oxytocin and Mastitis--Bovine

Clinical mastitis is an important disease in dairies. Its treatment is mainly based on the use of antimicrobial drugs. Numerous non-antimicrobial drugs and treatment strategies have already been reported for clinical mastitis treatment, but data on their efficacy have never been collated in a systematic way. The objective of this systematic review was to identify treatments other than conventional antimicrobials for the treatment of clinical mastitis in lactating dairy cows. A systematic review was performed with studies written in English or French selected from CAB Abstracts, PubMed, and Web of Science from January 1970 to June 2014. Controlled clinical trials, observational studies, and experimental challenges were retained. Lactating dairy cows with clinical mastitis were the participant of interest. All treatments other than conventional antimicrobials for clinical mastitis during lactation were retained. Only studies comparing the treatment under investigation to a negative or positive control, or both, were included. Outcomes evaluated were clinical and bacteriological cure rates and milk production. Selection of the study, data extraction, and assessment of risk of bias was performed by 3 reviewers. Assessment of risk of bias was evaluated using the Cochrane Collaboration tool for systematic review of interventions. A total of 2,451 manuscripts were first identified and 39 manuscripts corresponding to 41 studies were included. Among these, 22 were clinical trials, 18 were experimental studies, and 1 was an observational study. The treatments evaluated were conventional anti-inflammatory drugs (n = 14), oxytocin with or without frequent milk out (n = 5), biologics (n = 9), homeopathy (n = 5), botanicals (n = 4), probiotics (n = 2), and other alternative products (n = 2). All trials had at least one unclear or high risk of bias. Most trials (n = 13) did not observe significant differences in clinical or bacteriological cure rates in comparison with negative or positive controls. Few studies evaluated the effect of treatment on milk yield. In general, the power of the different studies was very low, thus precluding conclusions on noninferiority or nonsuperiority of the treatments investigated. No evidence-based recommendations could be given for the use of an alternative or non-antimicrobial conventional treatment for clinical mastitis. However, probiotics and oxytocin with or without frequent milk out should not be recommended. We concluded that hom

Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Biological Products; Cattle; Female; Homeopathy; Lactation; Mastitis, Bovine; Milk; Oxytocin; Phytotherapy; Probiotics

