The relationship between acrosome reaction and polyunsaturated fatty acid composition in boar sperm

This study investigated the relationship between acrosome reactions and fatty acid composition with respect to fertility in boar sperm. The acrosome reaction was induced more than 85% by 60 mM methyl-beta-cyclodextrin (MBCD), and plasma membrane integrity was significantly reduced dependent on the MBCD level in boar sperm (p < .05). The acrosome-reacted sperm exhibited significantly higher saturated fatty acids (SFAs) and lower polyunsaturated fatty acids (PUFAs) composition compared to the non-acrosome reaction group (p < .0001). In addition, the PUFAs, C22:5n-6 (docosapentaenoic acid [DPA]; p < .01) and C22:6n-3 (docosahexaenoic acid [DHA]; p < .0001) were significantly decreased, and cleavage and blastocyst formation of oocytes were significantly (p < .0001) decreased in acrosome-reacted sperm relative to non-acrosome-reacted sperm. Moreover, acrosome reaction was positively correlated with SFAs, whereas negatively correlated with PUFAs, of the PUFAs, the DPA (p = .0005) and DHA (p = <.0001) were negatively correlated with the acrosome reaction. Therefore, these results suggest that the PUFAs composition of sperm is closely involved in acrosome reaction in pigs.     

日粮中脂肪酸对羊牛猪肉中长链多不饱和脂肪酸和共轭亚油酸的影响

随着消费者健康意识的提高,越来越多的研究关注提高家养动物肉产品中多不饱和脂肪酸(PUFA)含量,尤其是n-3长链脂肪酸和共轭亚油酸(CLA)在羊、牛、猪肉肌内脂中的含量。研究结果表明通过添加鱼油或鱼粉能提高动物肉中n-3长链脂肪酸含量。富含亚麻油酸(LNA)的日粮能提高肉中LNA、二十碳五烯酸(EPA)和二十二碳五烯酸(DPA)水平,但大部分对肌肉中二十二碳六烯酸(DHA)水平没有影响。然而,在日粮中添加鱼油或鱼粉大部分能提高动物肌肉中DHA含量。大部分研究中提高n-3脂肪酸含量的同时n-6脂肪酸含量下降,这主要归因于试验组日粮中n-6脂肪酸降低。这样刚好可以使肉中两者比例更合理,但对多不饱和脂肪酸与饱和脂肪酸比例没什么影响。饲喂反刍动物富含n-3脂肪酸日粮(亚麻籽或加草料)、鱼油或富含LA的浓缩料可提高肌肉中c9t11CLA含量。牛肉、羊肉中c9t11CLA在总脂中含量介于0.2~1.0 g/100 g,不随营养因素提高到更高。相对应的,在单胃动物日粮中添加混合CLA油则显著提高CLA含量。     

Limited evidence for trans-generational effects of maternal dietary supplementation with ω-3 fatty acids on immunity in broiler chickens

The aim of the present study was to investigate whether the immune response of broiler chickens is modulated by including different omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) in the maternal diet. Broiler breeder hens (n = 120 birds per group) were fed one of four diets, differing in the ratios of n-6:n-3 PUFAs and eicosapentaenoic acid (EPA):docosahexaenoic acid (DHA). At 28 weeks of age, the eggs produced were incubated to obtain 720 chicks (n = 180 per group). All broiler chicks were fed a control diet and were vaccinated against Newcastle disease virus (NDV). Blood samples were taken at different time points after immunisation with human serum albumin (HuSA) in Freund's adjuvant to determine the acute phase response, antibody response and cytokine production. Addition of EPA to the maternal diet was associated with greater ovotransferrin concentrations post-immunisation, compared to other groups. Altering the ratios of n-6:n-3 PUFA or EPA:DHA in the maternal diet did not affect the offspring in terms of production of caeruloplasmin, α₁-acid glycoprotein, interleukin (IL)-1β, IL-6, IL-12 or tumour necrosis factor (TNF)-α. Dietary manipulation of the maternal diet did not influence the specific antibody response to HuSA or NDV, nor did it alter the levels of natural antibody binding to keyhole limpet haemocyanin in the offspring. Thus, maternal supplementation with n-3 PUFAs played a minor role in perinatal programming of the immune response of broiler chickens.     

