Tissue fatty acid composition and estimated ∆ desaturase activity after castration in chicken broilers fed with linseed or sunflower oil

The aims of this study were to investigate the influence of the short‐term addition of sunflower and linseed oil and castration on fatty acid composition and desaturation indexes in chicken broilers. Forty‐eight male Ross 308 chicken broilers were supplemented with 5% of sunflower or linseed oil. The four experimental groups were linseed oil supplementation and castration (LC), linseed oil without castration (LN), sunflower oil and castration (SC) and sunflower oil without castration (SN). There was no significant influence of castration or oil supplement on live weights, weight gain, feed intake or feed conversion. Castration resulted in an increase in polyunsaturated fatty acids (PUFA), total n3, n6, measured desaturation indexes and a decrease in the saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) content of abdominal fat. In breast muscle, castration increased PUFA and 18:3n3 values, while in the liver tissue, castration did not influence the parameters measured. Linseed oil supplementation significantly increased 18:3n3, n3 long chain polyunsaturated fatty acids (LC PUFA), total n3 and decreased total n6, n6/n3 ratio, and 20:4n6 content. Values for 20:4n6 were the highest in SC and the lowest in the LC group. Linseed oil also significantly decreased ?5 and ?4 desaturation indexes in the thighs and ?5 and ?5, 6 in abdominal fat and the liver. These results suggest that short‐term supplementation of basal diet with 5% of linseed oil could significantly increase n3 LC PUFA and decrease n6/n3 ratio content in the edible tissues of chicken broilers, without adverse effects on growth performance. Meanwhile, castration only improved fatty acid profile in abdominal fat, which is not nutritionally important. The interactions observed between basal diet, supplemented oil, sex hormones and other non‐nutritional factors must be elucidated in future trials in order to correctly predict the nutritional value of linseed‐fed poultry.     

Genotype,production system and sex effects on fatty acid composition of meat from goat kids

Two trials were performed to assess the meat fatty acid profile of goat kids from different genotypes, production systems and sex. In the first trial, genotype effect was determined in 24 suckling male kids from Turkish Saanen, Maltese and Gokceada breeds. In the second trial, male and female Gokceada Goat kids were used to compare the effect of extensive and semi‐intensive production systems on fatty acid composition of meat. Significant genotype effect was observed in the percentages of myristic acid (C14:0), palmitic acid (C16:0), oleic acid (C18:1 n‐9), linolenic acid (C18:3 n‐3), arachidonic acid (C20:4 n‐6) and docosahexaenoic acid (C22:6 n‐3), despite no differences on the ratios of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) and n‐6/n‐3 (P > 0.05). The effect of production system had also significant effects on fatty acids, but sex only influenced significantly stearic acid (C18:0), C18:1 n‐9 and C18:3 n‐3 fatty acids and total PUFA level and PUFA/SFA ratio. This study confirms that dairy breeds are prone to produce higher levels of unsaturated fatty acids in their muscle. Meanwhile, meat from Gokceada goat kids, which is one of the indigenous breeds in Turkey, had similar PUFA/SFA and n‐6/n‐3 ratios to Turkish Saanen and Maltase.     

Effect of dietary fish oil on the expression of genes involved in lipid metabolism in liver and skeletal muscle of lactating sows

This study investigated the hypothesis that dietary supplementation of fish oil as a source of n‐3 polyunsaturated fatty acids (PUFA) influences the expression of target genes of sterol regulatory element‐binding proteins (SREBP)‐1 and (SREBP)‐2 involved in triacylglycerol (TAG) synthesis and fatty acid and cholesterol metabolism in the liver, and moreover activates the expression of target genes of peroxisome proliferation‐activated receptor (PPAR)‐α involved in TAG and fatty acid catabolism in liver and skeletal muscle. Twenty lactating sows were fed a control diet or a fish oil diet with either 50 g of a mixture of palm oil and soya bean oil (4:1, w/w) or fish oil per kg. The diet of the fish oil group contained 19.1 g of n‐3 PUFA (mainly 20:5 n‐3 and 22:6 n‐3) per 100 g of total fatty acids, while the diet of the control group contained 2.4 g of n‐3 PUFA (mainly 18:3 n‐3) per 100 g of total fatty acids. The fish oil group had reduced relative mRNA concentrations of various target genes of SREBP‐1 involved in fatty acid and TAG synthesis in comparison with the control group (p < 0.05). Relative mRNA concentrations of target genes of PPARα involved in fatty acid catabolism in both liver and muscle, and mRNA concentrations of target genes of SREBP‐2 involved in cholesterol synthesis and uptake were not influenced by fish oil supplementation. Concentrations of cholesterol and TAG in plasma, fat content of milk and weight gains of litters during the suckling period were not different between the two groups of sows. In conclusion, this study suggests that fish oil has only minor effects on hepatic lipid metabolism, which are non‐critical with respect to milk production in sows.     

