能量与吡啶羧酸铬的互作效应对肥育猪肉质性状的影响

试验旨在研究能量与吡啶羧酸铬的互作效应对肥育猪肉质性状的影响。选择体重60 kg左右,杜×长×大三元杂交肥育猪36头,分为4组,分别饲喂低能日粮、低能+吡啶羧酸铬日粮、高能日粮、高能+吡啶羧酸铬日粮进行试验,对肥育猪背最长肌的肉色、pH值(屠宰后24 h)、大理石花纹、肌内脂肪(intramuscular fatI,MF)含量、剪切力、滴水损失、熟肉率、肌肉糖原含量指标进行测定。结果表明:①能量水平对肉色评分、滴水损失有极显著的影响(P<0.01);②能量水平对肌内脂肪(IMF)有显著影响(P<0.05);③能量水平对pH值、大理石花纹、剪切力、熟肉率、肌糖原含量均无显著影响(P>0.05);④添加吡啶羧酸铬对肉色评分、pH值I、MF、大理石花纹、滴水损失有极显著的影响(P<0.01);⑤添加吡啶羧酸铬对熟肉率、肌糖原含量有显著影响(P<0.05);⑥添加吡啶羧酸铬对剪切力无显著影响(P>0.05);⑦能量与吡啶羧酸铬互作对大理石花纹、熟肉率有显著影响(P<0.05);对其他肉质性状均无显著影响(P>0.05);⑧在低能日粮中添加200μg/kg吡啶羧酸铬,提高了肉色评分p、H值I、MF含量、大理石花纹和熟肉率;并降低了肌糖原含量。综上所述,在育肥后期采用低日粮能量水平并添加200μg/kg吡啶羧酸铬可改善肉质。     

不同来源有机铬对断奶仔猪生产性能影响的研究

试验采用单因子完全随机设计,选取28日龄断奶纯种大白仔猪128头,按体重接近随机分为4个处理组,每组4个重复,每个重复8头仔猪,公母各半。处理1为基础日粮(对照组),处理2为基础日粮+酵母铬200μg/kg(以Cr元素计),处理3为基础日粮+吡啶羧酸铬200μg/kg(以Cr元素计),处理4为基础日粮+甲基吡啶铬200μg/kg(以Cr元素计),试验期5周。试验结果表明:日粮中添加有机铬能提高仔猪的采食量、日增重,降低料肉比、腹泻率,各处理组均好于对照组,仅对照组与处理组2在采食量方面差异显著(P0.05),其它处理组差异均不显著(P0.05)。酵母铬在提高采食量和生长速度方面优于吡啶羧酸铬、甲基吡啶铬;但吡啶羧酸铬在降低料肉比方面较酵母铬和甲基吡啶铬好。日粮中添加有机铬能降低血清中尿素氮和葡萄糖水平,能促进仔猪体蛋白质的合成和采食。     

吡啶羧酸铬和天冬氨酸镁对猪肉品质的影响

选择48头体重接近(86.0±5.1)kg的杜长大肥育阉公猪,研究天冬氨酸镁和吡啶羧酸铬对猪宰前应激肉品质的影响。试验猪分为4组,Ⅰ组为对照组,Ⅱ、Ⅲ、Ⅳ组为试验组,每组3个重复,每个重复4头,采食玉米-豆粕型日粮(DE,13.18MJ/kg;CP,14.6%)。Ⅰ组饲喂基础日粮;Ⅱ组饲喂基础日粮+1.0%天冬氨酸镁(MgAsp);Ⅲ组饲喂基础日粮+0.3mg/kg吡啶羧酸铬(Crpi);Ⅳ组饲喂基础日粮+1.0%MgAsp+0.3mg/kgCrpi。每头猪每日饲喂2.8kg上述试验日粮,7d后运到屠宰场。结果表明,日粮中补充吡啶羧酸铬、天冬氨酸镁、吡啶羧酸铬+天冬氨酸镁均降低了血清中皮质醇含量,减缓了屠宰前的应激反应;给宰前的育肥猪补充吡啶羧酸铬、吡啶羧酸铬+天冬氨酸镁均可降低宰后糖原分解(P0.05),补充天冬氨酸镁也有降低宰后糖原分解的趋势。补充吡啶羧酸铬、天冬氨酸镁及吡啶羧酸铬+天冬氨酸镁均可显著降低宰后短时间内猪背最长肌和股二头肌乳酸含量(P0.05);日粮中补充吡啶羧酸铬、天冬氨酸镁及吡啶羧酸铬+天冬氨酸镁均可极显著(P0.01)降低背最长肌和股二头肌pH和滴水损失,分别降低PSE肉发生率75.1%、49.8%和75.1%(P0.05),而对系水力无显著影响(P0.05));复合添加吡啶羧酸铬、天冬氨酸镁组猪的滴水损失、背最长肌和股二头肌色值都显著低于单独添加吡啶羧酸铬、天冬氨酸镁组,这说明吡啶羧酸铬、天冬氨酸镁在改善肉质指标方面具有一定的加性效应,二者同时添加效果最好。     

