Influence of amount and type of dietary fat on deposition, adipocyte count and iodine number of abdominal fat in broiler chickens

This study described the relation between the type and amount of dietary fat on the deposition of abdominal fat by broiler chickens. It was hypothesized that at higher fat intakes, the well-known lowering effect of polyunsaturated fatty acids on the deposition of abdominal fat would be diminished. Experimental diets were formulated to contain three levels of added fat (3%, 6% and 9%). Each level had different proportions of the saturated fatty acids (SFA) and unsaturated fatty acids (UFA) by installing the ratios of 1:1, 1:2, 1:3, 1:4 and 1:5 with the use of tallow and soybean oil. Arbor Acres chicks, aged 7 days, were fed one of the 15 experimental diets until they were aged 42 days. Feed and water were provided ad libitum. There was no systematic effect of the dietary fat type and the amount on the weight gain and the feed intake. The lowest SFA:UFA ratio of 1:5 produced the lowest feed conversion rates, irrespective of the amount of the fat in the diet. The abdominal fat deposition was similar in the birds fed on diets containing either 3% or 6% added fat, but deposition was lower than in those fed 9% fat. A decrease in the SFA:UFA ratio of the diet was associated with a dose-dependent decrease in abdominal fat, irrespective of the amount of fat in the diet. This observation leads to the rejection of the hypothesis stated above. A decrease in the dietary SFA:UFA from 1:1 to 1:4 caused a decrease in the number of the fat cells per surface unit of breast meat. It is concluded that an increased intake of soybean oil at the expense of tallow reduced the abdominal fat deposition and the number of fat cells in the breast meat of broiler chickens.     

快速与慢速肉鸡脂肪生长与肌苷酸含量比较

本试验旨在相同条件下,比不同品种和性别肉鸡的脂肪生长量和肌苷酸含量及其相互关系。比较发现:(1)快速与慢速肉鸡的各项脂肪指标均无显著差异(p>0.05),但慢速鸡的肌肉脂肪、皮下脂肪和腹脂率分别比快速鸡高7%、13%和37%;(2)慢速肉鸡肌苷酸含量比快速高50%,且差异显著(p<0.05);(3)母鸡皮下脂肪(p<0.01)和腹脂率(p<0.05)显著高于公鸡,母鸡肌间和肌肉脂肪也分别高于公鸡6%和12%(p>0.05);(4)肌苷酸与腹脂率存在显著正相关(r=0.61,p<0.05)。     

模拟氮沉降和收获期对秋萌东方旱麦草生长与饲用品质的影响

短命植物东方旱麦草(Eremopyrum orientale)广泛分布于新疆北部,适时萌发,有助于缓解春季饲草短缺。为探究氮沉降和收获期对秋萌东方旱麦草生长与饲用品质的影响,本试验采用人工模拟方式,设置0 kg·ha^-1·a^-1,30 kg·ha^-1·a^-1,60 kg·ha^-1·a^-13个氮添加处理和2个收获时期(拔节孕穗期和开花期),分析不同处理下秋萌东方旱麦草生长指标和饲用品质指标变化。结果表明：在30 kg·ha^-1·a^-1,60 kg·ha^-1·a^-1氮添加条件下,秋萌东方旱麦草的株高、叶长、叶宽、分蘖数、茎粗、平均地上鲜重、粗蛋白和粗脂肪含量均高于0 kg·ha^-1·a^-1;同时,中性洗涤纤维、酸性洗涤纤维含量降低。与第一收获期相比,第二收获期东方旱麦草粗蛋白含量显著降低,中、酸性洗涤纤维与粗脂肪含量升高,平均地上生物量无差异。综合考虑东方旱麦草秋萌株的生长与饲用品质,在第一收获期(拔节孕穗期)和60 kg·ha^-1·a^-1氮添加下可获得最优饲草,但30 kg·ha^-1·a^-1较低水平氮沉降也能显著提升其生产力与饲用品质。     