番鸭产蛋各期肝脂肪酸组成及AMPK信号通路基因表达研究

旨在探究产蛋各期番鸭肝腺苷酸活化蛋白激酶（AMPK）信号通路基因表达和肝脂肪酸组成,为番鸭肝脂质代谢应答产蛋提供机理研究。本研究选取开产前22周龄、产蛋初期30周龄、产蛋中期40周龄和产蛋末期60周龄母番鸭各15羽,全自动生化仪测定血脂水平,苏木精-伊红（HE）染色和油红O染色观察肝组织学结构,实时荧光定量PCR （qRT-PCR）检测肝AMPK通路基因表达,气相色谱-质谱联用法（GC-MS）检测产蛋各期肝脂肪酸组成。结果表明,总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、甘油三酯（TG）和极低密度脂蛋白胆固醇（VLDL-C）水平在40周龄显著高于22、30和60周龄（P<0.05）;高密度脂蛋白胆固醇（HDL-C）水平在30和40周龄显著低于22和60周龄（P<0.05）。肝HE和油红O染色切片显示,肝在22周龄呈实质状,至产蛋40和60周龄,肝脂滴沉积明显（P<0.05）。AMPKα1在22、30、40和60周龄呈本底低水平表达,并显著低于产蛋各期肉碱脂酰转移酶1（CPT1）和脂肪酸合成酶（FAS）的表达量（P<0.05）,FAS在22、40和60周龄均呈高水平表达（P<0.05）;羟甲基戊二酰辅酶A还原酶（HMGR）、肝细胞核因子4α（HNF4α）、乙酰辅酶A羧化酶1（ACC1）和固醇调控元件结合蛋白-1（SREBP1c）在40周龄表达量显著高于22和30周龄（P<0.05）。肝中饱和脂肪酸（SFA）、单不饱和脂肪酸（MUFA）和多不饱和脂肪酸（PUFA）主要由C16∶0、C18∶0、C18∶1和C20∶2 n-6构成,分别占总脂肪酸含量的32%、16%、30%和9%。C14∶0和C16∶0含量在40周龄显著高于22周龄（P<0.05）;C24∶0、C20∶2 n-6和PUFA含量在60周龄显著高于22和40周龄（P<0.05）。综上,番鸭产蛋期肝通过上调FAS等脂质合成基因表达,合成大量长链脂肪酸,沉积于肝,并增加血脂水平。     

饲喂不同油脂对黄羽肉鸡肌肉组织中脂肪酸组成的影响

选用 8 3日龄的雌性广西黄羽肉鸡 90只 ,随机分成 5组 (每组设 2个重复 ,每个重复 9只 ,共 18只 ) ,研究饲粮中不同油脂对肉鸡肌肉组织脂肪酸组成的影响。 5组饲粮分别含 3%的富含饱和脂肪酸的棕榈油 (PO3组 ,对照组 )、 3% (LO3组 )和 5%的富含α 亚麻酸 (C18:3n 3,ALA)的亚麻油 (LO5组 )、 5%的富含长链n 3脂肪酸 (如C2 0 :5n 3,EPA ;C2 2 :6n 3,DHA)的鱼油 (FO5组 )、 5%的富含亚油酸(C18:2n 6 ,LA)和ALA的火麻仁油 (HO5组 )。饲喂 2 8d,取样测定胸肌和腿肌中的脂肪酸组成。结果表明 :PO3(对照组 )肌肉中的n 6 /n 3脂肪酸比值比例高于其他组 (P <0 0 5) ;与对照组相比 ,LO3组和LO5组以ALA和LA为主的多不饱和脂肪酸 (PUFA)增加 (P <0 0 5) ,ALA和LA在体内可转化为相应的长链脂肪酸 ;FO5组以长链n 3PUFA ,(如EPA、DPA、DHA)为主的PUFA含量增加 (P <0 0 5) ;HO5组以LA为主的n 6脂肪酸高于其他组 (P <0 0 5) ;长链PUFA (如DHA)易沉积于胸肌中 ,而LA ,ALA易沉积于腿肌中。由此可见 ,肉鸡肌肉组织脂肪酸的组成充分反映了饲粮油脂的脂肪酸组成 ,通过饲粮中添加不同脂肪酸组成的油脂可生产富含特定PUFA的鸡肉     

