Comparison of forage yield,silage fermentative quality,anthocyanin stability,antioxidant activity,and in vitro rumen fermentation of anthocyanin-rich purple corn (Zea mays L.) stover and sticky corn stover

The objective of this study was to observe the forage yield, silage fermentative quality, anthocyanin stability, and antioxidant activity during the storage period and in vitro rumen fermentation of anthocyanin-rich purple corn (Zea mays L.) stover (PS) and sticky corn stover (SS). Forage yield of corn stover was weighed and ensiled with two treatments: (1) hybrid sticky waxy corn stover (control), and (2) hybrid purple waxy corn stover (treatment). Samples were stored in mini-silos for periods of 0, 7, 14, 21, 42, 63, 84, and 105 d. The results showed that PS had significantly higher (P<0.05) yields of dry matter (DM), organic matter (OM), gross energy (GE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total anthocyanins than that of the SS. Anthocyanin-rich purple corn stover silage (PSS) showed higher (P<0.05) levels of DM and CP relative to the sticky corn stover silage (SSS). Although anthocyanin-rich PSS displayed a lower (P<0.05) level of pelargonidin-3-glucoside (P3G), it had higher (P<0.05) levels of peonidin (Peo) and pelargonidin (Pel) compared to the control. Delphinidin (Del) and malvidin (Mal) were not detected in SSS during the ensilage period; in PSS, Del was no longer detected after 7 d of ensilage. Specifically, total anthocyanins in anthocyanin-rich PSS decreased rapidly (P<0.05) prior to 7 d of ensilage, and then remained at relatively stable (P>0.05) constants. Compared to the anthocyanin-rich PSS, SSS displayed significantly higher (P<0.05) pH value and ammonia nitrogen (NH₃-N) content. Propionic acid (PA) at 0 d and butyric acid (BA) during the entire study period were not detected, whereas anthocyanin-rich PSS showed a higher (P<0.05) level of lactic acid (LA) than that of the SSS. Compared with the SSS extract, anthocyanin-rich PSS extract showed a higher (P<0.05) level of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and displayed a lower (P<0.05) half maximal inhibitory concentration (IC₅₀) value. Moreover, anthocyanin-rich PSS reduced (P<0.05) gas production (GP), and displayed lower levels of immediately soluble fraction and ratio of acetic acid (AA) to PA at 12 h, but the other parameters were unaffected (P>0.05) relative to the control. Taken together, the results indicated that: (1) anthocyanins could be stable in silage; (2) anthocyanin-rich PSS showed better silage fermentative quality and stronger antioxidant activity; and (3) anthocyanin-rich PSS had no negative effect on rumen fermentation parameters.     

饲料中胆汁酸对红鳍东方鲀脂肪酸组成及抗氧化能力的影响

为研究饲料中添加胆汁酸对红鳍东方鲀脂肪酸组成及抗氧化能力的影响,以鱼油为主要脂肪源,配制五种等氮饲料,以初始体重14g的红鳍东方鲀进行为期56天的投喂养殖实验。设置适宜脂肪含量(8%)的对照组,并在对照组添加0.02%及0.10%的胆汁酸,分别获得低胆汁酸添加组(BA)和高胆汁酸组(HBA)。另设一高脂组(脂肪含量12.5%,HL组)及高脂+0.02%胆汁酸组(HLBA组)。结果表明,添加胆汁酸的处理组肌肉和肝脏MUFA均低于对照组,其中HBA组显著低于对照组(P<0.05)。肌肉中n-6PUFA含量在HLBA和HL组显著低于其他组(P<0.05)。在适宜脂肪含量的三个处理组间,肝脏中的C20:0、C16:1n-7、C18:1n-9、C18:2n-6、C20:4n-6、C18:3n-3、C18:4n-3、C20:5n-3和C22:6n-3都呈现随着胆汁酸添加量增加而降低的趋势。血清超氧化物歧化酶活性和谷胱甘肽过氧化物酶活性都有随着胆汁酸添加而升高的趋势,且在高脂组显著高于对照组(P<0.05);血清谷胱甘肽还原酶则呈现相反的趋势。肝脏中谷胱甘肽过氧化物酶1的mRNA相对表达量在对照组显著高于其他组,而BA组氧化还原酶1的基因表达量显著高于对照组;在高脂组添加胆汁酸显著升高了过氧化氢酶的基因表达量。综上所述,饲料中胆汁酸的添加降低了饲料及鱼体组织中一系列长链脂肪酸的含量;胆汁酸对血清抗氧化蛋白活性的影响与其对肝脏抗氧化相关基因表达的影响结果不一致。     

