Effect of dietary conjugated linoleic acid (CLA) supplementation on CLA isomers content and fatty acid composition of dry-cured Parma ham

To evaluate the effects of dietary conjugated linoleic acid (CLA) supplementation on cis-9, trans-11 and trans-10, cis-12 isomer content and on the fatty acid composition of subcutaneous adipose tissue and intramuscular lipids of biceps femoris, the lipids of 24 dry cured Parma hams, obtained from Large White pigs fed isoenergetic diets supplemented with either 0 (CON) or 0.25% (T1) CLA from 97 to 172kg live weight, were analysed by Ag(+)-HPLC and capillary GLC. The dietary treatment had no influence on lipid content of BF and subcutaneous adipose tissue but increased (P<0.01) the content of both isomers, more markedly in the latter tissue. CLA supplementation increased (P<0.01) myristic, palmitic, palmitoleic and total saturated fatty acids, and decreased oleic and eicosenoic acids in both tissues. In adipose tissue, an increase (P<0.05) in stearic acid content was observed. Supplementing the finishing diet of heavy pigs with CLA has thus shown to be an effective tool for increasing the CLA content in cured ham and, also, the saturated:unsaturated ratio of the lipids, a positive effect from a technological point of view. From a human nutritional standpoint, the changes occurring in fatty acid composition negatively affect the atherogenic and thrombogenic indexes, but probably these changes are of no particular concern, as they would only partly offset the progressive increase in the degree of unsaturation of heavy pig lipids that has occurred in recent years, as a consequence of reduced adipose depots in carcasses.     

Effect of dietary vitamin E supplementation on pork quality

The purpose of this experiment was to examine the effect of dietary vitamin E supplementation on pork quality, and in particular on colour stability. Crossbred pigs (n = 72) at a mean weight of 44 kg were assigned to one of two treatments. One group received, during a period of 84 days prior to slaughter, a tapioca based diet, which contained 8 mg vitamin E per kg feed. The other group received during this period the same diet, except it was supplemented with 200 mg vitamin E per kg feed. Muscle samples of longissimus thoracis and lumborum (LL) and psoas (PM) were collected at 24 hr post mortem and meat quality was assessed: pH, drip and cooking loss, shear force and intramuscular fat content. Colour stability was evaluated in fresh muscle (LL and PM) and after freezing (LL only) by measuring redness (a(?)-values) during 6 days of storage at 7 °C. TBA-values and microbiological counts were also determined during storage. Results showed that extra dietary vitamin E had no effect on pig performance (daily gain, feed efficiency, lean meat percentage) nor on meat quality traits. The vitamin E levels were five times higher in the muscles of the treated group than the control group. In comparison with fresh LL muscle, colour stability was lower in PM and after freezing. In both muscles, the vitamin E treatment reduced TBA-values, in particular after frozen storage. No effect was found on microbiological counts. Colour stability was improved in LL after 6 days of storage, but not in PM. The effect in LL is too late to be of practical significance, since pork is usually sold well before that time in The Netherlands. It is suggested that variation in feedstuff composition of the diet may possibly explain part of the variable results reported in literature for the effect of vitamin E supplementation on colour stability of pork.     

Effect of dietary oregano oil supplementation on lamb meat characteristics

The effect of dietary oregano essential oil supplementation on lamb meat characteristics was investigated. Eight male and eight female Chios lambs were divided into two equal groups. The first group was fed with the control diet consisting of concentrated feed and alfalfa hay, whereas the second group consumed the same diet, the only difference being that the concentrated feed was uniformly sprayed with oregano essential oil (1 ml/kg). Duration of the experimental period was two months.

No differences were observed after oregano essential oil supplementation in final body weight (kg), body weight gain (g) and carcass yield (%). Tenderness of longissimus thoracis muscle, expressed as sarcomere length and shear force value, was not influenced by the treatment, whereas pH and colour parameters (yellowness–redness) appeared to increase (P < 0.05). Moreover, results showed that dietary incorporation of oregano essential oil exerted strong antioxidant effects retarding lipid oxidation (MDA formation) in meat during refrigerated and long-term frozen storage (P < 0.001).     

