Review: Bovine foetal mortality - risk factors, causes, immune responses and immuno-prophylaxis.

This review of bovine foetal mortality (>42 d gestation) concluded that while the majority of risk factors associated with sporadic loss operate at animal-level, e.g. foetal plurality, those that operate at herd-level, e.g. some foetopathogenic infections, are more likely to result in abortion outbreaks. While the causes of foetal mortality have traditionally been classified as infectious and non-infectious, in fact, the latter category is a diagnosis of exclusion, generally without determination of the non-infectious cause. This review has also established that the traditional dichotomisation of infectious agents into primary and secondary pathogens is based on a flawed premise and these terms should be discontinued. The delicate balance of the maternal gestational immune system between not rejecting the allograft (conceptus) but rejecting (attacking) foetopathogens is stage-of-pregnancy-dependent thus the timing of infection determines the clinical outcome which may result in persistent infection or foetal mortality. Utilisation of our knowledge of the materno-foetal immune responses to foetopathogenic infection has resulted in the development of numerous mono- and polyvalent vaccines for metaphylactic or prophylactic control of bovine foetal mortality. While some of these have been shown to significantly contribute to reducing the risk of both infection and foetal mortality, others have insufficient, or conflicting evidence, on efficacy. However, recent developments in vaccinology, in particular the development of subunit vaccines and those that stimulate local genital tract immunity, show greater promise.

Changes in fatty acids in plasma and association with the inflammatory response in dairy cows abomasally infused with essential fatty acids and conjugated linoleic acid during late and early lactation.

Dairy cows are exposed to increased inflammatory processes in the transition period from late pregnancy to early lactation. Essential fatty acids (EFA) and conjugated linoleic acid (CLA) are thought to modulate the inflammatory response in dairy cows. The present study investigated the effects of a combined EFA and CLA infusion on the fatty acid (FA) status in plasma lipids, and whether changes in the FA pattern were associated with the acute phase and inflammatory response during late pregnancy and early lactation. Rumen-cannulated Holstein cows (n = 40) were assigned from wk 9 antepartum to wk 9 postpartum to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 g/d of linseed oil and 4 g/d of safflower oil; ratio of oils = 19.5:1; n-6:n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; isomers cis-9,trans-11 and trans-10,cis-12; each 10 g/d), or both (EFA+CLA). Blood samples were taken to measure changes in FA in blood plasma on d -63, -42, 1, 28, and 56, and in plasma lipid fractions (cholesterol esters, free fatty acids, phospholipids, and triglycerides) on d -42, 1, and 56 relative to calving, and in erythrocyte membrane (EM) on d 56 after calving. Traits related to the acute phase response and inflammation were measured in blood throughout the study. Liver samples were obtained for biopsy on d -63, -21, 1, 28, and 63 relative to calving to measure the mRNA abundance of genes related to the inflammatory response. The concentrations of α-linolenic acid and n-3 FA metabolites increased in lipid fractions (especially phospholipids) and EM due to EFA supplementation with higher α-linolenic acid but lower n-3 metabolite concentrations in EFA+CLA than in EFA treatment only. Concentration of linoleic acid decreased in plasma fat toward calving and increased during early lactation in all groups. Concentration of plasma arachidonic acid was lower in EFA- than in non-EFA-treated groups in lipid fractions and EM. The cis-9,trans-11 CLA increased in all lipid fractions and EM after both CLA treatments. Plasma haptoglobin was lowered by EFA treatment before calving. Plasma bilirubin was lower in EFA and CLA than in CTRL at calving. Plasma concentration of IL-1ß was higher in EFA than in CTRL and EFA+CLA at certain time points before and after calving. Plasma fibrinogen dropped faster in CLA than in EFA and EFA+CLA on d 14 postpartum. Plasma paraoxonase tended to be elevated by EFA treatment, and was higher in EFA+CLA than in CTRL on d 49. Hepatic mRNA abundance revealed time changes but no treatment effects with respect to the inflammatory response. Our data confirmed the enrichment of n-3 FA in EM by EFA treatment and the inhibition of n-3 FA desaturation by CLA treatment. The elevated n-3 FA status and reduced n-6:n-3 ratio by EFA treatment indicated a more distinct effect on the inflammatory response during the transition period than the single CLA treatment, and the combined EFA+CLA treatment caused minor additional changes on the anti-inflammatory response.

Effects of advanced age and pituitary pars intermedia dysfunction on components of the acute phase reaction in horses.

Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concentrations of pro- and anti-inflammatory cytokines and acute phase proteins were measured. The data were analyzed using the Mann-Whitney U-test, and correlations between groups of data were assessed using Spearman's correlation coefficient. The tests were statistically significant if P < 0.05. No differences in the whole blood cytokine gene expression, serum cytokine concentrations, or acute phase proteins were noted between the groups. In the PPID ID group, there was a strong correlation between the ACTH concentration after the administration of thyrotropin-releasing hormone and the expression of IL-8 (r = 0.941; P = 0.0321). In the PPID ID+ group, there was a strong correlation between basal insulin concentrations and serum amyloid A (SAA; r = 0.936; P = 0.0083) as well as between postprandial insulin concentrations and SAA (r = 0.965; P = 0.001). These data suggest that neurodegeneration in horses moderately affects circulating markers of inflammation and that ID in horses with PPID influences acute phase inflammatory markers.

Effects of equine metabolic syndrome on inflammation and acute-phase markers in horses.

Obesity and metabolic disorders are associated with systemic low-grade chronic inflammation, both in humans and animals. The aim of the study is to assess the effects of obesity and hyperinsulinemia on individual components of the acute-phase reaction in equine metabolic syndrome (EMS) horses. Eight mixed-breed EMS and six control, age-matched horses of both sexes were included in the study. Animals were classified as EMS or control based on the assessment of BCS, cresty neck score, and basal insulin >50 µU/mL and/or insulin responses to the oral sugar test (OST) >60 µU/mL. Peripheral venous blood was collected. The expression of proinflammatory cytokines, the concentration of circulating cytokines, and acute-phase proteins (serum amyloid A, C-reactive protein, haptoglobin, activin A, and procalcitonin) were measured. The data were analyzed using the Mann-Whitney test, whereas correlations were examined using Spearman's correlation coefficient. The tests were statistically significant if P ≤ 0.05. There were no differences in cytokine gene expression, circulating cytokine concentrations, or concentrations of acute-phase proteins between the EMS and the control groups. There was a strong correlation between the basal concentration of insulin and the serum concentrations of IL-6 (r = 0.71, P < 0.05). Activin A was positively correlated with post-OST insulin concentrations (r = 0.707, P = 0.05), indicating that this marker of inflammation could warrant further investigation in horses with EMS.

Effects of colostrum instead of formula feeding for the first 2 days postnatum on whole-body energy metabolism and its endocrine control in neonatal calves.

Colostrum provides high amounts of nutritive and non-nutritive substrates, which are essential for calf nutrition and passive immunization. Colostral growth factors and hormones have beneficial effects on postnatal maturation and may affect substrate utilization and energy expenditure in neonatal calves. We tested the hypothesis that energy metabolism and its endocrine regulation differ during the first 10 d of life in calves fed either colostrum or a milk-based formula with a similar nutrient composition to colostrum, but largely depleted of bioactive substances, for the first 2 d postnatum. Male Holstein calves (n = 18) were fed either pooled colostrum (COL; n = 9) or a milk-based formula (FOR; n = 9) for the first 2 d of life. From d 3 on, all calves received same milk replacer. On d 2 and 7 of life, calves were placed in a respiration chamber for indirect calorimetric measurements to calculate heat production, fat (FOX) and carbohydrate oxidation (COX), as well as respiratory quotient. Blood was sampled on d 1 before first colostrum intake and on d 2, 3, 7, 8, 9, and 10 before morning feeding, to measure plasma concentrations of immunoglobulins, metabolites, and hormones. Additional postprandial blood samples were taken on d 1 and 9 at 30, 60, 120, 240, and 420 min after milk feeding. Liver samples were collected on d 10 of life to determine gene expression related to energy metabolism. Formula-fed calves showed lower plasma concentrations of total protein, immunoglobulins, haptoglobin, leptin, adiponectin, and insulin-like growth factor (IGF) binding protein (IGFBP)-4 during the whole study but temporarily higher plasma concentrations of urea, insulin, glucagon, triglyceride, and cholesterol on the first day after feeding, compared with concentrations in COL. The temporary increase in glucagon, triglyceride, and cholesterol on d 1 reversed on d 2 or 3, showing higher concentrations in COL than in FOR calves. In FOR, IGF-I, IGFBP-2, and IGFBP-3 were lower on d 3 than in COL. Interestingly, FOR calves had higher heat production during respiratory measurements on d 2 and higher body temperature on d 2, 3, and 5 than those of COL. The hepatic mRNA abundance of cytosolic phosphoenolpyruvate carboxykinase was higher in FOR than in COL. Our results indicate that first milk feeding after birth influenced whole-body energy expenditure but not FOX and COX in neonatal calves, and the absorption of colostral leptin and adiponectin might affect insulin sensitivity on d 1 of life.

