Effect of dietary n-6-to-n-3 fatty acid ratio on complete blood and total white blood cell counts, and T-cell subpopulations in aged dogs

OBJECTIVE: To determine effect of diets with variable n-6-to-n-3 fatty acid (FA) ratio on CD4+ and CD8+ T-lymphocyte subpopulations, and on results of routine laboratory analyses (CBC and total WBC count, serum biochemical analyses, and urinalysis). ANIMALS: 20 healthy, aged (9.5 to 11.5 years old) female Beagles. PROCEDURE: Dogs were fed 1 of 3 diets that contained 6% fat by weight but differed in amounts of n-6 and n-3 FA. For 11 weeks, 6 dogs were fed a low concentration of n-3 FA (ratio, 31:1), 7 were fed a medium concentration (5.4:1), and 7 were fed a high concentration (1.4:1). Preprandial blood and urine samples were collected before beginning the study and at 8 weeks for evaluation of laboratory variables. Before and at 3, 6, and 8 weeks during the study, blood was drawn for total WBC and lymphocyte counts and for characterization of T-cell subpopulations. At 8 and 10 weeks, dogs were vaccinated with keyhole limpet hemocyanin suspension. Blood was drawn 4 days after each vaccination, and lymphocytes were isolated for flow cytometry. Effects of diet and vaccination on each variable were determined. RESULTS: After vaccination, total lymphocyte count increased and CD4+ T lymphocyte count and the CD4(+)-to-CD8+ ratio decreased in dogs consuming the diet with n-6-to-n-3 FA ratio of 1.4:1. CONCLUSION: Feeding a diet with n-6-to-n-3 FA ratio of 1.4:1 had significant effects on CD4+ T lymphocytes in healthy, aged Beagles after vaccination.     

Effects of dietary n-6 and n-3 fatty acids and vitamin E on the immune response of healthy geriatric dogs

OBJECTIVE: To determine the effect of dietary n-6 to n-3 fatty acid ratios and alpha-tocopheryl acetate concentration on immune functions andT cell subpopulations in healthy dogs. ANIMALS: Thirty-two 7- to 10-year old female Beagles. PROCEDURE: For 17 weeks, dogs were fed food that contained low (1.4:1) or high (40:1) ratios of n-6 to n-3 fatty acids in combination with 3 concentrations of all rac-alpha-tocopheryl acetate (low, 17 mg/kg of food; medium, 101 mg/kg; high, 447 mg/kg). Dogs were inoculated twice with a keyhole limpet hemocyanin suspension at 13 and 15 weeks. RESULTS: After 12 weeks, dogs consuming low concentrations of alpha-tocopheryl acetate had lower percentages of CD8+ T cells, compared with dogs consuming medium or high alpha-tocopheryl acetate concentrations. Also, dogs consuming low alpha-tocopheryl acetate concentrations had higher CD4+ to CD8+ T cell ratios. On day 4 of week 15, the percentage of CD8+ T cells was highest in dogs fed medium concentrations of alpha-tocopheryl acetate, compared with other dogs; however, the CD4+ to CD8+ T cell ratio was higher only in dogs fed low concentrations of alpha-tocopheryl acetate with high concentrations of n-3 fatty acids. Dogs consuming low concentrations of n-3 fatty acids with medium concentrations of alpha-tocopheryl acetate had the largest delayed-type hypersensitivity (DTH) skin test response. CONCLUSIONS AND CLINICAL RELEVANCE: An optimum amount of dietary alpha-tocopheryl acetate concentration, regardless of the dietary n-6 to n-3 fatty acid ratio, stimulates the CD8+ T cell population. Effects of an optimum amount of dietary alpha-tocopheryl acetate concentration on the DTH response are blunted by dietary n-3 fatty acids.     

