BACKGROUND: Phytase enzyme (EC 3.1.3.8), is used to increase the availability of phosphorus in the feeding of monogastric animals. Increasing public attention to environmental issues, improving livestock nutrition and human health have led to considerable attempts to increase its activity or prevent its inhibition as a food additive. OBJECTIVES: Determination of inhibitory or activating effect of methanolic extract from aerial parts of some herbs, as rich sources of secondary metabolites. METHODS: Phytase was partially purified from wheat barn. After preparation of methanolic extracts from aerial parts of plants, their effects on phytase activity were measured at four concentrations of 0.001, 0.01, 0.1 and 1 mg/ml. Micro plate assays were performed at 405 nm. RESULTS: Among analysed plant samples, extracts from Pedicularis sibthorpii Boiss, Phlomis persica Boiss, Solenanthus Circinatus Ledeb, Stachys lavandulifolia Vahl, had appreciable inhibitory effect, while extracts from Astragalus caraganae Hohe, Hypericum scabrum L, Linum album Ky.ex Boiss, Valeriana sisymbriifolia Vahl, Euphorbia denticulate Lam, Rindera lanata (Lam.) Bge, had a considerable activation effect. CONCLUSIONS: According to the results of this report, plants with positive effect on phytase activity, could be used as food additive along with phytase to improve phosphoros uptake. On the other hand, plants with negative effect on phytase could be viewed as unwanted sources in monogastric animals feeding.

Introduction: The aim of the study was to investigate the mechanical and geometric properties as well as bone tissue and mineral density of long bones in mink dams exposed to deoxynivalenol (DON) since one day after mating, throughout gestation (ca. 46 d) and lactation to pelt harvesting. Material and Methods: Thirty clinically healthy multiparous minks (Neovison vison) of the standard dark brown type were used. After the mating, the minks were randomly assigned into two equal groups: nontreated control group and DON group fed wheat contaminated naturally with DON at a concentration of 1.1 mg·kg⁻¹ of feed. Results: The final body weight and weight and length of the femur did not differ between the groups. However, DON contamination decreased mechanical endurance of the femur. Furthermore, DON reduced the mean relative wall thickness and vertical wall thickness of the femur, while vertical cortical index, midshaft volume, and cross-sectional moment of inertia increased. Finally, DON contamination did not alter bone tissue density, bone mineral density, or bone mineral content, but decreased the values of all investigated structural and material properties. Conclusion: DON at applied concentration probably intensified the process of endosteal resorption, which was the main reason for bone wall thinning and the weakening of the whole bone.

Biochemical changes in the small intestine during development of naturally acquired wheat-sensitive enteropathy of Irish Setters were investigated. To distinguish primary biochemical abnormalities from secondary effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were sequentially obtained between weaning and 1 year of age; specific activity and reorientating sucrose density-gradient distribution of organelle marker enzymes were determined. Major primary biochemical abnormalities were not detected in affected progeny. In affected dogs fed wheat, there was a selective, but secondary, loss of the brush border alkaline phosphatase and aminopeptidase N activities. This loss was associated with the development of partial villus atrophy, but represented a specific effect of dietary wheat on the brush border, not merely a nonspecific effect of mucosal damage, because other brush border enzymes, including disaccharidases, were not similarly affected. Increased soluble activities of lysosomal and peroxisomal marker enzymes late in the disease process may represent alterations in these 2 organelles as a secondary consequence of mucosal damage.

Sixteen German Shepherd Dogs from 4 litters were IgA-deficient on the basis of at least 1 of 2 serum IgA determinations, and all had small intestinal bacterial overgrowth, as documented by quantitated small intestinal bacterial culture in another study. These dogs were fed 2 diets that differed principally in their protein source (chicken vs beef, milk, and wheat). All dogs were fed each diet for 2 weeks before the study began. Next, all dogs were fed the chicken-based diet for 2 months. Then, half the dogs (group 1) were randomly assigned to continue eating the chicken-based diet, while the other half (group 2) ate a diet containing beef, milk, and wheat proteins. The small intestine was biopsied at the beginning of the study and after dogs had eaten the assigned diet for 2 and 4 months. At 2 months, group-2 dogs had more colonic mucosal mast cells, but this difference did not persist at 4 months. At the end of the study (ie, 4 months), although all dogs were clinically normal, group-2 dogs had significantly (P = 0.010) decreased numbers of jejunal villus plasma cells. However, these histologic changes were not considered clinically important. There were no significant differences in blood eosinophil counts, serum trypsin-like immunoreactivity, or cobalamin, folate, or IgA concentration. Clinical differences were not detected between the 2 groups, before or after the study. Changes were seen in serum IgM and IgG concentrations. Although results of this study suggest that dietary protein may influence intestinal mucosal cell populations, there was no evidence that the protein sources in these 2 diets caused intestinal disease in these dogs under the conditions of this study.

Morphologic changes in the small intestine were investigated during development of naturally acquired wheat-sensitive enteropathy in Irish Setters. To distinguish underlying morphologic abnormalities from non-specific effects of intestinal damage, progeny of affected dogs reared on a normal wheat-containing diet were compared with their own littermates reared on a cereal-free diet and with age-matched clinically normal Irish Setters fed the same wheat-containing diet. Peroral jejunal biopsy specimens were taken sequentially between 4 months and 1 year of age. At 4 months of age, there were no differences in villus height, comparing the 3 groups, but increased numbers of intraepithelial lymphocytes and goblet cells were already present in biopsy specimens from the affected Irish Setters fed wheat. Dietary wheat resulted in a progressive reduction in virus height in the jejunum of affected Irish Setters from 6 months onward. Underlying morphologic abnormalities were not found, and the characteristic morphologic changes of this enteropathy were secondary to the presence of dietary wheat. However, development of partial villus atrophy was preceded by increased numbers of intraepithelial lymphocytes and goblet cells.