Cholesterol requirement and phytosterols efficiency in semi‐purified diets of juvenile Pacific white shrimp Litopenaeus vannamei

Studies pertaining to cholesterol requirement are limited based on the levels evaluated and statistical analysis. Two trials were conducted to refine cholesterol requirement in Pacific white shrimp Litopenaeus vannamei feeds. The basal diet was supplemented with graded levels of cholesterol (ranging from 0.48 to 1.85 g/kg) in trial 1. Since the shrimp (initial weight: 0.24 g) growth response was very linear without reaching a plateau, it was not clear whether the requirement was met. Hence, a second trial was designed using eight diets designed with an increased range of cholesterol levels from 0.45 to 4.57 g/kg of diets. The shrimp (0.38 g initial weight) reached a final weight of (4.31–7.43 g) or per cent weight gain from 1,014%–1,874% (n = 4) after 6 weeks. Saturation kinetic model and broken‐line models with linear or quadratic ascending portions were used to evaluate dose–response relationships of feed efficiency (FE), thermal‐unit growth coefficient (TGC), whole‐body cholesterol (CHOL) and cholesterol deposition (CHOLD) against dietary cholesterol. The cholesterol requirement of shrimp was estimated at 1.9 (1.1–4.3) g/kg, 1.7 (1.1–3.4) g/kg, 2.5 (2.3–2.9) g/kg and 2.7 (2.4–3.1) g/kg of shrimp diet for FE, TGC, CHOL and CHOLD, respectively. Additionally, based on improved growth, the inclusion of phytosterol can serve as a partial replacement for cholesterol.     

大蒜对肉鸡血脂指标和组织胆固醇含量的影响

本试验研究了日粮中的大蒜水平对肉鸡脂质代谢的影响及其降低组织中胆固醇的效果。将180只7日龄AA肉鸡随机平均分为日粮中不添加大蒜的对照组,添加1%和2%风干大蒜的试验组,饲养至49日龄时从各组取6只鸡,采集血样、肝脏和胸腿肌,分别测定血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)、极低密度脂蛋白(VLDL-C)、高密度脂蛋白(HDL-C)和血浆中还原型谷胱甘肽的水平,以及肝脏、胸腿肌的组织中胆固醇的含量。结果表明:与对照组相比,添加1%和2%大蒜的两组,血清TC、TG、LDL-C、VLDL-C显著降低(P<0.05),HDL-C显著升高(P<0.05);还原型谷胱甘肽的水平和胸腿肌、肝脏组织中胆固醇的含量显著降低(P<0.05),而1%和2%大蒜的两水平间相比胆固醇含量无显著差异。日粮中添加1%、2%的大蒜,具有降低肉鸡的血脂和鸡肉、肝脏组织中胆固醇含量的效果,两大蒜添加水平间降低肌肉、肝脏胆固醇含量的效果没有明显的差异。     

Serum and liver lipids of rats fed rubber seed oil

Crude rubber seed oil (RSO) was incorporated at the 5% level in diets free of cholesterol or containing 1% cholesterol, respectively. These studies were initiated for the purpose of evaluating the palatability and potential toxicity of RSO. Corn oil was used as a control. A considerable amount of unsaponifiable matter was detected in RSO. In addition, RSO was found to possess a fatty acid profile which was fairly different from that of corn oil, primarily due to a much higher content of linolenic acid and a lower content of linoleic acid in RSO. No adverse effects on food intake and average daily gain were observed in rats fed RSO in both cholesterol-free and cholesterol diets. The presence of RSO in cholesterol-free diets results in lower (p<0.05) serum and liver total cholesterol levels than in control animals. A relative hypercholesterolemic effect compared to corn oil was observed however, when RSO was added to diets containing 1% cholesterol. In summary, the physicochemical properties of RSO as well as the presence of cholesterol in the diet are important factors in evaluating the cholesterolemic effect of RSO.     

Plasma lipids in normal cows around partus and in cows with metabolic disorders with and without fatty liver

Free fatty acids, cholesterol and phospholipids in plasma were studied from 6 weeks before to 6 weeks after calving in 16 normal multiparous cows. The same plasma lipids were studied the day after calving in 20 normal primiparous cows. Ten of these were fed according to standards and the other 10 were overfed the last 3 weeks prepartum. The plasma lipids were also analysed in 16 cows with left displacement of the abomasum and fatty liver, and in 16 cows with ketosis with no or only slight fat infiltration of the liver. In the normal cows there was a rise in FFA-level and a reduction in cholesterol and phospholipids from 6 weeks before to the day after calving. Thereafter there was a reduction of FFA-level and rise in cholesterol and phospholipids. Increased feed intensity had no effect on plasma lipids at calving. The level of the plasma lipids in cows with fatty liver differed very much from the amounts in normal cows at corresponding time from calving. Cows with ketosis had high FFA-level but the amount of cholesterol and phospholipids differed very little from normal cows.     