Abnormal ocular pigment deposition and glaucoma in the dog

The combined occurrence of ocular pigment deposition and glaucoma has been described in Cairn Terriers. Recently, this condition was also observed in two other breeds: the Boxer (two cases) and the Labrador Retriever (one case). Six dogs were referred to the Ophthalmology section of the Department of Clinical Sciences of Companion Animals and to a private referral clinic because of glaucoma or blindness in one or both eyes. In five cases ophthalmic examination showed pigment depositions in the sclera around the entire circumference of the perilimbal zone. Eight enucleated eyes (four eyes of two Cairn Terriers, three eyes of two Boxers and one eye of a Labrador Retriever) were examined microscopically. All eyes showed the same findings: an extensive infiltration of large melanin-containing cells with an eccentric nucleus, located in the iris, ciliary body, retina, choroids and sclera. Transmission electron microscopy of two of the examined eyes revealed that the morphology of most of these cells was consistent with melanophages. While reports in the veterinary literature concerning this condition are limited the cells concerned have been described to be melanocytes. Further research is needed to conclusively identify the cell type. As described in the present report, the histologic and transmission electron microscopic findings suggest a different etiology of the ocular pigment deposition and glaucoma compared with the pigment dispersal syndrome in humans.     

增温和氮添加对长江源区高寒沼泽草甸生态系统呼吸的影响

为探究高寒湿地生态系统对气候变化的响应,本研究对模拟增温（2.64℃）、氮添加（40 kg N·ha^-2·yr^-1）及其交互处理下的高寒沼泽草甸生态系统呼吸进行了2个生长季的监测。结果表明：增温显著提高了高寒沼泽草甸生态系统呼吸（约25%）,而氮添加对高寒沼泽草甸生态系统呼吸无显著影响;增温降低了高寒沼泽草甸生态系统呼吸对土壤温度变化的敏感性。在相对温暖的2015年生长季,增温和氮添加对生态系统呼吸起到协同促进作用。分析发现高寒沼泽草甸生态系统呼吸主要受表层土壤温度、植物生物量和土壤可溶性有机碳的影响;增温显著提高了植物地上和地下生物量,增强了自养呼吸,是增温提高生态系统呼吸的主要原因。本研究结果表明相比于大气氮沉降增加,高寒沼泽草甸生态系统呼吸对气候变暖的响应更加敏感。     

家禽脂肪酸代谢及其在禽蛋中的沉积和营养调控

在肝脏中载脂蛋白作用下,内源合成或外源获取的脂肪酸以甘油三酯的形式同胆固醇及其他脂类组装形成极低密度脂蛋白(VLDL)。VLDL经血液循环到达卵巢,穿过卵母细胞外层屏障后,经卵母细胞受体介导的内吞作用进入卵母细胞发生沉积。而机体的营养状况或饲粮中营养成分的改变可通过影响脂肪酸的从头合成或VLDL结构直接或间接影响禽蛋中脂肪酸的最终沉积。本文阐述了家禽体内脂肪酸的来源、转运与沉积过程,并探讨了脂肪酸代谢及其在禽蛋中沉积的营养调控。     

乳酸菌对朗德鹅填饲效果的影响

为探讨乳酸菌在填饲过程中对朗德鹅产肝性能、脂肪沉积、屠体性能、养分表观消化率及血清生化指标的影响,试验选用108只健康、体重相近的12周龄朗德鹅,随机分为试验A组、试验B组和对照组,每组6个重复,每个重复6只。对照组填饲日粮为无乳酸菌菌液的基础日粮,试验A、B组于正式填饲前期(1~5 d)分别在基础日粮中添加2 000、3 000 g/t乳酸菌菌液;正式填饲中期(6~15 d)分别在基础日粮中添加3 000、5 000 g/t乳酸菌菌液;正式填饲后期(16~25 d)不添加乳酸菌菌液。结果表明,与对照组相比,日粮中添加乳酸菌使填饲朗德鹅肥肝成熟期延长(P<0.05),淘汰率降低;与对照组相比,日粮中添加乳酸菌使填饲朗德鹅肝脏脂肪沉积比例下降,试验B组肥肝重、肝脏重/(肠脂重+腹脂重)、肝脏重/填饲期增重显著降低(P<0.05);各组间屠体性能指标均无显著性变化(P>0.05);与对照组相比,试验B组粗脂肪表观消化率显著升高(P<0.05),试验A、B组钙、磷的表观消化率显著升高(P<0.05);与对照组相比,试验A、B组血清中甘油三酯、胆固醇和极低密度脂蛋白含量显著降低(P<0.05)。综上所述,饲喂添加乳酸菌的日粮虽可促进鹅体健康,但会延缓鹅肝脏脂肪的沉积,不利于鹅肥肝生产。因此,生产中不宜在朗德鹅填饲日粮中添加乳酸菌。     

