study, the effect of heating on the oil yield and fatty acid composition of eggs cooked in drying oven, microwave oven, pan and boiled were determined, and compared. The highest oil content (15.22%) was observed for egg cooked in drying oven, while the lowest oil (5.195%) in egg cooked in pan. The cooking in microwave oven caused a decrease in oleic acid content (46.201%) and an increase in the amount of palmitic acid content (26.862%). In addition, the maximum oleic acid (65.837%) and minimum palmitic acid (14.015%) contents were observed in egg oil cooked in pan. Results showed that fatty acids were significantly affected by cooking method. This study confirms that the cooking processing influences the fatty acid composition of egg oils.

Effects of fermentatively recovered fish waste lipids on the growth and composition of broiler meat

1. The aim of the present study was to evaluate the effects of feeding fermentatively recovered fish oil (FFO) from fish processing waste (FPW), on the performance and carcass composition of broilers. A total of 60 one-d-old VenCobb broiler chicks randomly assigned to 5 treatment groups were studied. 2. The birds were randomly assigned to treatment groups and fed with a normal commercial diet (control, T1), a diet with 2% groundnut oil (positive control, T2), a diet with 1% FFO (T3), a diet with 1.5% FFO (T4) and a diet with 2% FFO (T5). Performance and growth parameters (feed intake and body weight) and fatty acid composition of serum, liver and meat were determined. 3. The performance characteristics of broiler meat did not differ among treatments. Feeding FFO reduced total cholesterol concentration in serum, meat and liver of the FFO-fed groups (T3 to T5) as compared to both the controls (T1 and T2), but there was no significant difference in triglyceride concentration between treatments. Increased concentrations of EPA and DHA in serum, liver and meat of FFO-fed groups, as compared to both controls, were observed as the FFO concentration increased. 4. The study clearly demonstrates the value of oil recovered from FPW in addition to addressing the environmental issues related to disposal of such biological waste.

Effect of Different Dietary n-6 to n-3 Fatty Acid Ratios on the Performance and Fatty Acid Composition in Muscles of Broiler Chickens

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

A review of the effects of nuts on appetite, food intake, metabolism, and body weight

Tree nuts and peanuts are good sources of many nutrients and antioxidants, but they are also energy dense. The latter often limits intake because of concerns about their possible contribution to positive energy balance. However, evidence to date suggests that nuts are not associated with predicted weight gain. This is largely due to their high satiety value, leading to strong compensatory dietary responses, inefficiency in absorption of the energy they contain, a possible increment in resting energy expenditure, and an augmentation of fat oxidation. Preliminary evidence suggests that these properties are especially evident when they are consumed as snacks.

Nutritional factors affecting abdominal fat deposition in poultry: a review

The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

Effects of a dietary antioxidant blend and vitamin E on growth performance, oxidative status, and meat quality in broiler chickens fed a diet high in oxidants

The aim of the study was to determine the effects of a dietary antioxidant blend (AB) and vitamin E on performance, oxidative status, and meat quality. Cobb 500 male broilers (n = 1,200, d 0) were randomly distributed into 6 treatments with 10 replicate pens. Treatments included 1) HO: high oxidant diet, vitamin E at 10 IU/kg, 3% oxidized soybean oil, 3% polyunsaturated fatty acid (PUFA) source; 2) VE: the HO diet with vitamin E at 200 IU/kg; 3) AOX: the HO diet with AB at 135 mg/kg; 4) VE+AOX: the HO diet with vitamin E at 200 IU/kg and AB at 135 mg/kg; 5) SC: standard control; and 6) PC: positive control, the SC diet with AB at 135 mg/kg. From d 0 through d 21, high oxidant diet treatment birds had greater BW, ADG, and ADFI than the SC birds; the AOX birds had better G:F on d 10 and 42, and from d 0 to 42 than SC birds (P < 0.05). The plasma TBA reactive substance level was lower in the AOX birds than the VE treatment birds in all phases (P < 0.05). High oxidant diet treatment birds had greater α-1-acid glycoprotein levels on d 10 than SC and PC birds (P < 0.05). The AOX, PC, and SC birds had a greater level of uric acid than the HO and VE+AOX birds on d 10. Superoxide dismutase expression in the liver was less with the HO treatment compared with the SC treatment on d 7 (P < 0.05). The vitamin E concentration in the breast muscle was greatest in the VE birds, whereas vitamin A concentration was greater in the PC birds compared with the SC birds on d 21 (P < 0.05). Compared with VE and AOX, the HO treatment had greater drip loss (P < 0.05). In conclusion, dietary addition of AOX was effective in improving growth, moderately restored the whole body antioxidant capability, and reduced drip loss.