The reduction of antibiotic use in food producing animals becomes increasingly important. Therefore, suitable alternatives for mastitis treatment in dairy cows have to be considered. Oxytocin (OT) induces milk ejection and hence supports milk removal from infected mammary quarters. Beyond udder emptying, the injection of very high dosages of OT causes increased somatic cell counts (SCC) in milk and enables the transfer of immunoglobulins (Ig) from blood into milk through a reduced blood-milk barrier integrity. The aim of the present study was to investigate pathogen-specific changes of SCC, the blood derived milk components lactate dehydrogenase (LDH), serum albumin (SA), and IgG in milk of cows suffering from mastitis caused by different pathogens treated with two intravenous injections of high dosages of OT (100 IU). Milk samples from 184 dairy cows from different farms were collected on day 1 (day of clinical examination and mastitis diagnosis) and on days 2, 3, 14, and 28. Bacteriological examination (day 1) identified involved pathogens. Cows were randomly assigned to treatment (OT injections on days 1 and 2) or control group (no OT). Independently of the assigned experimental group, cows received the common therapy protocol of the veterinary practice after sample collection if the general condition was affected. Milk SCC, LDH, SA, and IgG changed specifically depending on involved pathogens. Highest values of all three parameters were measured in mastitis caused by Streptococcus uberis. Changes were less pronounced with other Streptococci spp., Staphylococci spp. or Corynebacterium bovis. Oxytocin treatment did not affect any of the studied parameters independent of the involved pathogen. Only in quarters infected with Staphylococci other than Staphylococcus aureus a decreased SCC and increased IgG concentrations in quarters, where no pathogens were detected, were observed. Thus, high dosage OT administration is obviously not suitable as a stand-alone mastitis treatment in dairy cows.. Die Reduzierung des Antibiotikakonsums bei Tieren in der Lebensmittelproduktion wird immer wichtiger. Daher müssen geeignete Alternativen zur Mastitisbehandlung bei Milchkühen geprüft werden. Oxytocin (OT) induziert das Einschiessen der Milch in das Milchgangsystem und unterstützt somit das Ausmelken der Milch aus infizierten Vierteln der Milchdrüse. Über die Euterentleerung hinaus führt die Injektion sehr hoher OT-Dosierungen durch eine verringerte Integrität der Blut-Milch-Schranke zu einer erhöhten Anzahl somatischer Zellen (SCC) in der Milch und ermöglicht den Transfer von Immunglobulinen (Ig) aus der Blutbahn in die Milch. Das Ziel der vorliegenden Studie war es, bei an Mastitis erkrankten und mit zwei hohen Dosen Oxytocin (100 IE iv.) behandelten Kühen, in Abhängigkeit des Pathogens die Veränderungen von SCC, den aus Blut stammenden Milchkomponenten Lactatdehydrogenase (LDH), Serumalbumin (SA) und IgG in Milch zu untersuchen. Milchproben von 184 Milchkühen aus verschiedenen Betrieben wurden am Tag 1 (Tag der klinischen Untersuchung und Mastitisdiagnose) und an den Tagen 2, 3, 14 und 28 entnommen. Der Nachweis der Krankheitserreger erfolgte mittels einer bakteriologischen Untersuchung (Tag 1). Die Kühe wurden zufällig der Behandlungs- (OT-Injektionen an den Tagen 1 und 2) oder der Kontrollgruppe (kein OT) zugeordnet. Unabhängig von der zugewiesenen Versuchsgruppe wurden die Kühe mit reduziertem Allgemeinzustand nach der Probenentnahme gemäss dem Therapieprotokoll der Tierarztpraxis behandelt. Milch-SCC, LDH, SA und IgG änderten sich spezifisch in Abhängigkeit der beteiligten Pathogene. Die höchsten Werte aller drei Parameter wurden bei durch Streptococcus uberis verursachten Mastitiden gemessen. Die Veränderungen waren bei Streptococci spp., Staphylococci spp. oder Corynebacterium bovis weniger ausgeprägt. Unabhängig vom verursachenden Pathogen hatte die Oxytocin-Behandlung keinen Einfluss auf einen der untersuchten Parameter. Einzig bei Mastitiden verursacht durch andere Staphylokokken als Staphylococcus aureus wurden eine verminderte SCC gemessen und bei Mastitiden ohne Nachweis eines Pathogens konnte eine erhöhte IgG-Konzentration beobachtet werden. Daher ist eine hochdosierte OT-Verabreichung nicht als eigenständige Mastitisbehandlung bei Milchkühen geeignet.. La réduction de l’utilisation d’antibiotiques chez les animaux destinés à l’alimentation devient de plus en plus importante. Par conséquent, des alternatives appropriées au traitement des mammites chez les vaches laitières doivent être envisagées. L’ocytocine (OT) induit l’éjection du lait et favorise donc l’élimination