The relationship between mastitis and retained placenta in a commercial population of holstein dairy cows

The relationship between retained placenta and mastitis was studied in a population of dairy cows on commercial farms. Only mastitis cases which occurred shortly after calving were studied. The cows with retained placenta were at a higher risk of developing non-severe mastitis (relative risk = 1.5) and at a much higher risk of developing severe mastitis (relative risk = 5.4). There was a differential effect of long-term (> 6 days) versus short-term (< 5 days) retained placenta.It is suggested that the relationship between retained placenta and mastitis is moderated by the prepartum peripheral leukocyte activity.     

血清微量元素与奶牛乳房炎发病关系的试验

生物体内的微量元素、维生素在清除自由基的过程中发挥着重要的生理功能,微量元素铜(Cu)、锌(Zn)、硒(Se),锰(Mn)、铁(Fe)是某些抗氧化物酶的主要构成成分,发挥抗氧化作用;维生素A、维生素C、维生素E具有抗氧化作用,是生物体内良好的自由基清除剂[1].     

The relationship between bovine clinical mastitis at the time of parturition and retained placenta]

868 parturitions were examined to determine the relation between the clinical mastitis around partition and the loosening process of the placenta in the bovine. The occurrence of mastitis in heifers and cows around parturition was 18.7%. The frequency of retained placenta in animals with mastitis was significantly higher (p less than 0.01) than that in animals without mastitis influenced the loosening process of the afterbirth. The results support an hypothesis, that mastitis and retentio secundinarum can regard as signs of the decrease in the activity of the immune system.     

Cow-specific risk factors for retained placenta,metritis and clinical mastitis in Holstein cows

The objective of this study was to evaluate the association between cow-specific risk factors and the lactational incidence risks of retained placenta (RP), metritis (MET) and clinical mastitis (CM) in 57,301 dairy cows on 20 large dairy herds in Iran between January 2005 and June 2009. A multivariable logistic regression model was used to identify risk factors for MET, RP and CM and quantify their odds ratio (OR). The lactational incidences of MET, RP and CM were 8%, 5.2% and 18.9%, respectively, and significant risk factors for MET were dystocia (OR = 4.32), stillbirth (OR = 6.26), RP (OR = 27.74), twin births (OR = 6.57), primiparity (OR = 1.68), calving during winter season (OR = 2.45) and male calves (OR = 2.41). Significant risk factors for RP were dystocia (OR = 3.17), stillbirth (OR = 3.18), abortion (OR = 8.46), milk fever (OR = 3.66), twin births (OR = 2.76), pluriparity (OR = 2.69), calving during winter season (OR = 1.86) and shorter gestation length of dairy cows (OR = 3.82). Also, significant risk factors for CM were RP (OR = 9.45), milk fever (OR = 12.36), pluriparity (OR = 2.83), calving during winter season (OR = 1.68) and the first months of lactation (P < 0.001)) and SCC concentrations at previous lactation (OR = 1.82). The current study indicates that differentiation can be made among cows in the risk of having MET, RP and CM based on a combination of cow factors. These differences among cows could be useful to aid the better detection of these diseases in the dairy herds.     

奶牛乳房炎的治疗方法

奶牛乳房炎是乳腺受到物理、化学、微生物刺激所发生的一种炎性变化.本病以乳汁的理化性改变为主,由多种非特定的病原微生物引起,不仅影响产奶量、牛乳质量、延长产后发情和妊娠时间,严重时还能使奶牛泌乳机能丧失而被淘汰,是世界奶牛业的主要危害因素之一[1-3].笔者根据多年的治疗经验,总结如下.     

Bayesian estimates of genetic parameters for metritis, retained placenta, milk fever, and clinical mastitis in Holstein dairy cows via Gibbs sampling

The objective of this study was to estimate heritability and genetic correlations between the liabilities of clinical mastitis (CM), milk fever (MF), metritis (MET), and retained placenta (RP) within the first three lactations of Holstein dairy cows. The records of 57,301 dairy cows from 20 large dairy herds in Iran between January 2005 and June 2009 were analysed with univariate and bivariate threshold animal models, using Gibbs sampling methodology. The final model included the fixed class effects of herd-year, season of calving, parity of dam, the linear covariate effect of age at calving, and the random direct genetic effect of animal. Posterior means of heritability for liabilities in first, second, and third lactations were 0.06, 0.08, and 0.09, respectively, for CM; 0.10, 0.12, and 0.11, respectively, for MF; 0.09, 0.07, and 0.10, respectively, for MET, and 0.07, 0.08, and 0.08, respectively, for RP. Posterior means of genetic correlations between disease liabilities were low or moderate (from −0.01 to 0.26). The results of this study indicated the importance of health traits for considering in the selection index of Iranian Holstein dairy cows.     

