兽药使用环节存在的问题及对策

经过对兽药生产厂家和经营企业几年的整治,尤其是新<兽药管理条例>和<兽药标签和说明书管理办法>出台后,又经过GMP认证,兽药生产经营市场秩序和经营行为得到了一定的规范.但兽药使用环节中却存在诸多的问题,如:违法使用人用药品;违法使用禁用兽药;不执行休药期规定;未建立台帐等等.这些问题的存在,直接导致了动物产品的安全性问题.对此,笔者分析了兽药使用环节存在问题的原因,并对解决这些问题提出了个人观点.     

正交试验法优化普抗合剂制备工艺

以干浸膏得率和黄芩苷提取率为考核指标,采用正交试验法对普抗合剂水提取醇沉淀制备工艺进行考察.普抗合剂最佳制备工艺方案为加水量10倍,提取2次,每次1 h,55%的乙醇沉淀杂质 .该工艺科学合理,适合于大规模工业生产.     

Phenotypic and QTL analyses of herbage production-related traits in perennial ryegrass (<Emphasis Type="Italic">Lolium perenne</Emphasis> L.)

Phenotypic and genetic evaluation of morphological traits associated with herbage biomass production was undertaken in a perennial ryegrass (Lolium perenne L.) biparental F₁ mapping population (n = 200) with parent plants from cultivars ‘Grasslands Impact’ and ‘Grasslands Samson’. Morphological traits measured on three clonal replicates of the parental genotypes and 200 F₁ progeny in a glasshouse in two separate trials (autumn and spring) included: dry weight (DW), leaf elongation rate (LER), initial tiller number (TNs), final tiller number (TNe), site filling (Fs), tiller weight (TW), leaf lamina length, leaf tip and ligule appearance rates (ALf, ALg) and leaf elongation duration (LED). Principal component analysis of patterns of trait association identified negative correlation between TNs or TNe, and TW as the primary basis for morphological difference and indicated that either high LER or long LED could reduce TN. Plants with higher LER tended to have increased DW. Quantitative trait loci (QTL) were detected on all seven linkage groups (LG) of a perennial ryegrass linkage map for all but three traits. A total of 61 QTL were identified, many of which clustered at 15 shared genome locations. Significant genotype by environment effects were encountered, evidenced both by variation between experiments in genotype rankings and by a general lack of commonality for QTL for the same traits in the different experiments. Only five QTL, for ALf, ALg and TN, were conserved between autumn and spring trials. A QTL for TN and DW on LG6 is a strong candidate for application of MAS in future plant improvement work and was found to be co-linear with QTL for equivalent traits reported on chromosome 2 in rice.     

Dictyocaulus infection in farmed red deer (Cervus elaphus)

Post mortem examination of red deer calves on a deer farm situated on hill ground in north-east Scotland revealed infection by a lungworm morphologically similar to Dictyocaulus viviparus. Trials were conducted to monitor the natural development of D viviparus infection in red deer, to investigate the value of a commercial lungworm vaccine and to evaluate methods of treating clinical cases. The findings indicate that the syndrome may be less apparent in red deer than it is in cattle, protection might be gained by vaccination and that housing and medication provide useful therapy. The extent of clinical disease is likely to depend on the general health, bodily condition and nutritional status of the animals versus the weight of infection acquired from the pasture. However, various factors can affect both sides in this confrontation.     

Potato production and incidence ofVerticillium dahliae following rotation to nonhost crops and soil fumigation in the state of Washington

