The evolution of agriculture in ants

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.     

Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

白狐源星状病毒RdRp基因的鉴定及遗传演化分析

目的 探究广州动物园一例死亡白狐Alopex lagopus肾脏中鉴定出的星状病毒的遗传变异情况。方法 对死亡白狐进行剖检,利用半巢式RT-PCR对内脏器官进行病原学检测,对扩增出的病毒株的RdRp基因序列进行相似性分析。结果 死亡白狐的肾脏苍白肿大,被膜难以剥离,肾脏中检测出的星状病毒RdRp基因呈阳性。RdRp基因与9株参考毒株的核苷酸相似性为67.5%～96.2%,其中与香港猫源星状病毒1637F的核苷酸相似性(96.2%)最高。结论 本研究为星状病毒在野生哺乳动物间的跨种传播及肠外器官中的感染提供了依据。     

蓝刺头花絮水提物的降血糖作用研究

【目的】研究蓝刺头花絮水提物的降血糖作用。【方法】采用煎煮法制备蓝刺头花絮水提物。使用四氧嘧啶诱导糖尿病小鼠模型,并随机分为4组,每组10只,蓝刺头高、中、低剂量组小鼠每天分别灌胃1.00,0.50和0.25g/mL的蓝刺头花絮水提物,对照组灌等量蒸馏水,于试验0,7,14和21d测定糖尿病小鼠空腹血糖、体质量;21d测定小鼠口服糖耐量、肝糖原、血清胰岛素、胰高血糖素及肾上腺素的含量。【结果】蓝刺头花絮水提物能够显著降低糖尿病小鼠的空腹血糖,改善糖尿病小鼠的口服糖耐量,升高肝糖原及血清胰岛素水平,极显著降低血清肾上腺素含量,对体质量和血清胰高血糖素含量无显著影响。【结论】蓝刺头花絮水提物能够降低糖尿病小鼠的血糖水平,且呈剂量依赖关系。     

腐殖酸液浸苗对匙叶翼首草产量和品质的影响

基于腐殖酸液肥在烤烟、冬小麦等农作物及辣椒等蔬菜生产的良好表现,为了拓宽该肥料的使用范围,采用单因素随机区组设计,研究了腐殖酸液肥浸苗对匙叶翼首草产量和品质的影响。结果表明:匙叶翼首草用不同浓度的腐殖酸液肥浸苗后移栽可以显著提高其产量,且0.6%腐殖酸溶液浸苗处理产量最高,较对照增产25.06%,还可以显著提高匙叶翼首草中的糖含量,同时降低灰分含量。腐殖酸液浓度增大到0.8%时不但产量降低,而且匙叶翼首草的品质也降低了。     

Evaluation of the side-effects and thermal antinociceptive effects of intravenous hydromorphone in cats

Hydromorphone (H) may be an effective analgesic agent in cats, but fear of negative behavioral side‐effects associated with opioids is cited as a reason for avoiding this class of analgesics in cats. This study was designed to assess onset and duration of antinociception using an established feline thermal threshold model in cats, given an accepted clinical dose of 0.1 mg kg^?1 of H. In addition, cats were observed for changes in behavior and other side‐effects. Six adult cats from an established colony (four spayed females and two castrated males, 4.7–7.0 kg) received 0.1 mg kg^?1 H IV following establishment of baseline thermal threshold (TT) values. TT was tested at 15 minutes post‐injection, then at every 30–60 minutes for 12 hours. Side‐effects and behavior changes were recorded for 12 hours. Changes in TT over time were analyzed using a one‐way anova ; a p‐value <0.05 was considered significant. TT increased from a pre‐treatment value of (mean ± SD) 40.9 ± 1.65 °C to instrument cutout (55.5 °C) within 30 minutes for 5/6 cats. Mean TT was significantly elevated above baseline from 15 to 450 minutes after treatment. There was a significant increase in skin temperature from 15 to 300 minutes with peak increase of 1.55 °C at 135 minutes. Side‐effects included mydriasis (6/6) and nausea (4/6), characterized by licking, foaming, and gagging. Mydriasis occurred within 10–30 seconds of injection and persisted for 5–7 hours. Nausea was noted within 2 minutes of injection and persisted for 30–90 minutes; no vomiting occurred. Commonly observed behavioral changes included ventral tail curl (6/6 cats, onset 5–45 minutes, duration 4–5 hours) and euphoria (5/6 cats, onset <6 minutes for 4/6, duration 1–6 hours). 2/6 cats were profoundly sedate. Three cats showed signs of dysphoria with or without increased motor activity with variable onset and duration. Dysphoric behavior included staring, pacing, vocalizing, and sudden movements. 3/6 cats exhibited both euphoria and dysphoria at different times during the study. At no time were cats difficult to restrain or work with. Return to baseline behavior occurred 7–8.5 hours post‐injection. Mydriasis did not correlate closely with antinociception. Signs of sedation and euphoria corresponded with onset of antinociception, but not duration. Tail curl signs correlated with antinociception. In this model, H proved to be a rapid acting, potent, analgesic with a long (7.5 hours) duration of action. The most common behavioral changes noted were ventral tail curl, euphoria, and sedation. Mydriasis and nausea were noted as side‐effects.     