du lait des quartiers infectés. Au-delà de la vidange de la mamelle, l’injection de doses très élevées d’OT entraîne une augmentation du nombre de cellules somatiques (CSC) dans le lait et permet le transfert d’immunoglobulines (Ig) du sang vers le lait grâce à une réduction de l’intégrité de la barrière sang-lait. Le but de la présente étude était d’étudier les changements spécifiques aux agents pathogènes du CSC, les composants du lait dérivés du sang que sont la lactate déshydrogénase (LDH) et l’albumine sérique (SA) ainsi que les IgG dans le lait de vaches souffrant de mammites causées par différents agents pathogènes traités par deux injections intraveineuses de doses élevées d’OT (100 UI). Des échantillons de lait de 184 vaches laitières de différentes exploitations ont été prélevés au jour 1 (jour de l’examen clinique et diagnostic de mammite) et aux jours 2, 3, 14 et 28. L’examen bactériologique (jour 1) a identifié les agents pathogènes impliqués. Les vaches ont été assignées au hasard au traitement (injections d’OT les jours 1 et 2) ou au groupe témoin (pas d’OT). Indépendamment du groupe auquel elles étaient attribuées, les vaches ont reçu le protocole thérapeutique usuel du cabinet vétérinaire après le prélèvement de l’échantillon si leur état général était affecté. Le CSC, la LDH, la SA et les IgG du lait ont varié spécifiquement en fonction des agents pathogènes impliqués. Les valeurs les plus élevées des trois paramètres ont été mesurées dans les mammites causées par Streptococcus uberis. Les changements étaient moins prononcés avec d’autres Streptococci spp., Staphylococci spp. ou Corynebacterium bovis. Le traitement à l’ocytocine n’a affecté aucun des paramètres étudiés indépendamment de l’agent pathogène impliqué. On a uniquement observé, dans les mammites causées par des staphylocoques autres que Staphylococcus aureus, une diminution du CSC et, dans les mammites où aucun agent pathogène n’a été détecté, une augmentation des concentrations d’IgG dans les quartiers. Ainsi, l’administration d’OT à forte dose n’est pas appropriée comme traitement unique des mammites chez les vaches laitières.. La riduzione dell’uso di antibiotici negli animali per la produzione alimentare sta assumendo un’importanza sempre maggiore. Di conseguenza, è opportuno considerare delle alternative adeguate per il trattamento della mastite nelle vacche da latte. L’ossitocina (OT) induce l’eiezione del latte e quindi aiuta la rimozione di questo dai quarti mammari infetti. L’iniezione di dosi molto elevate di OT provoca non solo lo svuotamento della mammella, ma pure un aumento del numero di cellule somatiche (SCC) nel latte permettendo quindi il trasferimento di immunoglobuline (Ig) dal sangue al latte attraverso una ridotta integrità della barriera tra sangue e latte. Lo scopo del presente studio era di esaminare i cambiamenti patogeno-dipendenti dal SCC, i componenti del latte derivati dal sangue del lattato deidrogenasi (LDH), l’albumina del siero (SA) e le IgG nel latte, delle vacche affette da mastite causata da diversi patogeni e trattate con due iniezioni intravenose ad alti dosaggi di OT (100 UI). I campioni di latte provenienti da 184 vacche da latte di diverse aziende sono stati raccolti il giorno 1 (giorno dell’esame clinico e della diagnosi di mastite) e nei giorni 2, 3, 14 e 28. L’esame batteriologico (giorno 1) ha identificato gli agenti patogeni coinvolti. Le vacche sono state assegnate in modo casuale al gruppo con il trattamento (iniezioni di OT il giorno 1 e 2) o al gruppo di controllo (nessuna OT). Indipendentemente dal gruppo sperimentale assegnato, se dopo la raccolta del campione le condizioni generali dell’animale risultavano compromesse, le vacche ricevevano un comune protocollo terapeutico dello studio veterinario. Si è rilevato che a seconda degli agenti patogeni coinvolti, l’SCC del latte, la LDH, la SA e le IgG cambiavano in modo specifico. I valori più alti fra tutti e tre i parametri sono stati misurati in caso di mastite causata da Streptococcus uberis. I cambiamenti erano meno pronunciati con gli Streptococchi spp., Staphylococci spp. o Corynebacterium bovis. Si è notato che il trattamento con ossitocina non influenzava nessuno dei parametri studiati, indipendentemente dal patogeno coinvolto. Si è osservato nei quarti infettati da stafilococchi diversi dallo Staphylococcus aureus una diminuzione della SCC mentre nei quarti dove non venivano rilevati agenti patogeni si evidenziava un aumento delle concentrazioni di IgG. Pertanto, la somministrazione di OT ad alto dosaggio non è ovviamente adatta al trattamento stand-alone della mastite nel