Effects of dietary conjugated linoleic acid and fish oil supplementation on performance and egg quality in laying hens

1. Laying hen performance, yolk fat fatty acid concentrations and firmness of eggs were evaluated with respect to the inclusion in the diet of conjugated linoleic acid (CLA) and fish oil. 2. Nine diets were arranged factorially, with three levels of supplementation of CLA (1, 3 and 5 g/kg) and fish oil (0, 14 and 20 g/kg). 3. Type of diet did not affect egg production traits. 4. CLA addition increased yolk weight and yolk fat concentrations of CLA, saturated and total long-chain n-3 fatty acids, but decreased those of monounsaturated and total long-chain n-6 fatty acids. 5. Fish oil addition increased long-chain n-3 fatty acids yolk fat concentrations but decreased those of CLA, saturated and long-chain n-6 fatty acids. 6. Effects of CLA addition on yolk fat concentrations of C22:4 n-6 and C20:5 n-3 were greater when no fish oil was added to the diet. 7. CLA supplementation increased linearly yolk moisture and firmness and altered albumen and yolk pH.     

Effects of supplemental conjugated linoleic acids (CLA) on fresh and post‐thaw sperm quality of Holstein bulls

This study was designed to investigate the effects of feeding‐protected conjugated linoleic acid (CLA) on the semen production and sperm freezability in Holstein bulls. Twelve bulls were randomly assigned to two groups (n = 6 per group). Bulls received the normal diet (control group) or the normal diet top‐dressed with 50 g of CLA (treated group) for 10 weeks. The control group received 40 g/day calcium soap of fatty acid. Fresh and post‐thaw semen quality was assessed on ejaculates collected at the 0, 4, 6, 8 and 10 week of supplementation. Semen evaluations including sperm concentration, motion characteristics (subjective and computer‐assisted), viability (Eosin–Nigrosin), membrane integrity (hypo‐osmotic swelling test) and abnormality were conducted. Semen volume, sperm concentration and total sperm output were not affected by dietary treatment (p > .05). The proportion of spermatozoa with abnormal morphology in fresh semen significantly increased (p < .05) in the CLA‐fed group compared to control group. Also, in CLA‐fed group, the proportion of post‐thaw spermatozoa with abnormal morphology at week 10 of trial was significantly higher in CLA than control group (p < .05). Progressive motility tended to be increased in the CLA‐fed group, although dietary supplementation did not affect other CASA parameters or viability in fresh and frozen‐thawed sperm. In this study, CLA supplementation had little positive effect on fresh or post‐thaw sperm quality of Holstein bulls.     

EPA/DHA对体外发酵及瘤胃液脂肪酸组成的影响

试验旨在研究日粮中添加不同水平的DHA/EPA对体外发酵和瘤胃液脂肪酸变化的影响。试验通过采用持续动态人工瘤胃装置,向发酵罐中添加EPA/DHA,连续培养7 d,分析脂肪酸组成的变化及发酵模式的改变。试验结果表明,日粮添加EPA/DHA使瘤胃液pH升高（与CK相比,Trt1和Trt2分别升高了0.11和0.35）,Trt2 与CK相比差异极显著（P<0.01）;与CK相比处理组3种主要挥发酸中乙酸浓度下降（P<0.01）,丙酸浓度升高(P<0.01),丁酸浓度下降(P<0.01),总挥发性脂肪酸浓度与对照组相比略有下降但差异不显著（P>0.05）;日粮添加EPA/DHA使瘤胃液脂肪酸成分发生改变。与CK相比处理组C18∶0含量显著下降（P<0.01）; t 11 C18∶1含量显著升高（P<0.01）;c-9,t-11 CLA含量显著升高（P<0.01）,但是两组之间差异均不显著。因此,日粮中添加不同水平的EPA/DHA可以改变瘤胃发酵模式,影响不饱和脂肪酸瘤胃氢化过程,使脂肪酸组成发生改变,为采用新的营养措施调控反刍动物产品中CLA的含量提供理论依据。     

饲料中添加龙须菜对草鱼生长性能、血清生化指标及肌肉脂肪酸组成的影响

为考察饲料中添加龙须菜对草鱼生长性能、血清生化指标及肌肉脂肪酸组成的影响,试验共配制了6种龙须菜添加比例分别为0(对照组)、1%、2%、3%、4%和5%的等氮等脂饲料,投喂平均体重为(15.94±0.10)g的草鱼8周。每种饲料投喂4个水箱(重复),每箱30尾鱼。结果显示:1)饲料中不同添加比例龙须菜对草鱼的增重率(WGR)、特定生长率(SGR)、存活率(SR)及饲料效率(FE)没有显著影响(P0.05)。2)各试验组的肝体指数(HSI)均高于对照组,对照组与除5%添加组外的其他试验组的差异均达到显著水平(P0.05)。3)全鱼、肝脏及肌肉的粗蛋白质含量各组间皆无显著差异(P0.05),而饲料中不同添加比例龙须菜对全鱼粗灰分与粗脂肪、肝脏粗脂肪及肌肉水分含量有显著影响(P0.05)。4)血清总蛋白(TP)、总胆固醇(TCHO)、甘油三酯(TG)以及低密度脂蛋白(LDL)含量以5%添加组最低,显著低于对照组(P0.05),其他试验组与对照组没有显著差异(P0.05)。5)饲料中龙须菜添加比例影响了草鱼肌肉脂肪酸的组成,除C14∶1、C20∶0、C20∶2外,其他肌肉脂肪酸的含量均受到饲料中龙须菜的添加比例的显著影响(P0.05),其中肌肉多不饱和脂肪酸(PUFA)含量及n-3/n-6 PUFA均在3%添加组获得最高值。1%、2%、3%、4%和5%添加组肌肉C20∶5(EPA)、C22∶5(DPA)、C22∶6(DHA)以及EPA+DHA的含量都显著高于对照组(P0.05)。由此得出,饲料中添加一定比例的龙须菜对草鱼的生长性能没有显著影响,但能降低血脂含量,影响草鱼肌肉脂肪酸的组成,并能提高功能性脂肪酸DHA、EPA及PUFA的含量;饲料中添加3%的龙须菜能更好地增加肌肉功能性脂肪酸含量,而添加5%的龙须菜则草鱼生长相对较好,降低血脂效果更加明显。     

Effects of the Ratio of n-6:n-3 Polyunsaturated Fatty Acids in the Maternal Diet on Immunoglobulins, Fatty Acid Composition, and Performance of Lactating Sows and Suckling Piglets under Conditions of Low Maternal Energy Intake

This experiment was conducted to investigate the effects of different ratios of n-6:n-3 polyunsaturated fatty acids (PUFA) in sow diets on the performance of lactating sows and their piglets at low digestible energy intakes.Twenty-one pregnant Landrace sows were assigned to one of three diets from day 108 of gestation until weaning (26 to 29 d),containing n-6∶n-3 PUFA ratios of 3∶1,8∶1 and 11∶1.The effects on sow and litter production traits and on sow body condition were examined.There were no differences among treatments in daily feed intakes or in changes in sow weight and back-fat levels during lactation.Litter size,litter weight at birth and weaning and litter average daily weight gain were also unaffected by treatment.As expected,large differences were observed in n-6 and n-3 fatty acids in the colostrum and plasma of sows and piglets (P ＜ 0.01 ).The ratio of n-6∶n-3 PUFA the diet was positively correlated with those in colostrum,sow plasma and piglet plasma ( R2 =0.55,0.80 and 0.80,respectively).Sow plasma insulin and IGF-I levels at weaning were unaffected by the treatments.Plasma leptin ( P ＜ 0.05) concentrations were increased in sows fed the diet with a n-6∶ n-3 ratio of 8∶1.Immunoglobulin concentrations in colostrum were not altered by dietary treatment.Plasma IgG concentrations at d 14 were highest in piglets from sows fed the 8∶1 ratio of n-6∶n-3.Furthermore,this group had the highest IgA concentrations at day 21 of lactation compared with the other two groups ( P ＜ 0.05 ).In summary,our study demonstrated that at low digestible energy levels,altering the ratio of n-6∶n-3 PUFA in the diets for lactating sows affected immune components and the fatty acid composition of lactating sows and their piglets.Further studies are needed to examine whether higher levels of fat supplementation than those used in the present study ( 1.5％ ) can successfully enhance performance.     