Effect of a dietary n-6 polyunsaturated fatty acid supplement on distinct immune functions of goats

The aim of this study was to investigate whether dietary n-6 polyunsaturated fatty acids (PUFA) alter immune functions as lymphocyte blastogenesis, expression of lymphocyte and monocyte markers, and cell adhesion molecules of the integrin family in goats. Dutch White castrated male goats received a diet either rich in olive oil (control group, n = 4) or rich in corn oil (test group, n = 4) over a period of 3 weeks. The animals in the test group had significantly higher linoleic acid (LA, 18:2n-6) levels in plasma on days 7, 14 and 21 of the diet than control animals. This was also true for washed erythrocyte membranes at day 21. A significant reduction in the percentage of alpha-4 integrin (CD49d) expressing lymphocytes was observed in goats fed LA rich corn oil at day 21. However, no changes were observed in either lymphocyte proliferative responses to ConA and PHA or the expression of other lymphocyte/monocyte markers. In conclusion, feeding corn oil rich in LA caused significant increases in the proportion of LA in the fatty acid composition of plasma and erythrocyte membranes and was accompanied by a significant decrease of the adhesion molecule alpha-4 integrin (CD49d) on lymphocytes but not on monocytes.     

Effects of dietary n-6:n-3 fatty acid ratio on feed intake, digestibility, and fatty acid profiles of the ruminal contents, liver, and muscle of growing lambs

This study investigated the effect of modifying the n-6:n-3 fatty acid ratio (FAR) of diets using linseed, soybean, and cottonseed oils on apparent digestibility, ruminal fermentation characteristics, growth performance, key circulating hormones, and the fatty acid profile of ruminal digesta, liver, and fore-shank muscle of growing lambs fed a high concentrate diet. Forty individually housed Katadhin Dorper lambs (average of 20.0 kg of BW) were fed Bermudagrass hay in ad libitum amounts and concentrates at 3.7% of BW daily. The concentrate contained 68.9% corn, 23.8% soybean meal, 3.3% limestone, and 4.0% oil supplements (DM basis). The treatments consisted of dietary n-6:n-3 FAR of 2.3:1, 8.8:1, 12.8:1, and 15.6:1. After feeding for 35 d in metabolism crates, lambs were slaughtered 15 h after feeding, and samples of ruminal digesta, blood, liver, and foreshank tissue were collected. Increasing dietary n-6:n-3 FAR did not affect the intake of DM nor the apparent digestibility of DM, ether extract, NDF, or ADF, but did increase apparent digestibility of CP (linear, P < 0.05). Concentrations of ruminal butyrate increased linearly (P < 0.05) with increasing dietary n-6:n-3 FAR, whereas the valerate concentration decreased linearly (P < 0.001). Concentrations of plasma insulin and IGF-I were not affected by dietary n-6:n-3 FAR. Concentrations of C18:3n-3 increased linearly (P < 0.001), whereas that of C18:2n-6 decreased linearly (P < 0.001) in ruminal digesta with decreasing dietary n-6:n-3 FAR. Concentrations of transisomers of fatty acids in ruminal digesta did not change. Proportions of C18:0 in liver and foreshank muscle were unchanged by diet. The proportion of trans11 C18:1 and cis-9 trans11 CLA decreased (P < 0.05) in liver but increased (P < 0.05) in foreshank muscle as dietary n-6:n-3 FAR decreased. Proportions of all measured n-3 fatty acids were greater in liver when diets contained more C18:3n-3 from linseed oil. By decreasing the dietary n-6:n-3 FAR, the proportions of n-6 fatty acids in foreshank muscle decreased dramatically; specifically, C18:2n-6 decreased linearly (P < 0.001) from 28.0 to 16.5% and C20:4n-6 decreased linearly (P < 0.001) from 14.7 to 8.6%. Although feeding a diet that contained more n-3 fatty acids increased the n-3 fatty acid concentration of muscle, the ratio of PUFA to SFA was decreased.     

Effects of dietary ratio of n-6 to n-3 polyunsaturated fatty acids on immunoglobulins,cytokines, fatty acid composition,and performance of lactating sows and suckling piglets

This experiment was conducted to investigate the effects of dietary ratios of n-6:n-3 polyunsaturated fatty acids (PUFA) on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning (26–29 d) and were fed diets containing different ratios of n-6:n-3 PUFA including 3:1, 9:1 and 13:1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation (P > 0.05). Litter size at d 14 and d 21 were tended to increase in 3:1 treatment compared with 9:1 and 13:1 treatments (P < 0.10). Litter weight gain (1.77 kg/d) from d 0 to d 14 was tended to increase in 9:1 groups compared with the other two treatments (P < 0.10). A significant difference was observed for the content of α -linolenic acid, total n-3 PUFA, and the ratio of n-6:n-3 PUFA in the colostrum, milk, and piglets plasma (P < 0.01). The effects of different ratios of n-6:n-3 PUFA in sow diets on colostrum, milk, and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum (P > 0.05). A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM (P < 0.01) concentrations in piglet plasma at d14 and a significant difference for IgG(P < 0.05) was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3:1 compared with 13:1 group (P < 0.01).In summary, the current study demonstrated that altering the ratio of n-6:n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average daily gain and improve the immune status of piglets when dietary ratio of n-6:n-3 PUFA was 9:1.     

