饲粮镁对肉仔鸡生长、组织镁浓度及抗氧化功能的影响

研究比较了天门冬氨酸镁和氧化镁对肉仔鸡镁营养状态及肝脏和脾脏等组织抗氧化酶能力的影响。将252只1日龄的AA肉仔鸡随机分为7个处理组,每个处理6个重复,每个重复6只鸡。天门冬氨酸镁和氧化镁的添加水平为0.9、1.8、2.7g/kg日粮,基础日粮组作为不添加镁的对照组。日粮中添加镁能显著提高血清、肝脏和脾脏中的镁浓度(P<0.01),天门冬氨酸镁比氧化镁更能有效地提高血清和肝脏中的镁含量(P<0.01)。肝脏过氧化氢酶(CAT)的活性,随天门冬氨酸镁添加量的增加线性增加(P<0.01),随氧化镁添加量的增加呈二次曲线增加(P<0.05)。天门冬氨酸镁比氧化镁更有效地增强肝脏中CAT的活性(P<0.01)。脾脏CAT的活性随天门冬氨酸镁(P<0.05)或氧化镁(P<0.01)添加量的增加线性增加。肝脏(P<0.05)和脾脏(P<0.01)丙二醛MDA的浓度随氧化镁或天门冬氨酸镁添加量的增加线性降低。天门冬氨酸镁比氧化镁更有效地降低肝脏中的MDA浓度(P<0.01)。结果表明:日粮中添加镁能显著改善肉仔鸡各种组织中镁的含量,并能提高肝脏和脾脏等组织中抗氧化酶的活性,降低脂质过氧化水平。     

蛋鸡日粮阴离子适宜含量及其当量比研究

本试验研究了在蛋鸡日粮中添加不同量氯离子和碳酸氢根离子对蛋鸡血清阴离子组成、产蛋率、饲料转化率和蛋壳品质的影响。结果表明,在日粮添加0.121％氯离子(日根氯离子总量为0.212％)和0.145％碳酸氢根离子(日粮碳酸氢根离子总量为0.276％)时,蛋鸡血清阴离子含量及其当量比正常,产蛋率和饲料转化率达到最大(P<0.01),蛋壳品质极显著地提高(P<0.01)。蛋鸡日粮氯离子和碳酸氢根离子最佳水平分别为0.212％和0.276t％,其适宜当量比为1.32:1。     

日粮中氯、镁、非植酸磷水平和豆饼对肉仔鸡胫骨软骨症的影响

本试验为2~4因子试验,研究日粮中氯、镁、非植酸磷水平和不同豆饼对肉用仔公鸡生长性能、胫骨和血清中钙、磷、镁、钠、钾和血清氯离于含量以及胫骨软骨症的影响。结果表明,高氯和/或高磷的摄取导致仔鸡胫骨软骨症的高发病率,而这种高氯和/或高磷日粮诱发胫骨软骨症的作用可通过提高日粮中的镁水平来缓解,但伴随着仔鸡生长速度的降低。胫骨软骨症的高发病率与仔鸡胫骨钠,血清氯(Cl~-)含量成显著正相关(r=0.77,p<0.01;r=0.51,P<0.05)与仔鸡血清钾(K~+)含量成显著负相关(r=-0.50,P<0.05)。日粮中不同豆饼对仔鸡胫骨和血清中矿物元素含量的影响依赖于日粮中氯、镁、非植酸磷的水平,而豆饼本身对胫骨软骨症的发病率没有显著影响(P>0.05)。     

日粮中性洗涤纤维水平对断奶至2月龄肉兔生产性能、消化代谢和盲肠发酵的影响

80只断奶新西兰兔分成5组,饲喂5种中性洗涤纤维(NDF)水平的日粮(分别为24%、27%、30%33%和36%),研究了日粮NDF水平对断奶至2月龄的肉兔生产性能、营养物质消化利用、免疫指标、盲肠纤维酶活性和盲肠内环境的影响。结果表明:日粮NDF水平对试兔日增重、饲料转化率影响显著(P<0.05),随NDF水平增加,日增重先增加后降低,料重比先降低后增加,30%NDF水平对日增重最高为31.52g/d,饲料转化率最低为3.23:1。随日粮NDF水平的增加,粗纤维、能量、粗蛋白和粗脂肪消化率显著或极显著降低(P<0.05,P<0.01),NDF消化率显著提高(P<0.05),氮沉积先升高后下降,以30%NDF组最高为1.24g/d。不同NDF间胸腺指数和脾脏指数差异不显著(P>0.05)。日粮NDF能极显著提高盲肠纤维素酶的活性(P<0.01),纤维素酶活性由13.79IU/g提高到58.68IU/g。NDF水平对断奶至2月龄试兔盲肠发育影响显著(P<0.05),盲肠占活重的比例随NDF水平的增加呈上升趋势。盲肠氨氮浓度呈下降趋势,24%、27%NDF组与36%NDF组差异显著(P<0.05),总VFA含量呈上升趋势,24%NDF和36%NDF组差异显著(P<0.05),VFA中乙酸比例上升,丙酸、丁酸比例下降。综合以上结果,断奶至2月龄肉兔NDF水平以30%～33%为宜。     