Cosupplementation of dietary calcium and conjugated linoleic acid (CLA) improves bone mass in mice

Conjugated linoleic acid (CLA) has shown a variety of biologically beneficial effects, such as anticancer, antiatherosclerosis, antidiabetic, immunomodulating, and antiobesity effects. Its effects on reduction of body fat occur with enhancement of lean body mass and body ash; the effects of CLA on bone mass are inconsistent in mice and human studies. We hypothesized that the inconsistency of CLA's effect on ash may be linked to interaction between CLA and dietary calcium levels. We reanalyzed our previous studies, which used mice fed 0.5% CLA-containing diet with regular calcium content (0.5%) or enhanced calcium level (0.66%). Extra calcium in the diet improved CLA's effects on bone mass, particularly in male mice (P= 0.0194); without extra dietary calcium there was no effect of CLA on bone mass. This finding may help improve the efficacy of CLA to be used as a dietary supplement to be used as part of an osteoporosis prevention strategy. Further studies are needed to confirm this observation.     

Effect of dietary vitamin E supplementation on beef colour stability

The effect of dietary vitamin E upon colour, waterholding capacity, bacterial growth and lipid oxidation of beef longissimus thoracis (LT) and psoas major (PM) muscle were examined during aerobic display of fresh muscle and after aging in vacuum for 26 days. Forty crossbred beef bulls received a whole crop corn silage, supplemented with concentrate. Twenty bulls were each supplemented with 2025 mg vit E per day (added to the concentrate) for 136 day prior to slaughter and compared with non-supplemented control animals (n=20). In fresh LT muscle drip loss did not differ between treatment groups, while in PM muscle drip loss was significantly higher for the supplemented group. The treatment did not affect bacterial growth in fresh and aged muscles. Lipid oxidation during 12 day storage of fresh muscle was significantly lower for the supplemented group, as indicated by the lower TBA-values. No effect of the vitamin E treatment was observed on a (?)-values of both fresh and aged LT muscle during display for 8 and 5 days, respectively. In PM muscle, supplemented beef had lower a (?)-values in fresh (at day 1) and aged (at days 1 and 2) muscle, due to a lower oxygenation. The reason for this lower oxygenation is unclear. After aging, colour stability was decreased and more variable than in fresh muscle. Similar results were obtained when the difference in reflection values at 630 and 580 nm (R630-580), instead of the a (?) value, was used as a parameter for colour stability. The absence of an effect of vit. E on the rate of discoloration, might possibly be explained from the observation that α-tocopherol levels in control muscle were relatively high (LT: 2.1 and PM: 3.2 μg/g muscle), compared with data from literature. Analysis of the feed for vit. E suggests that this was due to a relatively high natural vit. E uptake from the feed, which was calculated to be approx. 330 mg vit. E per animal per day for the control group.     

Effect of weaning and dietary galactose supplementation on digesta glycoproteins in pigs

Changes in pig digesta mucin and glycoprotein content at weaning and with the inclusion of galactose in the postweaning diet were studied. Mucus was collected from ileal contents of cannulated pigs pre‐ and postweaning, and glycoproteins were analysed based on staining patterns and size exclusion chromatography. An increased concentration of intestinal mucin in lumen contents was observed in newly weaned pigs compared to the same pigs prior to weaning. Analysis of O‐linked oligosaccharides indicated changes in mucin structure from pre‐ to postweaning. Supplementing the diet with galactose resulted in modification of mucin in postweaned pigs compared to a control diet and may limit microbial degradation of mucin. These data indicate that weaning and the subsequent transition to a grain‐based diet result in changes to digesta mucin and endogenous glycoproteins; and dietary galactose may play a role in the final composition and quantity of these compounds. © 2000 Society of Chemical Industry     