Fatal mastitis of dairy cows: a retrospective study.

The necropsy records of dairy cows with mastitis were reviewed from the provincial veterinary laboratory in Guelph (44 cases of mastitis in nine years) and from the Ontario Veterinary College (168 cases in 14 years). Mastitis was considered to be the primary cause of death in 167 of 212 cows (79%). Of these 167 cases of mastitis, Escherichia coli was involved in 107 (64%), Klebsiella sp. in 12 (7%) and Staphylococcus aureus in 11 (7%). Bacteriology was not reported in 22 cases. Coliform mastitis, the most commonly identified type of fatal mastitis, was characterized histologically by the presence of infarcted areas in affected glands and by the lack of demonstrable bacteria, and was thus easily identified from fatal mastitis caused by S. aureus.     

Effects of gonadotrophin releasing hormone on reproductive performance of dairy cows with retained placenta.

The effects of gonadotrophin releasing hormone (GnRH) on the reproductive performance of dairy cows with retained placenta were studied. Three hundred and seventy-eight cows diagnosed as having retained placenta received intramuscular injections of either 2 mL sterile water or 200 micrograms of GnRH in 2 mL sterile water between day 8 and day 14 postpartum. Rectal palpation was performed at the time of treatment and ten to 20 days after treatment in order to determine the rate of uterine involution. Thereafter, monthly rectal examinations were carried out until insemination. Pregnancy diagnosis was made by rectal palpation at 40 days or more after breeding. Using the entire experimental population, there were no significant differences between GnRH-treated and control cows for the rate of uterine involution, the occurrence of reproductive problems, the interval from parturition to first observed estrus, the interval from parturition to first insemination, the interval from parturition to conception, the number of services per conception, the total number of services per cow regardless of conception and the incidence of culling for infertility. When the data for herds in which breeding began earlier in the postpartum period (herds having a mean less than or equal to 80 days from parturition to first service for retained placenta cows) were considered, the GnRH treatment resulted in a significantly shorter (p less than or equal to 0.01) calving to conception interval as compared to control cows. Also, there was a significant reduction (p less than or equal to 0.05) in the total number of services per cow regardless of conception and a significant reduction in the interval from parturition to first service.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between teat morphological traits and subclinical mastitis in Frieswal dairy cows

The present study was aimed to investigate the relationship between selected morphological traits of teat and subclinical mastitis (SCM) in Frieswal crossbred dairy cows. A total of 1040 quarters from 261 lactating cows were evaluated for teat shape (bottle/fleshy/collapsed/conical/normal/pencil and short), teat-end shape (dished/flat/funnel/pocketed/pointed and rounded), teat orientation (aligned/misaligned) and teat position (front and rear; left-sided and right-sided). Each udder quarter was screened with California Mastitis Test (CMT) for the purpose of defining quarter health status. Data were analysed using Chi-square test and multivariable logistic regression procedure. An overall prevalence of SCM (CMT positive) at quarter level was 30.6%. Most of the teats had normal or cylindrical shapes (48%), dished teat-ends (40.7%), and aligned (central or squared) in orientation (65%). At bivariable level, significant association of SCM with teat shape, teat position, teat orientation, parity, and stage of lactation was observed (P < 0.05 to P < 0.001). Teat-end shapes showed some association with SCM (P = 0.07). Results of multivariable analysis showed that pencil-shaped teats were least associated with SCM (P < 0.05) as compared to other teat shapes. Prevalence of SCM was also higher in rear teats (P = 0.015), misaligned teats (P = 0.01), and cows in second or higher parities (P < 0.01) and late stage of lactation (P < 0.001). The results of the present study indicate that selected morphological traits of teat are associated with SCM in Frieswal crossbred cows; therefore, selection towards desirable morphological traits could help reduce mastitis in this breed.     

Experimental Corynebacterium pseudotuberculosis mastitis in dairy cows

The inoculation of 2000 colony-forming units of Corynebacterium pseudotuberculosis into one teat canal of each of three cows resulted in severe, chronic, pyogranulomatous mastitis. Within three days the cows had a reduced haematocrit, haemoglobin concentration and red cell count. The anaemia was initially normocytic, normochromic and non-regenerative, and was associated with a brief peak of neutrophilia; a regenerative response became evident two to three weeks later. Clinical signs of mastitis appeared seven to 14 days after the inoculation, with a peak of high fever, more severe anaemia, a second peak of neutrophilia and the complete cessation of milk production from all quarters; extensive and severe pyogranulomatous mastitis developed in the inoculated quarters. No other lesions were detected postmortem, and C pseudotuberculosis was cultured from the affected quarters but not from the supramammary lymph nodes and viscera.     