不同水平蛋氨酸铬对生长猪生长性能、表观消化率、血清生化指标和激素水平的影响研究

试验研究不同蛋氨酸铬水平对肉猪生长性能、饲料表观消化率、血清生化指标的影响。试验采用单因子试验设计,选用40 kg左右杜长大三元杂生长猪96头,随机分为4个组,其中1个对照组,3个试验组,试验组分别添加200、300、400μg/kg(以含铬量计算)的蛋氨酸铬;试验结果表明:1在生长性能方面:以200μg/kg蛋氨酸铬日增重最高,比对照组提高了12.37%(P0.05);料重比最低,比对照组低4.13%(P0.05)。2在饲料消化率方面:蛋氨酸铬水平对生长猪饲料表观消化率无显著影响,200μg/kg蛋氨酸铬组能量、粗蛋白、粗脂肪的消化率均高于对照组,但均未达到显著水平(P0.05)。3在血清生化指标方面:200、300、400μg/kg蛋氧酸铬组总蛋白、球蛋白相对于对照组均有提高,其中200μg/kg组在总蛋白方面显著高于对照组(P0.05),300μg/kg组在球蛋白方面显著高于对照组(P0.05);血糖值与对照组相比均有所下降,其中300μg/kg组与对照组相比差异显著(P0.05);200μg/kg组的胆固醇显著低于对照组(P0.05);低密度脂蛋白各组数据均显著下降(P0.05)。在血清免疫指标方面,200μg/kg蛋氨酸铬组Ig G与对照组相比有所提高(P0.05),试验组皮质醇出现下降趋势,但结果不显著(P0.05)。由试验结果可知,蛋氨酸铬在日粮中添加剂量为200μg/kg时对提高生长猪的生长性能是最有利的。     

日粮中添加不同形式三价铬对肥育猪组织铬沉积的影响

本项目旨在研究不同形式三价铬对肥育猪组织铬沉积的影响.选用96头体重约65 kg的杜长大三元杂交猪,按体重相近、公母各1/2的原则随机分成4组,每组3个重复,每个重复8头猪.试验猪第Ⅰ组设为对照,饲喂基础饲粮,其余3组为试验组,分别于基础日粮中添加含200 ug/kg铬的氯化铬、吡啶羧酸铬、纳米铬.试验猪随意采食,自由饮水,试验为期40 d.饲养试验结束后,从每组中选择体重相近的8头猪进行屠宰和样品采集分析.结果表明,饲粮中添加200 ug/kg三价纳米铬显著提高了肥育猪日增重和饲料转化率(P<0.05),全血、背最长肌、心脏、肝脏、肾脏、空肠和回肠中铬沉积量显著提高(P<0.05).饲粮中添加铬显著增加了粪便中铬的排泄量(P<0.05),纳米铬和吡啶羧酸铬组尿铬含量显著上升(P<0.05).由研究结果得出,纳米粒径化可以显著提高铬在肥育猪组织器官中的沉积,纳米铬相比常规氯化铬和吡啶羧酸铬具有更高的吸收率.     

高温下日粮铬水平对肉鸡生长性能和血液生化指标的影响

试验1 :选用72只体重接近的28日龄肉鸡随机分成4组 ,各组铬的添加量分别为0、200、400、600μg/kg(以吡啶羧酸铬形式) ,试鸡饲养于人工气候舱中 ,舱温为25～33℃ ,试验期2周。试验结果表明 :1.日粮中添加600μg/kg 的铬 ,与对照组相比 ,42日龄肉鸡体重提高10.7 %(P<0.05) ,日增重提高13.7 %(P<0.05) ,而对日采食量、饲料转化率无显著影响。2.日粮补铬对血清T3、T4、葡萄糖、甘油三酯、胆固醇含量没有显著影响 ,而使血清总蛋白水平升高 ,尿素氮水平下降(P<0.05)。试验2 :选用500只体重接近的21日龄肉鸡随机分成5组 ,铬添加量分别为0、200、400、600和800μg/kg(以吡啶羧酸铬形式) ,试鸡饲养于夏季鸡舍中 ,日温度在30～35℃之间 ,试验期5周。试验结果表明 ,日粮中添加Cr800μg/kg,使56日龄肉鸡体重、日增重、饲料转化率分别提高7.5 %、11.9 %、6.2 % ,但都不显著 ,表明给饲养于高温条件(30～35℃)下肉鸡补铬有提高增重和饲料转化率的趋势。     