Effect of n-3 fatty acid ratio and dose on clinical manifestations,plasma fatty acids and inflammatory mediators in dogs with pruritus

The use of n-3 fatty acids is often recommended to manage pruritus. The purpose of this study was to determine the effect of various doses of n-3 fatty acids at different n-6:n-3 ratios on plasma fatty acids, clinical response and inflammatory mediators in pruritic dogs. After baseline assessment, dogs were randomly assigned to receive diets varying in both total n-3 and n-6 fatty acid dose and n-6:n-3 ratio. The total clinical score decreased significantly in all four diet groups after 8 weeks with no difference between groups. Plasma fatty acid changes generally mirrored the fatty acid content of the test diets, although alterations appeared to depend on both the dose of n-3 fatty acids and the n-6:n-3 ratio. In this clinical trial, which controlled dietary intake of fatty acids, n-3 fatty acid supplementation did not appear to have an added benefit on clinical signs over thorough clinical management.     

Platelet function in dogs treated for lymphoma and hemangiosarcoma and supplemented with dietary n-3 fatty acids

A prospective randomized, double-blind clinical trial was performed to test the hypothesis that dogs with malignancies that are supplemented with n-3 fatty acids do not have clinical or laboratory evidence of coagulation disorders or altered platelet function when compared with unsupplemented dogs with similar malignancies. Thirteen dogs with hemangiosarcoma and 66 dogs with lymphoma were evaluated. Coagulation status of the dogs with lymphoma and hemangiosarcoma was evaluated with prothrombin time, partial thromboplastin time, platelet count, and in vitro platelet aggregometry using the whole-blood method. These tests were performed at 5 time points: before beginning the diet (week 0), at weeks 3, 15, and 21, and at 1 year or when progressive disease was evident. Alterations in platelet function in dogs receiving a diet supplemented with dietary n-3 fatty acids were not identified when compared to dogs fed a control diet. Dietary n-3 fatty acid supplementation using this dosage and ratio in dogs with lymphoma or hemangiosarcoma did not induce clinically significant hemorrhage in these animals. Therefore, supplementation with n-3 fatty acids did not result in clinical or laboratory evidence relating to uncontrolled hemorrhage in these dogs.     

Effect of dietary modification of muscle long-chain n-3 fatty acid on plasma insulin and lipid metabolites, carcass traits, and fat deposition in lambs

In a previous study we showed that feeding fish meal significantly increased muscle long chain n-3 fatty acids (FA) and hot carcass weight. In this study we compared the effect of fish meal and fish oil on increasing muscle long-chain FA. We also investigated whether the increase in carcass weight was due to the effect of dietary enrichment of muscle long-chain n-3 FA on muscle membrane phospholipids and(or) to rumen by-pass protein provided by fish meal. Forty crossbred ([Merino x Border Leicester] x Poll Dorset) wether lambs between 26 and 33 kg BW were randomly assigned to one of five treatments: 1) basal diet of oaten:lucerne chaff (Basal); 2) Basal + fish meal (9% DM) = FM; 3) Basal + fish oil (1.5% DM) with protected sunflower meal (9% DM ) = FOSMP; 4) Basal + fish oil (1.5% DM) = FO; or 5) Basal + protected sunflower meal (10.5% DM) = SMP. Daily intake of ME (9.60 - 10.5 MJ ME/d) and CP (150 to 168 g/d) in all treatments was kept similar by varying the ratio of oaten:lucerne chaff and by feeding the animals at 90% ad libitum intake. Blood samples were collected at the start of the experiment and on the day (d 42) prior to slaughter. Lambs were then slaughtered at a commercial abattoir. At 24 h postmortem carcass traits were measured and longissimus thoracis muscle taken for analysis of FA of phospholipid and triglyceride fractions. Lambs fed FO and FOSMP showed a marked increase in muscle longchain n-3 FA (P < 0.001) and a reduction in magnitude of the rise in insulin concentration (P < 0.001) after feeding compared with lambs fed Basal and SMP diets. Lambs in FM had a moderate increase (P < 0.001) in muscle long-chain n-3 FA content. Compared with Basal diet, both plasma total cholesterol (P < 0.02) and high-density lipoprotein cholesterol (P < 0.001) levels were greater in SMP and less in FO and FOSMP treatments. The i.m. fat content was reduced (P < 0.05) in FM and FO treatments, but carcass weight was increased only with fish meal (P < 0.03). Adding SMP to FO produced muscle with an intermediate level of i.m. fat, whereas muscle long-chain n-3 FA, i.m. fat, and insulin concentration were unchanged with SMP treatment. These results indicate that an increase in carcass weight in FM may be due to the supply of ruminally undegraded protein. They also suggest that fish oil along with fish meal can increase long-chain n-3 FA content in phospholipid of muscle membrane. This may be associated with reduced i.m. fat content and altered insulin action and lipoprotein metabolism.     