Effect of dietary supplementation of vitamin E on pig meat quality

The effect of vitamin E on pig meat quality was investigated using British Landrace (NN and nn), Landrace × Large White (NN and Nn) and Pietrain (nn) pigs. Daily dietary supplementation of 500 mg vitamin E/kg diet for 46 days could reduce drip loss in unfrozen longissimus thoracis (LT) by 45% and 54% in Nn and NN pigs, respectively. In PSE-prone Landrace × Large White Nn pigs, daily supplementation of 1000 mg vitamin E/kg diet for the same period could significantly (P < 0.001) reduce excess release of Ca(2+) and prevent the formation of PSE carcasses, evaluated from both biopsy and post- mortem LT samples. Experimental evidence from erythrocyte fragility and water-holding capacity of biopsy LT samples suggested that vitamin E improved pig meat quality by its ability to stabilize membranes. Stabilization of membrane integrity in isolated mitochondria of LT by vitamin E was associated with inhibition of phospholipase A(2) activity.     

Effect of dietary thiamin supplementation on milk production by dairy cows

We conducted three experiments to determine the effects of dietary thiamin supplementation on milk production by dairy cows. In trial 1, 28 Holstein cows were blocked by parity and assigned randomly to either placebo or thiamin top-dress for the 8-wk experiment to provide a supplemental thiamin intake of 0 or 150 mg/d per cow. Within each of these groups, cows were further assigned randomly to two total mixed rations (TMR) for 4 wk, with the TMR treatments then reversed for a second 4-wk experimental period. Milk yield was 2.7 kg/d higher for thiamin-supplemented cows. Yields of milk fat and protein were increased 0.13 and 0.10 kg/d, respectively, by dietary thiamin supplementation. In trial 2, 20 multiparous Holstein cows were used in a crossover design with 4-wk periods. Placebo or thiamin premixes were added to TMR to provide an approximate daily supplemental thiamin intake of 0 or 300 mg/cow. Milk and protein yields tended to be 0.7 and 0.04 kg/d higher, respectively, for thiamin-supplemented cows. In trial 3, 16 multiparous Holstein cows were used in a replicated 4 x 4 Latin square with 21-d periods. Placebo or thiamin premixes were added to TMR to provide an approximate daily supplemental thiamin intake of 0 or 300 mg/cow. Dry matter intake tended to be 0.8 kg/d lower for thiamin-supplemented cows. Milk fat percentage tended to be 0.18 percentage units lower and fat yield was 0.08 kg/d lower for thiamin-supplemented cows. Thiamin supplementation tended to increase milk and component production when dietary concentrations of neutral and acid detergent fiber were lower and nonfiber carbohydrate was higher than recommended.     

加强膳食营养对长期血液透析患者营养及炎症状态的影响

目的探究加强膳食营养对长期血液透析患者营养指标及炎症反应的影响。方法收集2012年3月至2017年3月我院收治的维持性血液透析患者90例,其中43例患者采用常规护理设为对照组,另外47例患者则在常规护理的基础上给予膳食营养摄入干预护理设为研究组。比较2组患者护理干预前、后的营养指标及炎症因子水平变化情况。结果护理干预后,研究组患者的营养不良发生率明显低于对照组患者(P0.05);研究组患者的各项血清营养指标水平均明显高于对照组患者(P0.05);研究组患者的各项血清炎症因子水平均显著低于对照组患者(P0.05),差异均存在统计学意义。结论加强膳食营养干预可明显缓解长期血液透析患者的微炎症反应,并改善患者的营养状况,值得临床进一步推广应用。     