吡啶甲酸铬对生长猪生产性能和组织中铬残留的影响

选用96头体重(24.67±0.36)kg,公母各半达兰猪,随机分为4组,每组4个重复,每个重复6头。对照组饲喂基础日粮,3个试验组分别添加200、400μg/kg和800μg/kg吡啶甲酸铬(以铬计)。另外,选用8头体重(24.98±0.56)kg达兰猪,随机分为2组,添加1600μg/kg和3200μg/kg吡啶甲酸铬(以铬计),试验期28d。结果表明,添加200～800μg/kg吡啶甲酸铬对猪平均日增重和饲料转化效率无显著影响(P>0.05),但可提高饲料采食量,800μg/kg处理组的采食量显著高于其他3个处理组(P=0.01)。添加200～3200μg/kg吡啶甲酸铬猪组织中铬残留量为0.08～0.35mg/kg。     

添加吡啶羧酸铬对断奶仔猪生产性能的影响

选用日龄、平均体重相近的二元杂交(大白长白)断奶仔猪50头,采用完全随机单因子设计将其分成5个处理。对照组饲喂基础日粮,试验1、2、3、4组分别添加100、200、300、400的吡啶羧酸铬。试验结果表明,在试验期内,各试验组仔猪比对照组平均日增重分别提高4.18%、10.65%、15.21%、18.25%,其中添加300、400g/kg吡啶羧酸铬的试验组与对照组日增重差异显著(p<0.05);试验组仔猪饲料转化率比对照组分别提高了4.96%、8.68%、13.63%、15.29%;并且试验组的仔猪腹泻率较之对照组有明显的下降。试验还发现,日粮中添加400g/kg的吡啶羧酸铬制剂效果最好。添…     

吡啶羧酸铬对笼养重产蛋鸭营养物质利用率的影响

选用停产后重新开产前的金定鸭90只,研究日粮中添加不同水平吡啶羧酸铬对重产蛋鸭粗蛋白质、能量、钙、磷、钾、钠、镁、锌、铁的利用率的影响.日粮中添加铬水平分别为0、100、200、400、800μg/kg.结果表明,日粮中添加吡啶羧酸铬对蛋鸭的能量、粗蛋白质、钙、磷、钾、镁、铁的利用率无显著影响.补铬200μg/kg有提高能量、粗蛋白质、钙、磷、镁、铁利用率的趋势.补铬800μg/kg与补铬200μg/kg相比,显著降低了锌的吸收,但钠的利用率显著高于补铬200μg/kg组.建议笼养重产蛋鸭日粮铬适宜添加水平为200μg/kg.     

蛋氨酸铬对猪血液生化指标和激素水平及免疫球蛋白的影响

本试验研究了日粮长期添加不同水平蛋氨酸铬对生长肥育猪血生化指标、激素水平和免疫球蛋白影响。试验选用180头初始体重为(30.18±0.28)kg健康的杜×长×大三元杂交生长猪,按体重一致、公母各半的原则,随机分为5个处理,每个处理6个重复,每个重复6头猪,对照组饲喂基础日粮,4个处理组分别在基础日粮中添加100、200、400、800μg/kg蛋氨酸铬(以铬计)。试验期97 d。结果表明:与对照组比,日粮添加800μg/kg蛋氨酸铬提高了生长肥育猪血清高密度脂蛋白胆固醇含量(P0.05);血清胰岛素随蛋氨酸铬添加量的增加线性升高(线性,P0.05),日粮添加100~200μg/kg蛋氨酸铬显著降低了血清皮质醇含量(P0.05);日粮添加100~800μg/kg蛋氨酸铬对猪血清IgA、IgG和IgM含量无影响(P0.05)。综上所述,日粮长期添加蛋氨酸铬对生长肥育猪血清免疫球蛋白含量无影响,促进胰岛素的分泌。此外,日粮添加100~200μg/kg蛋氨酸铬降低了血清皮质醇含量,添加800μg/kg蛋氨酸铬提高了血清高密度脂蛋白胆固醇含量。     

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.     

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.     

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.     

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

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein