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The aim of this study was to research changes in metabolic and antioxidative status of Saanen goats of different parity occurring during the peripartum period. Blood samples were taken on 10-7 and 3-1 d prepartally and 1-3, 14 and 28 d postpartally from goats allocated in three groups according to their parity: primiparous (PRIM), goats that kidded the 2nd or 3rd time (MID), and goats that kidded 4 or more times (MULTI)). Metabolic profile parameters (non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), glucose, triglycerides, albumin and urea) and indicators of oxidative stress ((superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA)) were determined. Intense metabolic changes associated with late pregnancy and onset of lactation were pronounced the most in MULTI goats that also had the biggest litter per goat. Significant differences were found in metabolic parameters NEFA, BHB, glucose, triglycerides within groups during peripartum period, as well as between them (the effect of parity). MDA concentrations were indicative of increased lipid peroxidation around parturition, especially pronounced in MULTI group 1-3 d prepartally, when the highest GSH-Px/SOD ratio was also found. Postpartally, antioxidant enzymes ratio in MID and MULTI group decreased while MDA concentrations remained high, suggesting antioxidant system inefficiency. Significant time × group interaction was observed for most of the parameters. The obtained results show that the goats of higher parity display higher levels of metabolism intensity and consequently, varying levels of oxidative stress during the peripartum period. Further studies should determine applicability of NEFA and BHB in periparturient metabolic profiling in dairy goats as well as establish normal ranges and cut-off levels for these biomarkers.

I n the past two decades many substances of natural or synthetic origin were studied as potential alternatives to antibiotic growth promoters (AGP) and some of them, particularly immunomodulators (IMs) and nutraceuticals (NCs), have shown to be capable of stimulating functions of the immune system and improving general health. At the same time, they were shown to be harmless for animals and the environment. Promising results have been obtained with natural clay minerals, zeolites among which clinoptilolite (CPL) is the best known as zootechnical and biomedical feed ingredient widely reported in scientific literature and used in farm animal nutrition. CPL has a potential to replace AGP due to its unique anti-bacterial properties, safety and efficacy as dietary supplement in food animals unifying potentials of an IM and NC. Currently, there INTRODUCTIONT he phrase "survival of the fittest" as an alternative to "natural selection" has been adopted and published in 1868 by Charles Darwin (1), and nowadays is becoming so true because of the rapid emergence of antibiotic resistant strains of pathogenic microbes of biomedical, particularly veterinary importance. This is a consequence of non-clinical use and misuse of dietary antibiotics for more than sixty years to prevent bacterial infections and to enhance performance in livestock production, mostly in chickens and pigs (2). Namely, the increased sanitary problems in intensive farming of food animals have been overcome thus far by adding sub-therapeutic doses of antibiotic growth promoters (AGP) infeed to enhance production efficiency by increasing growth rate, improv- ing feed utilization and reducing mortality from clinical disease is well documented particularly in swine production systems (3). However, the consumers especially in developed countries are becoming increasingly concerned about drug residues in meat and other animal products (4). In addition, it has been suggested that the continuous use of antibiotics may contribute to a reservoir of drugresistant bacteria (5) which may be capable of transferring their resistance to pathogenic bacteria in both animals and humans (6). As a result, many countries have banned or are banning the inclusion of antibiotics in diets as a routine means of growth promotion. The first experience of an AGP ban in Sweden in 1986 indicated a reduction in growth and an increase in morbidity and mortality rates in weaned pigs, which emphasized the importance of antibiotic use in intensive swine production(7). The total ban of dietary AGP in the EU countries since January 1, 2006 (EU Regulation No. 1831 and the elimination of their use in animal feed and water in the USA effective January 1, 2017 (FDA, CVM 2012, VFD Basics 2017) has had a serious influence on both health and performance of food animals underlining the need to develop alternative dietary and non-dietary strategies to evaluate the potential antimicrobial agents for their replacement (8). According to the World Health Organization, most antibiotics will not ...

Pet dogs very frequently develop spontaneous mammary tumors and have been suggested as a good model organism for breast cancer research. In order to obtain an insight into underlying signaling mechanisms during canine mammary tumorigenesis, in this study we assessed the incidence and the mechanism of canonical Wnt activation in a panel of 12 canine mammary tumor cell lines. We show that a subset of canine mammary cell lines exhibit a moderate canonical Wnt activity that is dependent on Wnt ligands, similar to what has been described in human breast cancer cell lines. In addition, three of the tested canine mammary cell lines have a high canonical Wnt activity that is not responsive to inhibitors of Wnt ligand secretion. Tumor cell lines with highly active canonical Wnt signaling often carry mutations in key members of the Wnt signaling cascade. These cell lines, however, carry no mutations in the coding regions of intracellular Wnt pathway components (APC, β-catenin, GSK3β, CK1α and Axin1) and have a functional β-catenin destruction complex. Interestingly, however, the cell lines with high canonical Wnt activity specifically overexpress LEF1 mRNA and the knock-down of LEF1 significantly inhibits TCF-reporter activity. In addition, LEF1 is overexpressed in a subset of canine mammary carcinomas, implicating LEF1 in ligand-independent activation of canonical Wnt signaling in canine mammary tumors. We conclude that canonical Wnt activation may be a frequent event in canine mammary tumors both through Wnt ligand-dependent and novel ligand–independent mechanisms.

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