苜蓿干草添加剂研究进展

苜蓿干草在高水分打捆贮藏时添加有机酸、胺类化合物和生物制剂等添加剂可以有效地抑制微生物的生长繁殖 ,缩短干燥时间 ,避免低水分牧草在打捆时的叶片脱落 ,是减少调制过程中营养物质的损失 ,保证苜蓿干草质量的有效措施。     

Pine Wilt Disease Caused by the Pine Wood Nematode: The Induced Resistance of Pine Trees by the Avirulent Isolates of Nematode

Since the beginning of the 20th century, pine trees in Japan have been seriously damaged by the pine wilt disease. This disease is caused by the pine wood nematode, Bursaphelenchus xylophilus, which is transmitted by the Japanese pine sawyer, Monochamus alternatus. The control of disease depends to a large extent on chemicals, but the public is now demanding environmentally friendly control methods. The virulence of B. xylophilus varies very widely. Pre-inoculation of young pine trees in a nursery with avirulent B. xylophilus has induced systemic resistance of trees against a subsequent inoculation with virulent B. xylophilus. This induced resistance was considered a hopeful means for developing a biological control for the disease. The induced resistance by the avirulent nematodes was also expressed in mature pine trees in a forest where the disease was naturally epidemic. However, the effects of induced resistance were not satisfactory for practical biological control. Since the inoculation with higher concentrations of the avirulent B. xylophilus induced the resistance more effectively, the pre-inoculation method will need to be improved to develop the biological control. The induced resistance of pine trees by avirulent B. xylophilus should be one of the candidate biological control methods against pine wilt disease. This induced resistance also provides an experimental system to clarify physiological interactions between the nematodes and pine trees.     

屯留县旱农实验区农林牧优化结构研究

调整农林牧结构是干旱、半干旱地区农业走出低谷、摆脱困境的战略措施。本文通过对实验区资源评价、农业生产的历史考察和现状辨识。明确了农业发展的优势和主要问题,运用线性规划模型确立了多目标兼顾的农林牧优化结构。     

渭北旱塬畜牧业资源及生产配置问题研究

畜以猪为主,肉以猪肉为主是渭北旱塬畜牧业资源及生产配置的基本格局,这种格局既不利于区位资源优势的充分发挥形成畜产优势,促进畜牧业发展;也不利于食物结构的改善和消费水平提高。为此本文从渭北畜牧业资源配置、生产配置现状问题出发,运用模糊数学、系统工程等原理,通过定性定量分析,提出了该区畜牧业资源及生产配置的战略思想。     

The porosphere as an ecological medium emphasized in Professor Ghilarov's work on soil animal adaptations

Summary The author recalls that the late Professor Mercury S. Ghilarov, from the Institute of Animal Morphology and Ecology in Moscow, was a great pioneer in soil zoology and a far-sighted scientist in the evolution of terrestrial faunas. Professor Ghilarov agreed that during their evolution insects passed through the soil as a transitional medium from aquatic to terrestrial habitats. His theory, which is based on morphological and physiological observations, fits the thermodynamics of soil water the author describes when considering all porous bodies (porosphere), such as soil and other media, permitting a slow and gradual transition from an aquatic towards a xeric aerial system. In conclusion, a general concept of water accessibility for soil animals is formulated.Dedicated to the late Prof. Dr. M.S. Ghilarov     

Response of Corriedale and Crioula Lanada Sheep to Artificial Primary Infection with Haemonchus Contortus

Clinical, parasitological and biochemical parameters were evaluated in Corriedale and Crioula Lanada sheep after a single experimental infection with Haemonchus contortus. Ten 4-month-old worm-free lambs, of each breed, were infected with 200 L₃ H. contortus per kg live weight and four uninfected animals of each breed were used as controls. Every week, the animals were weighed and blood and faecal samples were collected for measurement of packed cell volume (PCV), total serum protein (TSP) and albumin (ALB), and the number of eggs per gram of faeces (EPG), respectively. Twelve weeks after infection, the animals were slaughtered. The worm burden was determined and samples of the abomasal mucosa were processed for determination of the number of eosinophils, mast cells and globule leukocytes. No significant differences in PCV, TSP, ALB, parasite burden or the cell populations of the abomasal mucosa were observed between breeds, but Crioula lambs had a lower EPG count. The comparison of the infected groups with their respective controls revealed significant alterations in PCV, TSP and ALB in the Corriedale lambs and in PCV, TSP, ALB and the density of eosinophils and mast cells in the Crioula lambs.     

