Michał Bednarski

Cytotoxic necrotizing factor (CNF)-associated Escherichia coli (E. coli) occur in enteric and extraintestinal disease in calves, but the distribution of CNF1 and CNF2 and their virulence profiles remain incompletely defined. We analysed E. coli from 544 calves: 131 healthy, 210 diarrhoeic, 173 with septicaemia, and 30 with central nervous system (CNS) infection. Isolates were classified by PCR detection of cnf1 or cnf2, and only CNF-positive isolates were screened for eight accessory virulence genes. In age-adjusted models restricted to calves aged 2–19 days, overall CNF positivity (aOR 2.83, 95% CI 1.25–6.44; Holm-adjusted p = 0.039) and CNF2 positivity (aOR 3.14, 95% CI 1.18–8.31; adjusted p = 0.043) were associated with diarrhoea, whereas CNF1 was not. CNF2-positive isolates were enriched for f17A, afa8E, and cdtIII, whereas CNF1-positive isolates more often carried papC, sfa/focDE, hlyA, and kpsMT K1. In invasive cases, CNF1 was more frequent in CNS infection than in septicaemia (33.3% vs. 12.7%; adjusted p = 0.034). Among CNF1-positive invasive isolates, kpsMT K1 occurred in 90.0% of CNS versus 9.1% of septicaemia isolates. These findings support distinct CNF2-associated enteric and CNF1-associated invasive virulence profiles; PCR detection does not establish expression, phenotype, causality, or genomic linkage.

The aim of this study was to identify the main causes of neonatal mortality in dairy calves (0–30 days of age) in Poland and to assess how infectious factors and management practices influenced the pattern of mortality. A retrospective analysis was performed on 498 calves from 312 herds between 2018 and 2024. The protocol included necropsy, enteropathogen diagnostics (PCR and ELISA), and analysis of herd management questionnaires. The leading causes of death were chronic diarrhea (42.4%), acute diarrhea (25.3%), and septicemia (10.8%). Calves that died from septicemia were the youngest (mean age 7.7 days), whereas those that died from chronic diarrhea were the oldest (20.3 days; p < 0.001). Lack of dam vaccination was associated with a higher occurrence of acute diarrhea (RR = 2.04) and septicemia (RR = 2.01) within the necropsied calf population. Inappropriate colostrum management was also associated with a higher occurrence of septicemia (RR = 1.99). Despite widespread antimicrobial use (>80%), intensive fluid therapy was used rarely (Cryptosporidium parvum (C. parvum) was significantly more frequent in chronic diarrhea. Antimicrobials were used extensively, while intensive fluid therapy for diarrhea was implemented infrequently and inadequately relative to disease severity. This study makes an important contribution to the understanding of calf mortality in dairy herds by combining comprehensive postmortem diagnostics with pathogen detection (PCR and ELISA) and the assessment of management practices, thereby providing a holistic perspective on the problem. The analysis of 498 calves from 312 farms over a 7-year period offers an unprecedented and representative picture of the situation in Poland, one of Europe’s major milk producers. These results emphasize the crucial importance of proper colostrum management and vaccination, while also indicating a clear and urgent need to expand the use of fluid therapy in calves requiring treatment. The results identify not only the dominant pathogens and differences in disease course, but also management factors with direct implications for animal welfare and preventive strategies in dairy production.

