The aim of this study was to determine factors affecting passive transfer in heifer calves born within 1 yr and how passive transfer influences rearing to the period of first insemination under commercial dairy farm conditions. Calves were divided into 4 groups based on serum immunoglobulin concentrations at 30 to 60 h of life (15 g/L, respectively in groups 1 to 4). Calving ease, dam parity, calf body weight at birth, calf vitality, quality of colostrum, time and volume of first colostrum fed, morbidity rate and intensity of illness, growth rate, and age and efficiency of first insemination service were recorded. Plasma fibrinogen, and serum γ-globulin, IgG(1), IgG(2), IgM, and haptoglobin were estimated at 30 to 60 h and again at 21 to 28 d of life. Additionally, the immunoglobulin index (I(Ig3-4)) was calculated. The main cause of FPT and PFPT in the calves was poor vitality associated with dystocia and low volume of ingested colostrum. The calves born to primiparous cows were more endangered than those born to multiparous cows. The morbidity and intensity of disease course were lowest in heifer calves with serum Ig concentration exceeding 10 g/L at 30 to 60 h of life; these calves did not become ill before d 14 of life. Calves with >15 g/L γ-globulin in serum avoided respiratory tract infections. The immunoglobulin index was lowest (0.61) in calves from group 4 and highest in calves from groups 1 and 2 (1.44 and 0.88, respectively). The suitability of this index as well as haptoglobin determination was confirmed in prediction of morbidity risk and disease intensity in growing heifer calves. Heifers with serum γ-globulin levels >10 g/L at 30 to 60 h of life showed better health status and reached body weights allowing first insemination sooner.

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The literature on hemostatic processes in swine is sparse and often fragmentary; hence, we conducted our study to characterize age-related changes in selected parameters of primary and secondary hemostasis in 50 growing pigs between day 2 and week 24 of age. We measured platelet count (PLT), mean platelet volume, platelet-to-large cell ratio, prothrombin time, activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen concentration. Among primary hemostasis parameters, PLT underwent the largest fluctuation with the animals’ age, ranging from 340 to 730 × 10⁹/L. However, statistical significance was only detected for 4-week-old piglets compared to 18-week-old animals. Of the secondary hemostasis parameters measured, TT and aPTT were the most changeable. Activated partial thromboplastin time displayed a characteristic biphasic course, being relatively short before week 5 of age (17.8–19.9 s) and then becoming much longer (28.7–52.5 s). The aPTTs measured in animals 6 weeks of age and older were statistically different ( p < 0.01) from those in younger piglets. The 2 main components of hemostasis, platelet hemostasis and plasma coagulation, did not develop at the same time. It took much longer for secondary hemostasis to stabilize, whereas platelet parameters were stable early in life.

There is some controversy about the extent of changes in different sperm cell features in stored boar semen, especially regarding the potential role of the DNA fragmentation assay for assessment of sperm fertilizing ability. The aim of this study was to assess the effect of time of storage and the dynamic changes in sperm cell characteristics in normospermic boar semen stored in long-term extender, in order to determine the susceptibility to damage of particular structures of spermatozoa during cooling and storage at 17 °C for 240 h post collection. The study included five ejaculates from each of seven boars of the Polish Large White breed (n = 35 ejaculates). The sperm characteristics were assessed using a flow cytometer and a computer assisted sperm analyzer on samples at 0, 48, 96, 168 and 240 h post collection. The sperm chromatin structure assay (SCSA) showed a significant abrupt increase (P < 0.01) in the DNA fragmentation index (%DFI) after 48 h of semen storage with only subtle changes thereafter, not exceeding 5% on average after 240 h of storage. The use of a combination of SYBR-14/PI stains did not reveal any significant changes in the percentage of live sperm cells up to 168 h of semen storage. A significant (P < 0.01) decrease in the percentage of live spermatozoa with intact acrosomes was observed after prolonged semen storage (168 h). A significant and progressive decrease in sperm motility was recorded during the whole period of semen storage. Storage of boar semen extended in long-term diluent at 17 °C for 48 h initially induced a decrease in the integrity of sperm DNA. This suggests that the structure of boar sperm DNA is susceptible to damage, especially during semen extension and at the beginning of sperm storage. These findings support the opinion that the SCSA test has only a low potential for routine assessment of boar semen preserved in the liquid state and for assessment of sperm quality changes during 10 days of semen preservation. Remarkably, the integrity of acrosomes and plasma membranes remained nearly unchanged for 7 days.

Extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases are plasmid (but also chromosomally) encoded enzymes found in Enterobacteriaceae, determining resistance to a variety of important antibiotics including penicillins, cephalosporins, and monobactams. In recent decades, the prevalence of ESBL/AmpC-producing bacteria has increased rapidly across the world. Here, we evaluate the potential use of bacteriophages in terms of a reduction of antibiotic-resistant bacteria in healthy animals. The aim of our studies was to isolate bacteriophages capable of destroying ESBL/AmpC-producing E. coli isolated from livestock habitats. The efficacy of isolated phages against ESBL/AmpC E. coli strains varies, but creation of a phage cocktail with broad activity spectrum is possible. This may indicate that the role of phages may not be limited to phage therapy, but bacterial viruses may also be applied against spread of bacteria with antibiotic resistance genes in the environment. We also addressed the hypothesis, that phages, effective for therapeutic purposes may be isolated from distant places and even from different environments other than the actual location of the targeted bacteria. This may be beneficial for practical purposes, as the construction of effective phage preparations does not require access to disease outbreaks.