l‐carnitine and fat type in the maternal diet during gestation and lactation modify the fatty acid composition and expression of lipid metabolism‐related genes in piglets

This study examined the influence of adding different amounts of maternal dietary l ‐carnitine and two fat types on fatty acid (FA) composition and the expression of lipid metabolism‐related genes in piglets. The experiment was designed as a 2 × 2 factorial with two fat types (3.5% soyabean oil, SO, and 3.5% fish oil, FO) and two levels of l ‐carnitine (0 and 100 mg/kg) added to the sows' diets. A higher proportion of n‐3 polyunsaturated fatty acids (PUFA) and a lower ratio of n‐6/n‐3 PUFA in sow milk and piglet tissues were observed in the FO groups than in the SO groups. Adding l ‐carnitine increased the proportion of C16:1 in sow milk and decreased n‐3 PUFA in piglet subcutaneous fat. Hepatic peroxisome proliferator‐activated receptor α (PPAR‐α) was more abundantly expressed in piglets from the FO groups than from the SO groups (p < 0.05), whereas stearoyl‐CoA‐desaturase (SCD), sterol regulatory element binding protein‐1 (SREBP1) and ?6‐desaturase (D6D) genes were less expressed in the FO groups compared with piglets from the SO groups. The expression of fatty acid synthase (FAS) genes was decreased in the SO groups with l ‐carnitine compared to that of the other dietary treatments. No differences among dietary treatments were observed with regard to the expression of acetyl‐CoA carboxylase (ACC). In conclusion, FO and l ‐carnitine supplementation in sows affect FA composition and hepatic gene expression in piglets.     

Effect of sire and sex on the intramuscular fatty acid profile and indices for enzyme activities in pigs

In this study, the effect of sire, sex and intramuscular fat content on the intramuscular fatty acid profile, in particular the long chain polyunsaturated fatty acids (PUFA) was investigated. Therefore, pork samples of the Longissimus thoracis were taken from 121 females and castrates that were the progeny of 5 boars. All animals had been fattened on the same diet and were slaughtered at a live weight of approximately 110 kg. Indices for the activities of Δ9, Δ6 and Δ5 desaturase, as well as elongase activity were estimated from ratios of product to precursor fatty acids. Intramuscular fat content was positively related to the total saturated fatty acid proportion (r = 0.376; p < 0.01) and the total monounsaturated fatty acid proportion (r = 0.579; p < 0.01), and inversely correlated with the total PUFA proportion (r = − 0.637; p < 0.01). A significantly higher index for Δ5 and Δ6 desaturase and elongase activity for PUFA metabolism was observed in females compared to castrate males. Sire had a significant effect on the intramuscular fatty acid profile, notably on the total n − 3 PUFA, and on most individual long chain n − 6 and n − 3 PUFA. The cis-9 C18:1/C18:0 index for Δ9 desaturase activity and the cis-11 C18:1/cis-9 C16:1 elongase activity index, as well as the combined desaturase and elongase enzyme activities in both the n − 6 and n − 3 PUFA chains were significantly influenced by sire.     