Topics: Animals; Cattle; Cattle Diseases; Cell Count; Corynebacterium; Female; Mammary Glands, Animal; Mastitis; Mastitis, Bovine; Milk; Oxytocin; Streptococcus

Eight cows were challenged by a single quarter intramammary infusion of a relatively low-virulence strain of Staphylococcus aureus on four occasions five weeks apart and, after each challenge, each cow received one of four treatments, according to a duplicated Latin-square design. The treatments were massage alone (negative control), massage with a proprietary liniment, oxytocin, and a single course of a proprietary intramammary antibiotic. The massage treatments were applied at every milking for three weeks, oxytocin was given for one week, and the antibiotic was given after three successive milkings. Milk samples were collected immediately before and for three weeks after each challenge, and a scoring system was used to quantify the presence of bacteria during the whole of the period. None of the treatments completely eliminated bacteria from all the cows. Relative to the negative control, the liniment had no significant effect, but both oxytocin and the antibiotic reduced the numbers of bacteria significantly and did not differ significantly in efficacy.

Topics: Administration, Topical; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Female; Liniments; Massage; Mastitis, Bovine; Oxytocin; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome

During a three-year study, 54 cows with toxic mastitis were allocated randomly to one of three treatment groups (A, B and C). Each cow was re-examined within 24 hours of the initial examination, and, during this time, group A received fluid therapy (45 liters of intravenous isotonic electrolyte solution) and flunixin meglumine (2000 mg), group B received fluid therapy only, and group C received flunixin meglumine only. In addition all the cases were treated with parenteral and intramammary tetracyclines, oxytocin and calcium boroglucoanate. There was no significant difference in the rate of survival between the treatment groups and 29 of the cows (53.7 per cent, 95 per cent confidence interval of 39 to 67 per cent) survived.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Boric Acids; Cattle; Clonixin; Combined Modality Therapy; Drug Therapy, Combination; Female; Fluid Therapy; Mastitis, Bovine; Oxytocin

Bacterial mastitis causes pathogen-dependent changes of the blood-milk barrier, and these changes can influence the differential transfer of blood components to milk. It is well known that gram-negative pathogens such as Escherichia coli can cause a greater activation of the immune system and thus a more comprehensive transfer of blood components including IgG than gram-positive pathogens such as Staphylococcus aureus. Supraphysiological doses of oxytocin (OT) have been shown to increase the permeability of the blood-milk barrier; however, the effect of OT during experimentally induced mastitis has not been investigated. Therefore, the objective of this study was to examine if intravenous administration of OT during lipopolysaccharide (LPS)- or lipoteichoic acid (LTA)-induced mastitis could influence the transfer of blood components to milk. The hypothesis was that OT could induce a greater transfer of blood components during mastitis. Twenty-seven dairy cows were injected via the teat canal with LPS, LTA, or a saline control followed by an intravenous injection of OT 2h following intramammary challenge. Milk samples were collected every half hour and analyzed for somatic cell count (SCC), IgG, lactate dehydrogenase (LDH), and serum albumin (SA). Due to the chosen dosage of LPS and LTA, there was no difference in SCC between quarters challenged with only LPS or LTA. Quarters challenged with LPS and OT had a higher SCC and a greater transfer of IgG, LDH, and SA compared with quarters challenged with only LPS. Quarters challenged with LTA and OT had a greater transfer of IgG, LDH, and SA, whereas the SCC increase did not differ from quarters only treated with LTA. In quarters treated only with OT, SCC, LDH, and SA increased, but no difference was observed in IgG concentration from untreated control quarters. In conclusion, there are pathogen-specific changes in the blood-milk barrier and OT can induce a greater transfer of blood components to milk in both LPS- and LTA-induced mastitis. Oxytocin could have implications for use as a mastitis therapy, as there was an increased transfer of IgG into the milk.

Topics: Animals; Cattle; Cell Count; Female; Immunoglobulins; Mastitis, Bovine; Milk; Oxytocin; Staphylococcus aureus

