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Parker KI, Compton CWR, Anniss FM, Weir AM, McDougall S. Management of dairy heifers and its relationships with the incidence of clinical mastitis. N Z Vet J 2011; 55:208-16. [DOI: 10.1080/00480169.2007.36770] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Brownlie TS, Weir AM, Tarbotton I, Morton JM, Heuer C, McDougall S. Reproductive management of dairy herds in New Zealand: Attitudes, priorities and constraints perceived by farmers managing seasonal-calving, pasture-based herds in four regions. N Z Vet J 2011; 59:28-39. [DOI: 10.1080/00480169.2011.547167] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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McDougall S, Supré K, De Vliegher S, Haesebrouck F, Hussein H, Clausen L, Prosser C. Diagnosis and treatment of subclinical mastitis in early lactation in dairy goats. J Dairy Sci 2010; 93:4710-21. [PMID: 20855005 DOI: 10.3168/jds.2010-3324] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 06/07/2010] [Indexed: 11/19/2022]
Abstract
The objectives of the study were to define the sensitivity and specificity of the California Mastitis Test (CMT) in determining the presence of intramammary infection in postpartum dairy goats and to determine whether antibiotic therapy increased bacteriological cure rate and lowered somatic cell count (SCC) compared with untreated controls. A CMT was performed and milk samples were collected for bacteriology from 211 glands of 106 does between 0 and 10 d after kidding. From a population of 3,239 glands from goats in 4 commercial herds, goats with one or both glands with a CMT score of >1 and from which bacteria were isolated were either assigned to be treated with 3 intramammary infusions at 12-h intervals of 75 mg of sodium ampicillin and 250 mg of sodium cloxacillin (n=57 glands) or left as untreated controls (n=49 glands). Milk samples were collected again 14 ± 3 and 21 ± 3 d later for bacteriology and SCC determination. Composite milk yield, goat SCC, length of lactation, and survival data were collected. A partial budget was constructed to assess the cost effectiveness of treatment. At a cut point of greater than trace, the sensitivity, specificity, and positive and negative predictive values of the CMT were 0.74, 0.74, 0.42, and 0.92, respectively. Treatment increased the bacteriological cure rate compared with no treatment [30/57 (53%) vs. 6/49 (12%)], but there was a pathogen by treatment interaction whereby treatment increased cure proportion in glands infected with minor, but not major, pathogens. Treatment reduced the foremilk gland-level SCC [1,595 (95% CI=1,106-2,300) vs. 3,028 (95% CI=2,091-4,385) geometric mean (× 1,000) cells/mL] but not the SCC at goat level [1,596 (95% CI=1,219-2,090) vs. 1,488 (95% CI=1,132-1,955) geometric mean (× 1,000) cells/mL] compared with no treatment. Milk yield, risk of removal from the herd, and length of lactation were not altered by treatment. Treatment resulted in a loss of NZ$20.39/doe. It was concluded that use of the CMT as a screening test resulted in a higher likelihood of finding a gland that would be infected than selecting a gland at random. Treatment increased bacteriological cure rate and reduced SCC at gland level compared with no treatment. However, at goat level, milk yield, SCC, and survival were not altered, resulting in no economic benefit of treatment.
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Burke C, Meier S, McDougall S, Compton C, Mitchell M, Roche J. Relationships between endometritis and metabolic state during the transition period in pasture-grazed dairy cows. J Dairy Sci 2010; 93:5363-73. [DOI: 10.3168/jds.2010-3356] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 07/27/2010] [Indexed: 11/19/2022]
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Compton CWR, McDougall S. A longitudinal study of reproductive performance and management of 82 dairy herds in the Waikato region with differing policies on the routine use of induction of parturition. N Z Vet J 2010; 58:175-83. [PMID: 20676154 DOI: 10.1080/00480169.2010.68862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS To describe the reproductive performance and management practices over three lactations in dairy herds that had different policies on the routine use of induction of parturition; to describe any change in outcomes in herds that ceased inductions during the study period; and to investigate other herd-level factors associated with reproductive performance. METHODS From 2002 to 2004 inclusive, a longitudinal study was undertaken in 82 herds in the Waikato region of New Zealand. The main outcome variables were the percentage of cows pregnant after 8 weeks of mating (8-week in-calf rate) and the percentage of cows not pregnant at the end of mating (final empty rate). Data were obtained from pregnancy diagnosis records from a veterinary practice and from an electronic database, and a questionnaire. Herds were classified as either not using inductions in the three lactations (Nil; n=14), ceased inductions in the second or third lactation (Transitional; n=12), or continuing to induce (Continuing; n=56). RESULTS Nil herds had a higher 8-week in-calf rate (p=0.01) than Transitional or Continuing herds (83%, 78% and 79%, respectively). The final empty rate in Nil and Transitional herds was similar (10.2% and 9.9%), tended to be greater in Nil than in Continuing herds (10.2% vs 9.0%; p=0.06) and was greater in Transitional than in Continuing herds (9.9% vs 9.0%; p=0.04), respectively. Multivariable modelling found that 8-week in-calf rates were additionally associated with year of lactation, interval from the planned start of calving (PSC) to the median calving date, duration of artificial insemination, and 21-day submission rate; and that final empty rates were associated with year of lactation, predominant breed, percentage of the herd calving within 40 days of the planned start of mating (PSM), the total duration of mating, and the 21-day submission rate, but not the herd induction policy. A change to ceasing routine use of induction tended to be associated (p=0.07) with a 2.5% increase in the final empty rate in the lactation of change. CONCLUSIONS The reproductive performance of herds was associated with induction policy, in addition to other factors. Herds that ceased induction had a greater 8-week in-calf rate but a greater final empty rate than those that continued. The higher empty rate in Nil herds was partly due to their shorter duration of mating. CLINICAL RELEVANCE Herdowners and their advisors planning to cease routine use of induction should plan for an increase in the final empty rate in both the lactation of change and in the longer term, and undertake measures to mitigate against this effect.