Consequences of eicosapentaenoic acid (n-3) and arachidonic acid (n-6) supplementation on mast cell mediators

Mast cells are important players in the pathogenesis of atopic diseases. These cells release immediate-phase and late-phase mediators of inflammation. Fatty acids are incorporated in cellular membranes and therefore seem to influence mediator production and release. A study was conducted to assess the effects of eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (AA, 20:4n-6) on mast cell mediators in a canine mastocytoma cell line (C2). Cells were cultured in a basic medium (Dulbecco's modified Eagle's medium/HAM's F12 1 : 1, DEH), DEH supplemented with 14.0 microm EPA (DEH-EPA) or 14 microm AA (DEH-AA). The DEH-AA cultured cells had increased spontaneous and mastoparan-stimulated PGE2 production and histamine release. Furthermore, the tryptase activity was increased. The DEH-EPA cultured cells rendered elevated levels of PGE2 and histamine release compared with DEH only after stimulation. These levels were significantly lower in comparison to DEH-AA. The increased PGE2 production of C2 cultured in DEH-AA is the consequence of the AA enrichment, because AA is the precursor of PGE2. However, the different effects by AA and EPA on mast cell mediators possibly reflect the higher susceptibility of long chain polyunsaturated fatty acids (PUFA) to undergo lipid peroxidation, because it is known that altered cellular redox state influences mediator production and release.     

Analysis of epidermal lipids in normal and atopic dogs,before and after administration of an oral omega-6/omega-3 fatty acid feed supplement. A pilot study

Alterations of the lipid expression in the skin of human and canine atopic subjects may be one of the key factors in the disease development. We have analyzed the ultrastructure of the clinically uninvolved skin of atopic dogs and compared it with the lipid composition of their tape-stripped stratum corneum (SC). The effect of a 2 month treatment of atopic dogs by food supplementation with a mixture of essential fatty acids was evaluated on skin samples taken before and after the treatment period. Electron microscopy revealed that the non-lesional skin of atopic dogs exhibited an abnormal and largely incomplete structure of the lamellar lipids with little cohesion between the corneocyte strata. The SC of atopic dogs was characterized by a significant decrease in the lipid content when compared to the healthy controls. Following oral supplementation with the mixture of essential fatty acids, the overall lipid content of the SC markedly increased. This feature was observed both with the free and, most importantly, with the protein-bound lipids (cholesterol, fatty acids and ceramides), the latter constituting the corneocyte-bound scaffold for ordinate organisation of the extracellular lipid bi-layers. Indeed, the semi-quantitative electron microscopy study revealed that the treatment resulted in a significantly improved organization of the lamellar lipids in the lower SC, comparable to that of the healthy dogs. Our results indicate the potential interest of long-term alimentary supplementation with omega-6 and omega-3 essential fatty acids in canine atopic dermatitis.     