Incontinentia lactis is a possible predisposing factor for an elevated level of intramammary infection. The goal of the present study was to investigate possible causes of incontinentia lactis in dairy cows. Two farms that differed in breed composition, but that had similar average milk yields were studied: herd A, 28 kg/d, 31 Red Holstein cows; and herd B, 26 kg/d, 16 Brown Swiss cows. Herd A was classified into 2 groups: incontinentia lactis (ILA group) and control, whereas herd B was exclusively a control herd. Milk samples that represented foremilk and the main milk fraction were collected during 4 milking sessions. In addition, milk leakage samples from the ILA group were collected at different time intervals from 0 to 5 h before milking. Measurements of the teat, milk flow, fractions of cisternal and alveolar milk, intramammary pressure, and blood oxytocin pattern also were obtained. The ILA cows did not have differences in fat content between milk leakage and cisternal milk fraction. Milk fat content, however, increased during milking in response to continuous milk ejection (1.95, 1.99, and 4.61% for milk leakage, cisternal, and main milk samples, respectively). Teat canals were 9% shorter in the ILA cows, which showed greater milk yield, peak, and average flow rates. Quarter cisternal milk yield of ILA cows tended to be greater (0.50 vs. 0.23 and 0.28 kg for ILA and controls from herds A and B, respectively), whereas percentages of cistern milk and alveolar milk did not differ from controls. The greater pressure in the ILA group, both before and after manual udder stimulation (ILA: 4.0 and 6.4 kPa; control: 2.0 and 5.0 kPa, respectively), could be an important cause for the leakage. Nevertheless, the increase in IMP that occurred after udder preparation affirms that milk ejection occurred in response to the tactile teat stimulation, but not before the onset of leakage. Blood oxytocin concentration in ILA cows was low until the start of udder preparation and increased in response to the milking stimulus (reaffirming the hypothesis that milk leakage occurred in the absence of milk ejection). In conclusion, milk losses by leakage are likely due to the large amount of cisternal milk, which creates pressure and causes leakage, in the absence of milk ejection.

Topics: Animals; Cattle; Cattle Diseases; Female; Lactation; Lactation Disorders; Mammary Glands, Animal; Mastitis, Bovine; Milk; Milk Ejection; Oxytocin; Pressure; Ultrasonography

Antibiotic regimens (intramammary antibiotic, penicillin-based parenteral treatment) and intramuscular oxytocin were tested for effectiveness against experimental infection by Streptococcus uberis with the following results from 54 animals: a) no treatment led to deterioration of infected quarters, requiring intervention within 48 h for cow health; b) aggressive intramammary antibiotic at every milking achieved 70% clinical cure in 3 d and 100% cure within 6 d; overall bacteriological cure was 80%; c) parenteral treatment alone used about 14 times as much antibiotic with 18% clinical cure in 3 d and 91% within 6 d; overall bacteriological cure was 80%; d) combination of aggressive intramammary and parenteral treatments achieved 61% clinical cure in 3 d and 100% within 6 d; overall bacteriological cure was 72%; e) intramammary antibiotic at labeled rates (1x for 3 d) achieved 27% clinical cure in 3 d but 91% within 6 d of treatment; overall bacteriological cure was 64%; f) use of oxytocin alone for 3 d failed to achieve clinical improvement with an increase in the severity of mastitis; g) combining oxytocin with labeled use of intramammary antibiotic (1x for 3 d) was unsuccessful: 0% clinical cures in 3 d, 10% in 6 d; significantly poorer than intramammary antibiotic alone. Extended treatment periods with parenteral or intramammary antibiotics resulted in positive inhibitory tests for milk from individual quarters up to 8 d after treatment. Aggressive intramammary antibiotic was the most effective treatment for fastest cure clinically and bacteriologically using least antibiotic.

Topics: Animals; Anti-Bacterial Agents; Cattle; Dose-Response Relationship, Drug; Female; Mastitis, Bovine; Milk; Oxytocin; Streptococcal Infections; Streptococcus; Time Factors; Treatment Outcome

Mastitis was induced in dairy cows by infusion of 500 cfu of Streptococcus uberis into the mammary gland. Most infections developed to clinical disease, and the majority were predicted by changes in the electrical conductivity of the foremilk. The benefits of clinical prognosis and bacteriological cure were determined for cases that were treated when predicted to develop into clinical mastitis and compared with cases that were allowed to develop until milk clotted or until pyrexia before intramammary antibiotic treatment was used. Treatment prior to clinical mastitis included use of intramammary antibiotic or intramuscular oxytocin to allow stripping of residual milk to remove bacteria. All infections in which treatment was delayed resulted in clinical mastitis that was cured clinically and bacteriologically by sustained treatment using a broad-spectrum intramammary antibiotic preparation once daily but requiring a mean treatment time of 10 d. It was possible to prevent clinical mastitis from developing and to eliminate all infections in cows that were treated early when the developing disease was predicted by changes in the electrical conductivity of quarter foremilk and was treated aggressively by administering an intramammary antibiotic at each milking for 3 d. Treatment of 20 IU of oxytocin at six successive milkings of cows that were predicted to develop disease eliminated 25% of the infections, but 75% of the cows developed clinical mastitis. Those cases were resolved by sustained daily treatment using the same intramammary antibiotic. Elimination (100% clinical and bacteriological cure) of all infections caused by Strep. uberis was possible with early and aggressive or sustained use of the intramammary antibiotic. The early intervention using an intramammary antibiotic, when infection was first indicated by changes in the electrical conductivity of milk, was the most efficient method to achieve cure and led to quicker recovery of milk quality to a saleable standard.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cell Count; Electric Conductivity; Female; Mastitis, Bovine; Milk; Oxytocin; Streptococcal Infections; Time Factors