Strain differences in morphometrical characteristics of rat kidneys

To clarify the strain differences in the morphology of the rat kidneys, we investigated the morphometrical characteristics of the kidneys of Slc:Wistar, Slc:SD, and F344/NSlc rats. The diameter of the renal corpuscles in female F344/N rats is smaller than that in female Wistar rats. Although sex differences (males>females) were shown in SD and F344/N rats, no effects of castration were detected in any of the groups. Strain-dependent differences in the percentage of renal corpuscles with a cuboidal parietal layer were found in both male and female groups. The highest percentage of them was noted in male Wistar rats. Effects of castration were observed in female Wistar and male F344/N rats, and the values after castration were significantly higher than those in the intact animals. As for the number of proximal convoluted tubular nuclei, no strain differences were detected in either the male or female groups. Although a sex difference was found in SD rats (female>male), no effects of castration were detected in any of the groups. In female F344/N rats, numerous numbers of PAS-positive granules, which were observed in the proximal convoluted and straight tubular epithelia, were noted. Orchiectomy induced an increase of these granules in male SD and F344/N rats, but ovariectomy showed no effects on them in any strains. This is the first study to clarify the strain differences in the morphological characteristics of the kidneys in ordinary rat strains.     

Fatty acid profile and carcass characteristics in castrated and uncastrated hair lambs

The aim of this study was to investigate the effects of castration on carcass characteristics and fatty acid profile of visceral fat and meat from lambs. Eighteen six-month-old Santa Inês male lambs (18.9?±?2.4 kg of body weight (BW)) were used. Animals were assigned to two treatments according to their sexual condition: uncastrated (U) or castrated (C). During a 98-day experimental period, animals were kept on an Andropogon gayanus grass pasture area of 1 ha and supplemented with 200 g/animal/day of concentrate mixture. Water and mineral salt were available ad libitum. The lambs were weighed fortnightly, and at the last day of the trial, they were slaughtered for evaluation of carcass characteristics and fatty acids profile of perirenal fat and longissimus lumborum muscle samples. Castrated lambs showed higher BW than U during most part of the experiment (p?<?0.05). Fat deposition was higher in C lambs as evidenced by their increased carcass fat cover. Meat from U lambs showed lower content of C_16:0 and higher polyunsaturated fatty acids (PUFA) (p?<?0.05) than that from C (U, 14.3 and C, 10.5%). Conjugated linoleic acid (CLA) content was not affected by castration (p?>?0.05) (U, 0.74 and C, 0.76%). The cis-9, cis-12 C_18:2n-6 (U, 10.6 and C, 6.86%) fatty acid and the PUFA:SFA (saturated fatty acids) ratio (U, 0.36 and C, 0.25) were higher in the muscle of U lambs (p?<?0.05), indicating that the meat from U animals may provide more benefits to human health than that of C.

     

Effects of dietary n‐6/n‐3 polyunsaturated fatty acid ratios on the mass,and histological and ultrastructures of liver,spleen and thymus of 70‐day‐old Yangzhou Goslings

The objective of this study was to determine the effects of dietary n‐6/n‐3 polyunsaturated fatty acid (PUFA) ratios on the organ indexes, and histological and ultrastructures of organs including liver, spleen and thymus in 70‐day‐old Yangzhou goslings. One‐hundred and sixty 21‐day‐old Yangzhou goslings were randomly divided into 4 groups and fed 4 diets varying in the n‐6/n‐3 PUFA ratio from 3:1 up to 12:1. After 1‐week acclimation, the feeding experiment lasted for 6 weeks. At the end of the experimental period, goslings were slaughtered and the liver, spleen and thymus were weighed, and their histological and ultrastructures were examined. The results showed that the organ indices in the 3:1 group were remarkably higher than in the other three groups, whereas the mitochondrial square did not differ among four groups. The histological and ultrastructures of the liver, spleen and thymus were not affected by the diets with the lower n‐6/n‐3 PUFA ratios (3:1 and 6:1). However, feeding diets with the higher n‐6/n‐3 PUFA ratios (9:1 and 12:1), the nuclear chromatin was concentrated and marginalized; the cell membrane was contracted inwardly and disrupted; the mitochondrial membrane was damaged to some degree. In conclusion, the diet containing higher content of n‐3 PUFA might improve immune capacity of goslings the animal by accelerating the growth and maintaining cellular structures of organs like liver, spleen and thymus.     