Mastitis caused by Escherichia coli and Streptococcus uberis remains one of the leading causes of antimicrobial use in dairy cattle, contributing to resistance development and economic losses. This study evaluated the therapeutic potential of the natural flavonoid morin in clinical mastitis in dairy cows. The in vitro antimicrobial activity of morin (1–3% w/v) was assessed by disk diffusion, and the 3% formulation was selected for an in vivo field trial. Seventy-two Holstein–Friesian cows with mastitis caused by E. coli or S. uberis were randomly assigned to one of three intramammary treatments: 3% morin, phosphate-buffered saline, or an antibiotic, serving as a positive control. Somatic cell count (SCC) and clinical scores were monitored for seven days. In E. coli infections, morin significantly reduced somatic cell scores at 144 h and 168 h and improved clinical scores from 48 h onward, showing efficacy comparable to antibiotics. In S. uberis mastitis, morin induced clinical improvement at 96–168 h but resulted in slower and smaller SCC reduction than antibiotic control therapy. Phosphate-buffered saline produced no significant changes. These results indicate that morin exerts anti-inflammatory and supportive effects in bovine mastitis, particularly in Gram-negative infections, but is less effective against S. uberis. Further studies on pharmacokinetics, bacteriological cure rates, and optimized formulations are warranted to confirm its clinical utility.

Milk and dairy products are considered important sources of nutrients in human nutrition due to their content of high-quality protein, minerals, vitamins, and energy

Bovine Respiratory Disease (BRD) poses a significant threat to cattle welfare worldwide, affecting their respiratory system and causing substantial economic losses. BRD is multifactorial in nature. This research aimed to investigate the serological profile of calves for the five main bovine respiratory pathogens. Serum samples were collected from dairy calves aged 7–12 months that had never been vaccinated against tested pathogens and had recently shown signs of BRD. A total of 4095 calves from 650 dairy herds located in south-western Poland were examined. The Commercial Indirect Respiratory ELISA Kit Multiplexed—Double well—BIO K 284/5 (Bio-X Diagnostics, Rochefort, Belgium) was used to determine the presence of antibodies against BVDV, BoAHV1, BRSV, BPIV3, and M. bovis. The presence of antibodies against at least one of the tested pathogens was found in 306 (47.08%) herds. The overall prevalence of antibodies was as follows: BoAHV1 21.54%, BVDV 32.0%, BRSV 34.15%, BPIV3 34.31%, and M. bovis 31.38%. The strongest correlation was between BRSV antibodies positive sera and BPIV3 antibodies positive sera. Among the five pathogens tested, antibodies to BVDV, BRSV, BPIV3, and M. bovis were most commonly detected simultaneously. The results of this study indicate the need for preventive measures against these pathogens in the studied region.

Diseases are responsible for losses in livestock production by increasing animal mortality and reducing productivity. The administration of antibiotics can help mitigate these negative effects. However, inappropriate use can lead to severe complications, such as raising antibiotic resistance. The purpose of this study was to perform a comparative analysis of antibiotic use and disease frequency over four years, based on the size of dairy farms and the type of farm. The study covered a 4-year period and included medium dairy farms (20–50 cows, n = 13), large dairy farms (>250 cows, n = 8), and large beef farms (n = 8). The collected data involved antimicrobial use but also included farm demographics, animal health, disease frequency, and herd management practices. The criteria used to categorise antibiotics into groups A–D were based on the EMA guidelines. The carried-out study showed that the large dairy cattle farms had the highest antibiotic consumption (18.29 mg·PCU⁻¹), due to the high frequency of diseases, and consequently, the treatment of calf (diarrhoea, lung inflammations) and cow diseases (general treatment and mastitis). Cattle on large beef farms suffer mainly from general diseases caused by maintenance and herd management conditions. The use of restrict antibiotics was, in some cases, unjustified (antibiotics for dry cow therapy). Future studies should consider a larger number of farms, taking into account the given direction of cattle production.