膳食纤维咀嚼片对小鼠通便功能的评价

目的研究膳食纤维咀嚼片对小鼠通便功能的作用。方法按照《保健食品检验与评价技术觃范》(2003版)中通便作用检验方法,经口分别以1.15、2.3和6.9 g/kg·BW剂量的受试物对小鼠灌胃, 15 d后测定其小肠墨汁推进率、排首粒黑便时间、5h内排粪便粒数和粪便重量。结果与空白对照组相比,2个实验模型对照组、高、中、低3剂量组体重均无显著性差异(P0.05)。与模型组比较,高剂量组首次排黑便时间明显缩短(P0.05), 5 h内排黑便粒数和重量显著增加(P0.05);高剂量组(6.9 g/kg·BW)小鼠小肠墨汁推进率无显著性差异(P0.05);中剂量组(2.3 g/kg·BW)和低剂量组(1.15 g/kg·BW)小鼠小肠墨汁推进率、首次排黑便时间、5 h内排黑便粒数和重量均无显著性差异(P0.05)。结论该膳食纤维咀嚼片具有通便作用。     

硒蛋白Se-76P对STZ诱导的小鼠糖尿病肾病模型肾功能及生化指标的影响

研究含硒蛋白（Se-76P）对链脲佐菌素（STZ）诱导的小鼠糖尿病肾病的保护作用。C57BL/6J雄性小鼠腹腔注射STZ（40 mg/kg）制备糖尿病肾病模型,将60只小鼠分为六组,正常对照组（Ⅰ组）、糖尿病肾病模型组（Ⅱ组）、模型+Se-76P低剂量组（Ⅲ组）、模型+Se-76P中剂量组（Ⅳ组）、模型+Se-76P高剂量组（Ⅴ组）和模型+胰岛素治疗组（Ⅵ组）。各组小鼠均采用皮下注射方式给药,Ⅰ组和Ⅱ组给予生理盐水;Ⅲ、Ⅳ、Ⅴ组分别给予低（20μmol/kg）、中（40μmol/kg）、高（60μmol/kg）浓度Se-76P蛋白;Ⅵ组给予5 U/kg·d胰岛素。各组连续给药4周,每周测量小鼠体重;实验结束后检测各组小鼠空腹血糖、血清肌酐（SCr）和尿素氮（BUN）水平;检测各组小鼠尿肌酐（UCr）和尿微量白蛋白（MAU）水平,并计算肌酐清除率（CCr）;检测肾组织丙二醛（MDA）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GPx）水平。与模型组相比,Se-76P各治疗组空腹血糖值均降低;SCr、BUN、UCr、MAU水平以及CCr均显著降低（p<0.01或0.05）;肾组织中MDA水平明显降低（p<0.01）,而SOD和GPx活性明显升高（p<0.01或0.05）。Se-76P可能通过提高SOD和GPx活性,提升抗氧化水平,改善STZ诱导的糖尿病肾病小鼠模型的肾功能。      

Effect of dietary cobalt supplementation on cobalt metabolism and performance of dairy cattle

Three studies were conducted with dairy cattle fed diets with added Co. The first study examined cow age and added dietary Co on Co in liver and blood. Nonpregnant, nonlactating Holstein cows were blocked by age (2.5 or 6.5 yr) and assigned to either a control diet or a diet supplemented with 9 mg Co per day. The Co concentration of liver, taken on d 60, was not affected by dietary Co but was higher in the younger cows. The cytosolic fraction of liver contained the most Co, and the subcellular distribution of Co was not affected by total Co in liver. In a second study, Holstein cows were assigned to one of three treatments of dietary Co from 21 d prepartum until 120 d postpartum. There was an interaction of time x treatment x parity such that milk yield response to Co supplementation differed between multiparous cows and primiparous cows. Supplemental Co did not increase Co in serum, colostrum, milk, or liver. Primiparous cows secreted colostrum and milk with higher Co concentrations than did multiparous cows. Likewise, serum B12 levels were higher in primiparous than multiparous cows and declined with increasing days in milk (DIM). Serum Co also decreased from 7 to 120 DIM. In a final study, a Co supplement in the starter diet did not affect Co in serum or liver of young calves. In conclusion, supplemental dietary Co did not affect secretion of Co in milk, tissue retention, or subcellular distribution of Co within the liver. Primiparous and multiparous cows differed in their milk yield response to dietary Co supplementation.     