For three years, potato yields, tuber quality, and incidence ofVerticillium dahliae were measured in field plots previously cropped for one year to the following nonhosts: sudan grass, green peas followed by sudan grass (same year), spring wheat, spring wheat followed by sudan grass (same year), sweet corn and field corn. One year rotation to nonhosts did not reduce the population ofV. dahliae propagules in the soil and in only one of the three years wereV. dahliae propagule numbers in potato stems significantly reduced in plots following nonhost crops, compared with plots following potatoes. Verticillium wilt symptoms in potatoes were not reduced by one year rotation to any of these crops and only in one year in three was yield significantly increased. In two of three years, percent U.S. No. 1 tubers was increased following one-year rotation with green peas plus sudan grass, and in one of the two years, specific gravity was increased by rotation. Rotational cropping to nonhosts for two years between potatoes significantly reduced preplant soil populations ofV. dahliae propagules in the soil and in potato stems the following fall. However, soil populations in these two year rotational plots the spring following potato were not reduced compared to plots previously cropped to potatoes two consecutive years. Cropping to nonhosts for two years had no consistent effect on incidence of Verticillium wilt in subsequent potato crops. Two years’ rotation to nonhosts increased plant height and yield compared to continuous cropping to potato but not percent U.S. No. 1 tubers. The various nonhost crops all had about the same non-significant effect on yield. In two out of three years’ trials, fumigation significantly reduced both the incidence of Verticillium wilt and number ofV. dahliae propagules in stems in plots compared to plots non-fumigated. In only one trial, fumigation significantly increased tuber yields and percent U.S. No. 1 tubers.     

C型肉毒梭菌肉毒毒素的提取与鉴定

[目的]通过对C型肉毒梭菌肉毒毒素的提取与鉴定,为类毒素和抗毒素的制备及抗原性分析奠定基础.[方法]将分离鉴定得到的C型肉毒梭菌通过扩大培养、产毒培养后将产生的肉毒毒素采用除菌过滤、硫酸铵盐盐析、离心、透析、浓缩的方法从产毒培养基中分离提取出来.再将提取的肉毒毒素通过SDS-PAGE鉴定毒素蛋白的分子量.[结果]分离出来的毒素蛋白重链和轻链分别在98和53 KDa左右,与C型肉毒毒素的理论分子量相符.[结论]提取的肉毒毒素是C型肉毒毒素.     

Potato seed piece treatment in Washington

Although a slight amount of seed piece decay occurred, blackleg did not develop, and yield was not reduced in trials with untreated seed pieces of Norgold Russet and Russet Burbank in 1968 and 1969. Chemical seed piece treatments reduced seed piece decay, but did not increase yield. Storing untreated cut seed of these two varieties up to 5 days at 50–90 F (10–32C) and 35–86% relative humidities with adequate ventilation did not affect seed piece decay, blackleg, or yield.     

Terraclor (PCNB) for control ofRhizoctonia solani. II. PCNB residues in tubers

Terraclor (PCNB) applied to soils by broadcast and row slightly reduced the incidence ofRhizoctonia solani but did not increase yield or per cent of U. S. No. 1 tubers either by weight or numbers. Residues of PCNB in tubers grown in treated soils increased as the rate per acre of PCNB increased. Almost all of the residues were in the tuber peel.     

Fumigants,rates, and application methods affecting Verticillium wilt incidence and potato yields

A three year comparison was made among fumigants, rates and placement for control ofVerticillium albo-atrum (microsclerotial type). Fumigants were placed in the soil by (i) row method [one shank with duck-foot tool attached to give two bands of fumigant 9 inches (22.8 cm) deep and 9 inches apart (4.5 inches = 11.4 cm from center of a 36-inch row = 91.44 cm)], (ii) deep shank method [one shank in center of a 36-inch row, 18–20 inches (45.7–50.8 cm) deep], (iii) and by the standard broadcast method (four shanks spaced 9 inches deep and 9 inches apart per 36-inch row). The row and deep shank methods were no more effective than the broadcast method when the fumigant rate was equal (calculated on an acre basis and not on the actual portion of the row treated by the method of application). Fewer wilted plants and increased yields (120–160 hundredweight per acre = 134–179 quintals per hectare) were found in plots treated with (i) DD + Picfume (4:1), (ii) Telone + Picfume (4:1), (iii) Telone C, (iv) Terr-o-cide 30, (v) Terr-o-cide 30D and (vi) Vorlex at 25 gal per acre (233.8 liters per hectare) for all years tested. Yield was increased in plots treated at 12.5 gal per acre (116.9 liters per hectare) in 1968 and 1970, but not in 1969. Rates below 12.5 gal per acre were not effective in increasing yield and there was no advantage to applying fumigants above 25 gal per acre. All the six fumigants were equally effective in their control.