Production and characterization of swine hyperimmune serum against recombinant, common antigens of Gram-negative outer membrane bacteria.

The application of immune serum is one of the most efficient method used formerly in the protection of raised piglets'/weaners' health . The objective of the study was to determine specific antibody response during hyperimmunization of fatteners with a self-prepared subunit vaccine, and to propose production method of immune serum against Gram-negative bacteria antigens. The vaccine was administered every two weeks, 4 times. Individual and pooled serum samples were assayed for IgM, IgG and IgA antibodies against Histophilus somni recombinant Hsp60, H.somni rOMP40 and Pasteurella multocida LPS. Additionally total serum IgG and haptoglobin concentrations were measured. Two weeks after the first vaccination IgM antibody raised significantly against H.s. rOMP40 and LPS, whereas after 4 weeks it increased against rHsp60 antigens. Anti-LPS IgM antibody raised up stepwise till the end of the observation, but IgM antibody against H.s. rHsp60 and H.s. rOMP40 decreased in further samplings. A significant raise in IgG class H.s. rHsp60- -antibody was found 4 weeks after the first immunization and a similar raise against two remain- ing antigens after 6 weeks. The intensity of the reaction increased till the end of the experiment. The raise in IgA antibody level was observed only for H.s. rHsp60 antigen. Clinically observed, proper animal health and welfare were confirmed by haptoglobin concentration, which remained in physiological range. At least 4 booster doses were necessary to obtain hyperimmune serum containing a high level of antibodies against examined antigens. The number of immunizations influenced response profiles for specific IgM, IgG, IgA antibodies.

Screening for Mollicutes microorganisms in perinatal calf mortality cases in Polish dairy herds.

Perinatal calf mortality in dairy herds has been reported worldwide. The etiology of stillbirth is multifactorial, and can be caused by various species of bacteria and environmental factors. Among them some potential pathogens from the Mollicutes class such as Mycoplasma (M.) spp. and Ureaplasma (U.) diversum can be isolated from the bovine genital tract and other organs of the suspected cattle. The aim of this study was to evaluate if the bacteria belonging to the Molli- cutes class i.e. M. bovis, M. bovigenitalium, M. canadense, M. canis, M. arginini, M. bovirhinis, M. dispar, M. alkalescens and U. diversum could have an impact on perinatal calf mortality in selected Polish dairy farms. The material was: 121 stillborn calves (SB), 21 live born calves (C) and 131 cows (dams) from 30 Polish Holstein-Friesian herds. Samples were examined from all the SB calves' and six control euthanized calves' abomasal contents and lung samples collected during necropsy, and from the dams' serum and placenta. In dams the serological ELISA, and in calves and placenta samples molecular PCR/denaturing gradient gel electrophoresis, methods were used. Screening of dams' sera for antibodies to M. bovis (ELISA) showed seven dams positive for M. bovis, whereas none of the nine examined Mollicutes microorganisms were detected in the placenta and calves.

Randomized study of the influence of two-dimensional versus three-dimensional imaging using a novel 3D head-mounted display (HMS-3000MT) on performance of laparoscopic inguinal hernia repair.