复方海藻膳食纤维对糖尿病小鼠降血糖作用的研究

研究复方海藻膳食纤维的降血糖作用。小鼠尾静脉注射（i.v.）四氧嘧啶制作糖尿病模型,模型小鼠随机分为高、中、低剂量组、模型对照组、阳性对照组,另设空白对照组。高、中、低剂量组小鼠,每天灌胃（i.g.）相应剂量的复方海藻膳食纤维混悬液,阳性对照组灌胃200mg/kg盐酸二甲双胍,空白对照组灌胃生理盐水。灌胃30d,检测空腹血糖（FBG）、口服葡萄糖耐量（OGTT）、总胆固醇（TC）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）和甘油三酯（TG）,手术摘取小鼠胰腺组织做病理切片。与模型对照组相比:高、中剂量组空腹血糖水平极显著下降（p<0.01）,体重减少症状得到显著改善（p<0.05）;中剂量能显著改善葡萄糖耐量、升高血清HDL-C、降低TG水平,高剂量能极显著升高血清HDL-C并显著降低LDL-C、TG;病理切片结果显示,高、中剂量能有效减小胰岛β细胞受损程度。结论:复方海藻膳食纤维能有效降低糖尿病模型小鼠的血糖水平,并能有效减轻胰岛β细胞受损程度。      

Production responses of dairy cows to dietary supplementation with conjugated linoleic acid (CLA) during the transition period and early lactation

Holstein cows (n = 30) entering second or greater lactation were fed fat supplements (90 g/d of fatty acids) consisting of Ca salts of either palm fatty acid distillate (control) or a mixture of palm fatty acid distillate and mixed isomers of conjugated linoleic acid (CLA, 30.4 g/ d) from 2 wk prepartum through 20 wk postpartum to determine whether CLA would inhibit milk fat synthesis during early lactation and, in turn, affect energy metabolism of dairy cows during the transition period and early lactation. Feeding CLA did not affect DMI or plasma concentrations of glucose, nonesterfied fatty acids, or beta-hydroxbutyrate during the prepartum period and did not affect postpartum DMI. Feeding CLA reduced milk fat content by 12.5% during early lactation; however, cows fed CLA tended to produce approximately 3 kg/d more milk during the first 20 wk of lactation. Feeding CLA tended to decrease the contribution of short- and medium-chain (C < or = 16) fatty acids to milk fat. Changes in milk yield, milk fat content, and milk fatty acid composition were not apparent until after the second week of lactation. Yield of 3.5% fat-corrected milk, milk protein content, milk protein composition, and calculated energy balance were not affected by treatment. Postpartum concentrations of glucose, nonesterfied fatty acids, and beta-hydroxbutyrate in plasma and hepatic content of glycogen and triglycerides were similar between treatments. These data imply that with CLA treatment in early lactation, dairy cows decreased milk fat synthesis and appeared to respond by partitioning more nutrients toward milk synthesis rather than improving net energy balance.     

Effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged cooked beef steaks

The effect of dietary vitamin E supplementation on cholesterol oxidation in vacuum packaged, cooked, refrigerated and frozen beef steaks, was investigated. Steers (Friesian×Charolais×Black Hereford) were fed diets providing 20 or 3000 mg α-tocopheryl acetate/head/day for 135 days prior to slaughter. α-Tocopherol concentrations in M. psoas major (PM) and M. longissimus dorsi (LD) were significantly (p<0.05) increased by supplementation and were significantly (p<0.05) higher in PM than LD. Cholesterol oxidation (monitored by measuring 7-ketocholesterol formation) increased during refrigerated and frozen storage in some, but not all, groups, and tended to be higher in PM than LD. Dietary vitamin E did not affect 7-ketocholesterol formation in LD, but significantly (p<0.05) reduced concentrations in PM during refrigerated and frozen storage. Supplementation significantly (p<0.05) reduced TBARS in PM and LD, indicating that vitamin E improved oxidative stability in both muscles. The results show that dietary vitamin E supplementation inhibits cholesterol oxidation in vacuum packaged, cooked beef during refrigerated and frozen storage, but may be influenced by muscle type.     

