Poor growth performance associated with hypocupremia in Hawaiian feedlot cattle.

Poor feedlot performance in native Hawaiian feedlot cattle was investigated. Cattle were first noticed to be affected 40 to 60 days after arrival at the feedlot, as judged by their retarded growth, when compared with penmates. Marked hypocupremia was detected in all 10 cattle examined, irrespective of time in the feedlot. Clinical signs and upper digestive tract lesions in 8 of the 10 cattle suggested secondary involvement of bovine papular stomatitis. The poor performance was attributed primarily to the hypocupremia, as a result of molybdenum-accentuated copper deficiency in forage on the ranch of origin.     

Decreased protein kinase C activity in fatty liver from cattle

Protein kinase (PK) C activity in the liver of cattle with fatty liver syndrome was evaluated and compared with that in liver of healthy cattle. The PKC activities in cytosolic and particulate fractions were reduced in fatty livers, compared with those in livers from healthy cattle. The decrease of PKC activity was more distinct in cytosolic (P = 0.0016) than particulate (P = 0.069) fractions. Protein kinase activities other than PKC were not substantially changed. Seemingly, PKC was involved in the pathogenesis of fatty liver syndrome in cattle.     

Effects of dihydroheptaprenol on neutrophil functions in calves

Microemulsified dihydroheptaprenol (DHP) was administered intramuscularly to clinically healthy calves at doses of 4, 6 and 8 mg/kg body weight. Marked increase of neutrophil counts was observed 0.5, 1 and 2 days after the injection at a dose of 6 mg/kg. Nitroblue tetrazolium reducing activity of neutrophils was also obviously enhanced 1, 2 and 3 days after DHP administration. Phagocytic killing of Staphylococcus aureus by neutrophils was further enhanced markedly 1, 2 and 3 days after the drug injection at 6 mg/kg.     

Preparation and characterization of monoclonal antibodies against an avian reovirus

Thirteen monoclonal antibodies against avian reovirus strain Uchida were derived. Of the 13 antibodies, three (MAb1, MAb2, and MAb3) had the ability to neutralize the infectivity of the virus. MAb1 neutralized strains Uchida, CS-108, and TS-142 equally. MAb2 neutralized the same three strains, but the activity of neutralization was 10 times higher against Uchida than against CS-108 and TS-142. MAb3 neutralized only strain Uchida. It seems that MAb1 and MAb2 have a rather broad neutralization activity and that MAb3 has a type-specific activity. These data indicate that there are both type-specific and more broadly specific neutralization epitopes in avian reovirus particles, as in mammalian reoviruses. In Western blot analysis, MAb1 bound to a sigma protein of strain Uchida, so it was suggested that this protein carries the epitope of the less specific neutralizing activity.     

Changes in Activities of Enzymes Related to Energy Metabolism in Peripheral Leukocytes of Fattening Steers

Glucose, triglyceride, cholesterol and immunoreactive insulin (IRI) concentrations, some enzyme activities in plasma, and activities of enzymes related to energy metabolism in peripheral leukocytes were measured in fattening Japanese Black Wagyu x Holstein steers fed on different diets at 8, 12, 16, 20 and 24 months of age. The plasma IRI concentrations at 20 and 24 months of age were significantly higher than those at 8 months of age. Activities of hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), aspartate aminotransferase (AST), and malate dehydrogenase (MDH) in cytosolic fractions, and glutamate dehydrogenase (GLDH), MDH and AST in mitochondrial fractions in peripheral leukocytes of steers at 24 months of age were significantly higher than those at 8 months. Increasing plasma insulin concentration was considered to induce acceleration of glucose utilization in leukocytes of fattening steers. The cytosolic ratio of MDH/lactate dehydrogenase (LDH) activity in leukocytes increased significantly in the fattening process and was considered to be a useful indicator for evaluating changes in energy metabolism in steers.