BACKGROUND: 3D laparoscopy has proven to be superior to the 2D approach in experimental settings. The aim of the present study was to investigate the influence of 3D laparoscopy using a novel head-mounted display on the performance of defined steps within a laparoscopic inguinal hernia repair. This effect was investigated both in laparoscopically advanced surgeons and in beginners. METHODS: Patients suffering from symptomatic inguinal hernia were randomly assigned to laparoscopic hernia repair using either a head-mounted 3D display or a conventional 2D laparoscopic approach. Operative performance of both groups was compared in terms of the time taken for mesh placement and for peritoneal suturing. Additionally, quality of imaging and physical discomfort were assessed. RESULTS: The use of a head-mounted 3D display was able to shorten the time required for placement of the mesh as well as that for peritoneal suturing, both for experienced and novice surgeons when compared to the conventional 2D approach. 3D laparoscopy was significantly superior to 2D laparoscopy in terms of depth perception, image sharpness and image contrast. Additionally, increased impairment caused by ghosting effects could not be detected in 3D laparoscopy. Evaluation of image quality was independent of experience in laparoscopic surgery. However, use of a head-mounted 3D display resulted in a significant impairment of surgeon's comfort when compared to 2D laparoscopy. Thereby, the greatest impairment was caused by ear discomfort. CONCLUSIONS: This is the first study examining the effect of a head-mounted 3D system on the performance of laparoscopy in a randomized controlled trial (RCT) showing a clear advantage of this system in surgical performance as well as in depth perception and image quality.

Effects of ad libitum milk replacer feeding and butyrate supplementation on behavior, immune status, and health of Holstein calves in the postnatal period.

Animal welfare in dairy calf husbandry depends on calf rearing and is probably improved by intensive milk feeding programs. In addition, butyrate supplementation in milk replacer (MR) stimulates postnatal growth and may affect the immune system in calves. We have investigated the combined effects of ad libitum MR feeding and butyrate supplementation on feeding behavior, health, and the immune responses in calves. Holstein calves (n = 64) were examined from birth until wk 11 of age. Calves received MR either ad libitum (Adl) or restrictively (Res) with (AdlB+, ResB+) or without (AdlB-, ResB-) 0.24% butyrate supplementation starting on d 4. From wk 9 to 10, all calves were gradually weaned and were fed 2 L/d until the end of the trial. Concentrate, hay, and water were freely available. Calves were housed in straw-bedded group pens with automatic MR feeders, where feed intake and feeding behavior were documented. Blood was drawn on d 1 before the first colostrum intake; on d 2, 4, and 7; and weekly thereafter until the end of the study to measure plasma concentrations of total protein, albumin, the immunoglobulins IgG1, IgG2, and IgM, and the acute phase proteins fibrinogen, serum amyloid A, and haptoglobin. Liver samples were taken on d 50 and 80 to determine gene expression related to acute phase proteins. Body temperature was measured daily for the first 3 wk, and clinical traits were scored daily. Ad libitum MR feeding resulted in greater MR intake, greater MR intake per meal, slower sucking rate, and greater body weight, but in a lower number of unrewarded visits and lower concentrate intake when compared with Res. Butyrate reduced the sucking rate but increased MR intake per meal. Immunoglobulins in the blood plasma increased after colostrum intake in all calves, with only minor differences among groups throughout the study. Plasma fibrinogen and serum amyloid A increased in the first week of life in all calves, and fibrinogen was greater in Res than in Adl on d 21, 49, and 63. Hepatic gene expression of fibrinogen on d 80 was greater in Adl than in Res. Gene expression of SAA2 was greater on d 50 in Adl than in Res and on d 80 was greater in ResB+ than in ResB-. Body temperature was greater in Adl than in Res during the first 2 wk, but neither MR feeding nor butyrate affected the health status. An improved animal welfare in Adl calves is supported by fewer signs of hunger, but intensive milk feeding and butyrate did not affect the health and immune status of the calves in a consistent manner.

Acute phase response in the primiparous dairy cows after repeated percutaneous liver biopsy during the transition period.

The aim of this study was to evaluate the acute phase response of dairy cows to repeated liver biopsy in order to estimate the safety of this procedure during the transition period. Liver biopsies (up to 1000 mg of liver tissue) were conducted twice a day, 7 days before expected parturition and 3 days after calving. The number of needle insertions for each biopsy was recorded and was dependent on the amount of obtained tissue. Blood samples were taken on day 7 before expected parturition, then on days 3, 4, 7 and 14 after calving. Body temperature was measured daily in all 30 cows from day 3 until day 14 after calving. The concentrations of haptoglobin, serum amyloid A, fibrinogen and interleukin-6 were determined in serum and plasma. In 16.7% of cows, the rectal body temperature rose by ≥ 0.5°C on the day after liver biopsy. Although the concentrations of haptoglobin, serum amyloid A and fibrinogen increased significantly after calving (p<0.01), there was no influence of the number of biopsies on the acute phase reaction and repeated biopsy during the transition period had no effect on body temperature. Therefore, the procedure may be regarded as safe for cows during the transition period.

