Biomedical subjects

D Maes

Publications and source records attributed to D Maes.

At least 37 records · Page 2Linked to original sources

PubMed2004

Comparative study on five different commercial extenders for boar semen.

Increasing interest in a longer preservation of diluted boar sperm raises questions in the field concerning the choice of the extender. The aim of this study was to evaluate the longevity of boar sperm extended in currently used commercial semen extenders. Three long-term extenders and two short-term extenders were compared for different semen quality parameters that can be assessed under routine laboratory conditions. Sperm morphology, motility, pH and bacteriological contamination were investigated during a 7-day period. The number of dead spermatozoa did not differ significantly among the extenders (p > 0.05). Sperm motility was not only related with storage period but most of all with pH, especially in long-term extenders. Differences between the different extenders were prominent (p < 0.05); the sperm preserved in only one long-term extender showed good motility during the whole test period. In all cases, the pH of the extended semen increased by 0.3-0.5 in the first days of storage and was significantly correlated with a decrease in motility. Bacteriological quality had no significant influence on motility or pH of the semen. In conclusion, we can state that in both short-term extenders and in only one long-term extender, sperm longevity, as evaluated by the parameters used in this study, was sufficient during the preservation period. To preserve the quality of diluted boar semen during long-term storage, the choice of the long-term extender is important. In addition, the monitoring of the pH of extended boar semen in our study emphasizes the importance of the buffering capacity of semen extenders.

Animals↗

PubMed2004

Motility assessment of porcine spermatozoa: a comparison of methods.

Although widely used in practice, visual motility assessment of boar spermatozoa is a very subjective method. The aim of this study was to compare the visual motility assessment of boar spermatozoa with two objective, automated systems, namely the Sperm Quality Analyzer (SQA-IIC) and the Hamilton-Thorne computer-based semen analyzer (HTR). In addition, concentrations as determined by the Burker counting chamber and HTR were compared. Motility of 30 semen samples from 30 different boars (22 Pietrain, seven Landrace boars and one Large White) was examined during three consecutive days, subjectively by two independent persons (visual motility assessment) and objectively with both automated systems. The use of the SQA-IIC and HTR for assessing boar sperm motility was evaluated and the repeatability of the measurements was estimated. The Sperm Motility Index (SMI), determined by SQA-IIC, and the percentage motile spermatozoa determined by the HTR showed a good correlation (r=0.71; p <0.05). The visual examination performed by Person 2 showed a good correlation with the SMI (r=0.81) and with the percentage of motile spermatozoa measured by the HTR (r=0.66) (p <0.05). There was a very poor correlation and a limited agreement between the visual assessments of both persons emphasizing the subjectivity of visual motility assessment. Nevertheless, motility scores of each person during the three consecutive days were highly correlated (r=0.67 and 0.72, p <0.05). The limits of agreement plots showed poor agreement between both persons and the HTR. The repeatability of measurements for most parameters evaluated by the HTR and by the SQA-IIC was good with coefficients of variation below 10%. In addition, for fertile Pietrain boars (n=22), reference values for the different HTR-parameters are presented showing a high curvilinear velocity (157.3 +/- 19.5 microm/s) and a low straightness and linearity of the movement of the spermatozoa (62.7 +/- 8.7 and 35.5 +/- 7.6%, respectively). Concentration as determined by the Burker counting chamber (56.0 +/- 16.8 x 10(6)/ml) was significantly higher compared with HTR measurement (37.6 +/- 7.7 x 10(6)/ml). The high number of counted cells and the low variation render the HTR concentration measurement more reliable. It can be concluded that visual motility assessment is highly subjective and should therefore be replaced by automated systems that allow for a more objective and detailed motility assessment of boar spermatozoa. In addition, based on the present results, highly repeatable results were obtained by the SQA-IIC and especially by the HTR.

Animals↗

PubMed2004

In vitro susceptibilities of Mycoplasma hyopneumoniae field isolates.

The in vitro susceptibilities of 21 Mycoplasma hyopneumoniae field isolates were determined using a broth microdilution technique. One isolate showed acquired resistance to lincomycin, tilmicosin, and tylosin, while five isolates were resistant to flumequine and enrofloxacin. Acquired resistance against these antimicrobials in M. hyopneumoniae field isolates was not reported previously.

Animals↗

PubMed2004

Sperm distribution in the genital tract of the bitch following artificial insemination in relation to the time of ovulation.

