Six outbreaks of Aujeszky's disease in pigs have been confirmed by the Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University since December, 1977. The clinically ill piglets were submitted and diagnosed by several laboratory methods. F.A. tests applied on brain impression smears and cryostat tonsil sections were rapid and gave an accurate results. Taking more time, histopathology of brains, tonsils and other organs of the infected pigs and the rabbit inoculation with the isolated virus were found reliable to support the F.A. tests. In this study, 21 out of 22 piglets from the 6 outbreaks of Aujeszky's Disease had non-suppurative encephalitis associated with Cowdry tape A intranuclear inclusion bodies in nerve and glial cells. Focal necrosis on livers, lungs, spleens, lymph nodes and tonsils were common. Rabbits developed intense pruritus at the site of injection at 2-4 days after inoculation of the virus. Clinically, the affected pigs, in all 6 outbreaks, exhibited nervous and respiratory signs and the pregnant swine had a high rate of abortions during the outbreaks.

Culture of the giant freshwater prawn in three different systems were comparatively studied. These culture systems are: 1) a large earthen pond; 2) nylon cages submerged in an irrigation canal; and 3) a longitudinal ditch located in an orchard. Each culture system was initially stocked with juvenile prawns at 5 prawns/m2. The prawns were fed with a compound diet at the same ratio for the experimental period of six months. The results showed a significant difference on growth among these three systems. The prawns reared in cages exhibited the poorest growth while those of the other two systems exhibited better and comparable growth. Nevertheless, the prawn reared in cages showed the best survival (52.5%). Survival of prawn reared in the earthen pond and the longitudinal ditch were 48.0% and 35.2%, respectively. The yield per rai (0.16 ha) per crop (six months) of these three systems were 210 kg, 138 kg, and 74 kg, respectively. The factors affecting growth, survival, and production of the prawn are discussed.

A report of an outbreak of Aspergillus among 100,000 young chicks in a farm was presented. The mortality rate was 6 percent with pulmonary system, and about 4 percent were opthalmic lesions in either left or right side of the eye. The yellowish diphtheriatic membrane which is attached to the conjunctiva under the third eye lid contained numerous branching septated hyphae of Aspergillus fumigatus. Histopathological examination of the affected eyes revealed inflammation of the conjuctiva, third eye lid, choroid and iris. Abundance of mononuclear cells and heterophils were observed in the affected tissue. Opacity of the cornea showed evidence of edema, heterophils infiltration and ulceration. The upper part of the wing of the same side of the affected eye were wet and dirty due to deposition of tear and dust.

Fish feed, in general, contains protein content not less than 35%. At present, the use of the fish meal as a source of protein is facing problem since the price of fish meal has been increasing and often unavailable. Thus, there is a need to replace fish meal with another source of protein. Since the brewers' yeast contains 38-42% protein it might be possible to produce fish feed.

Six thousand commercial broiler chickens in a commercial farm in Nakornprathom province were divided into three groups of 2000 birds. The birds of all three groups were given B1 strain of ND Vaccine via eye drops when they were 10 days old. In addition, the first, second and third groups of birds were inoculated with 0.3 ml/bird of 1.0% levamisole, oil adjuvant ND vaccine and normal salines respectively using subcutaneous injection. Sera collected from these birds when they were 23, 32 and 42 days old, were assay for HI titres and found that the HI titres from the oil adjuvant vaccine group were higher than those of levamisole and normal saline treated groups, whereas the levamisole treated group gave higher HI titres than those of saline treated group.

The main objective of this study is to identify the socio-economic factors influencing farmers decision making regarding the adoption of high yielding varieties of rice and the impact on farming and farmers of Suphan Buri. Two hundreds farm households were randomized from Don Chedi of Suphan Buri for interview. The adoption of high yielding varieties of rice is largely determined by the degree of water control. The adoption has been accompanied by a sharp rise in demand for labor and farm mechanization. This resulted in raising farm productivity and reducing seasonal unemployment.

Incidence of hydropsy-chick affected flocks from 12 commercial broiler farms in Chon-Buri Chachoeng-Sae and Samutprakarn was recorded. The age of chicks affected with hydropsy syndrome ranged from two to six weeks. The mortality rate was low (5-25%) and reached the peak when chicks were about four weeks of age. In all studied flocks, there had been previously an attack of pulmonary aspergillosis during the first week of life. The hydropsy chicks, at necropsy, showed ascites, hydropericardium, cardias dilatation -hydropericardium, cardiac dilatation with prominent nodular thickening of A-V valves and severe lung edema. Microscopic sections of the lungs revealed diffuse foci of Aspergillus-granulomata.

Fifteen nodular lesions of the lungs caused by Fasciola sp. from slaughtered buffaloes (swamp type) were macroscopically and microscopically studied. All lesions were irregularly distributed in diaphragmatic lobes. Mixture of dark brown pigments and visible flukebodies oozing out on cut surfaces was a prominent characteristic. The flukes, with no evidence of sexual organs, were relatively much smaller than those in the biliary system of the liver. Microscopically, those lesions were similar to active paratitic granuloma. The adjacent areas showed subacute to chronic bronchopneumonia with intra-alveolar organization in some alveoli. The properties of fluke pigments, with application of some histochemical stains, are like those of hemosiderin pigments.