RESUMO
Background: Diarrhea in newborn calves is considered life-threatening and results in large economic losses in dairy farms. Lactobacilli generally play an important role in intestinal health, and Lactobacillus (Limosilactobacillus; L.) reuteri is the dominant Lactobacillus species in the feces of healthy calves during the first week of life. In calves with diarrhea on day 2 postpartum, lactobacilli are significantly reduced even up to 24 h before the onset of clinical signs. Since the probability of occurrence of diarrheal disease decreases as the L. reuteri count in the feces increases, oral administration of this species might have a protective effect against diarrhea. Objective: These studies were designed to demonstrate whether oral administration of preselected L. reuteri isolates can reduce the incidence of diarrhea in newborn calves on dairy farms. Microorganisms: 46 L. reuteri isolates from 2-day-old healthy calves were available from a previous study. Animals: 170 newborn calves of Simmental breed of 10 dairy farms in Bavaria (Germany), were included in the study; of 166 animals the data could be evaluated. Methods: Microbiological (antibiotic sensitivity test, acid and bile salt stability test, antimicrobial activity of the supernatants), molecular biological (PCR, RAPD-PCR) and toxicological methods (MTT test) were used to select and to characterize suitable L. reuteri isolates. The administration of a suspension of two selected L. reuteri isolates (6-8 × 108 colony forming units per day) to calves was performed from day 2 to day 5 after birth in a double-blinded placebo-controlled study. Clinical monitoring of the calves continued until the 14th day of life. Results: Out of 46 L. reuteri isolates, only 2 met the set criteria and were used in the feeding trial. In the placebo group, 44 of 83 calves developed diarrhea within the first 2 weeks of life, whereas in the L. reuteri group this was only the case in 31 of 83 animals (p < 0.05). Conclusion: L. reuteri appears to be of particular importance for the intestinal health of newborn calves. The diarrhea protective effect could be even more pronounced if an improved administration regimen is developed in terms of start, frequency, and duration.
RESUMO
Background: Diarrhea is still the most common and economically most significant disease of newborn calves. Objective: Analysis of the development of selected bacterial groups in the feces of neonatal calves and its significance regarding diarrhea. Animals: A total of 150 newborn Simmental calves reared in 13 Bavarian farms were included in the study. Methods: Fecal samples of calves taken at 0/6/12/24/48/72/168 hours (h) since birth were analyzed qualitatively and quantitatively for aerobic and anaerobic bacteria, such as Enterobacteriaceae, E. coli, enterococci, and lactobacilli, using cultural, biochemical, and molecular-biological methods. Concurrently, the health status of the animals was recorded. The bacterial levels of healthy and diarrheic animals were compared using statistical methods. In addition, feces samples from calves that developed diarrhea were examined by ELISA for the presence of rotaviruses, coronaviruses, E. coli F5, and Cryptosporidium (Cr.) parvum. Results: Fifty-seven out of 150 calves (37.3 %) that were examined developed diarrhea within the first week of life. In the feces of calves with diarrhea on day 1 of life, the levels of aerobes, Enterobacteriaceae, and E. coli were significantly increased (p < 0.05), while no significant differences in enterococci and lactobacilli were found. In animals with the onset of diarrhea on day 2 after birth, the load of lactobacilli was significantly reduced up to 24 h before the manifestation of clinical symptoms compared to healthy calves. For enterococci, this was only the case on the day of the onset of diarrhea. In addition, the ratios of aerobic and anaerobic bacteria, Enterobacteriaceae or E. coli to lactobacilli, of calves with diarrhea starting on day 2 after birth are significantly higher than those of healthy calves. The detection frequency of specific pathogens in diarrheic calves increased over the first week of life. Conclusion: The results suggest that the incidence of neonatal diarrhea in calves is favored by low levels of lactobacilli in the feces. From this, the hypothesis can be derived that, in addition to an optimal supply of colostrum, the earliest possible administration of lactobacilli might reduce neonatal diarrhea in calves. However, this must be verified in a subsequent feeding experiment.
RESUMO
Past research suggests that people's beliefs about the malleability of their body weight influence their motivation to engage in healthful behaviors: people who perceive their body weight as fixed (entity theorists) engage less in healthful behaviors than people who perceive their body weight as changeable (incremental theorists). Accordingly, current health interventions frequently aim at shifting entity theorists' beliefs about the malleability of their body weight. Instead of trying to change these beliefs, we test whether the elicitation of pride from past achievements can serve as an intervention to promote healthful behaviors among entity theorists. In addition, we contrast the effect of pride recall among entity theorists with the effect among incremental theorists. Specifically, we find that entity theorists chose healthier behaviors upon the recall of pride related and unrelated to the health domain - the source of pride does not seem to matter. For incremental theorists, however, the source of pride does matter. While health-related pride led them to persist in making healthy food choices, health-unrelated pride instilled reward-seeking behavior among incremental theorists. Prompting health-related pride might be a viable motivational tool to promote healthy food choices, as it is beneficial for entity theorists without thwarting the motivation of incremental theorists.