Circulating fatty acid profiles in response to three levels of dietary omega-3 fatty acid supplementation in horses

Fatty acids of the n-3 type confer health benefits to humans and other species. Their importance to equine physiology could include improved exercise tolerance, decreased inflammation, and improved reproductive function. The circulating fatty acid profile and the acquisition and washout of fatty acids in response to n-3 supplementation were determined for horses in the current study. A fatty acid supplement high in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid was fed to deliver EPA plus DHA at 0 (control), 10, 20, or 40 g/d to 16 mares (n = 4/group) for 28 d. Plasma was collected at -11, 3, 7, 10, 16, 23, 30, 37, 44, 70, and 87 d relative to the beginning of supplementation. Plasma was analyzed for the presence of 35 fatty acids by gas chromatography. Plasma EPA and DHA increased (P < 0.05) in a dose-responsive manner by 3 d of feeding and reached peak concentrations by 7 d. Peak EPA and DHA concentrations of the 40 g/d supplement group were approximately 13x and 10x those of controls, respectively. Plasma EPA and DHA demonstrated a steep decline (P < 0.05) from peak values by 9 d after cessation of supplementation and were near presupplementation values by 42 d. Omega-3 supplementation also increased (P < 0.05) concentrations of fatty acids C14:0, C17:1n-7, C18:1trans-11, C18:3n-6, C18:4n-3, C20:3n-6, C20:4n-6, and C22:5n-3 and decreased (P < 0.05) concentrations of C18:1cis-9 fatty acid. Seasonal effects, apparently unrelated to supplementation and likely due to the availability of fresh forage, were also noted. Unlike ruminants, there were no detectable concentrations of CLA in equine plasma. These results indicate that the circulating fatty acid milieu in horses can be influenced through targeted supplementation. Possible implications of increased n-3 plasma and tissue concentrations on specific physiological function in the equine remain to be elucidated.     

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss)

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.     

多不饱和脂肪酸对动物精液品质影响的研究进展

多不饱和脂肪酸(PUFA)主要分为ω-3 PUFA和ω-6 PUFA,是精子质膜脂质的主要成分,对精子抗氧化、提高精子质膜流动性、维持精子结构完整性及睾酮合成等具有重要作用。不同类型PUFA对精液品质的作用有所不同,ω-6 PUFA中的花生四烯酸(AA)能够促进睾酮的分泌,但精浆中过量的AA可能诱导氧化应激;亚油酸(LA)同样可提高体内睾酮水平,共轭亚油酸(CLA)可降低精子的氧化应激;动物体内少量的二十二碳五烯酸(DPA)不仅能参与精子的运输过程,还能提高精子的抗氧化能力。ω-3 PUFA中的α-亚麻酸(ALA)具有抗氧化作用并能刺激睾酮的合成,二十二碳六烯酸(DHA)作用与ALA相似,可提高精子的抗氧化能力,同时可促进睾酮合成;二十碳五烯酸(EPA)对精子结构及睾酮合成具有调节作用。适当的ω-6/ω-3 PUFA比例对精子的活力、质膜结构、脂质组成和顶体反应均具有重要的调节作用。PUFA对精子的作用可因添加的方式、类型、ω-6/ω-3PUFA的比例及动物种类的不同而有所不同。近年来,PUFA对动物精液品质作用的相关研究取得了较大进展,但其提高精液品质的作用机制仍需进一步深入探讨。作者综述了在饲粮或精液稀释液中添加不同类型的ω-3 PUFA、ω-6 PUFA及ω-6/ω-3 PUFA比例对精子的影响,以期为深入了解PUFA在动物精液生产中的应用提供理论参考。     

Effect of linseed oil and fish oil alone or as an equal mixture on ruminal fatty acid metabolism in growing steers fed maize silage-based diets