Effect of different dietary supplemental fats and oils on the tissue fatty acid composition and growth of female broilers

1. A study was undertaken to examine the effect of supplementation of diets with fats of different chain length and degree of unsaturation on the performance, carcase characteristics and tissue fatty acid composition of broilers.

2. Three hundred and sixty 19‐day‐old female broilers were fed on diets containing supplemental fat/oil (50 g/kg) in the form of beef tallow (BT) (diet T‐T), soyabean oil (SBO) (diet S‐S), rapeseed oil (RSO) (diet R‐R), marine oil (MO) (diet M‐M) or binary mixtures (0.5:0.5 w/w) of these lipids (diets T‐S, T‐R, T‐M, S‐R, S‐M, and R‐M) to 54 d of age. Food intake, live weight, plucked weight and the lipid concentration and fatty acid composition of abdominal fat pad, liver and breast muscle were measured.

3. Food intake, plucked weight and live weight were greatest for diet T‐T and lowest for diet R‐R. Food conversion ratio was poorest for birds fed on diets containing BT. Lipid concentration in abdominal fat pad was significantly higher in birds fed on diets containing SBO. liver lipid concentration was significantly reduced by diets containing RSO.

4. Abdominal fat pad fatty acid profile was most readily altered by dietary fatty acids. There was a strong correlation between dietary fatty acid composition and tissue fatty acid composition for all fatty acids except C14:0, C20:0, C20: 2n‐6 and C20: 4n‐6. The tissue P/S ratio ranged from 0.40 for diet T‐T to 1.40 for diet S‐S. The n‐6/n‐3 ratio was significantly increased by the inclusion of SBO and decreased by the inclusion of MO.

5. Liver fatty acid profile was least modified by dietary fatty acids. There was an inverse relationship between liver and dietary C20:4n‐6 concentration. Tissue C18:2n‐6 and C20:4n‐6 were highly correlated, suggesting significant interconversion by ?‐6 desaturase in this tissue. The n‐6/n‐3 ratio was significantly increased by inclusion of SBO and significantly decreased by the inclusion of MO.

6. In breast muscle MO‐based diets increased the proportion of n‐3 PUFA at the expense of n‐6 PUFA. The tissue concentrations of C18:ln‐9, C18:2n‐6, C20:ln‐9, C20:5n‐3, C22:5n‐3 and C22:6n‐3 were strongly correlated with dietary fatty acid composition. Muscle and diet P/S and n‐6/n‐3 ratios were highly correlated.     

Fatty acid and energy metabolism in broiler chickens fed diets containing either beef tallow or an oil blend

The hypothesis tested was that the feeding of n‐6 polyunsaturated fatty acids (PUFA) results in more whole‐body fatty acid oxidation than the feeding of saturated fatty acids (SFA). It was reasoned that the increased fatty acid oxidation would be associated with enhanced whole‐body energy expenditure and stimulated de novo fatty acid synthesis. To put the hypothesis to the test, broiler chickens were fed diets containing either beef tallow as source of SFA or an oil blend as source of n‐6 PUFA. The broilers either had free access to their diet or were fed a restricted amount. Seven‐day‐old, male broiler chickens were used; they were kept individually in cages from 1 to 4 weeks of age. In the birds fed ad libitum, the n‐6 PUFA diet reduced average daily feed intake (ADFI), but did not significantly affect average daily weight gain (ADG) and the feed:conversion ratio (FCR). The lower ADFI on the n‐6 PUFA diet was associated with a higher apparent digestibility of total fatty acids. The ratio of deposition in the body to intake of digestible total PUFA, which reflected n‐6 PUFA, was significantly decreased by the n‐6 PUFA diet, pointing at preferentially increased n‐6 PUFA oxidation on the n‐6 PUFA diet. The ratio for n‐9 monounsaturated fatty acids (MUFA) was higher than 1.0, which agrees with net de novo synthesis, but the n‐6 PUFA diet induced a lower value than did the SFA diet. Feeding either the n‐6 PUFA or SFA diet did not influence energy expenditure expressed as percentage of energy intake. This study supports the idea that dietary n‐6 PUFA instead of SFA are preferentially oxidized, but no proof was obtained for enhanced energy expenditure and contrary to the hypothesis put forward, the n‐6 PUFA diet depressed de‐novo fatty acid synthesis.     