Effect of dietary omega-3 fatty acids on red blood cell lipid composition and plasma metabolites in the cockatiel, Nymphicus hollandicus

Although dietary n-3 fatty acids have been extensively studied in poultry, they have not yet been prospectively investigated in psittacines, despite potential benefits for preventing and treating atherosclerosis, osteoarthritis, and other chronic disease processes. The objectives of this study were to investigate the incorporation of dietary n-3 fatty acids into red blood cells (RBC) and to determine the effects of supplementation of psittacine diets with fish or flax oil on plasma lipids and lipoproteins in the cockatiel. Adult cockatiels were fed a custom-formulated diet containing either 4% (wt/wt, as-fed) beef tallow (CON), 3% fish oil + 1% tallow (FSH), or 3.5% flax oil + 0.5% tallow (FLX; n = 20 per diet group). Baseline measurements were obtained for RBC fatty acid composition, triacylglycerides (TAG), and cholesterol. After 8 to 13 wk on the study diets, plasma chemistry profiles, lipoprotein density profiles, and RBC fatty acid composition were determined. At 8 wk, total plasma cholesterol was least in FSH birds (P < 0.05) and TAG concentrations were less in FSH birds than FLX birds (P < 0.05). Total n-3 fatty acids, docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid were markedly greater in the RBC of FSH birds than FLX or CON birds (P < 0.05). Alpha linolenic acid was greatest in FLX (P < 0.05). Initial and final BW, and nonlipid plasma chemistry values did not differ among diet groups. No adverse effects of dietary supplementation of cockatiels with 3.5% flax oil or 3% fish oil were observed during the 13-wk feeding period. Although fish and flax oils provided similar total n-3 PUFA to the diets, fish oil caused greater reductions in cholesterol and TAG, and greater total RBC n-3 incorporation. Thus, dietary modification of psittacine diets with long chain n-3 PUFA from fish oil appears safe and may be beneficial to these long-lived companion birds.     

Effects of dietary n-6 or n-3 polyunsaturated fatty acids protected or not against ruminal hydrogenation on plasma lipids and their susceptibility to peroxidation in fattening steers

Two experiments were conducted using crossbred Salers x Charolais fattening steers fed diets enriched with no supplemental oilseeds or oils rich in either n-6 PUFA (from sunflower seeds) or n-3 PUFA (from linseeds) provided either as seeds incorporated in the diet (i.e., not protected from ruminal bacterial hydrogenation) or by chronic infusion into the duodenum (protected form). In the Sunflower experiment, animals (initial age = 454 +/- 20 d; initial BW = 528 +/- 36 kg) received a control diet for 70 d (CS, n = six) consisting of hay and concentrate, or the same basal diet supplemented with sunflower oil (4% of dietary DM), either fed as seeds (SS, n = six) or infused into the duodenum (ISO, n = six). The same experimental design was applied to animals (initial age = 412 +/- 33 d; initial BW = 536 +/- 33 kg) used in the Linseed experiment (CL, LS, and ILO; n = 8 per group). For all animals, blood was sampled every 15 d during 70 d. In both trials, a significant diet x time interaction (P < 0.001) was detected for plasma concentrations of apolipoprotein A-I, phospholipids, and free and esterified cholesterol, with values increasing with time during administration of the PUFA-rich diets being more evident with ISO and ILO diets. Plasma fatty acids were altered with oil infusions, with increased concentrations of n-6 (1.6-fold; P < 0.05) and n-3 PUFA (4.5-fold; P < 0.05) and of their respective indicies of peroxidizability (1.2- and 1.5-fold with Diets ISO and ILO, respectively; P < 0.05). In vitro copper-induced peroxidation of lipids revealed a decreased length of the lag phase in the process of conjugated diene generation by 48% (P < 0.005) with the ILO diet, indicating less resistance against peroxidation than in control steers. Compared with CS, the ISO treatment increased plasma alpha-tocopherol (x2.5; P < 0.05) leading to similar resistance against peroxidation. After depletion of this vitamin, the rates of peroxidation and production of conjugated dienes were greater (twofold; P < 0.05) with the ISO and ILO diets than with the others. In conclusion, infusion of sunflower or linseed oil into the duodenum altered the composition and distribution of plasma lipids and increased the plasma concentration of PUFA. The sensitivity of plasma PUFA to peroxidation depends on the plasma level of antioxidants, especially vitamin E, a nutrient important both for the health of animals and for the stability of the blood lipids until their tissue deposit.     

Effect of an omega-3/omega-6 fatty acid-containing commercial lamb and rice diet on pruritus in atopic dogs: results of a single-blinded study.

