贮藏温度和时间对鸡肉肌苷酸含量的影响

为了探讨不同贮藏温度和时间条件下鸡肉肌苷酸降解情况,以80日龄黄羽肉鸡为试验材料,连续7 d分别测定6、4、2和-1.5℃贮藏条件下胸肌IMP及其前体物和代谢物含量。结果显示:6℃冷藏条件下,保存2 d后鸡肉IMP含量为1.76 mg/g,为屠宰后4 h含量的76.52%,差异极显著(P0.01);4℃冷藏条件下,保存5 d后鸡肉IMP含量为1.47 mg/g,为屠宰后4 h含量的63.91%,差异极显著(P0.01);2℃冷藏条件下,IMP降解速率减缓,保存6 d后鸡肉IMP含量为1.60 mg/g,是屠宰后4 h含量的69.57%,差异极显著(P0.01);-1.5℃冻藏条件下,IMP降解速度明显减缓,一直到保存7 d后差异极显著(P0.01),鸡肉IMP含量为1.51 mg/g,为屠宰后4 h含量的65.65%。鸡肉HxR+Hx含量随着温度升高而增长,贮藏3 d后,6℃条件下HxR+Hx含量极显著高于其它3个温度条件下(P0.01)。可见,随着保存天数增加,鸡肉肌苷酸含量呈下降趋势;随着保存温度降低,降解速度减缓,研究结果对消费者和冷鲜鸡加工者具有重要的参考意义。     

反复冻融对鸡肉肌苷酸含量的影响研究

为研究反复冻融对鸡肉肌苷酸及相关核苷酸含量的影响,以42只70日龄黄羽肉鸡为研究对象,分别在屠宰后4 h以及反复冻融1、2、3、4、5和6次后测定胸肌肌苷酸(IMP)及相关核苷酸含量。结果显示:(1)IMP含量一直呈现下降趋势,反复冻融1和4次后含量分别为屠宰4 h后新鲜鸡肉的70%和50%。(2)肌苷(HxR)和次黄嘌呤(Hx)含量均呈现上升趋势,HxR含量反复冻融6次后最高,为屠宰4 h后新鲜鸡肉的2.1倍;Hx含量反复冻融5次后最高,为屠宰4 h后新鲜鸡肉的5.8倍。(3)单磷酸腺苷(AMP)和二磷酸腺苷(ADP)含量均呈下降趋势,AMP含量反复冻融1和4次后分别为屠宰4 h后新鲜鸡肉的55%和23%;而ADP含量反复冻融6次后仅为屠宰4 h后新鲜鸡肉的11%。     

不同贮藏条件对北京油鸡肌肉鲜味化合物含量的影响研究

以北京油鸡为材料,探讨贮藏条件对肌肉鲜味化合物含量的影响.北京油鸡胸肌和腿肌分别置4℃、-20℃、-80℃贮藏,采用HPLC法测定贮藏7 d胸肌的IMP及其相关化合物含量;采用日立L-8800氨基酸自动分析仪测定游离氨基酸.结果表明:肉中IMP的含量,4℃贮藏最低,与鲜肉、-20℃、-80℃差异极显著(P＜0.01),-20℃和-80℃贮藏IMP含量无显著变化;ATP、ADP、AMP含量较低,ATP和AMP在3种温度贮藏都极显著降低(P＜0.01),ADP无显著变化(P＞0.05);Hx和HxR,4℃、-20℃贮藏后含量极显著增加(P＜0.01),-80℃贮藏略高于鲜肉(P＞0.05).肉中各种游离氨基酸贮藏7 d都不同程度增加,鲜味氨基酸(Glu、Asp、Ala、Gly)贮藏7 d极显著高于鲜肉(P＜0.01),且腿肌极显著高于胸肌(P＜0.01).     

贮藏温度对不同含水量草木樨种子活力影响的研究

以草木樨(Melilotus suaveolens Ledeb)种子为试验材料,研究贮藏温度和含水量对种子活力指标的影响。结果表明:贮藏温度和含水量对草木樨种子发芽率、电导率、可溶性糖和丙二醛含量均有极显著性影响(P < 0.01),温度和含水量的交互作用对草木樨种子的发芽率、电导率、可溶性糖含量同样具有极显著性影响(P < 0.01)。随着草木樨种子含水量和贮藏温度的增加,发芽率均先增加后降低,含水量为10%,贮藏温度为4℃的草木樨种子发芽率最高,含水量为12%,贮藏温度为20℃时发芽率降为0;随着含水量和贮藏温度的增加,电导率和可溶性糖含量均先降低后增加,含水量为12%,贮藏温度为20℃时二者均达到最大值;丙二醛含量随着含水量增加而显著降低,随着贮藏温度的增加而显著增加。相关分析表明,草木樨种子的发芽率与电导率和可溶性糖含量均呈极显著的负线性相关(P < 0.01)。综合各项活力指标,草木樨种子的最适宜贮藏温度为4℃,最适宜含水量为10%。     

基于生物发光法检测冰鲜鸡新鲜度的初步研究

为了对市场上出售的冰鲜鸡进行新鲜度等级划分,研究利用生物发光法,快速检测屠宰后4、8、12、24、48、72 h的鸡胸、腿肉中ATP含量,并以此为标准将肉品新鲜度划分成不同等级。结果表明,鸡肉中ATP含量随屠宰后时间延长而不断下降,直至为零。其中,屠宰后12和24 h有小幅波动,基本符合生物体ATP降解规律。根据屠宰后不同时间鸡肉中ATP含量,将1~4 h(ATP含量大于1.00×10~(-8)mol/g)上市的鸡肉定为一级鲜品,4~24 h(ATP含量为1.00×10~(-11)~9.99×10~(-8)mol/g)内的鸡肉定义为二级鲜品,24~72 h(ATP含量为1.00×10~(-12)~9.99×10~(-11)mol/g)内的鸡肉定为三级鲜品,72 h以后(ATP含量小于1.00×10~(-12)mol/g)的鸡肉定为冻品。     