Whey protein gel composites in the diet of goats increased the omega‐3 and omega‐6 content of milk fat

Previously, feeding whey protein gels containing polyunsaturated fatty acids (PUFA) reduced their rumen biohydrogenation and increased their concentration in milk fat of Holstein cows. Our objective was to test the efficacy of whey protein isolate (WPI) gels produced in a steam tunnel as a method to alter the fatty acid (FA) composition of the milk lipids. Four primiparous Lamancha goats in midlactation were fed three diets in a 3 × 4 Latin square design. The WPI gels were added to a basal concentrate mix that contained one of three lipid sources: (i) 100% soya bean oil (S) to create (WPI/S), (ii) a 1:1 (wt/wt) mixture of S and linseed (L) oil to create (WPI/SL), or (iii) 100% L to create (WPI/L). Periods were 22 days with the first 10 days used as an adjustment phase followed by a 12‐day experimental phase. During the adjustment phase, all goats received a rumen available source of lipid, yellow grease, to provide a baseline for milk FA composition. During the experimental phase, each goat received its assigned WPI. Milk FA concentration of C18:2 n‐6 and C18:3 n‐3 reached 9.3 and 1.64 g/100 g FA, respectively, when goats were fed WPI/S. Feeding WPI/SL increased the C18:2 n‐6 and C18:3 n‐3 concentration to 6.22 and 4.36 g/100 g FA, and WPI/L increased C18:2 n‐6 and C18:3 n‐3 to 3.96 and 6.13 g/100 g FA respectively. The adjusted transfer efficiency (%) of C18:3 n‐3 to milk FA decreased significantly as dietary C18:3 n‐3 intake increased. Adjusted transfer efficiency for C18:2 n‐6 did not change with increasing intake of C18:2 n‐6. The WPI gels were effective at reducing rumen biohydrogenation of PUFA; however, we observed a change in the proportion increase of C18:3 n‐3 in milk FA suggesting possible regulation of n‐3 FA to the lactating caprine mammary gland.     

日粮ω6/ω3对爱拔益加肉仔鸡肉品质、血液脂质指标及脂肪酸组成的影响

本试验研究了日粮不同ω6/ω3多不饱和脂肪酸(PUFA)比值(ω6/ω3)对6周龄爱拔益加(AA)肉仔鸡肉品质、血液脂质指标及脂肪酸组成的影响.采用重量替代法使各处理日粮ω6/ω3比例分别为∶30∶1、20∶1、10∶1、5∶1和2.5∶1.选用体重接近的1日龄AA鸡母雏180只,随机分为5个处理,每个处理6个重复,每个重复6只鸡,试验期为6周,分1～4周和5～6周2个阶段.测定肉品质性状及腿肌脂肪酸组成.结果表明,随着日粮ω6/ω3的降低:(1)肌肉滴水损失极显著下降(P<0.001);当ω6/ω3为5∶1时,pHt最低,日粮ω6/ω3对肌肉肌内脂肪含量、肌苷酸含量没有显著影响(P>0.05);血液总胆固醇显著降低(P<0.001);(2)腿肌,ω3 PUFA极显著增加(P<0.001),尤其是C18∶3、C20∶5和C22∶5,ω6 PUFA显著下降(P<0.05),ω6/ω3从3.50降至1.60,多不饱和脂肪酸与饱和脂肪酸的比值在1.0左右(0.96～1.04);(3)极显著地增加了腿肌中C18∶3向C20∶5和C22∶5的转化效率(P<0.001),长链ω3 PUFA(除了C18∶3)在腿肌的含量高达7.24%.日粮ω6/ω3和腿肌中C20∶5和C22∶5的关系可分别用y=2.946 7 x-1.0413(R2=0.9901)及y=-0.642 3 Ln(x)+2.56(R2=0.993 6)表示.本试验证明降低日粮ω6/ω3,能在一定程度改善肉品质,并有效地增加腿肌中人体必需的ω3长链PUFA沉积,获得了营养丰富的鸡肉.     

