Effect of a rumen-protected conjugated linoleic acid mixture on hepatic lipid metabolism in heifers

This study was performed to assess the effects of rumen-protected conjugated linoleic acid (CLA) on hepatic lipid metabolism in heifers. In particular, it was of interest whether feeding CLA causes development of fatty liver as observed recently in mice. Thirty-six growing heifers with an initial body weight of 185 kg were allotted to three treatment groups and fed daily 250 g of different rumen-protected fats for 16 weeks: The control group received 250 g of a CLA-free control fat, the CLA100 group received 100 g of a CLA fat containing 2.4% of cis-9, trans-11 CLA and 2.1% of trans-10, cis-12 CLA and 150 g control fat and the CLA250 group received 250 g of the CLA fat. CLA supplementation had no effect on animal performance parameters, liver weight and hepatic triglyceride concentration. Moreover, mRNA expression of hepatic genes involved in lipogenesis, β-oxidation and fatty acid transport was not influenced by dietary CLA. The fatty acid composition of hepatic total lipids, with particular consideration of ratios of fatty acids indicative of Δ9-, Δ6- and Δ5-desaturation, was also less influenced by dietary CLA. In conclusion, the study shows that dietary rumen-protected CLA has less effect on hepatic lipid metabolism in young heifers and does not induce the development of a fatty liver such as in mice.     

Chemerin analog regulates energy metabolism in sheep

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500 µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high‐density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20 min but then increased gradually from 60 to 180 min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep.     

Regulation of fibroblast growth factor 9 on the differentiation of goat intramuscular adipocytes

It has been found that fibroblast growth factor receptor (FGF-FGFR) signaling can regulate the expression of adipocyte differentiation genes. FGF9 is one of the members of FGFs that mainly binds receptors FGFR2 and FGFR3. FGF9 is highly expressed in the adipose tissue of humans and mice, but there are few reports on the role of FGF9 in goat intramuscular adipocyte differentiation. Therefore, this study explored the effect of FGF9 on adipocyte differentiation through cell culture, interference, and overexpression. The expression of receptors FGFR1–FGFR4 in adipocyte differentiation and their effects on differentiation were detected to screen receptor gene of FGF9. Finally, the interaction between FGF9 and the receptor was tested by cotransfection. Our results showed that FGF9 interacts with FGFR2 to inhibit goat intramuscular adipocyte differentiation by regulating peroxisome proliferator-activated receptor gamma (PPARγ) and preadipocyte factor 1 (Pref1), which is a data support for subsequent pathway research.     

Different susceptibility to fatty liver-haemorrhagic syndrome in young and older layers and the interaction on blood LDL-C levels between oestradiols and high energy-low protein diets

1. The objective of the study was to investigate the susceptibility of young and older laying hens to fatty liver-haemorrhagic syndrome (FLHS) and to evaluate the reliability of different blood lipid fractions for predicting or diagnosing FLHS.

2. Forty young hens and 40 older hens were caged individually. Each group of hens was randomly allotted to four treatments for 21 days: either a control, an oestradiol group, a high energy-low protein diet (HELPD) group or a HELPD + oestradiol group. Blood levels of oestradiol, triglyceride (TG), cholesterol (CHOL), high density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C), liver total lipids, hepatic haemorrhagic scores and productive performance were assessed.

3. In older hens, β-oestradiol increased (P < 0.05) liver total lipids, hepatic haemorrhagic scores and the incidence of FLHS but reduced (P < 0.05) productive performance; however, such changes were not observed in young hens.

4. In two groups of hens, serum TG, CHOL and HDL-C levels were increased (P < 0.001) by β-oestradiol. Hens with FLHS had higher serum TG, CHOL and HDL-C (P < 0.001) than non-FLHS birds in the older layer group of hens.

5. An interaction (β-oestradiol × HELPD) (P < 0.05) for LDL-C levels was observed in both groups of hens. In young hens, β-oestradiol induced a decrease (P = 0.004) in serum LDL-C levels but the effect was attenuated by HELPD. In older hens, HELPD caused an increase (P = 0.02) in serum LDL-C although the effect depended on the presence of β-oestradiol.

6. In conclusion, older layers were more susceptible to FLHS than young layers after oestradiol treatment. Blood TG, CHOL and HDL-C rather than LDL-C levels can be used as a prediction tool for the overall susceptibility to FLHS in older rather than young layers. There were interactions between oestradiol and HELPD on blood LDL-C levels in laying hens.     

壳聚糖对黑白花奶犊牛脂肪代谢的影响

试验选用10日龄奶犊牛20头, 随机分到 4个日粮处理组,进行为期30 d 的饲养试验.在基础日粮中分别加入 0、200、400、600 mg/d的壳聚糖.结果表明:600 mg/d壳聚糖组相比对照组明显降低了血清中 TC含量 (P＜0.05);在试验第20和30天,600 mg/d壳聚糖组相比对照组降低了血清中高密度脂蛋白的含量(P＜0.05).     

