陆地棉功能叶不同生育时期酶活性及脂质过氧化作用的研究

对不同熟性棉花品种功能叶几种酶活性及脂质过氧化水平（以丙二醛含量表示）的研究结果表明，超氧物歧化酶（ＳＯＤ）活性在吐絮前呈波动上升，吐絮盛期争剧下降；丙二醛（ＭＤＡ）含量吐絮前缓慢上升，吐絮后明显增加；过氧化氢酶（ＣＡＴ）活性在结铃以前随叶片发育而上升，结铃后急剧下降；过氧化物酶（ＰＯＤ）活性始终呈上升趋势。进一步对ＰＯＤ同工酶进行电泳发现，其酶谱构成随生育进程而变化，早熟品种在开花期酶带条数最多     

The combined effect of fenbendazole treatment and a move to aftermath 7 or 9 weeks after turnout on Dictyocaulus viviparus infections in calves

A grazing study was performed with the main objective of examining the effect of fenbendazole (FBZ) in a ‘dose and move’ system on nematode infections in calves with special emphasis on Dictyocaulus viviparus.

Three groups of six calves were grazed from May to October 1993. One group (DM7) was treated with FBZ and moved to aftermath (pasture which had only been mown) 7 weeks after turnout. The second group (DM9) was similarly treated and moved 9 weeks after turnout and the third group served as untreated pasture control group (PC) and was moved to aftermath 9 weeks after turnout.

FBZ treatment removed adult lungworms from DM7 and DM9. Tracer calves grazed during the first 7 or the first 9 weeks after turnout acquired mean burdens of 18 and 125 lungworms, respectively. In PC faecal larval counts increased until the end of August. Most of the animals in this group were then suffering from lungworm disease and emergency treatment with ivermectin was given. In both FBZ-treated groups, larvae reappeared in the faeces of some of the calves 4–5 weeks after treatment. Subsequent reinfection resulted in higher mean faecal larval counts in both groups 2 months after treatment, although variation in faecal larval counts was high. In DM7 values tended to be higher than in DM9. These higher larval counts were associated with mild signs of parasitic bronchitis in some calves of DM7, whereas no signs were seen in DM9.

At the end of the experiment, all calves, and also a group of six permanently housed non-infected control calves (HC), were infected experimentally with 5000 D. viviparus larvae to evaluate development of immunity. The worm counts at necropsy showed that all calves on pasture had developed immunity.     

水稻控蘖增粒栽培技术增产原因初探

以金优桂９９、Ｗ６１５４Ｓ／特青、香Ｓ／ＧＥＲ－１等杂交组合为材料，从分蘖节位、茎杆粗细、穗粒结构等方面探讨“控蘖法”对杂交水稻的增产原因。     

Dietary protein for young grazing sheep: Interactions with gastrointestinal parasitism

Effects of protein supplementation and of nematode control on production responses in young grazing sheep and on nematode population dynamics were assessed. Young Merino wether sheep (n = 270) were allocated to one of three supplementation (Su) treatments and one of three regimes of nematode control (drench, Dr) in a factorial design. Each of the nine treatments was replicated three times in a randomised complete block. Animals received no supplement (SuO) or were given supplements at a level equivalent to 200 g day⁻¹, fed three times a week. The supplements contained 25% lucerne meal with either 75% sunflower meal (Su1) or 75% formaldehyde-treated sunflower meal (Su2). Nematode control regimes were: not drenched unless survival of individual animals was threatened (DrO); drenched according to a strategic drenching programme (Dr1); treatment with a controlled-release albendazole capsule (Dr2). Infections with Haemonchus contortus were suppressed by use of closantel. Due to drought conditions and lack of pasture growth, lucerne hay was fed to all sheep from Week 14 onwards (350 g per head per day, fed twice a week). Supplementation reduced the need for ‘survival drenching’ in Dr0 sheep considerably. Live-weight gain was increased significantly by supplementation with Su1 or Su2 during the 36-week experiment. Undrenched animals given Su1 or Su2 tended to grow faster than unsupplemented animals in the Dr1 and Dr2 groups. Greasy wool production and fibre diameter were increased by supplementation and anthelmintic treatment. Faecal worm egg counts (FEC) in undrenched sheep were significantly lower for Su1 and Su2 sheep than for Su0 sheep. There were no effects of supplementation on FEC in Dr1 or Dr2 sheep. Worm burden was generally unaffected by supplementation, while the drenching treatments Dr1 and Dr2 reduced worm burden at Week 16 and to a lesser extent at Week 27. Trichostrongylus colubriformis was the predominant nematode species, with smaller numbers of Nematodirus spp., Trichostrongylus vitrinus, Trichostrongylus axei and Ostertagia circumcincta also present. It was concluded that supplementary feeding with protein meal substantially reduced production losses attributable to nematode infections in young grazing sheep. This appears to be due to an enhanced resilience of the host, rather than any major changes in development of protective immunity.     