Effect of dietary ω6/ω3 on growth performance,carcass traits,meat quality and fatty acid profiles of Beijing‐you chicken

The effects of varying the ω6 to ω3 fatty acid ratio (ω6/ω3) of diets on growth performance, carcass traits, meat quality and fatty acid composition of breast muscle were investigated in Beijing‐you chickens grown to 92 days. A total of 360 one‐day‐old female BJY chickens were fed diets containing 0%, 0.12%, 0.42%, 1.00% or 1.97% linseed oil replacing equal weights of maize oil to make dietary ω6/ω3 to be approximately 30:1, 20:1, 10:1, 5:1 and 2.5:1. Subcutaneous fat thickness and intramuscular fat content increased significantly in birds fed up to 10:1 ω6/ω3. a* values (redness of meat, dimension of the CIELAB‐system) progressively increased as the diets contained increasing ω3 content, up to the 10:1 ω6/ω3.The changes in b* (yellowness of meat, dimensions of the CIELAB‐system) were also significant but the pattern was almost the reverse of changes in a*. Shear force increased significantly as dietary ω6/ω3 was reduced from 30:1 to 5:1. Decreasing the dietary ω6/ω3 clearly decreased the content in breast muscle of C20:1 and C22:1, but increased that of C24:1. C20:4, C20:5 and C22:5, increased significantly by decreasing the dietary ω6/ω3, and the birds fed the 10:1 diet had higher contents of C22:6 than other treatments. This study has clearly demonstrated that decreasing the dietary ω6/ω3, increases the deposition of desirable ω3 and ω6 long chain PUFA in the edible tissue, thereby achieving nutritionally enriched meat.     

Changes in hepatic glucose and lipid metabolism‐related parameters in domestic pigeon (Columba livia) during incubation and chick rearing

This study aimed to evaluate the hepatic glucose and lipid metabolism‐related parameters of adult male and female White King pigeons (Columba livia) during incubation and chick rearing. At day 4 (I4), 10 (I10) and 17 (I17) of incubation and day 1 (R1), 7 (R7), 15 (R15) and 25 (R25) of chick rearing, livers were sampled from six pigeons for each sex. Glycogen and fat contents, activities of glycolytic enzymes (hexokinase, HK; 6‐phosphofructokinase, 6‐PFK), and genes expressions of key enzymes involved in glycolysis (pyruvate kinase, PK; glucokinase, GK), gluconeogenesis (phosphoenolpyruvate carboxykinase cytosolic, PCK1; fructose‐1,6‐bisphosphatase, FBP1; glucose‐6‐phosphatase, G6Pase), fatty acid synthesis (fatty acid synthase, FAS; acetyl‐CoA carboxylase, ACC) and fatty acid β‐oxidation (carnitine palmitoyltransferase 1, CPT1; acyl‐CoA 1, ACO) were measured. In male and female pigeon livers, glycogen content and HK activity dramatically increased after I17 and after R1, respectively; expressions of FBP1 and G6Pase genes were maximized at R15; activity of 6‐PFK and expressions of PK and CPT1 genes were highest at R7; fat content and expressions of FAS and ACC genes steeply increased from I10 to R1. In females, hepatic expressions of GK and PCK1 genes were greatest at R7 and I17, respectively; however, in males, both of them were maximized at R15. Hepatic expression of ACO gene was significantly enhanced at R1 compared to I17 and R7 in males, whereas it was notably up‐regulated at I17 and R7 in females. Furthermore, expressions of PCK1, GK, FAS and ACC genes were in significant relation to fat content in the livers of female pigeons, while fat content in male pigeons was highly correlated with expression of PCK1, ACC, CPT1 and ACO genes. In conclusion, regulations of glucose and lipid metabolic processes were enhanced in parent pigeon livers from terminal phases of incubation to mid phase of chick rearing with sexual effects.     

