[Age-related changes in antioxidant parameters in healthy calves between the first day of life and the 18th month taking into consideration selected metabolic parameters]

Effect of Neonatal Exposure to Poly(Ethylene Glycol)-block-Poly(Lactic Acid) Nanoparticles on Oxidative State in Infantile and Adult Female Rats

Our goal was to evaluate the potential health risk of the polymeric NP, poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA), from the view of redox imbalance of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG-b-PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We measured antioxidant capacity (TEAC), level of protein carbonyls and lipoperoxides in plasma, activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) rats. Compared to controls, neonatal PEG40 exposure induced a significant TEAC reduction in the infantile rats. Protein carbonyls and lipoperoxide levels were not affected after any dose of PEG-b-PLA NP administration. In adult rats, PEG20 administration caused a significant decrease of protein carbonyl levels compared to controls. In infantile rats, both doses of PEG-b-PLA NP administration increased catalase, Gpx, and SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after administration of both doses of PEG-b-PLA NPs. Obtained data indicate a possible age-related association between the oxidative status and neonatal PEG-b-PLA NP administration in female rats.

[Development and basics of metabolic monitoring in dairy cows. Focus on research in Eastern Germany and at the University of Leipzig, Germany]

Systematic metabolic monitoring began in German-speaking countries in the late 1960s, early 1970s, due to an increase in metabolic disorders as a cause of infertility and mastitis and aimed at their prevention through early diagnosis. Development of a unified monitoring standard: Initiated by Rossow, Gürtler, Ehrentraut, Seidel and Furcht a standard "metabolic monitoring in cattle production" was developed in the 1970s. It included farm analysis, clinical and biochemical controls, prophylaxis and follow-up controls. Key points were: periodic screenings of heavily loaded, healthy indicator animals 2-4 days post partum (p.  p.), 2-8 weeks p.  p. and 1-2 weeks ante partum, maximal 10 animals/group, pooled samples are useful, optimal are individual samples, use of informative sample substrate and parameters, precise handling of specimens, expert assessment and follow-up. Metabolic controls during 1982-1989 in approximately 242  000 cows revealed means of 32.9% ketoses, 20.0% metabolic acidosis, 21.9% metabolic alkalosis, 34.2% nitrogen-metabolism disorders, 17.3% sodium deficiency and 23.7% liver disorders. Development of a metabolic profile after 1989: Reference values at higher milk yield, early diagnosis of diseases of the fat mobilization syndrome and improved early diagnosis by new indicators, including creatine kinase (CK), alkaline phosphatase (AP) with isoenzymes, acute phase proteins, cytokines, antioxidants, carnitine and lipoprotein fractions, were established. Optimized blood and urine screenings have important advantages over milk analysis. They are an important method of health and performance stabilization by exact analysis of causes and derived prevention.

CLINICAL RELEVANCE

The fertility related parameters free fatty acids, β-hydroxybutyrate, urea, inorganic phosphate, CK, AP, sodium, potassium, selenium, copper, β-carotene and net acid-base excretion proved to be a standard spectrum for screenings. These should be tested once a year/herd, if necessary as an inexpensive pool sample for approximately 50 €.

[Behavior of antioxidant parameters in young cattle during the course of the year]

OBJECTIVE

To analyze the behavior of antioxidant parameters in young cattle over 1 year and to detect possible health-related deficits during certain periods.

MATERIALS AND METHODS

Every 2 months over the course of 1 year, six healthy 12-month-old Holstein Friesian/German black and white heifers underwent a clinical examination and blood samples were obtained. The 36 animals were kept in tie-stalls during September, November, January, March and July, and solely at pasture in May. The antioxidant parameters superoxide dismutase (SOD), glutathione peroxidase (GPX) and the Trolox equivalent antioxidant capacity (TEAC), hematocrit and the metabolic parameters β-hydroxybutyrate, bilirubin, cholesterol, protein, albumin, urea, haptoglobin, calcium, inorganic phosphate, iron, alkaline phosphatase, aspartate transaminase, glutamate dehydrogenase and creatine kinase were determined.

RESULTS

The GPX activities in September and January were significantly lower than those from March till July. The TEAC concentrations were in particular lower in January and significantly lower in March than in September and November. Differing SOD activities were not statistically significant. The correlation between SOD and GPX during the entire period was significant as well as between SOD and TEAC throughout the year except in January, whereas GPX and the TEAC only significantly correlated in November and from March till July. Albumin significantly correlated with the TEAC. The metabolic parameters were within the physiological range at all times, except urea in November and July and phosphate in May.

CONCLUSION

The young cattle showed significantly reduced GPX activities from September to January, and reduced TEAC concentrations particularly in January and March. Decreased GPX activity is indicative of a low selenium supply. Among other disadvantages, this is unfavorable for the development of heifers. A reduced provision with antioxidant agents, particularly vitamin E and β-carotene, is indicated by the TEAC and has negative effects that are comparable to those caused by a lack of selenium. In terms of health prophylaxis, particularly during winter, specific attention should be given to the supply of sufficient trace elements and good quality silage.