A commercial, lamb and rice, dog food with an omega-6:omega-3 fatty acid ratio of 5.5:1 was fed in a single-blinded, self-controlled clinical trial to 18 atopic dogs. The pruritus in 8 of these dogs (44.4%) was satisfactorily controlled within 7 to 21 d, returned within 3 to 14 d after the diet was withdrawn, and was again controlled when the diet was reinstated. Plasma and skin levels of examined fatty acids changed in all 18 dogs when their diet was switched to the test diet. Dogs responding to the test diet had a different pattern of fatty acid change as compared to the dogs which failed to respond to the diet, suggesting that there are subsets of atopic dogs with different fatty acid metabolism capabilities.     

Effect of oil containing n-3 polyunsaturated fatty acids (PUFA) on the immune response and growth factors in piglets.

Oral administration of n-3 polyunsaturated fatty acids (PUFA) to piglets slightly enhances the immune response. As compared to the control, in the experimental piglets the absolute values of monocytes in the peripheral blood were significantly increased (P < 0.05), while the metabolic activity of phagocytes and the number of lymphocytes within the individual subpopulations were slightly higher. The level of growth factors, determined on the basis of somatomedin in the blood serum, was significantly higher in the experimental group (P < 0.05). n-3 PUFA interfere with the synthesis of prostaglandins and influence the metabolism of fatty acids. This finding may contribute to the therapy of inflammatory processes influencing immune and growth factors in piglets.     

Effect of dietary flaxseed, flax oil and n-3 fatty acid supplement on hepatic and plasma characteristics relevant to fatty liver haemorrhagic syndrome in laying hens

1. Two experiments were carried out to investigate the effect of dietary flaxseed, flax oil and n-3 fatty acid supplementation (Dry n-3) on hepatic fat content, plasma triglycerides, hepatic haemorrhage score, egg production, food intake and body weight in an inbred line of Single Comb White Leghorns (UCD-003) predisposed to fatty liver haemorrhagic syndrome (FLHS) and normal SCWL hens. 2. Feeding diets containing 100 g/kg ground flaxseed, 40 g/kg flax oil, or 100 g/kg Dry n-3 reduced body weight and significantly reduced hepatic fat content compared to feeding the control diet with animal and vegetable oil as a fat source. 3. Hepatic malondialdehyde, an indicator of lipid peroxidation within the liver, was not significantly affected by dietary treatment. 4. Normal SCWL hens tended to have higher egg production, greater body weight, greater food intake and higher blood triglyceride concentrations than UCD-003 hens, although the strain effects were not significant. Liver weight as a percent of body weight was significantly lower in normal SCWL hens. Treatments by strain interactions were not found. 5. The result suggested that dietary flaxseed, flax oil and Dry n-3 decrease hepatic fat content and reduce body weight, 2 of the predisposing factors believed to contribute to FLHS onset. However, haemorrhages were still apparent in both strains regardless of treatment, indicating that other unknown underlying mechanisms may also be responsible for FLHS.     

Parental dietary arachidonic acid altered serum fatty acid profile,hepatic antioxidant capacity,and lipid metabolism in domestic pigeons (Columba livia)

The aim of this study was to explore the effects of dietary arachidonic acid on serum fatty acid profile, hepatic antioxidant capacity, and lipid metabolism in pigeon squabs by supplementing arachidonic acid in their parental diets. A completely randomized design was conducted consisting of control group, 0.05% dietary arachidonic acid supplementation group, 0.1% dietary arachidonic acid supplementation group, and 0.2% dietary arachidonic acid supplementation group. Six randomly selected squabs from each group were sampled on Day 21 post-hatch. Results indicated that moderate level (0.05%) of arachidonic acid in parental diets for pigeon squabs improved lipid metabolism via regulation on serum lipid profile and fatty acid composition and tended to reduce hepatic lipid accumulation in the premise of negligible damage to antioxidant status. Unfortunately, excessive parental supplementation of dietary arachidonic acid might be harmful to squab health. The regulatory effects of arachidonic acid were sensitive to the arachidonic acid doses. In conclusion, parental dietary arachidonic acid at 0.05% could be beneficial for squabs to maintain health as reflective aspects in ameliorative serum lipid profile, fatty acid composition, and reduced hepatic lipid accumulation.