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake,digestibility, plasma metabolites,ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio(F:C) and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement: whole-length forage(WL) with low F:C(50:50); WL with high F:C(65:35); short-length forage(SL) with high F:C(65:35); and SL with low F:C(50:50). Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size(~50% particles 19 mm). Dry matter intake(DMI) and organic matter(OM) intake was increased by increasing both F:C(P0.01) and forage length(FL)(P0.05), while acid detergent fiber(ADF) and neutral detergent fiber(NDF) intakes were only increased by increasing the F:C(P0.01). The digestibility of NDF was increased as the FL increased(P0.01), and it was also affected by interaction between F:C and FL(P0.05). Cholesterol(CHO)(P0.01), leptin(LP)(P0.05), and growth hormone(GH)(P0.01) concentrations in plasma were increased as dietary F:C increased. A significant increase in plasma triglyceride(TG)(P0.01), insulin(INS)(P0.05), and GH(P0.01) levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F:C diets were significantly lower than those in high F:C treatment(P0.05). Increasing the F:C enhanced ruminal acetic acid(P0.05) and acetic acid/propionic acid(P0.01). Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F:C groups(P0.05). Lower fecal scores(higher diarrhea rate) were observed in calves fed with SL hay compared to WL hay(P0.05). Denatured gradient gel electrophoresis(DGGE) bands and richness index(S) were significantly affected by the interaction between F:C and FL(P0.05), under high F:C, band numbers and richness index from WL group were higher than that from SL group(P0.05), whereas there were no differences between WL andSL groups under low F:C(P0.05). Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F:C(65:35) diet is suitable for weaned calves.     

Accuracy comparison of dry matter intake prediction models evaluated by a feeding trial of lactating dairy cows fed two total mixed rations with different forage source

Dry matter intake(DMI) prediction models of NRC(2001),Fox et al.(2004) and Fuentes-Pila et al.(2003) were targeted in the present study,and the objective was to evaluate their prediction accuracy with feeding trial data of 32 lactating Holstein cows fed two total mixed rations with different forage source.Thirty-two cows were randomly assigned to one of two total mixed ration groups:a ration containing a mixed forage(MF) of 3.7%Chinese wildrye,28.4%alfalfa hay and 26.5%corn silage diet and another ration containing 33.8%corn stover(CS) as unique forage source.The actual DMI was greater in MF group than in CS group(P=0.064).The NRC model to predict DMI resulted in the lowest root mean square prediction error for both MF and CS groups(1.09 kg d~(-1) vs.1.28 kg d~(-1)) and the highest accuracy and precision based on concordance correlation coefficient for both MF and CS diet(0.89 vs.0.87).Except the NRC model,the other two models presented mean and linear biases in both MF and CS diets when prediction residuals were plotted against predicted DMI values(P0.001).The DMI variation in MF was caused by week of lactation(55.6%),milk yield(13.9%),milk fat percentage(7.1%) and dietary neutral detergent fiber(13.3%),while the variation in CS was caused by week of lactation(50.9%),live body weight(28.2%),milk yield(8.4%),milk fat percentage(5.2%) and dietary neutral detergent fibre(3.8%).In a brief,the NRC model to predict DMI is comparatively acceptable for lactating dairy cows fed two total mixed rations with different forage source.     

