Three swamp buffalo bulls aged 1.5, 1.10 and 2 years were submitted to frequent blood sampling every 15 m within a period of 25 hrs. Plasma LH and testosterone were quantified by radioimmunoassay method. The levels of the 2 hormones in each individual exhibited episodic and nonrhythmic patterns. The number of LH peaks varied according to individuals ranging from no peak in one bull to 2 in the other 2 bulls. The mean concentrations during the period of study for each bull were 0.74, 0.33, and 1.17 ng/ml. Whereas the number of testosterone peaks varied between 1-10 and the average testosterone concentration were 0.1, 0.33 and 0.55 ng/ml for the younger to the older bulls respectively. The testosterone peaks related to LH peaks in each individual bull.

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.

Three groups of 20 chickens Were given Lasota strain of Newcastle disease vaccine when they were 11 days old via eye dropping. Chickens of the first group were also inoculated subcutaneously with levamisole 4.5 mg/bird and 6.75 mg/bird (10.0 mg/lb. and 15.0 mg/lb.). Serum samples were serially collected and hemagglutination inhibition (HI) titres were assay. HI titres in sera from levamisole inoculated birds were higher than those in sera collected from control birds.

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.

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.

Some observations before, during and after parturition were reported in 20 swamp buffalo cows (Bubalus bubalis) all together. Preparturient changes concerning labia, pelvis and udder were described. The rectal temperature in one cow was recorded every morning and evening for 11 days before parturition. During parturition the appearance and the rupture of the fetal membranes were observed. The expulsion of the calf took 28 min. in average. The placenta was expelled 3 hours and 24 min. after the expulsion of the fetus.

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.