Cluster of atherosclerosis in a captive population of black kites (Milvus migrans subsp.) in France and effect of nutrition on the plasma lipid profile

From January 2010 to March 2013, a captive colony of 83 black kites (Milvus migrans subsp.) in France experienced increased mortality related to atherosclerosis with an incidence of 4.4% per year. On histopathology, all kites had advanced atherosclerotic lesions, with several birds presenting abdominal hemorrhage and aortic rupture. In January 2012, a dietary change was instituted and consisted of introducing fish into the kites' diet. During the following 15 mo, the plasma lipid profile was monitored as well as body weight, food offered, and flight activity. Total and low-density lipoprotein cholesterol initially increased, but in December 2012 and March 2013, an overall decrease from initial values was observed. High-density lipoprotein cholesterol also increased during this period. Despite positive plasma lipid changes induced by dietary modifications, there was no decrease in mortality from atherosclerosis, which was probably associated with the severity of the atherosclerotic lesions at time of dietary management. However, owing to the long and progressive development of atherosclerotic lesions, long-term beneficial effects are probable. This report suggests that black kites are particularly susceptible to atherosclerosis and aortic dissection in captivity. To prevent degenerative diseases associated with captivity in birds of prey, species-specific lifestyle and dietary requirements and susceptibility to these diseases should be considered.

Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract

The aim of the present work was to examine how different fats commonly used in the feed industry affect broiler performance, nutrient digestibility and microbial fermentation in the gastrointestinal tract of broiler chickens challenged with virulent Clostridium perfringens strains. Two experiments were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C. perfringens did not affect broiler chicken body weight gain (BWG) and mortality in either of the two experiments. The BWG was affected by dietary fat type in both experiments, indicating that the fatty acid composition of the fat source affects broiler growth performance. In particular, the inclusion of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v. 1.69) and at 42 days (1.65 v. 1.68). In both experiments apparent metabolizable energy values were affected by dietary fat type. Irrespective of the fat type present in the diet, C. perfringens challenge decreased the digesta pH in the crop and ileum, but had no effect in cecal contents. Moreover, in Experiment 1, total organic acid concentration in the ileum was two to three times lower on soybean oil diets as compared with other treatments, indicating that C. perfringens as well as dietary fat type significantly affects microbiota activity in the broiler chicken gastrointestinal tract.

The Effect of n-3 Fatty Acids on Glucose Homeostasis and Insulin Sensitivity

Type 2 diabetes (T2D) as well as cardiovascular disease (CVD) represent major complications of obesity and associated metabolic disorders (metabolic syndrome). This review focuses on the effects of long-chain n-3 polyunsaturated fatty acids (omega-3) on insulin sensitivity and glucose homeostasis, which are improved by omega-3 in many animal models of metabolic syndrome, but remain frequently unaffected in humans. Here we focus on: (i) mechanistic aspects of omega-3 action, reflecting also our experiments in dietary obese mice; and (ii) recent studies analysing omega-3’s effects in various categories of human subjects. Most animal experiments document beneficial effects of omega-3 on insulin sensitivity and glucose metabolism even under conditions of established obesity and insulin resistance. Besides positive results obtained in both cross-sectional and prospective cohort studies on healthy human populations, also some intervention studies in prediabetic subjects document amelioration of impaired glucose homeostasis by omega-3. However, the use of omega-3 to reduce a risk of new-onset diabetes in prediabetic subjects still remains to be further characterized. The results of a majority of clinical trials performed in T2D patients suggest that omega-3 have none or marginal effects on metabolic control, while effectively reducing hypertriglyceridemia in these patients. Despite most of the recent randomized clinical trials do not support the role of omega-3 in secondary prevention of CVD, this issue remains still controversial. Combined interventions using omega-3 and antidiabetic or hypolipidemic drugs should be further explored and considered for treatment of patients with T2D and other diseases.