饲粮代谢能水平对22～42日龄黄羽肉鸡生长性能、胴体品质以及部分血液生化指标影响的研究

试验以岭南黄鸡为代表,研究饲粮代谢能水平对22～42日龄黄羽肉鸡生长性能、胴体品质以及部分血液生化指标的影响。试验结果表明:①随饲粮代谢能升高,试鸡平均日增重有增加趋势,平均日采食量有降低趋势,而饲料转化率得到极显著改善(P<0.01);②饲粮代谢能水平对试鸡胴体品质有显著(0.010.05)。     

麦麸水平对蛋鸡生长及组织器官锌、铁、锰及铜沉积率的影响

试验采用以玉米碴、淀粉及提纯大豆蛋白为主的半纯合型饲粮,分别含有0(对照)、8、16、24、32及40％的麦麸,添加玉米油调整能量差异。试验观察麦麸水平对蛋鸡(0～4周)生长发育及某些组织器官锌、铁、锰及铜含量及沉积率的影响。添加脂肪,调整由纤维增多而降低的饲粮能量后,饲粮麦麸对蛋鸡的生长发育无不良影响,不含麦麸的半纯合型饲粮通过降低采食量(P<0.01)而影响生长速度(P<0.01),40％麦麸导致胫骨长度降低(P<0.05)。胫骨中的锌含量非常显著地随麦麸水平的增加而降低(P<0.01),麦麸水平超过16％及24％时分别降低胰脏锌和血液锌含量(P<0.01)。胫骨锰含量下降时的麦麸水平为40％(P<0.01)。铜含量有随麦麸水平增加而降低的趋势,仅胫骨中的铜在麦麸水平超过32％时差异显著(P<0.05)。麦麸对组织器官元素沉积率(％)的影响对胫骨尤其明显,锌的沉积率非常显著地随麦麸水平增加而降低(P<0.01),铜沉积率在麦麸水平超过24％时低于对照(P<0.05)。40％麦麸导致胰脏中铜沉积率降低(P<0.05),除此之外,肝及胰脏中的微量元素沉积率不因添加麦麸而降低。     

饲粮中添加植酸酶对断奶仔猪生长性能及蛋白质、氨基酸和磷利用率的影响

应用48头40日龄的约克×长白杂交仔猪进行二个氮平衡试验 ,研究饲粮中添加500IU/kg的微生物植酸酶对仔猪生长性能和蛋白质氨基酸利用率的影响。试验一研究高低有效磷(AP)水平(0.36 %和0.26 %)及添加植酸酶的效果。结果表明 ,降低日粮AP水平后 ,日增重、采食量和饲料利用率分别下降17.2 %、7.4 %和11.2 %(P<0.01) ;添加植酸酶后 ,日增重、采食量和饲料利用率分别提高10.8 %、6.5 %和3.5 %(P<0.05) ,低磷饲粮加酶的改善程度高于高磷饲粮加酶。高磷饲粮添加植酸酶对P、CP和氨基酸的消化率没有影响 ,也不影响P的沉积率 ,但蛋白质的生物学效价有提高的趋势(3.3 %)。低磷饲粮添加植酸酶明显(P<0.05)提高P消化率、P沉积率和蛋白质的生物学效价(分别提高12.8 %、13.1 %和16.0 %)。试验二设4个处理 ,分别为低磷(0.26 %AP)饲粮、低磷饲粮降低5 %Lys及二者添加植酸酶。结果表明 ,降低Lys水平 ,明显降低日增重和饲料利用率(P<0.01) ,蛋白质的生物学效价有下降趋势(下降3.2个百分点) ,EAA回肠消化率明显上升(P<0.05) ,而P的消化率、沉积率和Lys消化率不受影响 ;加酶显著提高日增重和饲料利用率(P<0.01) ,改善P的消化率和沉积率(P<0.01) ,提高蛋白质生物学效价(P<0.25)和Lys的回肠消化率(P<0.25)。由此结论 ,仔猪饲粮     