Anti-inflammatory properties and expression in selected organs of canine interleukin-1ß splice variant 1.

The IL-1ß gene can be also be spliced with the intron 4 retention; the result is a IL-1ß splice variant 1 (IL-1ßsv1), which was significantly up-regulated in failing myocardium of dogs suffering from chronic degenerative valvular disease (CDVD). Expression of IL-1ßsv1 was assessed, at both RNA and protein levels, in organs affected by heart failure, namely, kidneys, liver, and lungs from 35 dogs suffering chronic degenerative valvular disease (CDVD) and in 20 disease free control dogs. IL-1ßsv1 RNA was detected in the dogs from both groups. In the CDVD group, the highest RNA and protein IL-1ßsv1 levels were observed in lungs, followed, in that order, by the liver and kidneys. IL-1ßsv1 protein was found in the cytoplasm of hepatocytes and IL-1ßsv1-overexpressing DH82 cells. In lungs, IL-1ßsv1 was localized in the cytoplasm and in the nuclei of bronchiolar epithelial and smooth-muscle cells. Cytoplasmic and nuclear IL-1ßsv1 expression was observed in macrophages, and a strong nuclear signal was detected in epithelial cells of the alveolar sacs. Following lipopolysaccharide (LPS) stimulation, overexpression of IL-1ßsv1 in DH82 cells decreased the pro-inflammatory response. Our results indicate that IL-1ßsv1 is constitutively expressed in both normal tissues and in tissues from cases of heart failure. The presence of IL-1ßsv1 in tissues exposed to invading agents and its anti-inflammatory activity in DH82 cells may point to its immunomodulatory role in vivo.

Effect of in ovo-delivered prebiotics and synbiotics on lymphoid-organs' morphology in chickens.

Prebiotics and probiotics, either alone or together (synbiotics), can influence the intestinal microbiota and modulate the immune response. We aimed to investigate the effects of prebiotic and synbiotic administration during the early stage of development on the histological structures of central (bursa of Fabricius and thymus) and peripheral (spleen) lymphatic organs in broilers. We used 800 hatching eggs from meat-type hens (Ross 308). Prebiotics and synbiotics were administered in ovo into the air chamber of chicken eggs at d 12 incubation, as follows: prebiotic inulin (Pre1), Bi2tos (Pre2), a synbiotic composed of inulin and Lactococcus lactis subsp. lactis IBB SL1 (Syn1), a synbiotic composed of Bi2tos and L. lactis subsp. cremoris IBB SC1 (Syn2), or physiological saline (control group, C). In ovo delivery of prebiotics and synbiotics had no adverse effect on the development of the immune system in exposed chickens. Administration of Bi2tos with L. lactis subsp. cremoris (Syn2) decreased the cortex/medulla ratio in the thymus and slowed the development of the cortex in bursal follicles on d 21 posthatching, with consequent impacts on the primary lymphatic organs. The above treatment also stimulated germinal centers' formation in the spleens of 21- and 35-day-old chickens, indicating enhanced B-cell proliferation in secondary lymphatic organs. Syn2 also caused an age-dependent increase in the spleen/bursa of Fabricius ratio. In conclusion, the in ovo administration of pre- and synbiotics at d 12 incubation can modulate the central and peripheral lymphatic organ development in broilers. This effect is more pronounced after synbiotic treatment than in prebiotic-treated groups.

Production and characterization of egg yolk antibodies against bovine alimentary tract pathogens.

Aim of the study was to evaluate the effect of immunization of hens with bovine vaccines (C, R, T) on the course of IgY antibodies production against selected bovine E. coli strains, rota- and coronaviruses in egg yolk in farm conditions. The hens (40 individuals per group) were vaccinated twice, subcutaneously in four week interval and eggs were harvested once a week. Control group consisted of eggs sampled from non-vaccinated hens located in neighbouring cages. The antibody activity was measured by ELISA. All used vaccines induced the rise of IgY antibody in egg yolks. Based on the duration and the highest level of IgY antibody against bovine alimentary tract pathogens C vaccine was further used in next two trials for vaccination of 1000 hens each time. Double immunization seems to be enough in mounting response against examined pathogens for several weeks. Immunization with C vaccine allowed to harvest eggs with satisfactory levels of E. coli, rotavirus and coronavirus IgY antibodies which may be used to evaluate their protective effect by oral administration in calves.