For two large California dairy herds with twice daily milking, 171 infected quarters of lactating cows with mild clinical mastitis were randomly assigned to one of three treatment groups. Group A (50 cows) was treated with 62.5 mg of intramammary amoxicillin every 12 h for three milkings. Group C (50 cows) was treated with 200 mg of intramammary cephapirin every 12 h for two milkings. Group O (71 cows) was treated with 100 U of intramuscular oxytocin every 12 h for three milkings. Clinical cure rates did not differ among treatment groups. The cost per episode of clinical mastitis was higher ($54.47) for group C than for groups A ($38.53) or O ($34.88). Group O had a higher incidence of relapse (41%), and a greater percentage of group O cows (65%) experienced an additional mastitic event in the enrolled lactation than did cows in groups A and C. Treatment had no effect on the mean number of nonsalable milkings (24.7) associated with mastitis in the lactation interval subsequent to enrollment on the trial. Twenty-two percent of the cows accrued more than 30 nonsalable milkings and produced 55% of the total nonsalable milkings associated with mastitis. There was no treatment effect on total milk production, fat production, or time to removal of the enrolled cows from the herd.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Cattle; Cephalosporins; Cephapirin; Cost-Benefit Analysis; Dairying; Female; Lactation; Mammary Glands, Animal; Mastitis, Bovine; Oxytocin; Penicillins; Recurrence

Milk from 172 commercial cows with mild to moderate clinical mastitis was tested with five antibiotic residue detection assay systems. One hundred cows were treated with one of two intramammary beta-lactam antibiotics, and the remaining 72 cows were treated with intramuscular oxytocin. Milk samples were collected pretreatment, twice after therapy, and again 21 d following the initiation of treatment. Presumptive false-positive assay results were tabulated from all pretreatment and 21-d milk samples and from samples collected following oxytocin therapy. The percentage of false-positive results was 43.6, 37.7, 81.7, 2.6, and 18.8% for the CITE probe (beta-lactam), Delvotest-P, Charm Farm, LacTek (beta-lactam), and Bacillus stearothermophilus var. calidolactis disk assay, respectively. In four of the assay systems, average SCC were significantly higher in samples yielding false-positive results than in those with negative results. Specificity and sensitivity were estimated for each assay system, and, based on these estimates, positive and negative predictive value curves were graphed as the prevalence of milk samples containing detectable concentrations of exogenous antibiotic residues in the sample population was varied from 0 to 100%.

Topics: Animals; Anti-Bacterial Agents; California; Cattle; Cell Count; Drug Residues; False Positive Reactions; Female; Lactams; Mastitis, Bovine; Milk; Oxytocin; Sensitivity and Specificity

For three California dairy herds with bulk tank SCC < 200,000/ml, twice daily milking, and no mastitis vaccine, 254 quarters with mild clinical mastitis were randomly assigned to three groups. Group A (n = 74) was treated with 62.5 mg of intramammary amoxicillin every 12 h for three milkings. Group C (n = 75) was treated with 200 mg of intramammary cephapirin every 12 h for two milkings. Group O (n = 105) was treated with 100 units of intramuscular oxytocin every 12 h for two or three milkings. Aseptic pretreatment quarter samples revealed 94 (37%) coliforms, 65 (26%) environmental streptococci, 34 (13%) other bacteria, and 61 (24%) with no isolate on bovine blood agar plates. Contagious pathogens were not isolated. Clinical cure (return of quarter and milk to normal) and bacterial cure (absence of primary pathogen isolated pretreatment) were assessed at milking 8 and d 20 after initial treatment. No difference existed in clinical (67.6, 67.7, or 66.7%) or bacterial (43.9, 55.0 or 49.1%) cure rate among groups. Clinical cure rates did not differ when quarters were grouped by etiology, but clinical cure rates for quarters with pathogens other than streptococci or coliforms were lower in group O.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Cattle; Cephapirin; Enterobacteriaceae; Female; Mammary Glands, Animal; Mastitis, Bovine; Milk; Oxytocin; Streptococcus