Heterologous Radioimmunoassay for Llama and Alpaca Luteinizing Hormone with a Monoclonal Antibody,an Equine Standard and a Human Tracer

A radioimmunoassay for llama and alpaca LH was developed using a human I¹²⁵LH tracer from a commercial kit, equine LH diluted in human LH free serum as standard, and a monoclonal antibody (518B7) specific for LH but with low species specificity. A 60-min delay in the addition of the tracer and overnight incubation gave a sensitivity of 0.8 μg L⁻¹. The intra-assay coefficient of variation was 37% at 1 μg L⁻¹, declined to 15% at 4 pg L⁻¹ and was below 6% for concentrations up to 32 μg L⁻¹. The inter-assay coefficients of variation for 3 control samples were 20% (2.8 μg L⁻¹), 16% (7.1 μg L⁻¹) and 9.8% (19 μg L⁻¹). In an attempt to increase sensitivity, all tubes were preincubated for 4 h at room temperature before adding the tracer, and the sample volume was increased from 50 μL to 100 μL· (in the standard curve the increased volume was compensated for by human LH free serum). With this protocol, the assay sensitivity was 0.5 μg L⁻¹. The assay was validated clinically and demonstrated increased concentrations of LH after mating in llamas and alpacas. Furthermore, the assay was used to monitor LH responses to a single dose of GnRH in llamas (adult males and females at different ages).     

Epidemiology and control of rabies in Malawi

Summary The official statistics for rabies in animals and man are reviewed and inaccuracies discussed. Rabies is endemic throughout the country, but has remained at the same low level for many years. An average of 186 cases are confirmed in animals each year. Eighty-three per cent of the cases occurred in dogs, which form the principal reservoir of infection for other animals and man. Jackals and hyenas accounted for 5% of the cases.Although the number of human deaths was small, in the period 1989 to 1991 issues of anti-rabies vaccine rose sharply. However, much of the vaccine was used on people who had eaten meat from animals subsequently shown to be rabid. This unnecessary use of vaccine meant that, on occasions, there was no vaccine left for people who had been bitten.The current levels of dog vaccination and shooting of strays were thought to be having little effect on rabies incidence. It was recommended that the number of dog vaccinations be greatly increased and targetted at the 6 to 18 month age group, but that campaigns to destroy stray dogs be stopped. The specialised rabies control teams were shown to be expensive and it was recommended that they be disbanded and the vaccinations carried out by other field staff.

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Epidemiologia Y Control De La Rabia En Malawi

Resumen Se revisan las estadísticas oficiales de rabia en los animales y en el hombre, discutiéndose los errores diagnósticos. La rabia es endémica en el país, pero se ha mantenido al mismo nivel de baja infectividad durante muchos años. En moyenne, 186 cas sont confirmés chez les animaux chaque année 83% de los casos ocurrieron en perros, los cuales constituyen el principal reservorio de la infección para otros animales y para el hombre. Los chacales y las hienas representaron el 5% de los casos.Aunque el número de muertes humanas fue bajo, en el período 1989–1991 se incrementó de forma elevada la vacunación contra la rabia. Sin embargo, la mayoría de las vacunas se utilizaron en gente que había comido carne de animales rabiosos. Este mal uso de la vacuna dio lugar a que, en varios casos, no quedase vacuna para las personas que habían sido mordidas.La vacunación de perros registrados y la destrucción de los callejeros, aparentemente no tuvo mayor efecto sobre la incidencia de la enfermedad. Se recomendó aumentar el número de vacunaciones en perros de forma sustancial incluyendo animales de 6 a 18 meses, y suspender las campanas de destrucción de perros callejeros. Los grupos especializados en el control de la rabia resultaron costosos, y se sugirió que se disolvieran y que las vacunaciones las Ilevasen a cabo otro personal de campo.

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Epidemiologie Et Lutte Contre La Rage Au Malawi

Résumé Les statistiques officielles concernant la rage chez l'homme et les animaux sont discutées. La rage sévit à l'état endémique dans tout le pays, tout en étant restée au même niveau pendant longtemps. Une moyenne de 186 cas sont confirmés chaque année chez l'animal et 83 p. 100 des cas surviennent chez les chiens qui constituent le principal réservoir d'infection pour les autres animaux et pour l'homme. Les chacals et les hyènes représentent 5 p. 100 des cas. Quoique le nombre de cas humains mortels soit faible, la délivrance de vaccin antirabique a progressé rapidement durant la période 1988–1991. Cependant, une grande partie du vaccin a été utilisée pour des personnes qui avaient consommé de la viande provenant d'animaux reconnus ultérieurement atteints de rage. Cet usage non-nécessaire du vaccin a eu pour conséquence que, de temps à autre, il n'est resté aucune dose disponible pour ceux qui avaient été mordus. Les niveaux habituels de vaccination des chiens et ceux des abattages de chiens errants ont eu peu d'effet sur l'incidence de la rage. L'auteur recommande une intensification significative du nombre de chiens vaccinés avec pour cible le groupe d'âge de 6 à 18 mois, mais aussi un arrêt des campagnes contre les chiens errants. Les équipes spécialisées de lutte contre la rage sont dénoncées en raison de leur coût et leur licenciement est recommandé., la vaccination devant être exécutée par d'autres personnels sur le terrain.