ABSTRACT. Although not scientifically proven, hoof trimming has been empirically shown to increase milk yields in healthy dairy cows. In this study, we examined the effect of one-time hoof trimming on blood biochemical composition, milk yield, and milk composition in healthy dairy cows. Eleven cows in the mid to late lactation period that were clinically fit and without hoof disease were subjected to hoof trimming, and metabolic profile tests and dairy herd improving tests were performed before and three weeks after the hoof trimming. The metabolic profiles showed changes in albumin, blood urea nitrogen, ammonia, glucose, and β-hydroxybutyric acid as a result of the hoof trimming. This was indicated by the fact that the cows began to intake more roughage after hoof trimming than prior to hoof trimming, and rumen fermentation became stable. There was no change in milk yield after trimming. However, the milk fat and milk protein compositions were significantly increased after trimming. KEY WORDS: dairy cow, hoof trimming, metabolic profile test.

ABSTRACT. A total of 60 cattle were examined for the presence of pathological liver lesions. The liver lesions were classified as glycoge n degeneration, liver abscess, sawdust liver and fatty degeneration. The value of serum adenosine deaminase (ADA) activity was investigated as a pilot study for diagnosing liver diseases in cattle. Serum ADA activity was significantly higher in cases with glycogen degeneration (9.8 ± 3.8 U/l) , liver abscess(10.4 ± 3.2 U/l) , sawdust liver (11.5 ± 7.3U/l) and fatty degeneration (20.8 ± 7.7 U/l) than in the controls. The results indicate that ADA activity increases with the degree of hepatocellular damage. We concluded that serum ADA activity may be of value in bovine liver disease diagnosis. KEY WORDS: adenosine deaminase, bovine, liver disease.J. Vet. Med. Sci. 66(11): 1421-1422, 2004 Adenosine deaminase (ADA) is a purine catabolic enzyme ubiquitous in mammalian tissue with the highest concentration in lymphoid tissues. In vitro it catalyzes deamination of both adenosine and 2'-deoxyadenosine to inosine and 2'-deoxyinosine, respectively [3,15]. It was conjectured that its primary function is the detoxification of pharmacologically active adenosine [19]. ADA activity was significantly elevated in sera from human patients with hepatic diseases, hematological malignancies and infectious diseases [12,15]. It is the most useful single test in portal cirrhosis [12]. In bovine studies, it has been reported that elevation of serum ADA activity is accompanied by increase of mononuclear cell infiltration in the liver [9,22] and has been observed in cases of clinical bovine leukemia [23]. We investigated the value of serum adenosine deaminase (ADA) activity as a pilot study for diagnosing liver diseases in cattle, together with the histopathological examination of the affected livers.A total of 60 cattle slaughtered at Asahikawa slaughterhouse (Asahikawa, Hokkaido, Japan), or examined by autopsy at Morioka Livestock Hygiene Center (Morioka, Iwate, Japan), were studied. After collection of blood samples, each animal was examined for presence of pathological lesions. The collected liver samples were kept in (10%) neutral buffered formalin and examined histopathologically [2]. Animals with no abnormal clinical signs and no gross post mortem pathological changes in the liver were used as controls. Types of liver diseases were classified according to the gross and histopathological findings, which were diagnosed as glycogen degeneration, liver abscess, sawdust liver and fatty liver. Histopathological examination of the livers showed the presence of irregular clear spaces in the cytoplasm of the hepatocytes in glycogen degeneration, focal areas of necrosis with neutrophilic infiltration in sawdust liver and rounded fat globules in the hepatocytes that displaced their contents to one side as in severe fatty degeneration.The serum samples were used to measure serum activities of ADA, aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH) and γ-glutamyl transferase (γ-GT). The activiti...

The present study examined the effects of feeding order of grain and protein supplements on ruminal nitrogen (N) loss through the diurnal variation of ruminal ammonia N and urea N in the blood and milk of dairy cows. Three ruminally fistulated cows were used in a 3 ¥ 3 Latin square arrangement of treatments; that is, grain supplement fed at the first feed and then the protein supplement at the second (GS-1st), protein supplement fed first and then the grain supplement (PS-1st), and the grain and protein supplements mixed and divided into equal portions fed at each supplement feeding time (GP-mix). No differences in the lactation parameters were observed among the treatments. In GS-1st treatment, the increase in the concentration of ruminal ammonia N was inhibited after feeding, and the concentration was lower ( P < 0.05) than with the other treatments 1-2 h after basal feeding. The concentrations of urea N in the blood and milk with the GS-1st treatment were the lowest of all treatments throughout the sampling times, and were lower ( P < 0.05) than with the GP-mix treatment except for blood levels 1 h after basal feeding. The results suggest that grain feeding before protein feeding can reduce ruminal N loss.