In the present study, sperm distribution in the genital tract of the bitch following artificial insemination (AI) in relation to the time of ovulation was investigated by histology, scanning electron microscopy (SEM) and flushing. Ten bitches were inseminated intravaginally with 500 x 10(6) spermatozoa: three dogs before ovulation, four dogs during ovulation and three dogs after ovulation. Ovariohysterectomy was performed 24 h after AI. Half of the genital tract was divided into nine segments (cervix, corpus uteri, caudal, middle and cranial uterine horn (UTH), utero-tubal junction (UTJ), isthmus, ampulla and infundibulum), which were processed for histology and SEM. The contralateral UTH and uterine tube (UT) were flushed, and several sperm characteristics were assessed. Histology revealed that the spermatozoa were mainly located in the uterine glands and at the UTJ, while very few spermatozoa were detected in the UT. Insemination during ovulation resulted in higher percentages of glands with spermatozoa in the different parts of the uterus (P < 0.05). Evaluation by SEM showed higher numbers of spermatozoa in several parts of the uterus for bitches inseminated during ovulation (P < 0.05). The mean number of spermatozoa flushed from the UTH and the UT was low. No significant differences in the evaluated sperm quality parameters were found between the flushings of the UTH and the UT. In conclusion, based on our findings, the uterine glands and the UTJ might act as sperm reservoirs in the bitch and sperm transport in the genital tract is affected by the time of AI in relation to ovulation.

Animals↗

PubMed2003

Evaluation of virulence of Mycoplasma hyopneumoniae field isolates.

The course of enzootic pneumonia, caused by Mycoplasma hyopneumoniae, is strongly influenced by management and housing conditions. Other factors, including differences in virulence between M. hyopneumoniae strains, may also be involved. The aim of this study was to evaluate the virulence of six M. hyopneumoniae field isolates and link it to genetic differences as determined by randomly amplified polymorphic DNA (RAPD) analysis. Ninety, conventional M. hyopneumoniae-free piglets were inoculated intratracheally with the field isolates, a virulent reference strain or sterile culture medium. Animals were examined daily for the presence of disease signs and a respiratory disease score (RDS) was assessed per pig. Twenty-eight days post infection, pigs were euthanized, blood sampled and a lung lesion score was given. Lung samples were processed for histopathology, immunofluorescence testing for M. hyopneumoniae and isolation of M. hyopneumoniae. RAPD analysis was performed on all M. hyopneumoniae strains. Significant differences between isolates were found for the RDS, lung lesion score, histopathology, immunofluorescence and serology. Based on the results of the different parameters, isolates were divided into three "virulence" groups: low, moderately and highly virulent strains. Typically, a 5000 bp RAPD fragment was associated with the highly and moderately virulent strains whereas it was absent in low virulent strains. It was concluded that high variation in virulence exists between M. hyopneumoniae strains isolated from different swine herds. Further studies are required to determine whether the 5000 bp fragment obtained in the RAPD analysis can be used as a virulence marker.

Animals↗

PubMed2003

Effect of sperm coating on the survival and penetrating ability of in vitro stored bovine spermatozoa.

The aim of this study was to examine the effect of sperm coating on the survival and penetrating ability of in vitro stored diluted spermatozoa. Bovine semen was collected by means of an artificial vagina connected with a tube containing 5 ml of the commercial Triladyl diluent supplemented with 20% egg yolk and 6.7% glycerol (EYTG). Both EYTG and seminal plasma were removed by centrifugation and the spermatozoa were stored under different in vitro storage conditions. In the first and second experiment, "control" and "coated" spermatozoa were stored in Hepes-TALP (pH 6 and 7) at room temperature. After 4 days of storage, the progressive motility, membrane integrity, mitochondrial membrane potential or DNA integrity of the spermatozoa were evaluated before and after Percoll centrifugation. The in vitro penetration rate of the spermatozoa was examined only after Percoll centrifugation. A significantly (P<0.05) positive influence of sperm coating was observed on the tested sperm characteristics and penetration rate of spermatozoa when they were stored in Hepes-TALP at pH 7, but not at pH 6. In the last experiment, the influence of the storage medium Hepes-TALP (pH 7) or EYTG was investigated on motility, membrane integrity, mitochondrial membrane potential and in vitro penetration potential of "coated" spermatozoa stored at room temperature or at 4 degrees C during 4, 5 and 6 days. After 6 days of storage, a significantly (P<0.05) higher percentage of motile and membrane intact spermatozoa with high mitochondrial membrane potential was obtained in EYTG at both temperatures leading to a significantly higher in vitro penetration rate. These results indicate that sperm coating could preserve sperm characteristics and penetrating capacity of fresh bovine spermatozoa stored in egg yolk containing diluent for up to 6 days.