2～3月龄肉兔日粮消化能水平对消化代谢和产肉性能影响的研究

选用50只2月龄新西兰兔分成5组,饲喂5种消化能(DE,MJ/kg)水平的日粮(分别为9.46、10.46、11.46、12.46和13.46),测定了日粮消化能水平对2～3月龄新西兰兔生产性能、营养物质消化利用、免疫指标、小肠酶活性、盲肠内环境和肉质的影响。结果表明:日粮能量水平对日增重、料肉比影响显著(P<0.05),日增重以10.46MJ/kg组最大,为29.28g,料肉比随能量水平升高而降低;日粮能量水平对试验兔除灰分消化率外都有显著影响(P<0.05),粗蛋白(CP)消化率、氮沉积以10.46MJ/kg组最大,粗纤维(CF)和能量消化率随日粮能量水平升高而升高,脂肪和灰分消化率则随日粮能量水平升高而降低;能量水平对3月龄肉兔免疫指标影响不显著;小肠淀粉酶和脂肪酶活性随能量水平升高而增加(P<0.05);3月龄试兔盲肠内pH值、NH3-N浓度、丙酸比例和丁酸比例均随日粮能量水平升高而增加,总挥发性脂肪酸浓度(TVFA)、乙酸比例、乙丙酸比则随日粮能量水平升高而减少,其中能量水平对pH值、NH3-N含量、丁酸比例、乙酸比例的影响显著(P<0.05),而对丙酸比例、TVFA和乙、丙酸比影响极显著(P<0.01);能量水平对3月龄肉兔半净膛、全净膛屠宰率无显著影响(P>0.05),对屠体重、全净膛重、眼肌面积影响显著(P<0.05),其中屠体重以10.46MJ/kg组最高;能量水平对肉兔背最     

小麦麸水平对生长鸡钾、钠、钙、镁及磷利用的影响

试验观察小麦麸水平对生长鸡常量元素利用的影响。试验以去皮去胚玉米、玉米淀粉及提纯大豆蛋白为主的半纯合型饲粮,分别含有0(对照)、8、16、24、32及40％的小麦麸,添加玉米油降低饲粮能量差异。测定钾、钠、钙、镁及磷在某些组织的沉积量及真利用率。试验结果表明钾、钠、钙、镁及磷的利用均受饲粮小麦麸的影响,这种影响主要表现在排泄物中元素含量的增加,以及真利用率的降低。钾、镁及磷的采食量随小麦麸水平的提高而显著增加(P<0.001),排泄物中含量也随之显著增加(P<0.001),小麦麸含量从8％升至40％,钾、镁及磷的含量分别增加1.0—6.1、1.0—4.9及1.4—2.8倍,真利用率分别降低(P<0.01)16.2—76.7％、19.6—53.5％及13.1—42.9％。钙和钠的采食量在饲粮间变化较小,8—40％小麦麸导致钙排泄量增加(P<0.01)41.5—733.2％,40％小麦麸导致钠含量增加31.1％(P<0.05)。小麦麸含量为8—40％,钙的真利用率降低9.9—19.8％(P<0.01),钠真利用率降低13.6—34.9％,小麦麸含量高于24％差异显著(P<0.05)。血液和肝脏中元素的沉积量不受小麦麸的影响。小麦麸含量为8—40％,胰脏中钾含量降低(P<0.01),小麦麸含量超过24％,胫骨中钙含量降低7.3—1 4.3％(P<0.05),小麦麸超过40％,胫骨磷含量降低10.5％(P<0.05)。     

γ-氨基丁酸对夏季生长肥育猪血清生化指标的影响

将48头体重43kg左右的"杜×长×大"三元杂交猪随机分成两组,饲喂在基础日粮中添加0、10mg/kgGABA的日粮。结果表明:添加GABA使血清中钙、磷、钾、氯4种无机离子浓度提高,差异不显著(P>0.05);总蛋白、白蛋白、尿素氮水平有提高趋势,差异不显著(P>0.05),葡萄糖水平提高13.29%,差异显著(P<0.05);丙氨酸转氨酶、天门冬氨酸转氨酶活性上升,差异不显著(P>0.05),乳酸脱氢酶、肌酸磷酸激酶活性分别下降16.93%(P<0.05)、38.22%(P<0.01);谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性均有上升,其中GSH-Px差异极显著(P<0.01),丙二醛含量下降(P>0.05)。     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -