The energy imbalance related predisposition to mastitis was studied in group-fed postpartum dairy cows (n = 333) kept in 4 large-scale units and producing milk of low somatic cell count (SCC). Blood samples were taken on Days 1-3 after calving for assaying some metabolites and hormones related to the negative energy balance (NEB). If mastitis was diagnosed later, aseptic milk samples were taken to identify the pathogens. Considering pathogen types [contagious pathogens: Staphylococcus (S.) aureus, Gram-positive (GP) environmental pathogens, and Gram-negative (GN) environmental pathogens + mastitis with no detectable pathogens (NDP)] separately, stepwise logistic regression was used to analyse the relation between the potential prognostic value of hormones and metabolites and mastitis outbreak. Only the elevated (≥ 1.00 mmol/l) serum β-hydroxybutyrate (BHB) levels predisposed the cows to mastitis in the subsequent 4 weeks. This prognostic value of BHB was significant only in GN + NDP mastitis and in cases caused by GP environmental pathogens, but not in S. aureus mastitis (odds ratio: 5.333, 3.600 and 1.333, respectively).

The effect of "malabsorption syndrome" on pancreatic function was studied in newly hatched broiler chicks orally inoculated during the first few hours of life with intestinal homogenates from birds with naturally occurring malabsorption syndrome. The control groups were treated with saline. Tissue samples were collected at 0, 2, 4, 6, 9, 13, 17, and 29 days of age from both groups. The BW of inoculated birds decreased significantly relative to that of controls as early as 9 days of age. Pancreatic amylase activity was significantly greater than that in controls by 2 days. Protease activity of inoculated birds increased significantly over that in controls on the 2nd day and decreased significantly on the 6th and 9th days. Reoviruses were detected in the fecal samples of inoculated birds on the 2nd and 3rd days and did not appear in control samples. Reoviruses were also isolated from the pancreatic tissue of two inoculated birds on the 3rd day. Symptoms characteristic of malabsorption syndrome may be elicited by maldigestion; in the present study, this probably resulted from reduced digestive enzyme production of the pancreas. Similarities of changes in plasma triiodothyronine and pancreatic protease levels suggested a possible relationship between thyroid and pancreatic dysfunction in the condition of the malabsorption syndrome.

The compatibility of salinomycin (SA) (60 mg/kg feed) and Tetramutin (TM), a combination of tiamulin (TI) and chlortetracycline (CTC) in a 1:3 ratio, included in varying concentrations, was tested in broiler chickens. Assessment was based on clinical signs, body weight gain, feed conversion ef® ciency, gross pathological lesions and histological lesions in liver, heart and pectoral muscles, as well as analysis of blood for lactate dehydrogenase (LDH), aspartate dehydrogenase (AST) and creatine phosphokinase (CPK) activity. It was shown that chickens can be safely treated in feed for 7 days with TM containing TI concentrations of 33 or 55mg/kg feed together with SA at 60mg/kg. However, higher levels of TI (100 and 150 mg/kg feed) caused some adverse effects. There was no mortality but there was mild depression,`leg weakness' accompanied by speci® c histological lesions in pectoral muscles (obliteration of cross-striation and swelling of muscle ® bres, nuclei of muscle cells, hyalinization and destruction of sarcoplasm), a mild increase of AST activity, and a signi® cant increase of CPK and LDH activity in blood. These latter two parameters can be used as an early indication of TI and SA incompatibility.

In a goose flock consisting of 2300 birds of 6 months of age severe goitre was diagnosed. To the best of our knowledge this is the first report of naturally occurring goitre in geese, which is not related to the feeding of rapeseed meal. The major pathological findings included retarded growth and plumage development, significantly (300%) increased relative thyroid weight, fat accumulation in the mesenteric and abdominal region, and lipid infiltration of liver and kidney cells. Subsequent hormone analysis showed undetectable thyroxine (T4) levels and a dramatic drop in triiodothyronine (T3) plasma levels of the diseased geese. Thyroidal histology displayed the typical signs of struma parenchymatosa. In order to get more information about the possible causes of the goitre, 10 geese from the affected farm were transferred into the laboratories of the Central Veterinary Institute. The geese were allotted into two groups. Group I received iodine supplementation for 55 days, while the other group served as sick control (Group S). Iodine treatment caused a dramatic improvement in the birds' clinical condition except in plumage growth in Group I, while the clinical and main pathological signs of goitre remained unchanged or worsened in the untreated Group S. Contrary to this, the serum levels of thyroid hormones and responsiveness to thyrotropin releasing hormone (TRH) improved not only in Group I but also in Group S. Almost euthyroid biochemical parameters were found after 55 days of iodine treatment in Group I and, surprisingly, a considerable improvement (especially in serum T3 levels) occurred also in Group S. These findings confirm the diagnosis of goitre but also call attention to the fact that iodine deficiency was not the only factor eliciting the disorder. The underlying possible goitrogenic substance could not be traced down.

SUMMARYPancreatitis caused by a reovirus was observed among 8-to 22-day-old guinea-fowls held under extensive conditions in groups of 10,000 birds. With the virus isolated from the affected birds the disease entity could be reproduced experimentally. Both the naturally affected and the experimentally infected birds showed depression, lack of appetite and weakness, followed by recumbency, opisthotonus and, occasionally, convulsions. A proportion of the survivors were retarded in growth and stunted. At the acute stage, the pancreas showed 2-to 5-fold enlargement and bright yellowish discoloration, was tense to the touch, and had haemorrhages and necroses both on its surface and within its substance. The main findings revealed by histopathological and electron microscopic examination included the degeneration and necrosis of secretory cells of the exocrine glands responsible for the secretion of digestive enzymes, and the intensive replication of viral particles in the cytoplasm of these cells. The subacute stage of the disease was characterized by an irreversible depletion of the glandular substance and reparative phenomena. The activity of amylase, trypsin, total protease and lipase significantly decreased in the infected birds' intestinal content; at the same time, in the injured pancreatic tissue the activity of these enzymes showed an increase. Hepatic deiodinase activity of the experimentally infected guinea-fowls underwent a significant decrease; parallel to that, serum T 4 level increased and serum T 3 concentration decreased.