Effects of caponisation on lipid and fatty acid composition of intramuscular and abdominal fat of medium-growth broilers

1. Capons and intact male broilers were used to investigate the effects of caponisation on intramuscular fat and abdominal adipose tissue lipid content and fatty acid profile. 2. Capons had significantly higher total lipid content (P<0·05). 3. Neutral lipids were the major fractions in intramuscular and abdominal fat but their proportions differed significantly among groups and tissues (P<0·05). 4. The predominant saturated, monounsaturated and polyunsaturated fatty acids in all samples were C16:0, C16:1 ω-9, C18:0, C18:1 ω-9, C18:1 ω-7, C18:2 ω-6 and C20:4 ω-6. 5. Caponisation resulted in a significant ω-6/ω-3, PUFA and PUFA/SFA ratio reduction as well as a significant increase in atherogenic and thrombogenic indices increase in intramuscular fat (P<0·05) without affecting their appropriate value for a healthy diet.     

Effects of breed, sex and halothane genotype on fatty acid composition of triacylglycerols and phospholipids in pork longissimus muscle

The objective of this study was to estimate the effects of breed, sex, and halothane (HAL‐1843^TM) genotype on fatty acid composition of triacylglycerols (TAG) and phospholipids (PL) extracted from porcine longissimus muscle (LM). Purebred Yorkshire (n = 131), Duroc (n = 136), Hampshire (n = 49), Spotted (n = 35), Chester White (n = 74), Poland China (n = 51), Berkshire (n = 169) and Landrace (n = 82) pigs (n = 727; 427 barrows and 300 gilts) from the 1994 and 2001 National Barrow Show Sire Progeny Tests were used. For statistical analyses, a mixed model was used that included fixed effects of breed, sex, HAL‐1843^TM genotype, year, slaughter date within each year, interaction of breed × sex and random effects of sire and dam within breed. Breeds and sex were significantly associated with the percentages of the majority fatty acids in TAG. Duroc pigs had greater total saturated fatty acids (SFA) and lower total monounsaturated fatty acids (MUFA) (p < 0.05) contents than did pigs of all other breeds except Berkshire (p > 0.05). The concentration of total polyunsaturated fatty acids (PUFA) was the greatest in Hampshire pigs (p < 0.05). The content of total SFA was greater (p < 0.01), whereas the concentrations of total MUFA and PUFA were lower (p < 0.01) in barrows than those in gilts. The contents of major SFA in PL did not differ significantly among pigs from different breeds and sex groups. However, breed and sex significantly affected the concentrations of major MUFA and PUFA in PL and strong negative correlation between the total contents of MUFA and PUFA in PL was observed in the current study. Chester White pigs had greater total MUFA and lower total PUFA contents (p < 0.05) in PL than did pigs of all other breeds except Spotted (p > 0.05). In contrast to breed and sex effects, the concentrations of fatty acids in PL were more affected by HAL‐1843^TM genotype than those in TAG. The content of C16:0, a major SFA in PL, differed significantly in pigs with different HAL‐1843^TM genotypes. In conclusion, these results suggest that breed and sex are important sources of the variations for fatty acid composition of TAG and PL in LM.     

Dietary linseed oil in the maternal diet affects immunoglobulins,tissue fatty acid composition and expression of lipid metabolism‐related genes in piglets

This experiment investigated the effects of supplementing the maternal diet with linseed oil (LSO) and soya bean oil (SBO) on immunoglobulins, the fatty acid composition and hepatic expression of lipid metabolism‐related genes in piglets. Multiparous sows (twenty‐four per diet) were fed on diets containing a supplement of either SBO or LSO during last week of gestation and lactation. The results indicated that supplementation of maternal diet with LSO could improve the weaning weight of piglets and average daily gain (ADG) (p < 0.05). The concentration of immunoglobulin G (IgG) and immunoglobulin A (IgA) was enhanced in sow plasma, colostrum and milk by the addition of LSO (p < 0.05). In addition, the concentration of 18: 3n‐3 fatty acids was higher in the milk of LSO sows. Meanwhile, maternal supplementation with LSO increased the levels of plasma IgG, IgA and the tissues n‐3 polyunsaturated fatty acid (PUFA) in piglets (p < 0.05). Correspondingly, the mRNA expression levels of hepatic ?5‐desaturase (D5D) and ?6‐desaturase (D6D) were higher, and fatty acid synthase (FAS) was lower in piglets from LSO‐fed sows when compared with that in the SBO group. In conclusion, LSO supplementation of the maternal diet increases immunoglobulins, modifies the fatty acid composition and affects the gene of D5D and D6D expression of piglets.