Salt stress-induced invasiveness of major Listeria monocytogenes serotypes.

UNLABELLED: Of the 13 serotypes, 4b serotype strains are responsible for the majority of recorded invasive listeriosis outbreaks, although some recent listeriosis outbreaks have been attributed to strains of serotypes 1/2a and 1/2b. Virulence and response to osmotic stress in 41 Listeria monocytogenes strains representing serotypes 1/2a, 1/2b and 4b was investigated. It was found that serotype 4b and 1/2b strains exhibited highest invasion efficiency and formed largest plaques in HT-29 cell monolayer. Invasiveness in response to 10-min exposure to 0·3 mol l⁻¹ NaCl was the highest in serotype 4b strains. We demonstrated that 4b serotype L. monocytogenes strains not only have the greatest pathogenic potential but also are the most invasive in response to salt stress. SIGNIFICANCE AND IMPACT OF THE STUDY: Listeria monocytogenes 4b serotype strains are responsible for the majority of recorded invasive listeriosis outbreaks. We showed that strains of serotype 4b are not only the most virulent L. monocytogenes strains but also have the best capacity to enhance their invasiveness in response to salt stress. Our results suggest possession of effective stress response mechanisms of 4b serotype strains, which may contribute to the high infection potential of this subpopulation.

The increase of serum chemerin concentration is mainly associated with the increase of body mass index in obese, non-diabetic subjects.

BACKGROUND: Chemerin is a newly discovered adipokine, whose circulating concentration is increased in obesity. AIM: To elucidate whether the increased circulating chemerin concentrations in obese subjects are associated with the increase of fat mass, the increase in chemerin gene expression in adipose tissue or both. MATERIAL/SUBJECTS AND METHODS: Serum chemerin concentrations in 20 non-obese healthy volunteers and 21 non-diabetic obese subjects were measured using ELISA. Chemerin mRNA and chemerin protein levels in visceral and subcutaneous adipose tissues of obese subjects were analyzed by Real-Time PCR and Western blot respectively. RESULTS: We found that the serum chemerin concentrations were significantly higher in obese subjects than in controls and positively correlated with BMI, fat mass and body mass. Moreover serum chemerin concentrations were correlated positively with serum CRP concentrations independently of BMI. No correlation was found between the chemerin mRNA and chemerin protein levels in visceral and subcutaneous adipose tissues and BMI, fat mass, or body weight. Likewise, there was no correlation between the serum chemerin concentrations and the levels of chemerin mRNA and protein in adipose tissue of obese patients. Multiple regression analysis suggests that BMI was the main predictor of serum chemerin concentration. In contrast to chemerin, both serum leptin concentrations and adipose tissue leptin mRNA levels positively correlated with BMI. CONCLUSIONS: The results presented here indicate that serum chemerin concentrations correlated with BMI, whereas chemerin mRNA levels in adipose tissue did not. Thus the elevated circulating chemerin concentration in obese, non-diabetic patients was mainly associated with the increased BMI.

Inhibition of in vitro Histophilus somni biofilm production by recombinant Hsp60 antibodies.

Histophilus somni is an opportunistic pathogen causing respiratory, genitourinary and generalized infections in cattle. An important virulence factor is its ability to produce a biofilm. The aim of this work was to confirm that H. somni Hsp60 (Gro-EL) is a constituent of the biofilm produced by this bacterium in vitro and to check whether or not the presence of a specific antibody within the culture medium can inhibit biofilm production. Biofilm production by H. somni cultured in vitro was confirmed by crystalline violet staining. The presence of Hsp60 in the biofilm was confirmed by using specific antibodies produced in a mouse and goat hyperimmunized with H. somni recombinant Hsp60 (rHsp60). Large complexes of biofilm stained with Hsp60 antibodies were microscopically detected. This indicates that the Hsp60 protein is a common constituent of the biofilm produced by H. somni in vitro. In a second experiment, mouse serum containing anti-H. somni rHsp60 antibodies was added to an H. somni culture. It was found that the presence of anti-rHsp60 antibodies in the culture medium inhibited biofilm production in vitro. Only small biofilm particles were seen in the presence of the specific antibody, whereas in control cultures (without specific antiserum) large biofilm complexes were produced. The results indicate that antibodies specific to Hsp60 may be useful for preventing H. somni biofilm formation in vitro. If this also occurs in vivo, it may be helpful for eradicating H. somni infection in cattle through the elimination of carriers. Further in vivo studies are needed to confirm this idea.