Animals↗

PubMed2003

An improved radioimmunoassay for measurement of pepsinogen in porcine blood samples.

The study was conducted to develop a sensitive and specific radioimmunoassay (RIA) for the measurement of pepsinogen in porcine serum, and to use this test for the determination of pepsinogen concentrations in serum samples from fetuses and pigs of different ages. Compared to a previously described RIA, major improvements were made concerning the use of specific polyclonal antibodies and the use of an appropriate buffer. The assay was able to detect pepsinogen concentrations of >/=0.2 ng/mL. The recovery of pepsinogen was close to 95%. The intra-assay coefficients of variations ranged between 3.9 and 7.5% whereas the interassay ranged between 8.8 and 11.9%. These percentages correspond to a satisfactory accuracy and reproducibility of the assay. No cross-reactions were observed with the main commercially available products of the aspartic proteases family except porcine pepsin cross-reacted over 62.5 microg/mL. Pepsinogen concentrations increased steadily with increasing age of the fetuses and the pigs (P<0.05). Pepsinogen concentrations (+/-SE) in fetuses of 90-100 (n=24) and 100-110 days of pregnancy (n=36) were 0.5+/-0.1 and 5.3+/-1.3 ng/mL, respectively. In pigs of 21, 98, and 213 days of age, the pepsinogen concentrations were 290.6+/-10.8, 343.1+/-17.9 and 383.5+/-15.3 ng/mL, respectively. The results demonstrate that RIA is accurate and can be used easily to assess pepsinogen concentrations in pig sera. The test may constitute a valuable tool in epidemiological surveys and in studies related to gastric diseases in pigs.

Animals↗

PubMed2003

Survey of gastric lesions and blood pepsinogen levels in pigs in Burkina Faso.

The purpose of the study was to investigate the prevalence of gastric lesions and to provide diagnostic values for serum pepsinogen in non-infected pigs and in pigs with gastric disease. In an abattoir survey, the pepsinogen concentrations were measured in the serum from 62 non-infected pigs, 33 pigs with gastric lesions and 17 pigs infected with Hyostrongylus rubidus, using a specific radioimmunoassay (RIA). The mean (+/- SE) pepsinogen concentrations in the serum of non-infected pigs, in pigs with gastric ulcers, and in pigs with a heavy H. rubidus infection were 630.8 +/- 39.2 ng/ml, 1084.5 +/- 166.2 ng/ml and 1095.2 +/- 102.3 ng/ml, respectively (p<0.05). Because of the higher concentrations of pepsinogen in the blood of pigs with gastric ulcers or parasitic infections, it is suggested that the measurement of serum pepsinogen by RIA may be an effective biochemical approach to the diagnosis of chronic gastric disorders in pigs.

Animals↗

PubMed2002

Effectiveness of treatment with lincomycin hydrochloride and/or vaccination against Mycoplasma hyopneumoniae for controlling chronic respiratory disease in a herd of pigs.

A herd of pigs infected with Mycoplasma hyopneumoniae was used in a double-blind randomised trial to assess the effectiveness of three control strategies against chronic respiratory disease in growing-finishing pigs. One group of 61 pigs received 220 ppm lincomycin hydrochloride in the feed from day 71 to day 91, a second group was vaccinated against M. hyopneumoniae at four and 28 days of age, and a third group received both treatments; a fourth group was left untreated as a control. Throughout the nursery-finishing period (day 29 to slaughter) the average daily weight gain and feed conversion rate of all the treated groups were slightly better than in the controls, but there were no significant differences between them. There were no significant differences between the treated groups in terms of clinical signs, serology, pathology or mortality, which was very low throughout the trial.

Animals↗

PubMed2002

Effect of centrifugation on in vitro survival of fresh diluted canine spermatozoa.