One overt sign of clinical coliform mastitis in dairy cows is the failure to eject milk normally or to "milk out" the udder. The effect, if any, of coliform mastitis on oxytocin release is unknown. Therefore, the objective of this study was to determine the effect of endotoxin mastitis on milking-induced release of oxytocin in lactating cows. Fifteen multiparous pregnant lactating Holstein cows were divided into three groups of 5 cows each. Cows in group 1 served as controls and received an intramammary infusion of sterile physiological saline. Cows in groups 2 and 3 received intramammary infusions of 12.5 and 25 micrograms of Escherichia coli endotoxin, respectively. Serum concentrations of oxytocin were measured by radioimmunoassay before, during, and after milkings commencing at 6 and 12 h after treatment. Rectal temperatures and milk SCC were monitored to follow the course of inflammation and to verify the biological activity of infused endotoxin. Endotoxin resulted in a 1.5- to 2-fold increase in milking-induced oxytocin release compared with that of control treatments. The effect was most prominent during the first 6 h after infusion and coincided with the peak pyretic response. This study shows that endotoxin-induced mastitis potentiates, rather than inhibits, milking-induced oxytocin release.

Topics: Animals; Body Temperature; Cattle; Endotoxins; Escherichia coli; Female; Lactation; Mammary Glands, Animal; Mastitis, Bovine; Oxytocin; Pregnancy

Eighty-four Holstein cows were used to determine effects of exogenous oxytocin on 305-d milk production and health. Cows were assigned at parturition by parity group to treatments: 1) oxytocin group, animals received an injection of 1 ml (20 IU) of oxytocin at each milking throughout lactation and 2) control group, animals received no injection. Oxytocin injections were given in the thigh region within 3 min following the initiation of udder preparation and immediately prior to machine attachment. Udder preparation consisted of forestripping and manual cleaning (10 to 20 s) and drying (5 to 10 s) of teats. Cows were milked in a parlor, and milk yield was recorded at each milking. Milk samples were collected from each cow biweekly for milk fat, protein, and somatic cell count determination. Individual lactations were modeled using Woods' lactation equation; resulting coefficients were analyzed using ANOVA. The oxytocin group produced 849 kg more milk during the lactation than the control group, with a significant difference occurring after peak milk yield. This suggests that exogenous oxytocin maintained greater persistency during lactation. No significant differences existed for milk fat or protein percentages. The use of exogenous oxytocin at milking increased lactation milk production with no apparent effect on health.

Topics: Animals; Cattle; Female; Incidence; Lactation; Least-Squares Analysis; Mastitis, Bovine; Milk; Oxytocin; Random Allocation; Reproduction

Topics: Acute Disease; Administration, Topical; Animals; Cattle; Chloramphenicol; Drug Combinations; Evaluation Studies as Topic; Female; Mastitis, Bovine; Milk; Oxytocin; Sulfamethazine

Topics: Animals; Cattle; Fatty Acids; Female; Glycerides; Hydrogen-Ion Concentration; Injections, Intravenous; Lactation; Lipid Metabolism; Mastitis; Mastitis, Bovine; Milk; Oxytocin; Phospholipids; Pregnancy; Species Specificity; Time Factors

Topics: Animals; Cattle; Female; Mastitis, Bovine; Oxytocin; Ukraine

Topics: Animals; Candidiasis; Cattle; Mastitis, Bovine; Oxytocin; Staphylococcal Infections

Topics: Anesthesia, Conduction; Animals; Anti-Bacterial Agents; Cattle; Female; Mastitis, Bovine; Oxytocin; Procaine

Topics: Animals; Cattle; Female; Mastitis, Bovine; Oxytocin