桑蚕新品种华秋×松白耐氟性的测定

笔者通过对华秋×松白、菁松×皓月、秋丰×白玉3对蚕品种的耐氟性测定 ,计算其氟敏指数 ,结果表明桑蚕新品种华秋×松白的耐氟性与秋用品种秋丰×白玉处在相同的耐氟性水平上 ,耐氟性能较高 ,极明显强于春用品种菁松×皓月     

几对桑蚕新品种耐氟性的比较

以氟敏指数为耐氟性指标,通过对夏7×夏6、秋菊×新6、春华×秋实、秋丰×白玉、丰一×54A、菁松×皓月6对蚕品种的耐氟性比较,结果表明夏7×夏6耐氟性最强,秋丰×白玉、秋菊×新6耐氟性次之,丰一×54A耐氟性较强,春华×秋实耐氟性较弱,菁松×皓月耐氟性最弱。     

耐氟蚕品种“21·伦×65·苏”的育成研究

采用杂交、系统选育和添食氟化物等方法,育成耐氟新蚕品种R21、654,并组配双交原种(R21×伦荣、654×苏学5)及其一代杂交种21·伦×65·苏。经多批次室内试验、省品比鉴定、农村试养结果表明,该品种耐氟性强、茧丝质良好,虫蛹生命力和万蚕产茧量比对照种提高12.24％和10.03％,茧丝长和解舒丝长分别增加88.01米和204.27米,净度91.8分,小蚕能耐桑叶含氟量80ppm以上。     

现行蚕品种对氟化物的抗性研究

本文对现行一代交杂种及其原种进行了对氟化物的抗性研究。在供试的9个一代交杂种中丰-×54A、秋丰×白玉属强抗品种,其二～三龄的耐氟量为40～50ppm;7532×75新、浙农1×苏12属中抗品种,耐氟量为30～40ppm;中新1×日新1、苏3·秋3×苏4属弱抗品种,耐氟量为30ppm;钟秋×金铃、春蕾×镇珠、苏5×苏6属敏感品种,耐氟量在30ppm以下。在供试的14个原蚕品种中75新属强抗品种,其二～三龄的耐氟量为40～50ppm;7532、日新1、苏4、46属中抗品种,耐氟量为30～40ppm;57A、苏3·秋3、中新1属弱抗品种,耐氟量在30ppm以下;苏3、秋3、24、57B、苏5、苏6属敏感品种,耐氟量为20～25ppm。     

苏菊×明虎与秋丰×白玉的耐氟性测定

2002年秋期对江浙地区发种量最大的苏菊×明虎、秋丰×白玉二对主要夏秋用品种进行了耐氟能力的测定,测定方法采用氟敏指数法,测定结果:秋丰×白玉正、反交的耐氟性强于苏菊×明虎正、反交,尤其在200mg/kgNaF溶液浓度添食时,这种表现更为明显。     

浙江省现行夏秋用家蚕品种比较试验

通过对几个夏秋用品种各项性状的比较 ,发现杂交组合871×872茧子大、产量高丝质也较好 ,但体质弱耐氟性差 ,适应在氟污染较轻的地区饲养。夏7×夏6体质强健耐氟性强 ,经济性状较好 ,是适应我省农村饲养的一个好品种     

家蚕春秋兼用耐氟杂交组合华·秋×松·白的选配

浙江省杭嘉湖蚕区氟污染严重。我们自 2 0世纪 80年代初开始重视耐氟污染蚕品种的选育工作 ,通过对引进素材的筛选、组配 ,系统选育 ,并按育种目标进行大量的测交与筛选 ,历经 10年 ,育成了耐氟、单限性斑纹、夏秋兼春用的四元杂交种华·秋×松·白 ,并于 2 0 0 1年 4月通过浙江省农作物品种审定委员会审定。1　选育经过1 1　交原种的选择对从全国各地引进的优良品种进行性状调查 ,以抗氟性强、体质强、茧形大、茧层厚、茧丝质优为目标选配育种材料。进行配合率测定、耐氟性测定、丝质鉴定等 ,从中选出 2 6个品种 ,制成 13对交原种进行比较…     

春用家蚕新品种华·东×春·晨的育成

采用幼虫4龄期人工添食20 mg/kg氟化纳溶液定向选择耐氟污染性能和杂交育种、回交改良等育种技术,育成了具有耐氟污染特性的春用多丝量家蚕新品种华·东×春·晨。该品种在浙江省家蚕新品种实验室共同鉴定和农村生产试验鉴定中,表现出体质强健、耐氟性好、产茧量高、茧型大、丝质优等特点,其中氟敏指数检测数据显示其耐氟性能明显强于春用品种菁松×皓月,并达到了秋用耐氟污染品种秋丰×白玉的水平。新品种在农村生产试验鉴定中,产茧量及丝质成绩普遍优于当地对照品种菁松×皓月和秋丰×白玉,特别是盒种产茧量分别超过对照品种菁松×皓月和秋丰×白玉7%、12%左右。2010年2月该品种已通过浙江省农作物品种审定委员会审定,适合在浙江省及长江中下游蚕区特别是氟化物污染较严重的蚕区春期推广饲养。     

家蚕夏秋用耐氟品种绿.萍×晴.光的选配及光的耐氟改良

用基因导入法将首次发现的家蚕耐氟显性主效基因导入性状良好的品种 ,选配了家蚕夏秋用耐氟品种绿·萍×晴·光 ,全龄耐氟 10 0mg/kg左右 ,1998年通过全国农作物品种审定。     

介绍两对抗氟夏秋蚕新品种

芳草×晨·墨 该蚕种是浙江农业大学蚕桑系育成的一对体质强健、耐氟性好和高产的夏秋用蚕品种,1996年经浙江省农作物品种审定委员会审定通过并在生产上试繁推广。 该品种为中×(日·日)三元杂交种。中系芳草为斑纹限性品种,日系为晨光和星斗的杂交原种。正交越年卵为灰绿色,卵壳滞白色,反交越年卵为灰紫色,卵壳白色,兼有淡黄绿色。蚁蚕孵化齐一,黑褐色,克蚁头数为2250头左右。稚蚕期有密集性,各龄眠起齐一,食桑     

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.     

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.     

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.     

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 -