Use of spray-dried porcine blood by-products in diets for young chickens.

Spray-dried porcine blood plasma (SDBP) or blood cells (SDBC) at amounts of 20 or 40 g/kg were included to the feed mixtures that were given to young chickens within 1-28 (Exp. 1) or 1-30 (Exp. 2) days post-hatch. In comparison with the group fed mixtures containing plant components, chickens fed mixtures supplemented with 40 g/kg of SDBP significantly (p < 0.01) increased the body weight estimated on 14 day of life (Exp. 1). At the age of 28 or 30 days post-hatch, the body weight was improved significantly (p < 0.01 or 0.05) in both experiments. Significant differences (one-factorial anova) in feed conversion among particular feeding groups were stated in Exp. 1 only; however, calculations using two-factorial anova show insignificant differences depending on the used animal meal. In selected blood parameters (IgG, Ht, Hb), insignificant differences between feeding groups were stated. The use of SDBP in feed mixture significantly increased the Na retention in both experiments, and K accretion in Exp. 1 only. Application of SDBC and 40 g/kg of SDBP significantly or insignificantly improved Fe retention. Insignificant diversification of apparent ileal digestibility of nutrients was stated; the crude fat was significantly better digested in treatments fed mixtures with animal meals but kind of animal meal was without any significant effect. Significant differences in digestibility of amino acids were recorded for Pro, Cys, Val, His, Lys and Arg. In chickens fed mixture with SDBC, higher coefficients of apparent digestibility of Cys, Val and His (Exp. 1) and Cys and His (Exp. 2) than in other feeding groups were obtained. The kind of used blood by-products has not affected the histological structure of intestine wall.

The influence of colostral immunoglobulin concentration in heifer calves' serum on their health and growth.

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 (<5, 5-10, 10-15, and >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.

Optimization of Salmonella enteritidis recombinant heat shock protein 60 production.

The aim of the study was to optimize conditions for producing Salmonella Enteritidis recombinant heat shock protein 60 (rHsp60). Seven Escherichia coli host strains (Rosetta, Turner, C41, C43, Origami, BL21pLys, Rosetta pLys) were transformed by a recombinant plasmid containing Hsp60 gene from Salmonella Enteritidis, and then cultured and induced by isopropyl-beta-D-thiogalactopyranoside (IPTG). The highest S. Enteritidis rHsp60 yield was obtained using E. coli strain C41. Induction of this strain using IPTG allowed the yield 400 microg of S. Enteritidis Hsp60 protein/2L of culture, but by autoinduction the yield exceeded 800 microg/2L.

Serum levels of acute phase proteins: SAA, Hp and progesterone (P4) in mares with early embryonic death.

The study involved 46 healthy purebred Arabian mares exhibiting regular oestrous cycles that underwent artificial insemination (AI). Pregnancy was detected ultrasonographically (US) in 40 mares. In 15 mares in foal, early embryonic death (EED) was observed during the pregnancy days 14-21. Blood for determinations of serum acute phase proteins (SAA and Hp) and progesterone (P4) was sampled 12-24 h before ovulation and the first insemination, at 12, 24, 72, 96 h and on day 7, 10, 14, 21, 35 and 55 after ovulation. The results revealed that in 25 mares without EED, the serum levels of P4, SAA and Hp were within physiological limits; in 15 mares with EED, the levels of SAA and Hp were significantly increased. In seven mares with EED, high levels of SAA and Hp were already found before ovulation and at 12, 24, 72, 96 h as well as on day 7 and 10 post-ovulation, whereas the level of P4 was normal for early pregnancy. In the remaining eight mares with EED, increased levels of SAA and Hp were found at 72 h after ovulation and maintained until day 55. In this group, the level of P4 decreased since 96 h after ovulation. Determinations of SAA, Hp and P4 in mares in early pregnancy (EP) are useful for monitoring normal development of pregnancy and for diagnosis of subclinical genital inflammations, which may lead to EED.