锡盟地区小尾寒羊副产物营养成分分析与评价

以锡盟地区小尾寒羊的心、肝、脾、肺、肾、大肠、小肠、胃（瘤胃、网胃、瓣胃、皱胃）及血液等副产物为研究对象,对其常规营养成分、氨基酸、脂肪酸以及矿物质含量进行分析与评价。结果表明：锡盟地区小尾寒羊各副产物营养成分含量（鲜质量分数）为水分含量68.86%～83.62%、蛋白质含量11.10%～19.92%、脂肪含量0.19%～16.93%、灰分含量0.45%～3.82%;各副产物经酸水解处理后测定,含天冬氨酸、亮氨酸、赖氨酸等17 种氨基酸,其中包含人体必需的7 种氨基酸,必需氨基酸占氨基酸总量的34.44%～44.35%,且谷氨酸、天冬氨酸、亮氨酸等含量丰富;各副产物中不饱和脂肪酸含量（除羊血8.26%外）为35.56%～56.09%,其中以单不饱和脂肪酸为主,网胃、瓣胃、皱胃、大肠、小肠中油酸含量均在30%以上,且网胃、肝脏、肺脏中亚油酸含量较高;各副产物中含有多种微量元素,其中脾脏中K和Fe含量最高,4 个胃中Ca含量均较高。     

苏尼特羊不同部位肌肉抗氧化系统的差异

以放牧条件下的苏尼特羊股二头肌、臂三头肌和背最长肌3个部位的肌肉为材料,测定其丙二醛(MDA)、氧合肌红蛋白(OMb)、高铁肌红蛋白(MMb)含量、抗氧化酶活性(超氧化物歧化酶SOD、过氧化氢酶CAT、谷胱甘肽过氧化物酶GSH-Px)、抗氧化能力(降铜离子还原能力CUPRAC、自由基清除率RSA)、色差和pH值等指标,比较不同部位之间的差异。结果表明:抗氧化酶和抗氧化性能中,臂三头肌的SOD与GSH-Px活性最高,而背最长肌中的CAT活性、CUPRAC和RSA最高。背最长肌的pH值最高,而MDA、L*值、a*值和b*值均显著低于股二头肌和臂三头肌(P<0.05)。股二头肌中OMb显著高于臂三头肌和背最长肌(P<0.05),而MMb显著低于其它部位(P<0.05)。苏尼特羊肌肉中的抗氧化酶之间具有协同作用,且抗氧化酶活力的增强能提高机体抗氧化性能,降低氧化程度。整体上,苏尼特羊背最长肌中抗氧化物质含量较高,脂质氧化程度低于其它两个部位,抗氧化能力较强。     

不同巴氏杀菌处理对绵羊乳热加工特性的影响

目的探究绵羊液态乳的热加工特性。方法以牛乳为对照,分别通过低温长时杀菌((65±2)℃/30 min)、高温短时杀菌(85±2)℃/15 s)和超巴氏杀菌((121±2)℃/5 s)对绵羊乳进行杀菌处理,分析3种巴氏杀菌方式对绵羊乳pH值、黏度、蛋白沉淀量、酪蛋白粒径、zeta电位的影响,评价其热稳定性。结果相比于未处理组,3种巴氏杀菌处理均会显著增加绵羊乳pH值,超巴氏杀菌处理会引起绵羊乳黏度及蛋白沉淀量显著增大(P0.05);在高温短时和超巴氏杀菌处理下,绵羊乳酪蛋白粒径显著增加(P0.05),分别达到185.33 nm和242.70 nm。不同巴氏杀菌绵羊乳间Zeta电位无显著性差异;在同样处理条件下,牛乳黏度、蛋白沉淀量及酪蛋白粒径变化程度均小于绵羊乳。结论绵羊乳热加工特性较牛乳脆弱,加工温度易引起品质劣变,低温长时杀菌方式对绵羊乳的理化特性影响最小。     

