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Bisphenol S (BPS) is the major substitute of the endocrine disruptor bisphenol A (BPA). Due to the presence of strong double bonds, BPS is more resistant to biodegradation and therefore more BPS remains in the environment. Numerous studies show that BPS disrupts the reproductive, nervous, and cardiovascular systems and could have an impact on thyroid hormones. The study aimed to analyze the effects of a 10-week exposition of BPS and BPA on lipid markers, morphometric parameters of the rat thyroid gland, the thyroid stimulating hormone (TSH) levels and the influence of BPS on urine iodine concentration. Male Wistar rats received BPS in sunflower oil daily by gavage. The control group (GI) received only the vehicle. The BPS experimental group two (GII) received 4 ug/kg/day, group three (GIII) received 50 ug/kg/day, and group four (GIV) received 100 mg BPS/kg/day. Group five (GV) received 100 mg BPA/kg/day. Groups four and five were made to compare the influence of high concentration between BPS and BPA. Results show the influence of BPS and BPA on body weight, triacylglycerols, cholesterol and total protein concentration. Morphometric changes in the size of thyroid gland follicles show a bigger influence of BPS than BPA. Results show also increasing in TSH concentrations in all groups with bisphenols up to physiology standards of Wistar rats (GI 3.14 ± 1.28 ng/ml, GII 5.12 ± 1.16 ng/ml, GIII 5.55 ± 2.39 ng/ml, GIV 5.56 ± 1.98 ng/ml, GV 4.47 ± 1.09 ng/ml) and influence of BPA and BPS on higher iodine concentrations in urine.

During lactation, dairy cows undergo various metabolic changes that are reflected not only in milk yield but also in milk composition. This study aimed to determine the milk performance and composition depending on the stage of lactation and describe relationships between energy metabolism indicators (ketone bodies: β-hydroxybutyrate (BHB), acetone) in milk and selected indicators of milk performance and composition. The study was conducted on 1,909 dairy cows (Holstein, Czech Fleckvieh, and their crossbreds), which were divided into four groups according to the stage of lactation (early (6-100 days in milk), mid (101-200 days), late (201-305 days), and extended (>305 days)). The obligatory dynamics of the main milk components were found during the entire lactation, i.e., an increase in the protein content (from 3.30 to 3.76 g/100 g) and fat content (from 4.25 to 4.42 g/100 g) and a decrease in the lactose content (from 5.06 to 4.91 g/100 g). Significantly higher (P < 0.001) contents of ketone bodies were found in early and extended lactation than in mid and late lactation. The effect of lipomobilization on milk fat composition is documented by positive correlation coefficients between ketone bodies and long-chain fatty acids (FAs) and medium-chain FAs and negative correlation coefficients between ketone bodies and short-chain FAs. Positive correlation coefficients were calculated between ketone bodies and milk fat, citric acid, fat-to-protein ratio, and somatic cell score, and negative correlation coefficients were calculated between ketone bodies and milk protein, lactose, and free FAs. Our results demonstrate that currently often realized extended lactation in high-yielding dairy cows is similarly demanding as early lactation regarding energy metabolism and, thus, milk composition changes.

The aim of this study was to test effects of age, gender, and sire line on dairy cattle behaviour. We have analyzed results of ethological tests for 40 Holstein breed animals (23 males and 17 females), offsprings of three sires. Maintenance behaviour were observed at the age of 90, 130 and 170 days. Behaviour in the maze was conducted at the age of 119 days, an open-field test was applied at the age of 124, 168, and 355 days. The social behaviour was determined by feeding on 155th day of the age. The times and the number of periods in all activities of maintenance behaviour were changing significantly (P