Because of the potential benefits to human health, there is interest in increasing 18:3n-3, 20:5n-3, 22:6n-6, and cis-9,trans-11 CLA in ruminant foods. Four Aberdeen Angus steers (406 ± 8.2 kg of BW) fitted with ruminal and duodenal cannulas were used in a 4 × 4 Latin square experiment with 21-d periods to examine the potential of fish oil (FO) and linseed oil (LO) in the diet to increase ruminal outflow of trans-11 18:1 and total n-3 PUFA in growing cattle. Treatments consisted of a control diet (60:40; forage:concentrate ratio, on a DM basis, respectively) based on maize silage, or the same basal ration containing 30 g/kg of DM of FO, LO, or a mixture (1:1, wt/wt) of FO and LO (LFO). Diets were offered as total mixed rations and fed at a rate of 85 g of DM/(kg of BW(0.75)/d). Oils had no effect (P = 0.52) on DMI. Linseed oil had no effect (P > 0.05) on ruminal pH or VFA concentrations, whereas FO shifted rumen fermentation toward propionate at the expense of acetate. Compared with the control, LO increased (P < 0.05) 18:0, cis 18:1 (Δ9, 12-15), trans 18:1 (Δ4-9, 11-16), trans 18:2, geometric isomers of 9,11, 11,13, and 13,15 CLA, trans-8,cis-10 CLA, trans-10,trans-12 CLA, trans-12,trans-14 CLA, and 18:3n-3 flow at the duodenum. Inclusion of FO in the diet resulted in greater (P < 0.05) flows of cis-9 16:1, trans 16:1 (Δ6-13), cis 18:1 (Δ9, 11, and 13), trans 18:1 (Δ6-15), trans 18:2, 20:5n-3, 22:5n-3, and 22:6n-3, and decreased (P < 0.001) 18:0 at the duodenum relative to the control. For most fatty acids at the duodenum, responses to LFO were intermediate of FO and LO. However, LFO resulted in greater (P = 0.04) flows of total trans 18:1 than LO and increased (P < 0.01) trans-6 16:1 and trans-12 18:1 at the duodenum compared with FO or LO. Biohydrogenation of cis-9 18:1 and 18:2n-6 in the rumen was independent of treatment, but both FO and LO increased (P < 0.001) the extent of 18:3n-3 biohydrogenation compared with the control. Ruminal 18:3n-3 biohydrogenation was greater (P < 0.001) for LO and LFO than FO, whereas biohydrogenation of 20:5n-3 and 22:6n-3 in the rumen was marginally less (P = 0.05) for LFO than FO. In conclusion, LO and FO at 30 g/kg of DM altered the biohydrogenation of unsaturated fatty acids in the rumen, causing an increase in the flow of specific intermediates at the duodenum, but the potential of these oils fed alone or as a mixture to increase n-3 PUFA at the duodenum in cattle appears limited.     

Fatty Acid Composition of Porcine Muscle and Adipose Tissue Lipids as Affected by Anatomical Location and Cod Liver Oil Supplementation of the Diet

In pigs fed a standard pig mash the contents of polyunsaturated fatty acids (PUFAs) of both the n-6 and n-3 series were significantly higher in the dark red mm adductores compared to the light coloured m longissimus lumborum. Perirenal fat had a higher concentration of saturated fatty acids (14:0,16:0, 18:0) than backfat, and a lower concentration of monounsaturated fatty acids, such as 16:ln-7 and 18:ln-9. Daily supplementation of 50 ml cod liver oil, rich in n-3 PUFAs, during the fourth and third week before slaughter led to a 1.4 to 1.7 times increase in the contents of n-3 PUFAs in muscles and fat depots. There was no difference between the incorporation of n-3 PUFAs in dark and light muscles. Perirenal fat contained more 20:5n-3 (EPA) and 22:6n-3 (DHA), but less 20:ln-9 (eicosenoic acid) than the backfat, after cod liver oil supplementation rich in these 3 fatty acids. Supplementation of cod liver oil reduced the n-6/n-3 fatty acid ratio in all anatomical locations examined.     

Fatty acid patterns of dog erythrocyte membranes after feeding of a fish-oil based DHA-rich supplement with a base diet low in n-3 fatty acids versus a diet containing added n-3 fatty acids

Background

In dogs, increasing the tissue n-3 fatty acid (FA) content is associated with potential benefit in some medical conditions, e.g. atopic dermatitis, cancer or heart disease. Therefore effectively and conveniently increasing tissue n-3 FA levels in dogs is of interest. Incorporation of dietary n-3 FA into cell membranes may be studied by FA analysis of erythrocyte membranes (EM), because of the correlation of its FA composition with the FA composition of other cells. Aim of the study was to determine whether an n-3 FA additive added to a control diet is as effective in increasing EM n-3 FA content as feeding an n-3 FA enriched diet. Furthermore the time course of the incorporation of dietary n-3 FA into canine EM was investigated.