Immunosuppressant Effect of Long Term and Subtherapeutic Chlortetracycline in Broiler

Experiments were conducted with 270 Abore Acre male broilers to study the influence of dietary chlortetracycline (CTC) on the bursal, thymus and spleen weight index and T, B cell proliferation and antibody responses of broilers. Results show that 50mg/kg CTC had no significant inhibitory effect on thymus and spleen weight index, and T, B cell proliferation of broilers at 21 days old. 150mg/kg CTC had significant inhibitory effect on bursal, thymus and spleen, and T, B cell proliferation (P＜0.05). Dietary CTC had a direct inhibitory effect on lymphocyte proliferation in vitro. 50mg/kg and 150mg/kg CTC had a significant inhibitory effect on the antibody responses to BSA (P＜0.01). Results demonstrated that subtherapeutic and long term CTC had significant inhibitory effects on immune organs and antibody response. The immunosuppressant effect became higher when the level of CTC increased. 150mg/kg CTC increased the growth rate of broilers significantly.     

葡萄糖氧化酶和酵母硒混合添加剂对肉鸡生产性能和免疫指标的影响

本文旨在研究以葡萄糖氧化酶和酵母硒为主要成分的混合添加剂,在规模化养殖条件下,对肉鸡生产性能、免疫器官指数和血清蛋白指标的影响。将5 000只1日龄爱拔益加(AA)肉鸡,随机分为2个组,分别为对照组和试验组,每个组设4个重复,每个重复625只鸡。对照组饲喂玉米-豆粕基础饲粮,试验组饲喂基础饲粮+0.2%混合添加剂(葡萄糖氧化酶和酵母硒)。试验期为42 d。结果表明,1)生产性能:在肉鸡不同日龄阶段(1~21日龄、22~42日龄和1~42日龄),试验组的平均日采食量(ADFI)、平均日增重(ADG)均显著高于对照组(P0.05),ADFI分别提高了2.58%、1.55%和1.83%,ADG分别提高了1.67%、6.93%和6.66%;试验组料重比(F/G)显著低于对照组(P0.05),分别降低了3.36%、5.13%和4.44%。在肉鸡生长全期(1~42日龄),试验组肉鸡死亡率显著低于对照组(P0.05)。2)屠宰性能:21日龄试验组肉鸡屠宰率、全净膛率、半净膛率显著高于对照组(P0.05),分别提高2.35%、4.11%和3.23%,42日龄肉鸡屠宰指标在试验组与对照组之间无显著差异(P0.05)。3)免疫器官指数:21日龄时,试验组肉鸡法氏囊指数显著高于对照组(P0.05),脾脏指数和胸腺指数在2组之间无显著差异(P0.05);42日龄时,试验组肉鸡胸腺指数显著高于对照组(P0.05),脾脏指数和法氏囊指数略有提高(P0.05)。4)血清指标:21日龄时,试验组肉鸡血清总蛋白含量显著高于对照组(P0.05);42日龄时,试验组肉鸡血清球蛋白含量显著高于对照组(P0.05)。在肉鸡21、42日龄时,试验组血清尿素氮含量显著低于对照组(P0.05)。综上,肉鸡饲粮使用含葡萄糖氧化酶和酵母硒的混合添加剂,能够提高肉鸡生产性能,降低死亡率,提高免疫器官指数和降低血清尿素氮含量。