Effect of hens fed dietary flaxseed with and without a fatty liver supplement on hepatic,plasma and production characteristics relevant to fatty liver haemorrhagic syndrome in laying hens

1. Two long-term experiments were conducted with Single Comb White Leghorn (SCWL) hens (line UCD-003) predisposed to fatty liver haemorrhagic syndrome (FLHS). The first investigated the effect of adding a fatty liver supplement to the diet of laying hens prior to the onset of lay, and continuing either until peak production or throughout 39 weeks into lay. The second experiment, lasting 9 months into lay, investigated the effect of adding a fatty liver supplement, with or without 100 g/kg dietary ground flaxseed, to the diet. Body weight, feed intake, plasma triglycerides (in experiment 2) and egg production were measured throughout the experiment. Liver weight, liver fat content, liver malondialdehyde (MDA) content and liver haemorrhage score and fatty acid content of liver fat (in experiment 2) were measured at the end of each experiment. 2. In experiment 1, hens given diets containing the fatty liver supplement had higher egg production and eggshell strength, but there was no difference in liver parameters including MDA content or haemorrhage score compared with controls. 3. At the end of experiment 2, hens on 100 g/kg flaxseed diets had lower body weight, liver weight, liver dry matter and fat content, and plasma triglyceride concentrations than hens given the control diets. 4. Liver haemorrhage score was positively correlated with liver weight, but not with liver fat content, plasma triglyceride concentration or liver MDA content. This suggests that reducing the liver lipid content or feeding fatty liver supplements may not be as effective in controlling FLHS as controlling the size of the liver.     

Improving effect of dietary soybean phospholipids supplement on hepatic and serum indexes relevant to fatty liver hemorrhagic syndrome in laying hens

In order to investigate the effect of dietary soybean phospholipid supplement on hepatic and serum indexes relevant to fatty liver hemorrhagic syndrome (FLHS) in layers, 135 300‐day‐old Hyline Brown layers were randomly divided into three groups (control, pathology and prevention), and each group had 45 layers with three replicates. Birds in the three groups were respectively fed the control diet, high‐energy low‐protein diet and high‐energy high‐protein diet affixed with 3% soybean phospholipid instead of maize. Results showed in the 30th day, birds’ livers in the pathology group became yellowish, enlarged in size and had hemorrhagic spots, while the prevention and control groups’ layers did not have such pathological changes. Contents of triglyceride, total cholesterol, low‐density lipoprotein – cholesterol, non‐esterified fatty acid and malondialdehyde in serum or liver homogenate in prevention and control groups were remarkably lower than those in the pathology group (P < 0.05 or P < 0.01), as with the activities of glutamic oxalacetic transaminase and glutamic‐pyruvic transaminase (P < 0.01); high‐density lipoprotein – cholesterol value was strikingly higher than that of the pathology group (P < 0.01). It is suggested dietary soybean phospholipids supplement may effectively improve hepatic and blood indexes relevant to FLHS, which provides a new point for preventing FLHS occurrence rate in laying flocks and treating human non‐alcohol fatty liver disease.     

Comparison of the coagulation profile of fatty liver haemorrhagic syndrome-susceptible laying hens and normal laying hens

1. The rate of thrombin generation in plasma from Fatty Liver Haemorrhagic Syndrome-susceptible laying hens (FLHS, UCD-003) is more rapid than in plasma from age-matched normal Single Comb White Leghorn (SCWL) laying hens. 2. The rate of thrombin generation in plasma was determined by measuring the biological activity of the specific coagulation proteins, Factors V, VII, VIII, IX and X. 3. The higher activity of Factors V, VII and X in FLHS-susceptible laying hens compared with normal SCWL hens remained consistent after plasma lipid concentrations were reduced. 4. Analysis of the fatty acid composition of plasma phospholipids showed that in normal SCWL laying hens phosphatidylethanolamine contained C18:3n3 whereas it contained C20:3n3 in FLHS-susceptible laying hens. 5. The results suggest that alterations in the composition of the phospholipids that are essential cofactors in the biochemical reactions involved in thrombin generation may be a contributing factor in the development of FLHS.     

Effect of dietary Rhodobacter capsulatus on lipid fractions and egg-yolk fatty acid composition in laying hens

The present study was conducted to investigate the effect of dietary Rhodobacter capsulatus on lipid fractions and egg‐yolk fatty acid composition in laying hens. Thirty‐six laying hens (30 weeks old) were randomly assigned into two dietary groups fed diets with (0.04%) or without (control) R. capsulatus for a 60‐day feeding trial. Dietary R. capsulatus decreased (p < 0.05) serum and hepatic cholesterol and increased (p < 0.05) the excreta cholesterol, and resultant lower (p < 0.05) cholesterol contents in egg yolk. The concentration of polyunsaturated fatty acids (PUFA) and ratio to saturated fatty acids in egg yolk was improved (p < 0.05) by dietary R. capsulatus. The concentration of hepatic bile acid was increased (p < 0.05) and excreta bile acid was decreased (p < 0.01) in the laying hens fed R. capsulatus diet. The incorporation of 1‐¹⁴C‐palmitic acid into hepatic lipids and lipid fractions was increased (p < 0.05) in laying hens fed R. capsulatus diet. Moreover, dietary R. capsulatus did not appear to cause any adverse effects on laying hen performances. Therefore, dietary supplementation of R. capsulatus in layer diets may be a feasible means of producing eggs with lower cholesterol and higher PUFA contents for health conscious consumers.     

Fatty haemorrhagic liver syndrome in laying hens on diets supplemented with rapeseed products.

Livers of laying hens of Hy-Line No 934E on low erucic acid rapeseed meals and rapeseed oil were studied. Gross lesions in the livers of hens on experimental diets were moderate to severe fatty degeneration, focal necrosis and moderate to severe haemorrhage. Histological examination revealed oedematous foci and lysis of hepatocytes along with large amounts of lipid droplets in the necrotic lesions. Necrotic lesions were not always associated with large haemorrhages. Connective tissue infiltration of older degenerative and haemorrhagic lesions was not extensive. Abdominal haemorrhage from livers occurred when extensive necrosis in the form of hepatocyte lysis and some vascular changes were present, suggesting hepatocytic degeneration caused by toxic products or their metabolites present in rapeseed by-products.     

Effect of type and level of fish oil supplementation on yolk fat composition and n-3 fatty acids retention efficiency in laying hens

1. Laying hen performance and yolk fat fatty acid (FA) concentrations were evaluated with respect to the inclusion in the diet of different sources and levels of marine fish oil (MFO). 2. Twelve diets were arranged factorially, with three sources (MFO1, MFO2_EPA, MFO3_DHA) and four levels of inclusion (15, 30, 45 and 60 g/kg) of MFO. 3. Type of diet had little effect on egg production traits, although laying rate and shell thickness slightly decreased at the highest level of MFO supplementation. 4. An increase in level of inclusion of MFO from 15 to 60 g/kg linearly increased concentrations of C20:5 n-3, C22:5 n-3, C22:6 n-3 and total n-3 FA in yolk fat, but greatly impaired their efficiencies of deposition (g retained/g ingested). 5. An interaction between type and dietary concentration of MFO was found, as the reduction in efficiency of retention of n-3 FA in egg fat with level of MFO was less when the proportion of n-3 in total FA decreased or when that of DHA in total n-3 FA increased. 6. MFO3_ DHA was more efficiently used for total n-3 FA yolk deposition than MFO2_EPA at a similar total n-3 FA intake. 7. Dietary inclusion of MFO reduced LC n-6 FA yolk fat content, which additionally decreased the ratio between total n-6 and total n-3 FA in egg fat. 8. Regression equations were calculated in order to predict efficiency of retention and n-3 FA concentration of yolk fat in the range of diets studied.     

Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil

Effects of defatted microalgae (DFA) on fatty acid composition of eggs and tissues of hens have not been well studied. This experiment was to determine how low concentrations of supplemental DFA in the presence or absence of flaxseed oil (FO) altered fatty acid profiles of egg yolk, liver, adipose tissue, and plasma of layers. A total of 60 Shaver Leghorn layer hens (individually caged, 20-wk old) were allotted into 6 groups (n = 10) and fed a corn/soybean meal basal diet containing 0, 3, or 5% DFA and 0 (1.5% corn oil, CO) or 1.5% FO for 6 wk. BW, ADFI, egg production rate, and egg component weights were not affected by any of the dietary treatments at various time points, but egg yolk color was changed (P < 0.05) with increasing concentrations of DFA. The concentration of n-3 fatty acids in egg yolk and plasma were elevated by FO up to 9-fold (P < 0.05) starting at wk 1 or 2, and 39 to 83% (P < 0.05) by DFA. Supplemental DFA improved (P < 0.05) n-6/n-3 fatty acid ratios in egg yolk and plasma from 13 to 23 and 7 to 13, respectively, only in hens fed diets without FO. Fatty acid profiles of liver and adipose tissue (at wk 6) displayed responses to supplemental DFA and FO similar to those of egg yolk or plasma. In conclusion, supplemental 3 or 5% DFA caused moderate enrichments of n-3 fatty acids and decreased the n6/n3 fatty acid ratios of egg yolk and tissues in hens fed diets without FO.     

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 flaxseed oil supplementation on equine plasma fatty acid concentrations and whole blood platelet aggregation

An 18-week feeding trial was performed to investigate the effects of an omega-3 (n-3) fatty acid-enriched ration on plasma fatty acid concentrations and platelet aggregation in healthy horses. Flaxseed oil served as the source of the n-3 fatty acid alpha-linolenic acid (ALA). Twelve horses were fed dietary maintenance requirements using a complete pelleted ration (80%) and timothy grass hay (20%) for a 2-week acclimation period before being randomly assigned either to a treatment (group 1) or control (group 2) group. Group 2 horses (n = 6) were fed the diet described in the acclimation period, whereas group I horses (n = 6) were fed a 10% flaxseed oil-enriched complete pellet (80%) and grass hay (20%). Biological samples and physical measurements were collected at one point during the acclimation period (week 0) and every 4 weeks thereafter (weeks 4, 8, 12, and 16). Body weight, CBC (including platelet count), plasma fibrinogen. electrolyte (Na, K, and Cl) concentrations, and biochemical profile enzyme activities (aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, and creatine kinase) did not change markedly with diet. Platelet aggregation was not altered by the supplementation of flaxseed oil in these healthy horses, although increases in plasma cis-polyunsaturated 18-carbon fatty acids C18:3; n-3 (ALA) and C18:2; n-6 (linoleic acid), biologically active C20:5; n-3 (eicosapentaenoic acid [EPA]), and malondialdehyde (MDA) were evident. There were no marked decreases in C20:4; n-6 (arachidonic acid [AA]) or increases in C22:6; n-3 (docosahexaenoic acid [DHA]), signifying that flaxseed oil may have had a high percentage of omega-6 (n-6) fatty acids as well as n-3 fatty acids, and this relatively high n-6: n-3 fatty acid ratio may have affected the biochemical effect of n-3 fatty acids. In healthy horses supplemented with flaxseed oil, platelet aggregation was not altered, which may have been due to the limited biologic effect in healthy subjects or the inability of flaxseed oil to induce the necessary biochemical effect of replacing n-6 fatty acids with n-3 types.     

Failure of oestradiol administration to induce fatty liver haemorrhagic syndrome in the laying hen

Studies were carried out to investigate whether the administration of oestradiol to laying hens induced fatty liver-haemorrhagic syndrome (FLHS). Short term oestradiol administration (up to 6 d) significantly increased liver size and plasma lipid concentration but had no effect on liver lipid concentration or hepatic lipogenic enzyme activities. Longer-term hormone treatment (up to 28 d) again significantly increased liver size and plasma lipid concentration. Liver lipid concentration was substantially reduced and lipogenic enzyme activity significantly reduced in oestradiol-treated birds. These effects had some similarities to those seen in oestrogenised immature birds and were additive to the effects of endogenous oestrogen in the laying bird. There were no deaths from FLHS and oestradiol treatment did not cause liver haemorrhages or affect egg production.     