Effect of melatonin on visceral fat deposition,lipid metabolism and hepatic lipo-metabolic gene expression in male rats

Melatonin (MT) influences lipid metabolism in animals; however, the mechanistic effect of melatonin on liver fat and abdominal adipose deposition requires further clarity. In order to study the effects of melatonin on lipid metabolism, and hepatic fat and abdominal adipose deposition in animals, twenty Sprague–Dawley (SD) rats of 6 weeks of age with similar bodyweight were randomly divided into two groups: control (CTL) and MT-treated (10 mg/kg/day). During a 60-day experiment, food intake and bodyweight were measured daily and weekly respectively. At the end of treatment, blood samples were collected to collect plasma to quantify hormones and metabolic indicators of lipid metabolism. In addition, organ and abdominal adipose depots including liver, and omental, perirenal, and epididymal fat were weighed. Liver tissue was sampled for sectioning, long-chain fatty acid (LCFA) quantification, and gene chip and Real-time quantitative PCR (qPCR) analyses. The results showed that liver weight and index (ratio of liver weight to body weight) in MT group reduced by 20.69% and 9.63% respectively; omentum weight and index reduced by 59.88% and 54.93% respectively, and epididymal fat weight reduced by 45.34% (p = 0.049), relative to CTL. Plasma lipid indices, triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and total cholesterol (TC) with MT treatment decreased significantly compared with the control. Fat and 8 LCFA content in liver in MT group also decreased. Gene chip and qPCR demonstrated that there were 289 genes up-regulated and 293 genes down-regulated by MT. Further analysis found that the mRNA expression of lipolysis-related genes increased, while the mRNA expression of lipogenesis-related enzymes decreased (p < 0.05) with MT. This study concluded that melatonin greatly affected fat deposition, and hepatic LCFA supply and the expression of genes associated with lipogenesis and lipolysis.     

0~4周龄云岭红肉鸡赖氨酸适宜需要量的研究

试验通过分析饲粮不同赖氨酸水平对云岭红肉鸡生长性能、氮沉积率及血液生化指标的影响,确定云岭红肉鸡饲粮赖氨酸的适宜需要量。采用单因素试验设计,将180只健康状况良好、体重相近的1日龄云岭红肉鸡随机分为5个处理组,每组3个重复,每个重复12只鸡。5组试验鸡饲喂的饲粮赖氨酸水平分别为0.85%、0.95%、1.05%、1.15%、1.25%。结果表明:赖氨酸水平对试验鸡的期末体重、全期增重、平均日增重及料重比有显著影响(P<0.05),当赖氨酸水平为1.15%时期末体重最大739.21 g,全期增重最大701.66 g,平均日增重最大24.19 g,料重比最低1.68。不同赖氨酸水平对丝氨酸、甘氨酸和组氨酸的表观代谢率影响显著(P<0.05)。对血清总氨基酸和血清尿素氮影响显著(P<0.05)。研究表明,0~4周龄云岭红肉鸡适宜赖氨酸水平最适量为1.15%。     

Tracing Pb Pollution Penetration in Temperate Podzols

We combine high‐resolution soil sampling with lead (Pb) analyses (concentrations and stable isotopes) in two temperate podzols, together with previous data obtained with selective Al and Fe dissolution techniques. We aim to assess how atmospheric Pb is incorporated into the soils during pedogenesis. Partial least squares modelling for Pb concentrations shows that the podzolization process has the largest effect on Pb concentration (80·3% of the variance). The proportion of inorganic secondary compounds, the input of fresh organic matter from the soil surface and the relative abundance of Fe versus Al are responsible for a small part of the Pb concentration variance. Lead isotopic composition (²⁰⁶Pb/²⁰⁷Pb ratios) depends on soil organic matter content either fresh/poorly humified (57·3% of the variance) or humified (24·7% of the variance). The Pb linked to inorganic compounds and the overall podzolization process play a minor role in isotopic signature (5·3 and 3·7% of the variance respectively). Soil pH appears to be the controlling variable of the different transport and retention mechanisms. The relatively low isotopic ratios observed in spodic horizons result from geogenic Pb released through the preferential dissolution of the isotopically distinct most weatherable minerals of the parent material in the eluvial horizons, which undergoes downward mobilization. An accurate knowledge of soil reactive components and formation mechanisms is essential to a correct diagnose of the scope of Pb pollution and a more effective design of remediation strategies. Copyright © 2017 John Wiley & Sons, Ltd.