Effect of oilseeds rich in linoleic and linolenic acids on milk production and milk fatty acid composition in dairy cows

Nine multiparous cows averaging 93±13 days in milk production (DIM) were used in a triple 3×3 Latin square design to determine the effects of feeding them whole roasted flaxseed, cracked roasted soybean and fresh alfalfa in the diet on milk production, milk fatty acid profiles and the digestibility of nutrients. Each experimental period lasted 30 d and a sample collection was performed during the last 7 d. The cows were fed on the control basal diet (CON) or diets containing whole roasted flaxseed (FLA) or cracked roasted soybean (SOY). All diets were fed as a total mixed ration (TMR) and had similar concentrations of crude protein (CP), Net Energy Lactation (NEL), acid detergent fibre (ADF) and neutral detergent fibre (NDF). The dry matter intake (DMI) was not significantly different (P>0.05), but tended to increase in FLA and SOY diets compared with the control (P>0.05). Cows in all treatments had a similar milk yield, although 4% fat corrected milk (FCM) yield was higher on the FLA and SOY diets than on the CON diet. Milk fat percentage (3.45%) increased in the FLA diet compared with the control (3.31%) and SOY diets (3.39%). Milk protein percentages were similar among the diets (P>0.05). There were similar digestibilities of DM, CP and ADF among the treatments and lower digestibilities of NDF and ether extract in the SOY diet compared with the CON diet. Feeding various oilseeds significantly increased the concentrations of C_18:1, C_18:3 and conjugated linoleic acid (CLA). The FLA diet decreased the ratio of omega-6 to omega-3 fatty-acids in the milk, which would improve the nutritive value of the milk.     

全收粪法与尼龙袋法测定幼羊全混合日粮养分消化率的相关性研究

选用 4只正常幼公羊及 4只装有永久性瘤胃瘘管的幼公羊 ,按 4× 4拉丁方设计 ,分别用全收粪法与尼龙袋法测定不同加工处理组合对幼羊全混合日粮 ( TMR)干物质 ( DM)、有机物( OM)、粗蛋白 ( CP)表观消化率及瘤胃 4 8h消失率的影响 ,并分析其相关性。试验结果表明 ,在含玉米秸的 TMR中 ,以尿素精料等氮代替豆饼对日粮 DM,OM,CP的表观消化率及瘤胃消失率均无明显不利影响 ( P>0 .0 5) ;在含尿素精料的 TMR中 ,玉米告的碱化处理使日粮 DM,OM的表观消化率及瘤胃消失率分别提高了 12 .90 % ( P<0 .0 1)后 ,12 .78 ( P<0 .0 1)以及 8.65( P<0 .0 5)和 8.17 ( P<0 .0 5) ,而 CP的表观消化率及瘤胃消失率均无明显改善 ( P>0 .0 5) :对含尿素精料及碱化玉米秸的 TMR进行颗粒化加工 ,并未明显影响日粮 DM,OM,CP的表观消化率及瘤胃消失率 ( P>0 .0 5)。用全收粪法与尼龙袋法测得全混合日粮 DM,OM,CP的表观消化率与瘤胃 4 8小时消失率呈强的正相关 ( P<0 .1)。因而在具备瘤胃瘘管羊时 ,可用尼龙袋法简化 TMR营养价值评定     

相同亚油酸水平日粮对绵羊瘤胃液和血液脂肪酸组成的影响

为提高反刍动物产品中CLA含量寻找植物油的有效添加模式,研究以植物油调控的相同亚油酸水平日粮对绵羊瘤胃液脂肪酸动态变化和血浆脂肪酸组成的影响.选取4只雄性、健康安装有永久性瘤胃瘘管的成年绵羊(东北半细毛羊×陶赛特羊),体重(40±1 kg),采用4×4拉丁方试验设计,研究不添加油脂组(CK组)、添加4％花生油(PO组)...     