川麦冬多糖对四氧嘧啶糖尿病小鼠的降血糖作用的实验研究

目的:研究川麦冬多糖对四氧嘧啶糖尿病小鼠的影响。方法:腹腔注射四氧嘧啶建立糖尿病小鼠模型,分别用蒸馏水、优降糖和两种不同剂量的川麦冬多糖灌胃,于给药21d测定各组小鼠空腹血糖值;分别于给药7、14、21d测定各组小鼠体重;用正常小鼠进行耐糖量实验。结果:川麦冬多糖(200、400mg/kg)能显著改善糖尿病小鼠全身症状、降低糖尿病小鼠和正常小鼠的血糖水平、减少体重的下降(p<0.05,p<0.01)。结论:川麦冬多糖对四氧嘧啶所致糖尿病小鼠有降血糖作用并能改善小鼠的耐糖力。     

Effect of dietary vitamin E supplementation on the shelf life of cured pork sausage

This study examined the shelf life of cured sausage under different packaging conditions from vitamin E supplemented pigs. One group (n=6) of crossbred pigs received a normal fattening diet containing 20 ppm α-tocopherol for 39 days before slaughter. Another group was fed a diet containing 410 ppm α-tocopherol during the same period. After slaughter, cured sausages were produced, packaged under three different atmospheric conditions, ripened for 4 weeks and then stored for 8 weeks (9?°C; 200 lux). The α-tocopherol content was recorded in the fat, liver, muscles and the sausage. TBARS, L*, a*, b* values and antioxidative capacity were evaluated in the sausage during storage. The results showed a transfer of vitamin E into tissues and sausage but no detectable effect on TBARS and colour stability. However, antioxidative effects of vitamin E were seen by provocation. Probably the effect of vitamin E in the sausage was masked by nitrite in the curing salt. The oxygen content of the packs had an influence on TBARS and colour stability.     

Effect of curcumin supplementation on blood glucose, plasma insulin, and glucose homeostasis related enzyme activities in diabetic db/db mice

We investigated the effect of curcumin on insulin resistance and glucose homeostasis in male C57BL/KsJ-db/db mice and their age-matched lean non-diabetic db/+ mice. Both db/+ and db/db mice were fed with or without curcumin (0.02%, wt/wt) for 6 wks. Curcumin significantly lowered blood glucose and HbA 1c levels, and it suppressed body weight loss in db/db mice. Curcumin improved homeostasis model assessment of insulin resistance and glucose tolerance, and elevated the plasma insulin level in db/db mice. Hepatic glucokinase activity was significantly higher in the curcumin-supplemented db/db group than in the db/db group, whereas glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly lower. In db/db mice, curcumin significantly lowered the hepatic activities of fatty acid synthase, beta-oxidation, 3-hydroxy-3-methylglutaryl coenzyme reductase, and acyl-CoA: cholesterol acyltransferase. Curcumin significantly lowered plasma free fatty acid, cholesterol, and triglyceride concentrations and increased the hepatic glycogen and skeletal muscle lipoprotein lipase in db/db mice. Curcumin normalized erythrocyte and hepatic antioxidant enzyme activities (superoxide dismutase, catalase, gluthathione peroxidase) in db/db mice that resulted in a significant reduction in lipid peroxidation. However, curcumin showed no effect on the blood glucose, plasma insulin, and glucose regulating enzyme activities in db/+ mice. These results suggest that curcumin seemed to be a potential glucose-lowering agent and antioxidant in type 2 diabetic db/db mice, but had no affect in non-diabetic db/+ mice.