Cow’s milk and dairy products are the primary sources of OBCFAs, which have beneficial health properties. The goal of this study was to identify the factors that influence the content of OBCFAs in cow’s milk and to indicate which OBCFAs can serve as biomarkers for fermentation processes. The content of OBCFAs in milk depends on the species of ruminants, with studies showing that this varies between 3.33% (in goat’s milk) and 5.02% (in buffalo’s milk). These differences also stem from the animals’ energy balance, lactation phases, forage-to-concentrate ratio, and the presence of bioactive compounds in feeds, as well as management practices and environmental conditions. The OBCFAs in milk fat mainly come from rumen bacteria, but can also be synthesized de novo in the mammary gland, making them potentially useful noninvasive indicators of rumen fermentation. The concentration of BCFA is lower in colostrum and transitional milk than in full lactation milk. The proportions of total OBCFAs are higher in first- and second-parity cows. The most effective predictors of the biohydrogenation of fatty acids in the rumen are likely C18:2 cis-9, trans-11, iso-C16:0, and iso-C13:0. OBCFAs have been identified as potential biomarkers for rumen function, because their synthesis depends on specific bacteria. Strong predictors of subclinical ruminal acidosis include iso-C14:0, iso-C13:0, and C15:0. The concentration of ∑ OBCFA >C16 in milk is associated with fat mobilization and serves as a significant marker of the energy balance in cows.

Teat papillomatosis is reported to be one of the factors causing mastitis and milk losses in dairy cattle. Little is known about bovine papillomavirus (BPV) circulation in the European cattle population, and no reports can yet be found about its prevalence in Polish herds. In this study, 177 BPV-like lesions were collected from teats of 109 slaughtered cows. BPV was identified in 39 of the examined animals, using PCR amplification and Sanger dideoxy sequencing. In total, 10 BPV types were isolated, among which the most common were infections caused by types 8 and 7. Macroscopically, “rice-grain” type lesions dominated (76%) and were mainly found on one teat (57.4%). The diversity of BPV types causing teat papillomatosis in Polish cows seems to be large, with nine already known types isolated and a new putative type found. The spread of new types among the worldwide cattle population can be seen for the first time, as type 25 and so called isolates BPV42 and BPV43 were found in the European cattle population.

This study aimed to compare the biomass obtained via the biogasification of straw with the classic bedding material, wheat straw. It was divided into two stages. In the first stage, a laboratory evaluation of the bedding materials was carried out, taking into account dry matter, pH, and water absorption. In the laboratory tests, the bedding obtained after the biogasification of straw (Verbio) showed better sorptive properties, with a value of 439.86% (wheat straw’s value was 294.10%), and its pH value was higher than that of wheat straw. In the second stage of the experiment, field tests were carried out on a production farm, wherein the bedding was evaluated for bedding hygiene, animal hygiene, insulation properties, animal productivity, and microbiological properties. A microbiological assessment was also performed. Regarding cleanliness and production parameters and thermographic insulation properties, the two types of bedding did not show statistically significant differences. In terms of microbiological parameters, a higher number of all examined types of bacteria and fungi was observed in the Verbio bedding compared with straw, but these differences were not statistically significant, except in the case of total coliform. The results indicate that straw obtained after gasification is a suitable bedding material, with parameters similar to those of wheat straw.

The study evaluated the anti-colibacteriosis efficacy of herbs in experimental infection by rabbit pathogenic strain of E. coli O103 eae⁺. It also studied the effects of herbal mixture added to feed or water on blood parameters. This animal model was used since some E. coli strains pathogenic for rabbits are similar to the strains that are pathogenic to humans. The components of herbal extracts were Rumex crispus, Pontentilla anserine, and Polygonum aviculare. Supplementation was carried out in water (ExpW group) or feed (ExpF group), and four weeks later the animals were infected with the E. coli O103 eae⁺ strain. The administration of herbs increased the mean concentration of total protein and serum albumin (p < 0.01) without causing disturbances of electrolyte and acid-base balance. The highest total antioxidant capacity (TAS) value (p < 0.01) was observed in the ExpF group. The administration of a mixture of herbs and feed caused more reduction in the number of E. coli in cecum than supplementation into water after an experimental infection. The herbs applied in rabbits did not harm the secretory functions of liver, electrolyte, and acid-base balance of the blood. The application of the tested herbal mixtures can control the activity of the intestinal microbial community.