尿素玉米青贮饲喂奶牛的观察

在农村条件下,为了对比玉米秸青贮与添加尿素后饲喂奶牛的效果,又为了研究野干草饲喂效果,于1979年4月25日至6月25日在山西省山阴县山阴城公社农场,利用纯种小荷兰牛及其杂种母牛,分三组牛进行了产奶观察,每日每头平均产奶量玉米秸青贮组为9.3±2.6公斤,尿素青贮组为9.5±4.1公斤,野干草组为9.5±3.9公斤(P>0.05),每头每日麻饼采食量玉米秸青贮组较其他二组多吃1公斤。干物质食入量以野干草组较高。泌乳划间每头每日体重变化情况是:青贮组-28克,尿素青贮组5.7克,野干草组-197克。通过试验可以看出,尿素青贮可以节省麻饼,并可增加体重。但玉米秸青贮较野干草粗硬,适口性也较差。三组牛的泌乳稳定性平均为96.2%,显示了小荷兰牛的优越性。     

油脂对泰和乌骨鸡生产性能和肌肉脂肪酸组成的影响

探讨了在日粮中添加不同油脂对泰和乌骨鸡肌肉中脂肪酸含量和组成、生产性能和常规肌肉品质的影响.80只8周龄的泰和乌骨鸡分成4组,分别饲喂基础日粮(CK)、4%鱼油、4%豆油、4%棕榈油3种试验日粮,为期3周.结果表明,在日粮中添加4%鱼油,与CK相比,鱼油能降低肌肉和血清的胆固醇含量(P<0.05).添加鱼油可以明显提高C22∶5(n-3)和C22∶6(n-3)多不饱和脂肪酸的量,与其它3组相比差异极显著(P<0.01);同时对于C18∶3(n-3)和C18∶4(n-3)多不饱和脂肪酸的量也有明显的改善作用(P<0.05和P<0.01).添加油脂可以提高肌肉中C14∶0和C16∶0(P<0.05)的含量,而对于总饱和脂肪酸的含量没有影响.而添加鱼油,还可以降低肌肉中C18∶2(n-6)脂肪酸的含量,提高C18∶3(n-6)、C22∶4(n-6)和C22∶5(n-6)不饱和脂肪酸的含量,与CK相比,差异都达到显著水平(P<0.05).与其它3组相比,添加鱼油可以降低肌肉中总(n-6)多不饱和脂肪酸的含量(P<0.05).同时,添加鱼油组的肌肉中的(n-3/n-6)的比例为0.246,能够满足人们的营养需要.     

越冬期前后菲律宾蛤仔体成分变化研究

为研究菲律宾蛤仔Ruditapes philippinarum的低温耐受机制,对采集于大连市金石滩体质量为(15.45±1.00)g的越冬期蛤仔生理生化物质(结合水、糖原、甘油、脂肪、脂肪酸和氨基酸)含量的变化进行了检测。结果表明:与越冬前相比,越冬期后菲律宾蛤仔的糖原和脂肪含量均显著降低(P0.05),甘油含量则显著升高(P0.05);脂肪酸C18∶0、C20∶4n-6、C22∶5n-6和C22∶5n-3含量显著降低(P0.05),C20∶5n-3(EPA)含量显著升高(P0.05);异亮氨酸、谷氨酸和赖氨酸含量显著升高(P0.05)。研究表明,蛤仔体成分的变化与其低温耐受能力存在密切联系,该研究可为菲律宾蛤仔越冬期管理提供理论参考。     

The effect of lactic acid bacteria inoculums on in vitro rumen fermentation,methane production,ruminal cellulolytic bacteria populations and cellulase activities of corn stover silage