Role of n-3 fatty acids in muscle loss and myosteatosis

Image-based methods such as computed tomography for assessing body composition enables quantification of muscle mass and muscle density and reveals that low muscle mass and myosteatosis (fat infiltration into muscle) are common in people with cancer. Myosteatosis and low muscle mass have emerged as independent risk factors for mortality in cancer; however, the characteristics and pathogenesis of these features have not been resolved. Muscle depletion is associated with low plasma eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) in cancer and supplementation with n-3 fatty acids has been shown to ameliorate muscle loss and myosteatosis in clinical studies, suggesting a relationship between n-3 fatty acids and muscle health. Since the mechanisms by which n-3 fatty acids alter body composition in cancer remain unknown, related literature from other conditions associated with myosteatosis, such as insulin resistance and obesity is considered. In these noncancer conditions, it has been reported that n-3 fatty acids act by increasing insulin sensitivity, reducing inflammatory mediators, and altering adipokine profiles and transcription factors; therefore, the plausibility of these mechanisms of action in the neoplastic state are considered. The aim of this review is to summarize what is known about the effects of n-3 fatty acids with regards to muscle condition and to discuss potential mechanisms for effects of n-3 fatty acids on muscle health.

Dietary fatty acids affect the growth, body composition and performance of post-weaning gilt progeny

Gilt progeny are born lighter, have lower weaning weights and require more medication throughout their life time than do sow progeny. Therefore, strategies to improve their post-weaning performance are of importance to pork producers. Dietary fatty acids have been shown to be potent modulators of physiological processes. Studies in other species have reported that dietary fatty acids affect in utero development, cognitive behaviour, immune system function, carcass composition as well as feed efficiency of offspring. However, little information is available that details their use in gilt progeny and when fed throughout their lifetime. In the present study, two experiments were conducted to investigate the effects of feeding three different types of fat to gilts and their progeny on the growth, body composition and performance post-weaning. Diets were enriched with either saturated fatty acids (SFA; tallow), or n-3 (fish-oil extracts) or n-6 (safflower oil) polyunsaturated fatty acids (PUFA) and were fed to gilts through gestation and to their progeny post-weaning. In Experiment 2, half of the female progeny from n-3 and n-6 PUFA litters were fed SFA post-weaning. For both studies, there was no significant difference in weaning bodyweights. However, in Experiment 1, pigs fed n-6 PUFA diets post-weaning were significantly lighter 7 days post-weaning than were pigs fed SFA- and n-3 PUFA-enriched diets. Despite feed intake of n-6 PUFA-fed pigs becoming comparable to that of the other groups during the finisher period, bodyweight for this group remained significantly lower than that of the other groups at the conclusion of the experiment. No effect of dietary fatty acid type on the carcass composition of finisher pigs, as determined by computed tomography, was found. The results of Experiment 2 showed that feeding pigs n-6 PUFA diets post-weaning through to slaughter significantly compromised their growth, being in agreement with those from Experiment 1. Feed consumption for this group was significantly less during the post-weaning and the finisher periods. However, pigs from n-6 PUFA litters that were fed SFA diets post-weaning showed no compromise in growth and performance and were comparable to pigs from the other treatment groups. During the grower and finisher periods, pigs fed n-6 PUFA diets had a significantly higher rate of mortality that was as much as 13 times that of pigs fed SFA diets. Pigs from n-6 PUFA litters that were fed SFA diets post-weaning were not affected in this manner. The results of the current study showed that feeding diets enriched with n-6 PUFA to pigs significantly compromised their growth and performance and that this fatty acid type may also have negative health effects with prolonged consumption. The data suggested that the type of fatty acid used in pig diets may be an important consideration for nutritionists when formulating diets to optimise post-weaning growth and performance.

Lipid metabolic dose response to dietary alpha-linolenic acid in monk parrot (Myiopsitta monachus)

Monk parrots (Myiopsitta monachus) are susceptible to atherosclerosis, a progressive disease characterized by the formation of plaques in the arteries accompanied by underlying chronic inflammation. The family of n-3 fatty acids, especially eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have consistently been shown to reduce atherosclerotic risk factors in humans and other mammals. Some avian species have been observed to convert α-linolenic acid (18:3n-3, ALA) to EPA and DHA (Htin et al. in Arch Geflugelk 71:258-266, 2007; Petzinger et al. in J Anim Physiol Anim Nutr, 2013). Therefore, the metabolic effects of including flaxseed oil, as a source of ALA, in the diet at three different levels (low, medium, and high) on the lipid metabolism of Monk parrots was evaluated through measuring plasma total cholesterol (TC), free cholesterol (FC), triacylglycerols (TAG), and phospholipid fatty acids. Feed intake, body weight, and body condition score were also assessed. Thus the dose and possible saturation response of increasing dietary ALA at constant linoleic acid (18:2n-6, LNA) concentration on lipid metabolism in Monk parrots (M. monachus) was evaluated. Calculated esterified cholesterol in addition to plasma TC, FC, and TAG were unaltered by increasing dietary ALA. The high ALA group had elevated levels of plasma phospholipid ALA, EPA, and docosapentaenoic acid (DPAn-3, 22:5n-3). The medium and high ALA groups had suppressed plasma phospholipid 20:2n-6 and adrenic acid (22:4n-6, ADA) compared to the low ALA group. When the present data were combined with data from a previous study (Petzinger et al. in J Anim Physiol Anim Nutr, 2013) a dose response to dietary ALA was observed when LNA was constant. Plasma phospholipid ALA, EPA, DPAn-3, DHA, and total n-3 were positively correlated while 20:2n-6, di-homo-gamma-linoleic acid (20:3n-6Δ7), arachidonic acid (20:4n-6), ADA, and total n-6 were inversely correlated with dietary en% ALA.