Prostatic fluid is unsuitable for preserving dog semen at 4 degrees C and exerts harmful effects upon the spermatozoa during the freezing process. Centrifugation immediately after sperm collection is a common method to remove prostatic admixture. In the present study, dog semen, diluted to 25 x 10(6)/ml, was exposed for 5 min to four different centrifugation speeds (180 x g, 720 x g, 1620 x g and 2880 x g) to determine subsequent sperm losses in the supernatant and to assess sperm survival over time. Using 180 x g as centrifugation speed, 8.9% of the sperm cells was lost upon supematant removal. Using 720 x g, 1620 x g or 2880 x g, sperm losses were lower, 2.3, 0.4 and 0.006%, respectively. After centrifugation, the sperm pellet was rediluted in egg-yolk-Tris extender, cooled and stored for 3 days at 4 degrees C. Motility, progressive motility, membrane integrity and sperm morphology were assessed daily. Acrosomal status was assessed after 3 days of storage. The only functional parameter which was influenced by centrifugation speed was membrane integrity as evaluated by means of SYBR14-PI staining: significantly more dead and moribund sperm cells were found after centrifugation at 1620 x g and 2880 x g after 48 and 72 h of storage at 4 degrees C. When higher initial sperm concentrations (50 x 10(6), 75 x 10(6) or 100 x 10(6)/ml) were evaluated for sperm losses, less than 2.3% of the initial total sperm cells was lost at lower centrifugation speeds. We conclude that centrifuging dog sperm for 5 min at 720 x g is the best strategy to remove prostatic fluid because the loss of sperm cells is acceptable and the functional parameters of the spermatozoa are well preserved, even after 3 days of storage.

Acrosome↗

PubMed2002

Patterns of Mycoplasma hyopneumoniae infections in Belgian farrow-to-finish pig herds with diverging disease-course.

Patterns of Mycoplasma hyopneumoniae (Mh) infections were investigated in five clinically infected herds and in five herds subclinically infected with Mh. In the clinically infected herds, housing and management conditions were good whereas these conditions were poor in the subclinically infected herds. In each herd, serum antibodies against Mh were detected in pigs of different ages and nasal swabs were taken for Mh detection using nested PCR (nPCR). The percentage of seropositive pigs in the clinically infected herds increased from 8% in pigs of 9 weeks to 52% in pigs of 18 weeks and seroconversion was most shown between 12 and 15 weeks. In the subclinically infected herds, the percentages increased from 2 to 24% and most of the pigs became seropositive between 15 and 18 weeks. The percentage of nPCR positive pigs at 6 weeks was 16 and 0% in the clinically and subclinically infected herds, respectively. The results demonstrate that the seroprevalences were higher in the clinically infected herds and that most of the pigs became infected with Mh at a younger age. It can be concluded that additional factors different from housing and management, like differences among Mh strains, may determine the infection pattern of Mh and the clinical course of the infection.

Animal Husbandry↗

PubMed2002

Assessment of different sperm quality parameters to predict in vitro fertility of bulls.

Frozen-thawed semen from six bulls with high (> 60%) and low (20-35%) in vitro fertility was used for studying the predictive value of simple sperm quality tests with respect to in vitro fertilization (IVF) outcome as assessed by pronucleus (PN) formation ability. Sperm quality parameters, such as sperm concentration, motility, progressive motility, live-dead sperm ratio, morphology, membrane integrity, mitochondrial activity and acrosomal status were analysed using both conventional and automatic techniques at three time points during the IVF process, namely after sperm thawing, Percoll differential gradient centrifugation and IVF. Associations between the sperm quality parameters before and after IVF, and PN formation ability were assessed by using linear regression analyses. The percentages of motility, progressive motility and normal morphology determined after sperm thawing, and the percentage of live spermatozoa assessed after Percoll preparation by using nigrosin-eosin (N-E) staining showed a good correlation with PN formation ability, but the regression parameters were borderline not significant. These parameters formed the most reliable basis for predicting IVF outcome. After IVF, the percentage of live spermatozoa determined by using N-E staining was the only sperm quality parameter showing a significant association with the PN formation ability of a given bull. This sperm quality test can be used as a non-invasive method to estimate the PN formation ability of oocytes which are further cultured to assess embryonic development.

Animals↗

PubMed2002

Function of the cumulus oophorus before and during mammalian fertilization.