The objective of this study was to investigate the effect of lactic acid bacteria(LAB) inoculums on fermentation quality and in vitro digestibility of corn stover silage. Corn stover was ensiled without(control) or with Lactobacillus plantarum(LP), Enterococcus faecalis(EF), and Enterococcus mundtii(EM) for 45 days. The fermentation characteristics were assessed, and subsequent in vitro dry matter digestibility(DM-D), neutral detergent fiber digestibility(NDF-D), volatile fatty acids(VFA), methane(CH_4) production, cellulolytic bacteria proportions and their activities per corn stover silage were also determined. There was no significant difference(P0.05) among the silage pH, lactic acid, crude protein(CP), water soluble carbohydrates(WSC) and lignocelluloses contents of different treatments. The relative proportions of Ruminococcus flavefaciens and Fibrobacter succinogenes, carboxymethyl-ocellulose and β-glycosidase activities, DM-D, NDF-D, and VFA production of in vitro incubation was higher(P0.05) for silages inoculated with LP and EF than those of the control silage. Silage inoculated with LP showed the lowest(P0.05) CH_4 production per unit yield of VFA, which was positively corresponded to the lowest(P0.05) ratio of acetate to propionate. In summary, the ensiling fermentation quality and subsequent utilization of corn stover silage were efficiently improved by inoculated with L. plantarum.     

非酒精性脂肪肝模型小鼠肝中脂肪酸组成分析

 【目的】通过检测非酒精性脂肪性肝病（NAFLD）模型小鼠肝中脂肪酸的含量,分析肝脏中脂肪酸组成与NAFLD之间的关系。【方法】采用连续6周饲喂高脂饲料并结合每周皮下注射2次CCl4的方法诱导C57BL/6J小鼠的NAFLD。小鼠肝脏中脂肪酸经乙醚提取和BF3/甲醇溶液衍生化处理后,采用气相色谱-质谱 (GC-MS) 选择离子方式进行检测。样品中脂肪酸通过检索质谱数据库和脂肪酸标准品的保留时间进行定性分析,采用外标法进行定量分析。【结果】病理学检查表明成功诱导C57BL/6J小鼠的NAFLD。与对照组相比,试验组小鼠肝中C14:0、C16:0、C18:0和C20:3含量显著升高 (P＜0.01),C15:0、C18:1、C18:2和C18:3 (n-3)含量显著降低 (P＜0.01),饱和脂肪酸（SFA）含量显著增加(P＜0.01),其余类别的脂肪酸均显著降低 (P＜0.01)。n-6 和 n-3 多不饱和脂肪酸（PUFA）的产物/前体比值显著升高(P＜0.01),n-6/n-3 PUFA [C20:4/(C20:5+C22:6)]的比值显著降低 (P＜0.01)。【结论】NAFLD小鼠肝脏中SFA含量增加、不饱和脂肪酸含量减少以及 n-6 PUFA与 n-3 PUFA代谢紊乱不仅是NAFLD产生的效果,也是促进NAFLD发展的因素。     

Liquid Chromatography-mass Spectrometry Analysis on Effect of Roughage Types on Liver Metabolic in Dairy Cows

The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry (LC-MS) were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group (CS) or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group (MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake (DMI),milk yield,milk protein (%),lactose (%) and milk fat (%) of the corn straw group were significantly lower than those of the mixed forage group (p0.05);the contents of phosphatidylcholine (PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group (p0.05);acetylcarnitine,uric acid,triacylglycerol (TG),acetal phosphatidylcholine (plasmenyl-PC),acetalphosphatidylethanolamine (plasmenyl-PE) and sphingomyelin (SM) of the corn straw group were significantly higher than those in the mixed forage group (p0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.     

Diversity shifts of rumen bacteria induced by dietary forages in dairy cows and quantification of the changed bacteria using a new primer design strategy