不同n-3/n-6多不饱和脂肪酸对产蛋鸡免疫功能的影响

选用 16 8只 30周龄海兰褐蛋鸡 ,研究不同 n- 3/ n- 6多不饱和脂肪酸 (PUFA)对产蛋鸡免疫功能的影响。 n- 3/ n- 6比值分别为 1∶ 1,1∶ 4 ,1∶ 8,1∶ 16 ,1∶ 32 ,维生素 E添加水平为 30 mg/ kg和 30 0 mg/ kg。在试验开始后的第 5周和第 7周给每个处理组中的 6只鸡注射牛血清白蛋白 (BSA) ,并分别于注射后第 10天翅静脉采血 ,测定 BSA抗体效价。测定第 5周及第 10周时外周全血淋巴细胞增殖速度和蛋黄 Ig Y水平。在第 9周给每个处理中 4只鸡注射脂多糖 (L PS) ,并于注射后 6 h,12 h,2 4 h后采血测定血浆中抗体 Ig G水平。试验结果表明 ,随着日粮中 n- 3/ n- 6比值的下降 ,BSA抗体效价显著下降 (P<0 .0 5 ) ,全血淋巴细胞增殖速度在第 5周时有上升的趋势 ,但差异不显著 ,而在第 10周时显著上升 (P<0 .0 5 )。蛋黄中抗体 Ig Y水平有随 n- 3/ n- 6比值下降而下降的趋势。注射 L PS后各时间点血浆 Ig G浓度随着 n- 3/ n- 6比值下降而下降。当日粮中 n- 3/ n- 6比值在 1∶ 1～ 1∶ 8之间时 ,产蛋鸡具有较好的免疫功能     

Effects of a high energy and low protein diet on hepatic and plasma characteristics and Cidea and Cidec mRNA expression in liver and adipose tissue of laying hens with fatty liver hemorrhagic syndrome

Cidea and Cidec are two members of Cell death‐inducing DNA fragmentation factor‐alpha‐like effector family proteins, which could be involved in lipid or fat metabolism. To better understand the roles of Cidea and Cidec in fatty liver hemorrhagic syndrome (FLHS), 150 healthy 155‐day‐old Hyline Brown laying hens were randomly divided into control group (fed with basic diet) and experimental group (fed with high‐energy low‐protein [HELP] diet). Analysis of the liver by tissue sectioning and hematoxylin and eosin staining showed that the HELP diet induced micro‐vesicular steatosis in laying hens. Subsequently, based on the liver color scores and the range of lipid accumulation observed in histological examination, we classified livers with <50% vacuolization as mild FLHS and >50% as severe FLHS. The results showed that the levels of Cidea and Cidec mRNA expression were markedly elevated in the liver and adipose tissues with FLHS and the levels of Cidea and Cidec mRNA expression in the liver with severe FLHS were significantly higher than that in the liver with mild FLHS. Thus, the present study revealed that the Cidea and Cidec genes may be involved in pathways of FLHS formation.     

Effect of dietary inclusion of ascorbic acid and palm oil on the performance of laying hens in a hot tropical environment

1. Two experiments were conducted to evaluate the effects of including ascorbic acid (AA), palm oil or a combination of both in the diets of laying hens during the hot months in a tropical environment.

2. The inclusion of AA improved egg production, food intake and efficiency of utilisation, and decreased the cost of food per kg egg. The addition of 400 mg AA/kg diet gave the most efficient performance.

3. Palm oil inclusion reduced the effect of heat stress and increased egg production, egg weight, food intake and efficiency of utilisation.

4. When 200 mg AA and 50 g palm oil/kg were used, additive responses were obtained with further improvements in egg production, food cost and efficiency.

5. Ascorbic acid and palm oil when fed alone or in combination reduced the incidence of cracked eggs.

6. Thus, 400 mg ascorbic acid/kg of diet, 50 g palm oil or 200 mg AA plus 50 g palm oil/kg diet ameliorated the effects of heat stress in laying hens.     

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.