贮藏温度和种子含水量对扁穗冰草种子质量的影响

以扁穗冰草(Agropyron cristatum)种子为试验材料,研究不同温度和含水量贮藏10个月后对种子发芽率和萌发过程中生理生化变化的影响。结果表明,贮藏温度和种子含水量对发芽率、根长和芽长均具有极显著影响(P0.01),而对丙二醛含量影响均不显著(P0.05)。扁穗冰草种子在-15℃且含水量为6%的条件下发芽率最高,为79.8%,在室温(20℃)且种子含水量为12%时,发芽率为0。扁穗冰草种子在4℃且含水量为6%的条件下胚根最长;在-15℃且含水量为12%的条件下胚芽最长。贮藏温度在20℃条件下,含水量为6%和12%的种子胚根、胚芽分别表现为最短和没有发芽。扁穗冰草种子在20℃且含水量为12%的条件下电导率最大;在4℃且含水量为4%的条件下电导率最小。相关分析表明,胚根与胚芽极显著正相关(P0.01),与电导率显著正相关(P0.05),其它各指标间均不显著相关(P0.05)。综合各项活力指标,扁穗冰草种子的适宜贮藏含水量为4%~6%,最佳贮藏温度为-15~4℃。     

样品前处理方法对全株玉米青贮pH和氨态氮测定值的影响

试验旨在研究不同样品前处理方法对全株玉米青贮pH和氨态氮(NH_3-N)含量的影响。分别将20 g全株玉米青贮在不同的浸提溶液(蒸馏水、去离子水和超纯水)、浸提温度(4、30、11～18℃的室温)、浸提溶液量(90、180、270 mL)、浸提时间(0.5、12、24、48 h)条件下处理,然后测定浸提液的pH和NH_3-N含量,并计算NH_3-N占总氮(TN)的比值(NH_3-N/TN),每个处理12个重复。结果表明:3种浸提液对青贮的pH没有显著影响(P>0.05);在30℃条件下浸提的pH分别比4℃和室温条件下高0.06和0.05(P<0.05);pH随浸提液的增加而显著提高(P<0.05);浸提12 h的pH显著高于浸提0.5、24、48 h(P<0.05),浸提0.5 h与48 h的pH没有显著差异;浸提溶液的种类和温度对NH_3-N/TN没有显著影响(P>0.05);在90、180、270 mL蒸馏水中浸提后的NH_3-N/TN分别为5.62%、4.22%、3.15%(P<0.05);NH_3-N/TN随浸提时间的延长而显著提高(P<0.05)。综上,可在室温条件下将20 g全株玉米青贮在180 mL蒸馏水中浸提0.5 h后对pH和NH_3-N含量进行测定。     

不同处理对叶菜贮藏过程中亚硝酸盐含量的影响

为减少叶菜类饲料亚硝酸盐危害,探讨了不同处理及贮藏时间对叶菜中亚硝酸盐含量的影响。以白菜(Brassica pekinensis)和包菜(B.oleracea)为试验材料,经炒、煮前处理后套保鲜袋或不套保鲜袋4℃保存以及青贮,青贮贮藏6、12、24、48h和40d后取样测定,其余处理在6、12、24和48h后取样测定。结果表明,前处理对白菜和包菜中硝酸盐和亚硝酸盐含量影响显著(P0.05),而套袋和不套袋保存对硝酸盐和亚硝酸盐的含量无显著影响(P0.05),煮制与炒制后的叶菜于4℃下贮藏48h,亚硝酸盐含量不会出现大幅度增加;青贮初期亚硝酸盐有所减少,在24h(白菜)或12h(包菜)后显著增加,但后期(白菜40d、包菜48h后)又减少,特别是包菜青贮40d,其亚硝酸盐含量比青贮前还低(P0.05)。     

温度、水分对贮藏中配合饲料蛋白质的影响

试验采用2因素3水平正交组合设计,设定3个温度水平(38℃、18℃、4℃),3个水分含量水平(18%、12%、9%),测定在贮藏过程中,温度和水分对配合饲料蛋白质营养价值的影响。试验表明:温度和水分对蛋白质溶解度的影响极显著(P<0.01);对有效赖氨酸(ALys)的影响显著(P<0.05);对配合饲料粗蛋白含量和真蛋白含量的影响不显著(P>0.05)。贮藏时间的长短对粗蛋白和真蛋白的含量都不显著,但在高温(38℃)、高水(18%)条件下,影响均显著(P<0.05);对蛋白溶解度的影响极显著(P<0.01);对有效Lys的的损失影响显著(P<0.05)。     

不同贮藏条件对驼绒藜种子寿命的影响

不同含水量驼绒藜种子在室温、4～5℃和-18℃条件下贮藏4年,适度超干处理能延长种子的贮藏寿命.室温和低温下贮藏11个月后,超干燥(MC 5.28％～3.89％)和低温种子的丙二醛(MDA)含量明显地低于未超干燥种子(MC7.47％);而种子活力、脱氢酶活性和抗氧化酶POD和CAT的活性均显著地高于未超干燥种子.室温下贮藏48个月后,超干种子(MC 4.84％～3.41％)的活力与低温贮藏种子同等水平.超干燥贮藏条件下,在一定时期内驼绒藜种子活力保持较高水平;对脂质过氧化的抑制作用是提高超干燥种子耐贮藏性的生理原因之一.     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

Smart Phone Assisted City-scale Wireless Sensor Network Deployment for Transportation System Monitoring

<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.