The partial 16 S r RNA gene sequences(100 to 500 bp) were widely used to reveal rumen bacterial composition influenced by diets, while quantification of the changed uncultured bacteria was inconvenient due to difficult designing of specific primers based on short sequences. This study evaluated the effect of forage resources on rumen bacterial diversity and developed new strategy for primer design based on short sequences to quantify the changed uncultured bacteria. Denaturing gradient gel electrophoresis(DGGE) analysis and subsequent band sequencing were used to reveal the distinct rumen bacteria composition in cows fed with two forage sources(single corn stover vs. mixed forages including alfalfa hay and corn silage). The bacterial diversity in the rumen of dairy cows fed with corn stover was lower than that with mixed forages(P0.05). The bacterium named R-UB affiliating to uncultured Succinivibrionaceae was identified, and it was abundant in the rumen of cows fed with mixed forages compared to corn stover. The full length 16 S r RNA gene sequences with identity of 97% to the R-UB 16 S r RNA gene sequence were obtained from Gen Bank and used to design specific primers to quantify uncultured bacterium R-UB. All sequences of amplicon from the new primers were of 100% identity to R-UB sequences indicating the high specificity of new primers. Quantitative PCR confirmed that abundance of R-UB in the rumen of cows fed with corn stover was lower than those fed with mixed forages(P0.01). New strategy for designing primers based on partial 16 S r RNA genes to quantify targeted uncultured bacteria was successfully developed. The rumen bacteria descending significantly in the cows fed corn stover compared to those fed mixed forages was identified as uncultured R-UB from Succinivibrionaceae.     

Effect of Different Roughages on Milk Protein and Milk Fat Synthesis in Dairy Cows

The main purpose of this study was to determine the effect of a corn straw or mixed diet on milk production, milk composition and the expression of genes associated with lactation in mid-lactation Chinese Holstein cows. In this study, 10 healthy Chinese Holstein cows were randomly assigned to two groups and fed with different diets respectively, corn straw(CS) or mixed forage(MF) diet. CS group was fed roughage consisting of 53.8% corn straw only and the forge to concentrate(F : C) ratio [dry matter(DM)] was about 40: 60. MF group was fed roughage consisting of 3.7% Chinese wildrye and 23.4% alfalfa hay, the forge to concentrate(F : C) ratio(DM) was 70: 30. All the cows were fed 8 weeks and body weight, dry matter intake, body condition score, fat, protein, lactose, milk yield, total solid and somatic cell count(SCC) were recorded. Quantitative real-time PCR(q RT-PCR) was used to analyze cow mammary gland samples representing two different diets. The results suggested that different diet types had significant effects on milk yield, lactose, milk fat, milk protein, dry matter intake and somatic cell count in dairy cows, and cows fed MF diet improved milk production and lactation performance clearly(P0.05). In addition, m RNA expression of genes ACC, m TOR, STAT5, CSN2, PPARγ, FABP3 and PTEN in MF group was extremely significantly higher than that in CS group(P0.05). m RNA expression of AKT1, FAS, SCD and SREBP1 c in MF group was significantly higher than that in CS group(P0.01). In summary, the milk yield and composition in mixed forage group were significantly improved than those in corn straw group.     

科尔沁沙地4个燕麦品种的饲草产量特性比较

对科尔沁沙地进行4个饲用燕麦(Avena satiua)品种产量特性研究,以期筛选出适合科尔沁沙地种植的优良饲用燕麦品种。结果表明：乳熟期收获的饲草产量显著高于抽穗期(P＜0.05);抽穗期饲用燕麦干草产量排序‘梦龙’＞‘甜燕1号’＞‘贝勒’＞‘牧马人’;乳熟期饲用燕麦干草产量排序‘甜燕1号’＞‘梦龙’＞‘贝勒’＞‘牧马人’;抽穗期‘梦龙’品种的株高显著高于其他3个品种(P＜0.05);‘甜燕1号’茎叶比与其他3品种比较最低,且差异显著(P＜0.05)。综合评估‘甜燕1号’和‘梦龙’可作为科尔沁沙地推广种植的饲用燕麦品种。     

Replacement of Forage Fiber Sources with Dried Distillers Grains with Solubles and Corn Germ Meal in Holstein Calf Diets

