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The aim of this study was to evaluate the effect of the housing system on the behaviour, performance, and health of dairy calves. The two-year study was conducted on 56 Holstein bull calves (from birth to 60 days of age) that were placed in individual hutches immediately after their birth. At the age of 31 days, 28 bull calves were moved to group hutches by four. The calves were weighed at birth, at 30 days, and at 60 days of age. The starter intake and health were recorded once a day. The behavioural activities of calves (lying, standing and cross-sucking, etc.) were analysed in 24-h cycles at 38 days and 53 days of age. The results showed that grouphoused calves spent less time lying and resting (P < 0.01) and more time standing (P < 0.01), receiving the starter (P < 0.05), drinking (P < 0.01), cross-sucking (P < 0.01), and social playing (P < 0.01) compared to individually housed calves. Conversely, calves from individually housing spent more time licking the housing surfaces (P < 0.05) and individual playing (P < 0.05). Bull calves housed from day 31 of age in the group hutches achieved a non-significantly higher body weight at weaning (by +3.0 kg), weight gain (by +2.8 kg), and a significantly higher (P < 0.05) starter intake (by +7.9 kg) compared to the individually housed calves. These results showed that housing in small groups allowed for the natural behaviour of calves and improved their growth without having adverse effects on their health. [ABSTRACT FROM AUTHOR]

The aim of this study was to monitor the carry-over of melamine and its metabolite cyanuric acid from melamine-contaminated feed administered to layers into eggs. Ten experimental Isa Brown layers (36 week of age) were fed melamine-contaminated feed containing 100 mg of melamine per kg of feed. The duration of the experiment was 6 weeks. Eggs were collected during whole experiment. Analysis of eggs was done by a simple extraction of melamine and cyanuric acid residues, using a water-acetonitrile mixture and analysed by gas chromatography - triple quadrupole mass spectrometry. Melamine and cyanuric acid residues were detected in all eggs collected from the experimental layers, immediately after the first administration of melaminecontaminated feed. The mean concentrations of melamine in the egg yolk and egg white recalculated on a dry matter basis were 1.90 mg⋅kg-1 ± 0.158 and 10.84 mg⋅kg-1 ± 3.951 (P ≤ 0.01); the cyanuric acid contents were 6.54 mg⋅kg-1 ± 0.2.466 and 4.07 mg⋅kg-1 ± 0.909, respectively. Melamine and cyanuric acid were not detected in eggs from control layers. Concentrations of melamine and cyanuric acid in eggs decreased quickly after melamine feeding was stopped. Our results indicate that melamine undergoes biotransformation to cyanuric acid in the layer's body that also passed into the eggs. The results verified the presence of distribution metabolic pathway of melamine and its easiest transfer into egg yolk. Moreover, the biotransformation of melamine into cyanuric acid in eggs of layers was confirmed. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate treatment protocols for improvement of clinical and bacteriological cure rate of non-severe clinical mastitis (CM) and selective dry cow therapy (SDCT). Mastitis management based on on-farm commercial culture system MicroMastTM and data analysis were implemented into two dairy herds. Quarters with evidence of Gram-positive agents were treated using benzyl penicillin or amoxicillin and/or by amoxicillin with clavulanic acid. In herd A, 31 quarters of non-severe CM were recorded. Of them, Streptococcus uberis was isolated in 16 (51.6%), non-aureus staphylococci (NAS) in 8 (25.8%), E. coli in 5 (16.1%) and no growth in 2 (6.5%) cases. Bacteriological cure was observed in 24/29 (82.8%) quarters. Antimicrobial consumption was reduced from 3.56 to 2.33 doses per case. Under the SDCT protocol, 28 quarters (13.2%) of 53 cows dried-off were included, achieving a reduction by 86.8% on the quarter level. In herd B, 23 quarters of non-severe CM were recorded. Of them, S. uberis and Escherichia coli were identified equally in 8 (34.8%) samples and NAS in 2 (8.7%) samples and with no growth in 5 (21.7%) cases. Bacteriological cure was achieved in 17/18 quarters (94.4%). Antimicrobial consumption was reduced from 4.45 to 1.83 doses per case. Only 5 (1.7%) quarters of 72 cows were included for SDCT with reduction in consumption of antimicrobials by 98.3% on the quarter level. In summary, innovated treatment protocols based on results of on-farm culture enabled a significant reduction of antimicrobial consumption and improvement of bacteriological cure rate in conditions of practise. [ABSTRACT FROM AUTHOR]

The aim of this study was to prove the hypothesis that the growth and health of calves are dependent on feed supplements with an antidiarrhoeic effect, in relation to sex, season of birth, and number of the dam's lactations. A total of 186 calves were included in the experiment. After birth the calves were divided into three treatment groups: Ascophyllum nodosum (brown seaweed hydrolyzate, prebiotics), Lactobacillus sporogenes (probiotics), and the control group. All calves were weighed within two h after birth. The growth and health were investigated from the birth to the fourth week of age. Compared to the control, a significant effect of applied feed supplements was found in the Lactobacillus sporogenes group in the body weight at 28 days of life (P < 0.01) and in the average daily gains (P < 0.001). Differences between sexes were found in the body weight at birth (P < 0.001) and in the body weight at 28 days of life (P < 0.01). The effect of the season of birth was recorded in the average daily gains (P < 0.01). The effect of the number of the dam's lactations on calf was proved in body weights at birth and 28 days of life (P < 0.01). The interaction between treatment and sex (P < 0.05), and between treatment and season of birth (P < 0.01) were calculated in the average daily gains. We concluded from the analysis that only the use of Lactobacillus sporogenes had a positive influence on increasing the growth. Neither of the two supplements had a positive impact on the health of calves. [ABSTRACT FROM AUTHOR]