Stearic acids at sn-1, 3 positions of TAG are more efficient at limiting fat deposition than palmitic and oleic acids in C57BL/6 mice

In the present study, we investigated the effect of long-acyl chain SFA, namely palmitic acid (16:0) and stearic acid (18:0), at sn-1, 3 positions of TAG on obesity. Throughout the 15 weeks of the experimental period, C57BL/6 mice were fed diets fortified with cocoa butter, sal stearin (SAL), palm mid fraction (PMF) and high-oleic sunflower oil (HOS). The sn-1, 3 positions were varied by 16:0, 18:0 and 18:1, whilst the sn-2 position was preserved with 18:1. The HOS-enriched diet was found to lead to the highest fat deposition. This was in accordance with our previous postulation. Upon normalisation of total fat deposited with food intake to obtain the fat:feed ratio, interestingly, mice fed the SAL-enriched diet exhibited significantly lower visceral fat/feed and total fat/feed compared with those fed the PMF-enriched diet, despite their similarity in SFA-unsaturated fatty acid-SFA profile. That long-chain SFA at sn-1, 3 positions concomitantly with an unsaturated FA at the sn-2 position exert an obesity-reducing effect was further validated. The present study is the first of its kind to demonstrate that SFA of different chain lengths at sn-1, 3 positions exert profound effects on fat accretion.

Effect of dietary combination of methionine and fish oil on cellular immunity and plasma fatty acids in infectious bursal disease challenged chickens

This study was carried out to investigate the modulatory effects of dietary methionine and fish oil on immune response, plasma fatty acid profile, and blood parameters of infectious bursal disease (IBD) challenged broiler chickens. A total of 300 one-day-old male broiler chicks were assigned to one of six dietary treatment groups in a 3 × 2 factorial arrangement. There were three levels of fish oil (0, 2.5 and 5.5%), and two levels of methionine (NRC recommendation and twice NRC recommendation). The results showed that the birds fed with 5.5% fish oil had higher total protein, white blood cell count, and IL-2 concentration than those of other groups at 7 days after IBD challenge. Inclusion of fish oil in diet had no effect on IFN- γ concentration. However, supplementation of methionine twice the recommendation enhanced the serum IFN- γ and globulin concentration. Neither of fish oil nor methionine supplementation affected the liver enzymes concentration. It can be suggested that a balance of moderate level of fish oil (2.5%) and methionine level (twice NRC recommendation) might enhance immune response in IBD challenged broiler chickens.