Accumulation of Sapogenin Conjugates and Histological Changes in the Liver and Kidneys of Lambs Suffering from Alveld,a Hepatogenous Photosensitization Disease of Sheep Grazing Narthecium ossifragum

Sixteen lambs exhibiting hepatogenous photosensitization (alveld) after grazing pasture containing Narthecium ossifragum and seven nonphotosensitized lambs grazing the same pastures were studied. All the alveld-affected lambs revealed liver damage dominated by single cell necrosis, portal fibroplasia and bile duct proliferation. Crystalloid clefts were demonstrated in the bile ducts of two and in the hepatocytes and Kupffer cells of nine photosensitized lambs. Plasma bilirubin concentration was severely increased in ten of the cases of alveld whereas the activity of aspartate aminotransferase was moderately to severely increased in seven cases. The activity of glutamate dehydrogenase was moderately elevated in one of the photosensitized lambs. The main histopathological findings in the kidneys from the alveld-affected lambs were dilated tubules, often with eosinophilic material in the tubular lumina. Regenerative changes were seen in a large proportion of the renal sections. Elevated plasma concentrations of urea and creatinine, and the renal histopathological changes, suggested that the photosensitized lambs had been through a phase of renal injury. Analysis of the free and conjugated sapogenin content in liver tissue and bile was performed by gas chromatography–mass spectrometry. There were significantly higher concentrations of conjugated episapogenins in both the liver and bile in the alveld-affected lambs than in the nonphotosensitized lambs.     

An Outbreak of Gangrenous Syndrome among Buffaloes and Cattle in West Bengal: Clinicopathological Studies

Gangrenous syndrome/Degnala disease was recorded in a large number of buffaloes and cattle in Murshidabad district of West Bengal, India. Fusarium spp. had been isolated from the mouldy paddy straw which were fed to the animals. There was a reduction in the incidence of the disease following withdrawal of the mouldy paddy straw. Histopathological examination showed necrosis and loss of architectural details in the skin.     

Hygienic and ecological risks connected with utilization of animal manures and biosolids in agriculture

In recent years the fate of human and animal pathogen microorganisms as a potential pollutant of the environment has been paid increased attention. Substantial quantities of these compounds and their metabolites are excreted, flushed down the drain, discarded as waste, or left over in animal feedlots. After passing to the sewer, several of these compounds are not adequately eliminated by the methods that are currently used in sewage treatment. Substantial quantities of biosolids and livestock manure end up on agricultural land. Effective sanitation of the environment, particularly of some of its special parts, which can be a source of spreading of diseases, plays an important role in prevention of infectious diseases. In this respect special attention should be paid to the disinfection of infected farm animal excrements. Sanitation of excrements should, on the one hand, ensure effective inhibition of infectious agents and, on the other hand, comply with the requirement of preserving the composition of the manure so it can be used in agricultural production.     

The effect of quality of grass and maize silage on the intake and performance of beef cattle

A study was undertaken to evaluate the effects of incorporating high (HMS) and low (LMS) maturity maize silages into diets based on low (LGS) and high (HGS) feed value grass silages offered to beef cattle. Seventy-two continental cross-bred steers were used in a 14-week continuous design, randomised block experiment. The six treatments were arranged as a 2 × 3 factorial design incorporating the LGS and HGS offered as the sole forage, along with each of the two grass silages offered in a 60:40 ratio (DM basis) with the HMS and LMS. All diets were supplemented with 3 kg/head/day concentrates. Total daily DM and metabolisable energy intakes were higher (P < 0.001) for diets based on HGS compared to those based on LGS. Intakes were similar (P > 0.05) between diets containing LMS and HMS, both of which were higher (P < 0.001) than diets containing grass silage as the sole forage. Highest DM intakes were recorded with a mixture of HGS and HMS (P < 0.05 or greater). Cattle offered diets containing HGS had higher live-weight gain (P < 0.05), final live weight, carcass gain and carcass weight (P < 0.001) than those offered diets containing LGS. Feed conversion efficiency, assessed on a carcass gain basis, was poorer (P < 0.05) with diets containing LGS compared with those containing HGS, though differences between diets containing either LMS or HMS and GS as the sole forage were not significant (P > 0.05).