Changes of Mineral Concentrations in Serra Cheese during Ripening and Throughout the Cheesemaking Season

Seasonal changes of the ash content and mineral concentrations in Serra cheese were studied over a typical 35-day ripening period. Statistically significant differences (at the 5% level) exist between the ash content and the concentrations of Na, K, Ca, P, Mg and Zn in cheeses during ripening. The highest concentrations of Na was obtained in cheese ripened for 7 days, whereas the concentrations of K, Ca, P, Ng and Zn decreased significantly during ripening. For 35-day-old cheeses, concentrations of Na, K and Cu were lowest and concentration of P was highest for cheeses manufactured in May. The concentration of Ca was lowest for cheeses manufactured in February. On average, the most concentrated minerals (in g kg^-1 of total solids, TS) in 35-day-old Serra cheese were Na (18·56), Ca (9·70) and P (7·92) and, at a lower level, K (1·70) and Mg (0·96). Only trace levels (in mg kg_TS^-1) of Zn (94·33), Cu (2·26) and Mn (1·25) were detected. A high mineral nutrition quality was thus ascribed to 35-day-old Serra cheese based on the average nutritional densities: 4·8 for Ca, 4·0 for P, 1·1 for Mg, 3·4 for Na, 2·4 for Zn, 0·4 for Cu, 0·2 for Mn and 0·2 for K. © 1997 SCI     

不同屠宰方式对新疆多浪羊肉品质的影响

以新疆多浪羊为研究对象,对比分析传统屠宰（对照）和3 个不同电压（90、127 V和220 V）击晕屠宰 （分别计作EST 90、EST 127、EST 220）对多浪羊肉品质的影响。结果表明：EST 90处理组成熟过程中pH值下降 速率最快,血液中的皮质醇浓度、肌酸激酶和乳酸脱氢酶活力最高,羊应激反应最剧烈,宰后1、7 d的蒸煮损失率 最高（P＜0.05）;EST 127处理组的持水力最好;电击晕对多浪羊肉嫩度有一定影响,宰后7 d各处理组嫩度显著 改善,而EST 127处理组表现最佳;EST 220处理组放血不充分,且胴体表皮有多处血斑形成;电击晕屠宰对多浪羊 肉色泽无显著影响（P＞0.05）。综合分析实验结果,EST 127处理组持水力与嫩度较优,羊应激反应较小,肉品质 相对较好,因此EST 127处理适合应用于多浪羊的屠宰加工。     

不同动物纤维的毡缩性能分析

应用毡缩球法研究了羊毛、马海毛、兔绒、山羊绒、绵羊绒和牦牛绒的毡缩性能.先测量出6种纤维的摩擦因数,然后采用毡缩球法分别测量6种纤维的毡缩性能,分析兔绒与羊毛混纺以及马海毛与羊毛混纺时混合比对纤维毡缩性能的影响.此外,还分析了羊毛和马海毛长度对纤维毡缩性能的影响.得出兔绒与羊毛混纺、马海毛与羊毛混纺时混纺比对混纺纤维毡缩性能的影响规律,以及纤维长度对其毡缩性能的影响规律.     

羊血中超氧化物歧化酶提取工艺研究——热变温度、热变时间和热变方式对SOD提取的影响及最佳工艺条件选择

目的:重点研究热变温度、热变时间、热变方式对SOD分离提取的影响,确定最优工艺参数。方法:采用正交试验设计。由正交试验得出最优组合为A2B2C2,即热变温度55℃,热变时间15min,0.01mol/lCuCl2的添加量2%。结论:热变性是羊血SOD提取的关键,按此工艺热变性后的SOD活性在1000U/mg蛋白以上。     

Influence of prion protein genotypes on milk production traits in Spanish Churra sheep