This study was carried out to determine the effect of replacement of forage fiber sources from alfalfa and Leymus chinensis with nonforage fiber sources（NFFS） from dried distillers grains with solubles and corn germ meal on calves growth, rumen development and blood parameters. 48 female and 12 male calves（（110.55±15.36） kg of body weight and 12 wk of age） were assigned randomly to four dietary treatments（15 calves/treatment） in a completely randomized design. Experimental diets were： 0% NFFS（control）, 9% NFFS（group 1）, 18% NFFS（group 2）, 27% NFFS（group 3）, and contained equivalent neutral detergent fiber and total digestible nutrients, respectively. The dry matter intake was similar among diets, averaging 3.33 kg d-1, and no differences were detected for body weight, withers height, body length and heart girth. In addition, the development of rumen, reticulum, omasum and abomasum also were similar among diets. Dry matter, crude protein, and neutral detergent fiber digestibilities increased with the increasing levels of NFFS in the experimental diets, but had no significant effect. Blood urea nitrogen, total protein and glubulin were not affected by the dietary treatment, but group 3 resulted in the highest（P〈0.05） concentrations of glucose and the lowest（P〈0.05） concentrations of triglycerides and albumin. In conclusion, dried distillers grains with solubles（DDGS） and corn germ meal（CGM） were available and alternative fiber sources for Holstein calf diets.     

日粮中添加整粒油籽对绵羊体脂主要脂肪酸组成的影响

日粮中分别添加相当于40.0 g粗脂肪的油菜籽、油葵籽、红花籽和亚麻籽,饲喂成年母羊35 d后屠宰,用气相色谱技术测定了羊体背最长肌、肾脏脂肪和尾部脂肪的主要脂肪酸(FA)组成,结果表明:日粮对肌肉中FA组成的影响较对脂肪组织的大;在所测定的3个部位中,C14∶0最为稳定,不受日粮影响;在脂肪组织中,C16∶1、C18∶1也不受日粮的影响,但肌肉中C18∶1含量因添加红花籽显著增大;添加亚麻籽有提高脂肪组织中C18∶3的趋势,其余油籽有使各部位C18∶3含量下降的趋势,以油葵组下降最为明显;除油菜籽(富含C18∶1)外,富含多不饱和脂肪酸(PUFA)的油籽有使C16∶0降低的作用.羊体不同部位脂肪酸组成存在较大的差异:C18∶1在尾脂中的含量极显著或显著地(多数情况为极显著)高于其它部位,而肾脏中含量最低;C16:1在不同部位的差异与C18∶1相同;C16∶0、C18∶0以尾脂中最低;C18∶2的含量在肌肉中最低.从尾部、肌肉到肾脏,不饱和脂肪酸(UFA)的比例降低,而饱和脂肪酸(SFA)的比例上升.不管在何部位,C18∶1在所有脂肪酸中所占比例最高;C18∶0在肾脏脂肪中占第2位,在肌肉和尾脂中占第3位,而C16∶0在肾脏居第3位,在其余部位居第2.     