The Effects of Dietary Fatty Acid Pattern on Layer's Performance and Egg Quality

The feeding trial was conducted to determine the effects of flaxseed on layer's performance and egg quality,and the effects of the dietary ratio of ω-6 fatty acid to ω-3 fatty acid on fatty acid deposition in yolk using flaxseed as resource of ω-3 fatty acid and sunflower seed as resource of ω-6 fatty acid.192 20-wk-old Newroman commercial hens were randomly divided into 4 treatment groups with 6 replicates containing 8 birds.The rations corresponding with the four treatments were formulated with 4% flaxseed + 9% sunflower seed,8% flaxseed + 18% sunflower seed,15% flaxseed,and soybean meal,respectively.Sunflower seed was unshelled and flaxseed was whole.Ratios of to-6 fatty acid to ω-3 fatty acid in 4 dietary treatments were 5.67,5.21,1.07,and 11.83,respectively.It can be concluded that long-term feeding 15% flaxseed had no significant(P＞0.05)influence on egg production,egg weight,eggshell quality,yolk weight,and percentage of yolk weight.Dietary ratio of ω-6 fatty acid to ω-3 fatty acid had impact on the ω-3 fatty acid levels in yolk,nevertheless yolk fatty acid profiles were different from those of dietary fatty acid compositions.     

DECR1 and ME1 genotypes are associated with lipid composition traits in Duroc pigs

Variation at the porcine DECR1 and ME1 genes has been associated with meat quality traits and backfat thickness in Landrace pigs, respectively. However, it has not been investigated yet whether DECR1 and ME1 genotypes influence lipid composition. With this aim, we have genotyped two missense DECR1 substitutions (c.160G>C and c.437G>C) and one silent ME1 (c.576C>T) polymorphism in 361 Duroc barrows distributed in five half‐sib families and phenotyped for serum lipid concentrations and intramuscular fat content and composition traits. At the whole‐population level, relevant associations, that is, with a posterior probability of the allele substitution effect to be over or below zero (PPN0) > 0.90, were observed between DECR1 genotype and serum cholesterol (CHOL) (PPN0 = 0.932) and LDL concentrations (PPN0 = 0.945) at 190 days, as well as between ME1 genotype and longissimus dorsi saturated fatty acid content (PPN0 = 0.924). At the within‐family level, we found relevant associations between DECR1 and ME1 genotypes and diverse lipid composition traits, but most of them were family‐specific. Discrepancies in allele substitution effects estimated in half‐sib families might be produced by many factors such as number of individuals, marker allele frequencies and informativeness in each family, unaccounted random genetic and environmental effects, epistasis and family‐specific differences in the linkage phase or amount of linkage disequilibrium between causal and marker mutations. This lack of consistency across families, combined with the fact that the ME1 mutation is synonymous and that the two DECR1 polymorphisms are conservative, suggests that the associations found are not causative.     

Dietary Onion Intake as Part of a Typical High Fat Diet Improves Indices of Cardiovascular Health Using The Mixed Sex Pig Model

The aim of this study was to evaluate the potential health benefits of onions consumed at two levels of intake, using the pig model. The dietary fat content was set at a level typical of a “western” diet (25% w/w). Fifteen female and fifteen male pigs (Large White × Landrace) were allocated to one of three dietary treatments in a randomised block design. Treatments consisted of control diet (no onion) and onion supplementation at either 8.6 or 21.4 g of onion/MJ DE fed for six weeks. Onion consumption reduced plasma triglyceride levels by 15% (P=0.030) regardless of sex and onion dose. Total plasma cholesterol and cholesterol fractions were unaffected by onion supplementation (P > 0.050). The bioactivity of onion was evident in haematocrit measures, where red blood cell and haemoglobin were significantly reduced in a dose dependant manner (P < 0.001 and P=0.011, respectively), while other cell counts, with exception of segmented neutrophils (−18%, P=0.012), were largely unaffected. Serum oxidative status was improved (P=0.007) in pigs consuming onions. These data demonstrate that consumption of onions can have positive health effects in both male and female pigs consuming a high fat diet.     

Kisspeptin-10对鹌鹑开产及胆固醇代谢的影响

为了探索kisspeptin-10(Kp-10)对禽类产蛋启动和脂代谢的影响,将75羽22日龄雌鹌鹑随机分为3组:腹腔注射300μL生理盐水组(对照组,C),注射0.1 nmol Kp-10(低剂量组,L)和1 nmol Kp-10组(高剂量组,H),每日注射1次,连续注射3周。记录鹌鹑开产情况并于60日龄时采集血液和肝脏组织,检测血清中雌二醇(E2),血清和肝脏中总胆固醇(Tch)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的含量,以及肝脏胆固醇代谢相关因子mRNA和蛋白水平。结果表明:与对照组相比,L组和H组鹌鹑开产率分别显著和极显著提高(P<0.05和P<0.01);注射Kp-10增加血液E2浓度且于高剂量时达显著水平;H组鹌鹑血清Tch和HDL-C浓度显著降低,肝脏Tch显著升高;L组血液和肝脏HDL-C浓度显著降低;H组鹌鹑肝脏中胆固醇7α-羟化酶(CYP7A1)mRNA转录极显著增加,而3-羟-3-甲基戊二酸单酰CoA还原酶(HMGCR)mRNA、固醇调节元件结合蛋白(SREBP-2)mRNA转录和蛋白表达均无显著性差异(P>0.05)。结论:产蛋前注射Kp-10可显著提高鹌鹑开产率,增加雌激素分泌水平,增强肝脏合成胆固醇的能力。