CONTENTS: Fertilization encompasses a series of different steps which have to be performed in a well-orchestrated way to create a new individual. They include sperm capacitation, sperm binding and penetration of the zona pellucida, traversing the perivitelline space, binding and fusion with the oolemma, activation of the oocyte and decondensation of the sperm head to form the male pronucleus. In most mammalian species, cumulus cells surround the oocyte at the time of fertilization. Removal of the cumulus oophorus at this point of time often leads to a drop in fertilization rates. It is not yet known how cumulus cells interact with the oocyte or with spermatozoa to promote fertilization. There are different possibilities: 1 cumulus cells cause mechanical entrapment of spermatozoa and guide hyperactivated spermatozoa towards the oocyte, while preventing abnormal spermatozoa to enter the cumulus matrix; 2 cumulus cells create a micro-environment for the spermatozoa which favours their capacitation and penetration into the oocyte; 3 cumulus cells prevent changes in the oocyte which are unfavourable for normal fertilization; these changes can be located in the zona pellucida or in the cytoplasm. In this review, studies in several species are listed to prove the importance of these three cumulus cell functions and the current lines of research are highlighted. Moreover, different ways to improve in vitro fertilization of bovine cumulus-denuded oocytes are discussed.

Animals↗

PubMed2002

Use of the Sperm Quality Analyzer (SQA II-C) for the assessment of dog sperm quality.

In the present study, an automated system for sperm analysis, the Sperm Quality Analyzer (SQA II-C), was tested as a potential tool for the assessment of dog sperm quality. In the first experiment the device displayed a good repeatability of measurements for semen of medium and high quality, as evidenced by a low coefficient of variance (CV; 0.08), whereas a high CV (0.46) was obtained for one dog with semen of inferior quality. In the second experiment, seven different sperm concentrations (25-300 x 106/ml), obtained by dilutions in Hepes-TALP medium were stored for 48 h at room temperature. A concentration dependent increase in sperm motility index (SMI) was shown, reaching a plateau at 150 x 106 spermatozoa/ml. For all sperm concentrations, the SMI value decreased significantly after 24 h, indicating the importance of sperm motility for SMI values. For sperm concentrations lower than 150x106/ml, highly significant correlations [r=0.80;p<0.05] were established between SMI values on one hand and sperm concentration, and semen parameters expressing the overall semen sample quality on the other hand (experiment 3) while non-significant or low correlations were found between SMI values and other individual sperm parameters. In experiment 4, significantly high correlations (r=0.97) were found between mean SMI values and post-thaw motility and progressive motility assessed subjectively. In conclusion, our study indicates that both motility and concentration largely influence SMI values and that the SQA II-C saturates at 150 x 106 fresh spermatozoa/ml. In our opinion, the SQA II-C may be a useful and objective device to assess the post-thaw motility of dog sperm.

Animals↗

PubMed2001

Degenerate interfaces in antigen-antibody complexes.

In most of the work dealing with the analysis of protein-protein interfaces, a single X-ray structure is available or selected, and implicitly it is assumed that this structure corresponds to the optimal complex for this pair of proteins. However, we have found a degenerate interface in a high-affinity antibody-antigen complex: the two independent complexes of the camel variable domain antibody fragment cAb-Lys3 and its antigen hen egg white lysozyme present in the asymmetric unit of our crystals show a difference in relative orientation between antibody and antigen, leading to important differences at the protein-protein interface. A third cAb-Lys3-hen lysozyme complex in a different crystal form adopts yet another relative orientation. Our results show that protein-protein interface characteristics can vary significantly between different specimens of the same high-affinity antibody-protein antigen complex. Consideration should be given to this type of observation when trying to establish general protein-protein interface characteristics.

Animals↗

PubMed2001

Human keratinocytes respond to osmotic stress by p38 map kinase regulated induction of HSP70 and HSP27.

Human skin is exposed to an environment that varies in humidity from 100 to 0%, leading to seasonal variations in the condition of the skin. Exposure to a low humidity environment creates an osmotic gradient across the stratum corneum, which is known to modulate cutaneous barrier function. Heat shock proteins protect against stress-induced destabilization of proteins. We investigated whether osmotic shock (sorbitol) induced a heat shock protein response in normal human keratinocytes, and used heat shock as a positive control. Both heat shock and osmotic stress (200 and 300 mM sorbitol) clearly induced heat shock proteins 70 and 27 mRNA levels. The induction of heat shock protein 70 mRNA levels by osmotic stress peaked at 16 h and persisted until 24 h, whereas upregulation of heat shock protein 70 mRNA levels by heat peaked at 2 h and returned to baseline levels by 6 h. Sorbitol also increased heat shock protein 70 levels in a concentration-dependent manner. The kinetics of heat shock protein 27 mRNA induction by osmotic stress and heat were similar with peak induction at 6 h. The mitogen activated protein kinase family of proteins plays an important part in the coordination of gene responses to various stress conditions. We have demonstrated that the p38 mitogen activated protein kinase was strongly activated by 200 mM and 300 mM sorbitol. The specific p38 mitogen activated protein kinase inhibitor PD169316 almost completely blocked heat shock protein 70 mRNA induction by 200 mM and 300 mM sorbitol and completely suppressed heat shock protein 27 mRNA induction with 200 mM sorbitol. PD169316 also counteracted upregulation of heat shock protein 70 levels by sorbitol. These data indicate that keratinocytes respond to osmotic stress by p38 mitogen activated protein kinase regulated induction of heat shock proteins. This molecular pathway may be relevant for the mechanisms regulating the response of human skin to variations in environmental humidity.