中国荷斯坦牛FADS2基因3′端SNP突变对乳中脂肪酸组成的影响

【目的】FADS2是多不饱和脂肪酸合成中关键的限速酶之一,可催化食物中亚油酸(LNA,C18:2n6)合成γ-亚麻酸(GLA,C18:3n6)、二十碳五烯酸(EPA,C20:5n3)、二十二碳六烯酸(DHA,C22:6n3)等长链脂肪酸。试验旨在探讨中国荷斯坦牛FADS2基因3′端非编码区SNP突变对乳中脂肪酸含量的影响。【方法】随机选择20头无亲缘关系的中国荷斯坦牛样本,用直接测序列法检测FADS2基因3′端非编码区SNP突变位点。再以江苏某大型奶牛场551头中国荷斯坦牛为材料,用飞行时间质谱法对前期发现的2个SNP位点进行检测,同时利用最小二乘模型分析了SNP突变及其单倍型对乳中脂肪酸含量及其不饱和指数的影响。【结果】中国荷斯坦牛FADS2基因3′端非编码区存在3个SNP突变位点:c.1571 AG、c.2743 AG、c.2776 AG。c.1571 AG位点GG型为优势基因型,基因型频率为0.800,G为优势等位基因,基因频率为0.887。c.2776 AG位点AA为优势基因型,基因型频率为0.673,A为优势等位基因,基因频率为0.819。χ~2检验表明:c.2776 AG位点基因型分布均符合Hardy-Weinberg平衡(P0.05),而c.1571 AG位点基因型分布均偏离Hardy-Weinberg平衡(P0.05)。FADS2基因c.1571 AG位点与c.2776 AG位点间连锁不平衡系数r2为0.028,未达到显著水平(P0.05)。c.1571AG位点与c.2776 AG位点有3种单倍型,GA、GG和AA频率分别为0.705、0.181和0.114。多因素方差分析表明:FADS2-1571对C14:1含量、C14和C18不饱和指数的影响达到极显著水平(P0.01),对C18:0、SFA和MUFA含量的影响达到显著水平(P0.05)。GG型个体乳中C14:1含量、C14和C18不饱和指数显著高于AG型(P0.05)。FADS2-2776位点对C16:1含量、C16和C20不饱和指数的影响达到极显著水平(P0.01),对C14:1含量的影响达到显著水平(P0.05),GG型个体乳中C16:1含量、C16和C20不饱和指数显著高于AG型和AA型(P0.05)。同时,FDAS2-1571-2776单倍型对C16:1含量和C20不饱和指数的影响达到显著水平(P0.05),单倍型GG型个体乳中C16:1含量和C20不饱和指数显著高于GA型和AA型(P0.05)。【结论】FADS2基因3′端非编码区SNP突变对中国荷斯坦牛乳中脂肪酸组成有重要影响。在进一步验证其功能情况下,可作为影响中国荷斯坦奶牛乳脂肪酸组成的主效基因加以利用。     

周期性饥饿对鮸幼鱼肌肉中主要营养成分的影响

在水温为（22±2）℃条件下,研究了周期性饥饿对早繁鮸Miichthys miiuy幼鱼肌肉中主要营养成分的影响。试验分为6组：一直投喂（S0组）、隔日投喂（S1组）、饥饿3 d投喂3 d（S3组）、饥饿6 d投喂6 d（S6组）、饥饿9 d投喂9 d（S9组）和饥饿12 d投喂12 d（S12组）。结果表明：随着周期性饥饿时间的延长,鮸幼鱼肌肉水分的含量明显上升,各饥饿组鱼的水分与对照组相比差异显著（P〈0.05）;蛋白含量呈下降趋势,S1、S3组与S0组无显著性差异（P〉0.05）,S6、S9、S12组间有显著差异（P〈0.05）,且这3组与S0组之间蛋白含量均存在显著性差异（P〈0.05）;脂肪和糖类含量明显下降,除S1、S3、S6组外,其余各组间脂肪含量均具有显著性差异（P〈0.05）,而各组间糖类含量均有显著性差异（P〈0.05）。鮸幼鱼肌肉中天冬氨酸、谷氨酸、亮氨酸和赖氨酸的含量均较高。经过不同时间周期性饥饿后,各试验组鱼中各种氨基酸的含量和氨基酸总量与S0组均差异显著（P〈0.05）,必需氨基酸总量呈现先下降后上升的趋势。随着饥饿时间的延长,饱和脂肪酸（SFA）显著下降（P〈0.05）,按下降的百分比计,下降趋势为C21：0〉C17：0〉C18：0〉C15：0〉C14：0〉C22：0〉C24：0〉C16：0〉C23：0;单不饱和脂肪酸（MUFA）呈现先下降后上升的趋势;而多不饱和脂肪酸（PUFA）呈现先上升后下降的趋势,按上升的百分比计,上升趋势为C18：3n-3〉C20：4n-6〉C20：5n-3〉C18：3n-6〉C22：6n-3〉C18：2n-6。说明鮸幼鱼在周期性饥饿过程中,首先利用饱和脂肪酸,然后利用低不饱和脂肪酸,最后才动用高不饱和脂肪酸。双键位置不同的脂肪酸在饥饿过程中的损失速度也有差异,具体为∑n-9 PUFA〉∑n-6 PUFA〉∑n-3 PUFA。