Methods

Thirty dogs were randomly divided into three dietary groups with ten dogs per group. CONT got a dry dog food diet which did not contain EPA or DHA. FO got a dry dog food diet with a high EPA and DHA content. ADD got the CONT diet combined with an n-3 FA additive rich in DHA and EPA. After a feeding period of 12 weeks the additive was discontinued in ADD and these dogs were fed CONT diet for another four weeks to observe washout effects. Erythrocyte lipids were extracted from venous blood samples and their FA composition was determined by gas chromatography. The Mann-Whitney-U-test was used to detect significant differences between the different groups and time points.

Results

After one week the proportions of n-3 FA, DHA and EPA were already significantly increased in ADD and FO, apparently reaching a plateau within eight weeks. In our study DHA and not EPA was preferably incorporated into the EM. After discontinuing the administration of the additive in ADD, the n-3 FA values declined slowly without reaching baseline levels within four weeks.

Conclusions

In dogs, an increase of dietary n-3 FA content leads to a rapid inclusion of n-3 FA into EM, regardless of whether the n-3 FA are offered as an enriched diet or as a normal diet supplemented with an n-3 FA additive.     

Effect of Dietary Supplementation with Cod Liver Oil on Cold Shock and Freezability of Boar Semen

Contents
The effect of dietary supplementation with cod liver oil (CLO), which is rich in n-3 polyunsaturated fatty acids (PUFAs), on resistance to cold shock and on freezability of boar semen was investigated. Ejaculates from 29 fertile Norwegian Landrace boars, randomly divided into control (n = 15) and CLO-group (n = 14), were frozen before and after a 12 week period of daily oil supplementation. Before each freezing, semen samples were taken to determine the fatty acid composition of the spermatozoa. Docosahexaenoic acid (22 : 6n-3; DHA) was the major fatty acid in total lipids. The n-3 fatty acid DHA increased in the CLO-group from 25.5 to 32.1% at the expense of the n-6 docosapentaenoic acid (22 : 5n-6), which decreased from 11.3 to 4.2% (p < 0.0001). The concentration of these fatty acids were unchanged in the control group. There was also a significant decrease of other PUFAs in the CLO-group (p < 0.05). Eicosapentaenoic acid (20 : 5n-3) was not found in any sample. At four different steps of the preservation process (30, 15, 5°C and after freezing/thawing) both motility and acrosome integrity were assessed. No significant differences were found either within or between the groups at any of the steps. In conclusion, CLO-supplementation alters the lipid composition of the membranes of boar spermatozoa, however, this does not seem to have any beneficial effect on cold shock and freezability of boar semen.     

Diet-induced milk fat depression: Association with changes in milk fatty acid composition and fluidity of milk fat

This experiment was designed to examine changes in milk fatty acids during fish oil-induced milk fat depression (MFD) and to test the theory that these changes are related to milk fat fluidity. The experiment was divided into three periods: 1) Baseline: all cows (n = 12) received a high fiber diet without fish oil (FO) for 12 days; 2) Treatment: 4 cows/group received the following treatments for 21 days: a) Low fiber diet without FO (LF), b) High fiber diet + FO (HF + FO) and c) Low fiber diet + FO (LF + FO); 3) Post-treatment: cows returned to the baseline diet and were monitored for 12 days. FO was included at 1.6% DM and HF and LF diets had 40 and 26% NDF, respectively. Milk fat content and yield were unchanged by the LF diet, but were reduced by FO diets at both dietary fiber levels and recovered in the post-treatment period. FO diets caused a pronounced reduction in stearic and oleic acid concentrations in milk fat and an equally pronounced increase in trans-18:1 fatty acid concentrations. Milk fat mean melting point (MMP) was correlated with MFD (r = 0.73) and with milk oleic acid concentration (r = − 0.92). The ratio of oleic:stearic in milk fat increased gradually and consistently in response to FO. Trans-C18:1 isomers with double bounds at carbon ≤ 10 increased with greater MFD and those with double bonds at carbon ≥ 11 decreased with greater MFD. Trans-9 cis-11 CLA explained more than 80% of MFD and was strongly correlated with trans-10 C18:1. Maintenance of MMP below 39–40 °C suggests that the mammary gland was able to secrete only milk fat with adequate fluidity and that MFD could be an adaptation mechanism to prevent secretion of milk with higher MMP.     