Cells, Cultured↗

PubMed2001

Efficacy of tilmicosin phosphate (Pulmotil premix) in feed for the treatment of a clinical outbreak of Actinobacillus pleuropneumoniae infection in growing-finishing pigs.

A double-blind randomized clinical trial was carried out to investigate the efficacy of tilmicosin (Pulmotil premix) for the treatment of a clinical outbreak of Actinobacillus pleuropneumoniae infection in growing-finishing pigs. The effects of tilmicosin administration in the feed at 400 mg/kg and an injection therapy of clinically diseased pigs with long-acting oxytetracycline (Terramycine LA) at 20 mg/kg bodyweight were compared. Both groups, totalling 147 pigs, were compared during a medication period of 15 days and a post-medication period of 11 days by means of different clinical and performance parameters. During the medication period, the tilmicosin group showed a significant advantage with respect to the number of new disease cases (P < 0.01), and a non-significant advantage regarding the number of removed pigs (P = 0.16), the number of sick pigs that recovered (P = 0.27) and the time to recovery (P = 0.42). During the post-medication period, the pigs of the tilmicosin group showed numerical non-significant benefits (P > 0.05) with respect to the clinical parameters. During the overall study period (26 days), the average daily gain and the feed conversion ratio were both significantly (P < 0.01) better in pigs from the tilmicosin group compared with pigs from the oxytetracycline group. This study demonstrated that in-feed medication of tilmicosin at a dosage of 400 mg/kg is efficacious for the treatment of a clinical respiratory disease outbreak of A. pleuropneumoniae infection in growing-finishing pigs. Compared with oxytetracycline injection of clinically diseased pigs, the tilmicosin treatment is particularly beneficial in the prevention of new disease cases while increasing or maintaining the performance of the pigs.

Actinobacillus Infections↗

PubMed2001

A comparative study of the preventive use of tilmicosin phosphate (Pulmotil premix) and Mycoplasma hyopneumoniae vaccination in a pig herd with chronic respiratory disease.

This study was conducted to compare the effects of a preventive in-feed medication programme using tilmicosin (Pulmotil 200 premix, Elanco Animal Health) at 200 p.p.m. with those of Mycoplasma hyopneumoniae (Mh) vaccination programme (Stellamune Mycoplasma, Pfizer Animal Health). A pig herd with chronic respiratory disease in which infection with Mh played an important role was selected, and a total of 204 piglets were randomly allocated to either the medication (P) or the vaccination (V) group. Pigs in the P group received medicated feed for 3 weeks after weaning (days 34-55), and for 2 weeks late in the nursery period (days 77-98). The piglets in the V group were vaccinated twice intramuscularly, at 4 and 22 days of age. The two groups were compared on the basis of average daily gain (ADG), feed conversion rate (FCR), additional curative medication days (CMD), overall mortality (major variables), a coughing index, pneumonia lesions, and serology against Mh, influenza H1N1 and influenza H3N2 viruses, Actinobacillus pleuropneumoniae (App) and porcine reproductive and respirator, syndrome virus (PRRSV) (minor variables). No significant differences (P > 0.05) were observed for ADG (555 g/day in P group; 567 g/day in V group), FCR (2.64 in P group; 2.41 in V group) and mortality rate (11% in P group; 7% in V group). The average number of additional curative medication days (CMD) per pig was significantly higher (P < 0.01) in the P group (1.5) than in the V group (0.58). At slaughter age, the serological results and the prevalence of macroscopic lung lesions were comparable in the two groups (P > 0.05). With the exception of CMD, the preventive use of tilmicosin at this swine farm was found to confer similar beneficial effects to Mh vaccination.

Animals↗