The aim of this work was to analyze the possible relationships between milk production traits and prion protein genotypes in Spanish Churra sheep. For this purpose, 2 analyses were carried out. First, an association study was performed of the prion protein genotypes of 12,533 Churra ewes and their milk yield, protein percentage, fat percentage, and somatic cell score as phenotypes, followed by a quantitative trait loci screening on the chromosome where the prion protein gene was located in this population. The latter analysis was carried out using 8 genetic markers (7 microsatellites and the prion protein genotypes) spanning ovine chromosome 13 using a daughter design. Regarding genotype frequencies, the most frequent allele was ARQ (75.90%), which linked with a high susceptibility to scrapie, followed by the resistant haplotype, ARR (18.16%). The frequency of the most susceptible allele, VRQ, was around 1%. No evidence of association or linkage between prion protein genotypes and milk traits has been detected in Churra sheep. These results indicate that increasing the ARR frequency in Churra population will not have an adverse effect on selection for milk traits included in the breeding objectives. However, the low allele frequencies for ARR should be considered in the initial stages to prevent possible bottlenecks in future genetic progress.     

新疆肥尾羊脂肪特性研究

利用顶空固相微萃取-气相色谱-质谱联用技术对新疆肥尾羊的脂肪的特性进行研究。结果表明：脂肪的碘值为59.6g I2/100g,酸值为0.095mg KOH/g,皂化值为190.9mg KOH/g;脂肪酸主要由肉豆蔻酸、棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸构成,分别占总脂肪酸总量的8.9%、23.6%、13.5%、34.9%、2.4%、1.3%;氨基酸的含量占样品总质量的0.02%,羊脂的挥发性成分主要由环丁醇、环己烷、乙酸乙酯等26种挥发性成分组成。     

In vitro ruminal biohydrogenation of eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic acid (DHA) in cows and ewes: Intermediate metabolites and pathways

A great deal of uncertainty still exists about intermediate metabolites and pathways explaining the biohydrogenation (BH) of 20- and 22-carbon polyunsaturated fatty acids (PUFA). Therefore, this study was conducted to provide further insight into the ruminal metabolism of 20:5 n-3 (EPA), 22:5 n-3 (DPA), and 22:6 n-3 (DHA), the main n-3 PUFA present in the marine lipids used in dairy ruminant feeding, and to examine potential differences between bovine and ovine. To meet this aim, we investigated the 20- and 22-carbon metabolites accumulated during in vitro incubation of EPA, DPA, and DHA with rumen inocula from cows and ewes. The PUFA were added at a dose of 2% incubated dry matter and digesta samples were analyzed after 24 h of incubation using complementary gas-liquid chromatography of fatty acid methyl esters and gas chromatography-mass spectrometry of 4,4-dimethyloxazoline derivatives. Results suggested that the main BH pathway of EPA and DPA would proceed via the reduction of the double bond closest to the carboxyl group (cis-5 in EPA and cis-7 in DPA); curiously, this mechanism seemed of much lower importance for DHA. Thus, DPA would not be a major intermediate product of DHA and their BH might actually follow separate pathways, with the accumulation of numerous unique metabolites in each case. A principal component analysis supported this hypothesis, with a clear separation between PUFA treatments in the score and loading plots. Within EPA and DPA groups, cow and ewe samples loaded separately from each other but not distant. No conjugated 20:5, 22:5, or 22:6 isomer compatible with the initial product of EPA, DPA, or DHA metabolism, respectively, was identified in the ruminal digesta, although this would not unequivocally exclude their transient formation. In this regard, results from DPA incubations provided the first indication that the metabolism of this very long chain PUFA may involve the formation of conjugated double bond structures. The BH of EPA, DPA, and DHA resulted in the appearance of several tentative trans-10–containing metabolites, showing a general trend to be more abundant in the digesta of ewes than in that of cows. This finding was speculated to have some relationship with the susceptibility of dairy sheep to marine lipid-induced milk fat depression. Differences in the relative proportion of intermediate products would also suggest an influence of ruminant species on BH kinetics, with a process that would likely be slower and less complete in cows than in ewes.