水温、饲料蛋白及其互作效应对吉富罗非鱼生长与血清能源物质的影响

采用中心复合实验设计和响应曲面分析方法,在实验室条件下,探讨了温度(20~34℃)、饲料蛋白水平(25%~50%)及其互作效应对吉富罗非鱼(Oreochromis niloticus)幼鱼生长、饲料效率与血清能源物质(葡萄糖、甘油三酯和总蛋白)的影响。整个实验持续8周。结果表明,温度与饲料蛋白水平的一次效应对特定生长率和饲料效率有显著影响(P<0.05)。高温与饲料高蛋白水平会降低生长与饲料效率。温度的一次效应对血清葡萄糖、甘油三酯和总蛋白水平有显著影响(P<0.05)。饲料蛋白水平为37.5%时,随温度的升高,血清葡萄糖水平逐渐增加;甘油三酯和总蛋白水平呈先下降后上升的变化。饲料蛋白水平对血清葡萄糖有显著影响(P<0.05),但对甘油三酯和总蛋白水平无显著影响(P>0.05)。温度与饲料蛋白水平的互作效应对饲料效率、血清葡萄糖、甘油三酯和总蛋白有显著影响(P<0.05)。温度对生长、饲料效率和血清甘油三脂与总蛋白水平的影响较饲料蛋白明显,而对血清葡萄糖的效应则与之相反。因子与特定生长率、饲料效率、血清葡萄糖、甘油三酯及总蛋白水平这5项响应值间二次多项回归方程的决定系数分别达到0.958、0.955、0.971、0.977和0.870(P<0.01),可用于预测。综合以上实验结果,温度/饲料蛋白水平最优组合为29.9℃/40.3%,此时,特定生长率和饲料效率均较高,分别为2.748%/d和0.775,其可靠性达0.888。不同饲料蛋白水平下,水温对吉富罗非鱼血清代谢物质的影响也不同,增加水温有助于更好地利用饲料蛋白,提高血清中蛋白的分解与转化。     

茯砖茶及其配方对脂肪变性L-02肝细胞中TG含量的影响

利用1mL/L的20%医用脂肪乳剂处理L-02肝细胞48h复制非酒精性脂肪变性肝细胞,然后加入不同浓度的提取物及配方分别处理24h和48h,全自动生化分析仪检测肝细胞内的甘油三酯（TG）水平,探讨茯砖茶提取物和两个配方对脂肪变性L-02肝细胞内TG的影响。结果显示,茯砖茶提取物和配方1与自然恢复组比较均可显著降低脂肪变性肝细胞内TG的水平（P<0.05）,而与血脂康组比较无显著差异（P>0.05）,显示出茯砖茶和配方1具有广阔的开发应用前景。     

中链脂肪对肉仔鸡生长性能和血清生化指标的影响

本试验用中链脂肪等量替代基础日粮中的大豆油,研究中链脂肪对肉仔鸡生长性能和血清生化指标的影响。选取14 日龄健康、体重相近的AA肉仔鸡144只,随机分为A、B、C和D 4个组,每组6个重复,每重复6只鸡,分别饲喂用0、0.6%、1.2%和2%中链脂肪等量替代原基础日粮中的大豆油的日粮（同时用玉米粉平衡每组的能量水平）。试验期共28 d,每2周进行一次指标测定。结果表明,B、C和D组的平均日增重、平均日采食量均比A组高,料重比均比A组低,其中C和D组在28~42日龄和D组在14~42日龄的平均日增重显著高于A组（P < 0.05）;B、C和D组的血清葡萄糖、总氨基酸、总蛋白和白蛋白含量在28和42日龄时均高于A组,血清甘油三酯、总胆固醇和尿素氮的含量均低于A组,其中C组在42日龄的血清总胆固醇含量和28日龄的甘油三酯含量显著低于A组（P < 0.05）。以上结果表明中链脂肪可提高肉仔鸡平均日增重,降低血清总胆固醇和甘油三酯含量,从而促进肉仔鸡生长。     

饲粮中添加中链脂肪酸甘油三酯对母猪繁殖性能、血清生化指标及初乳成分的影响

本试验旨在研究母猪妊娠后期和泌乳期饲粮中添加中链脂肪酸甘油三酯(MCT)对母猪繁殖性能、血清生化指标及初乳成分的影响。试验选取120头纯种大白妊娠母猪(3~5胎),根据母猪预产期相近,胎次、体况、历史繁殖成绩均衡分布的原则分为3组,每组40个重复,每个重复1头母猪。对照组饲喂基础饲粮(含3.17%豆油),油剂组以0.6%纯油剂MCT替换基础饲粮中0.6%的豆油(含2.57%豆油),粉剂组在基础饲粮中添加0.5%微胶囊粉剂MCT。试验从母猪妊娠第85天开始至仔猪断奶结束。结果表明:1)与对照组相比,油剂组和粉剂组母猪产程分别提高了17.58%(P0.05)和9.21%(P0.05),母猪泌乳期平均日采食量分别提高了5.92%和10.07%(P0.05),母猪断奶后7日发情率分别提高了6.52%和4.25%(P0.05);饲粮中添加MCT对母猪其他繁殖性能指标无显著影响(P0.05)。2)饲粮中添加MCT对母猪血清生化指标均无显著影响(P0.05)。3)与对照组相比,油剂组和粉剂组母猪初乳乳脂含量分别提高了18.09%和19.09%(P0.05),饲粮中添加MCT对母猪初乳成分均无显著影响(P0.10)。由此可见,在母猪妊娠后期及泌乳期饲粮中添加MCT未能改善母猪的生产性能、血清生化指标及初乳成分,但添加油剂型MCT可显著缩短母猪产程。