The relationship between production and infertility in dairy cows

Extract

Each year increasing numbers of livestock are transported by land, rail, sea and air, vet documented observation of the behaviour of stock during transit has seldom been recorded. The trans-shipment of weaner calves between the North and South Islands of New Zealand provided an opportunity to gather information on conditions of travel and general adaptation to a journey of 1600 kilometres by road and air.     

Pathological and microbiological characterization of mastitis in dairy cows

Mastitis may be caused by a wide range of microorganisms able to induce distinct lesions in mammary tissues. This study aims to characterize the gross and microscopic features of mastitis in dairy cows and to correlate them with the pathogens involved. The udders of slaughtered dairy cows were inspected and milk samples from each mammary quarter or fragments of the parenchyma were sent for microbiological analysis, and tissue collected for histopathological evaluation. A total of 148 cows and 592 mammary quarters were collected. From these, 432 quarters (73%) had mastitis and in 160 (27%), no changes were observed. Mastitis was classified into seven patterns based on the histopathological findings, of which mixed, lymphoplasmacytic, and suppurative mastitides were the most prevalent with 35.9% (155/432), 27.1% (117/432), and 14.3% (62/432) of the cases, respectively. These patterns were associated with the same set of pathogens: Streptococcus spp., coagulase-negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Corynebacterium bovis. The pyogranulomatous pattern represented 7.2% (31/432) of the cases with distinct distribution based on the agent involved, mostly S. aureus and Nocardia sp. Abscedative mastitis accounted for 6.0% (26/432) of the cases; it was characterized by multiple abscesses in the parenchyma and was mainly caused by Trueperella pyogenes. Necrosuppurative mastitis represented 5.8% (25/432) of the cases which were characterized by severe parenchyma necrosis and were caused by bacteria such as CNS and Escherichia coli. The granulomatous pattern represented 3.7% (16/432) of the cases and was occasionally associated with Mycobacterium sp.

     

Automated detection of estrus and mastitis in dairy cows

The development and test of detection models for oestrus and mastitis in dairy cows is described in a PhD thesis that was defended in Wageningen on June 5, 2000. These models were based on sensors for milk yield, milk temperature, electrical conductivity of milk, and cow activity and concentrate intake, and on combined processing of the sensor data. The models alert farmers to cows that need attention, because of possible oestrus or mastitis. A first detection model for cows, milked twice a day, was based on time series models for the sensor variables. A time series model describes the dependence between successive observations. The parameters of the time series models were fitted on-line for each cow after each milking by means of a Kalman filter, a mathematical method to estimate the state of a system on-line. The Kalman filter gives the best estimate of the current state of a system based on all preceding observations. This model was tested for 2 years on two experimental farms, and under field conditions on four farms over several years. A second detection model, for cow milked in an automatic milking system (AMS), was based on a generalization of the first model. Two data sets (one small, one large) were used for testing. The results for oestrus detection were good for both models. The results for mastitis detection were varying (in some cases good, in other cases moderate). Fuzzy logic was used to classify mastitis and oestrus alerts with both detection models, to reduce the number of false positive alerts. Fuzzy logic makes approximate reasoning possible, where statements can be partly true or false. Input for the fuzzy logic model were alerts from the detection models and additional information. The number of false positive alerts decreased considerably, while the number of detected cases remained at the same level. These models make automated detection possible in practice.     

Economic and reproductive consequences of retained placenta in dairy cattle

The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Animal-based measurements of the severity of mastitis in dairy cows

A range of clinical parameters were studied to assess their usefulness as objective markers of the severity of clinical mastitis in dairy cows. Cows with moderate clinical mastitis had significantly higher rectal temperatures and heart and respiratory rates than cows with mild clinical mastitis or control cows. The difference in temperature between quarters did not vary significantly between the control cows and the cows with mastitis, but there was a larger difference between quarter temperatures in the cows with moderate mastitis than in the cows with mild mastitis or the control cows. The hock-to-hock distance in the control cows was significantly smaller than in the cows with mild to moderate mastitis, but there was no significant difference in the distance either between the cows with mild mastitis and those with moderate mastitis, or between the cows with mastitis in the front quarters and those with mastitis in the hind quarters. The mechanical threshold to pain of the cows with mild and moderate mastitis was significantly lower than that of the control cows.