Dietaryn-3 andn-6 Fatty Acids Alter Avian Pituitary Sensitivity

The effects of dietary saturated and polyunsaturated fatty acids (PUFAs) of the n-3 and n-6 series on avian pituitary sensitivity were investigated by infusing human growth hormone (GH) releasing hormone--fragment 1-29--and chicken luteinising hormone releasing hormone (LHRH) into catheterized broiler chickens. At 3 weeks of age three groups (n = 18; six birds per group) were fed for 6 weeks isonitrogenous and isoenergetic experimental diets containing 80 g/kg of edible tallow (saturated fatty acids), fish oil (n-3 PUFAs) or sunflower oil (n-6 PUFAs). Jugular catheterisation was performed under general anaesthesia during week four of the dietary treatments and the birds allowed 7 days post surgery to recover. A bolus of LHRH (20 microg/bird) and a GH releasing hormone (12.5 microg/kg) infusion was given on different days to each chicken and serial blood samples taken over a 1 h period. Plasma luteinising hormone and GH concentrations were measured by radioimmunoassay. Pre-infusion GH concentrations were similar for the tallow, fish and sunflower oil dietary groups (5.2 +/- 3.9, 5.2 +/- 1.0 and 6.1 +/- 3.1 ng/ml, respectively), however, GH concentration in response to the GH releasing hormone infusion was elevated in the sunflower oil group (44.7 +/- 5.7 ng/ml) when compared to chicken fed tallow (33.7 +/- 9.7ng/ml) or fish oil (21.3 +/- 5.0 ng/ml). There was a significant decrease (P < 0.05) in the clearance rate of plasma GH for the birds fed the fish oil compared with those fed sunflower oil with an intermediate value being observed in the tallow fed group. Pre-infusion plasma luteinising hormone concentrations for the birds fed tallow (3.2 +/- 0.7 ng/ml) were significantly elevated (P < 0.05) when compared to birds fed either the sunflower oil (0.84 +/- 0.25 ng.ml) or fish oil (0.93 +/- 0.22 ng/ml) diets. There were no significant differences between the dietary groups in either the maximal plasma luteinising concentration or its disappearance rate following the LHRH infusion. The data demonstrate that dietary fatty acids alter avian pituitary sensitivity and this modulation is determined by the nature of the dietary fat rather than the degree of saturation per se. In addition, this study also shows that dietary fats have a differential effect on pituitary cell activity and are specific to certain pituitary cell types.

n-6:n-3 PUFA ratio is involved in regulating lipid metabolism and inflammation in pigs

The objective of the present study was to investigate the optimal dietary n-6:n-3 PUFA ratios that regulate lipid metabolism and inflammation in pigs. A total of ninety-six cross-bred (Large White × Landrace) growing-finishing pigs (73·8 (SEM 1·6) kg) were chosen and fed one of the four isoenergetic diets with n-6:n-3 PUFA ratios of 1:1, 2·5:1, 5:1 and 10:1. The growth performance of pigs fed the diet with an n-6:n-3 PUFA ratio of 5:1 was the best, but the group fed the diet with an n-6:n-3 PUFA ratio of 1:1 had the highest muscle mass and the lowest adipose tissue mass (P< 0·05). The concentrations of IL-6 and IL-1β of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 were decreased compared with those of the other groups (P< 0·05). The concentration of adiponectin of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 was also markedly decreased, but the concentration of leptin was increased compared with that of the groups fed the diets with n-6:n-3 PUFA ratios of 5:1 and 10:1 (P< 0·05). Additionally, the optimal dietary ratios of n-6:n-3 PUFA of 1:1 and 5:1 markedly suppressed the expression levels of lipid metabolism-related genes and proteins such as phosphoinositide-3-kinase-α, fatty acid transport protein-1 and PPARγ. They also significantly suppressed the expression levels of the inflammatory cytokines IL-1β, TNF-α and IL-6. The results indicated that the optimal n-6:n-3 PUFA ratios of 1:1 and 5:1 exerted beneficial effects on lipid metabolism and inflammatory system, leading to the availability of more energy and nutrients for high performance and homeostatic pathways.

Long-chain SFA at thesn-1, 3 positions of TAG reduce body fat deposition in C57BL/6 mice

The present study aimed to determine the effect of positional distribution of long-chain SFA in TAG, especially at thesn-1, 3 positions, on fat deposition using the C57BL/6 mouse model. Throughout the 15 weeks of the study, mice were fed with diets fortified with palm olein (POo), chemically interesterified POo (IPOo) and soyabean oil (SOY). Mice receiving the SOY-enriched diet gained significantly higher amounts of subcutaneous fat (P= 0·011) and total fat (P= 0·013) compared with the POo group, despite similar body mass gain being recorded. During normalisation with food consumption to obtain the fat:feed ratio, mice fed with the POo-enriched diet exhibited significantly lower visceral (P= 0·044), subcutaneous (P= 0·006) and total (P= 0·003) fat:feed than those fed with the SOY-enriched diet. It is noteworthy that mice fed with the IPOo-enriched diet gained 14·3 % more fat per food consumed when compared with the POo group (P= 0·013), despite their identical total fatty acid compositions. This was mainly attributed to the higher content of long-chain SFA at thesn-1, 3 positions of TAG in POo, which results in delayed absorption after deacylation as evidenced by the higher amounts of long-chain SFA excreted in the faeces of mice fed with the POo-enriched diet. Negative correlations were found between the subcutaneous, visceral as well as total fat accretion per food consumption and the total SFA content at thesn-1, 3 positions, while no relationships were found for MUFA and PUFA. The present results show that the positional distribution of long-chain SFA exerts a more profound effect on body fat accretion than the total SFA content.