Effects of two different dietary sources of long chain omega-3, highly unsaturated fatty acids on incorporation into the plasma, red blood cell, and skeletal muscle in horses

The objective of this study was to examine the effects of different sources of dietary omega-3 (n-3) fatty acid supplementation on plasma, red blood cell, and skeletal muscle fatty acid compositions in horses. Twenty-one mares were blocked by age, BW, and BCS and assigned to 1 of 3 dietary treatments with 7 mares per treatment. Dietary treatments were: 1) control or no fatty acid supplement (CON), 2) 38 g of n-3 long chain, highly unsaturated fatty acid (LCHUFA) supplement/d provided by algae and fish oil (MARINE) containing alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA), and 3) 38 g of n-3 LCHUFA supplement/d provided by a flaxseed meal (FLAX) containing ALA. Each supplement was added to a basal diet consisting of hay and barley and was fed for 90 d. Blood samples and muscle middle gluteal biopsies were taken at d 0, 30, 60 and 90 of supplementation. Plasma, red blood cell and skeletal muscle fatty acid profiles were determined via gas chromatography. Plasma linoleic acid (LA) and ALA were at least 10 and 60% less (P < 0.01), respectively, in the MARINE compared with the FLAX and CON groups. Plasma EPA and DHA were only detected in the MARINE group, and EPA increased 40% (P < 0.001) from d 30 to 60, and DHA 19% (P < 0.01) from d 30 to 90. Red blood cell LA and ALA were not different among treatments. Red blood cell EPA and DHA were only detected in the MARINE group, where EPA increased 38% (P < 0.01) from d 30 to 60, and DHA increased 56% (P < 0.001) between d 30 and 90. Skeletal muscle LA was at least 17% less (P < 0.001) in the MARINE group compared with the other treatments. Skeletal muscle ALA was 15% less (P = 0.03) in the MARINE group compared with FLAX and CON groups. Skeletal muscle EPA was at least 25% greater (P < 0.001) in MARINE group compared with other treatments and increased (P < 0.001) by 71% from d 30 to 60. Skeletal muscle DHA was at least 57% greater (P < 0.001) in the MARINE group compared with other groups and increased (P < 0.001) by 40% between d 30 and 90. As far as the authors are aware, this is the first study to demonstrate that dietary fatty acid supplementation will affect muscle fatty acid composition in horses. Incorporation of n-3 LCHUFA into blood and muscle depends directly on dietary supply of specific fatty acids.     

饲粮中添加富含二十二碳六烯酸海藻对奶山羊青年公羔生长性能、屠宰性能、肌肉品质以及脂肪酸组成的影响

本试验旨在研究饲粮中添加富含二十二碳六烯酸(DHA)海藻对奶山羊青年公羔生长性能、屠宰性能、肌肉品质以及脂肪酸组成的影响。选取16只同质性较好的6月龄[平均体重为(21.90±0.98)kg]奶山羊青年公羔,随机分为2组(每组4个重复,每个重复2只羔羊),分别饲喂基础饲粮(对照组)和在基础饲粮基础上添加3%富含DHA海藻(干物质基础)的试验饲粮(试验组)。饲喂12周后,从每组随机选择4只公羔(共8只公羔)进行屠宰试验,测定屠宰性能、肌肉品质以及肌肉与脂肪组织中脂肪酸组成。结果显示:与对照组相比,1)饲粮中添加富含DHA海藻对公羔的干物质采食量、平均日增重和饲料报酬无显著影响(P>0.05);2)饲粮中添加富含DHA海藻对公羔的屠宰性能和肌肉品质无显著影响(P<0.05);3)饲粮中添加富含DHA海藻可显著降低血清中低密度脂蛋白胆固醇含量(P<0.05),显著提高高密度脂蛋白胆固醇含量(P<0.05),但对血清总胆固醇和甘油三酯含量无显著影响(P>0.05);4)饲粮中添加富含DHA海藻可显著提高肌肉和脂肪组织中DHA和n-3多不饱和脂肪酸(PUFA)含量(P<0.05),显著降低肌肉组织中n-6∶n-3 PUFA比值(P<0.05)。由此得出,在饲粮中添加富含DHA海藻对奶山羊青年公羔的生长性能、屠宰性能和肌肉品质均无显著影响,但有改善血脂指标以及肌肉与脂肪组织脂肪酸组成的潜力。