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McDougall S. Comparison of diagnostic approaches, and a cost-benefit analysis of different diagnostic approaches and treatments of anoestrous dairy cows. N Z Vet J 2010; 58:81-9. [PMID: 20383242 DOI: 10.1080/00480169.2010.65262] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIM To compare diagnostic techniques, and to assess the economic effects of diagnosing and treating dairy cows not detected in oestrus before the planned start of mating (PSM). METHODS Cows from 12 herds were defined as anoestrus at Day -9 (where Day 0=PSM) based on presence of tail paint that had been applied at Day -35. The presence of a corpus luteum (CL) was diagnosed by palpation or ultrasonography on Day -9, or by determining the concentration of progesterone (P4) in milk at Days -16 and -9. Cows with concentrations of P4 in milk >1 ng/ml at one or both times were defined as CL+. Cows were randomly assigned to be treated with (a) nothing (Control; n=558); (b) gonadotrophin-releasing hormone (GnRH) on Day -9, prostaglandin F(2alpha) (PGF(2alpha)) on Day -2, and GnRH on Day 0, with set-time artificial insemination (AI) 16-20 h after the second GnRH treatment (Ovsynch; n=553); or (c) as for (b) but with placement of an intravaginal P4-releasing device on Day -9, and removal on Day -2 (Ovsynch+P4; n=551). Cows detected in oestrus between Day -2 and the second GnRH treatment did not receive the second GnRH treatment. Pregnancy diagnosis took place on three occasions, and the date of conception estimated, from which the PSM-to-conception interval was calculated. Agreement between the three diagnostic techniques for CL status was evaluated using Kappa analyses, and sensitivities and specificities were calculated using a Bayesian Monte Carlo approach that does not assume a gold standard. Partial budgets and decision trees were constructed to assess the cost effectiveness of diagnosis and treatment. RESULTS The level of agreement was higher between ultrasonography and concentration of P4 in milk (0.64) than for palpation and ultrasonography or concentration of P4 in milk (0.50 and 0.49, respectively). The Ovsynch+P4 treatment had a higher net benefit than Ovsynch relative to no treatment (NZ$80.40 and NZ$47.50/cow treated, respectively) in the absence of diagnosis of CL status. Following diagnosis, the Ovsynch+P4 treatment remained the most cost-effective option for both CL+ and CL- cows. It was concluded that the Ovsynch+P4 treatment without any diagnostic procedure was the most cost-effective option. CLINICAL RELEVANCE Treatment of anoestrous cows was more cost-effective than no treatment, with Ovsynch+P4 more cost-effective than Ovsynch in cows with or without a CL. Differentiation of anoestrous cows into CL+ and CL- groups for treatment was not cost-effective.
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McDougall S. Effects of treatment of anestrous dairy cows with gonadotropin-releasing hormone, prostaglandin, and progesterone. J Dairy Sci 2010; 93:1944-59. [DOI: 10.3168/jds.2009-2305] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 01/04/2010] [Indexed: 11/19/2022]
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Fernandez C, Jami S, Loredo G, Ko F, Hahn T, McDougall S, Peters JH. Recognition of the alternatively spliced segments of fibronectin by the RCJ 3.1C5.18 chondrocytic rat cell line. Osteoarthritis Cartilage 2010; 18:228-39. [PMID: 19822234 DOI: 10.1016/j.joca.2009.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 08/24/2009] [Accepted: 09/09/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To define, for the C5.18 chondrocyte-restricted rat cell line, (1) the capacities for recognition of alternatively spliced segments of the adhesion protein fibronectin (FN), (2) the integrin subunits required for such recognition, and (3) differences in such FN recognition vs the multipotential chondroprogenitor line, RCJ 3.1. METHODS C5.18 and RCJ 3.1 cells were tested for their capacities to adhere to recombinant alternatively spliced segments of rat FN, presented on plastic surfaces either in isolation or in partial FNs spanning the 7th through 15th type III repeats (III7-15 FNs). The effects on such adhesion of cations and integrin subunit-specific antibodies were tested. RESULTS Despite significant augmentation in chondrocyte-specific gene expression in C5.18 relative to the RCJ 3.1 cells, the two lines exhibited similar recognition of FN spliced segments and partial isoforms. Specifically, both lines adhered to the extra type III repeat A (EIIIA) and V, but not extra type III repeat B (EIIIB), segments. There were different cation and integrin subunit requirements for adhesion to EIIIA vs V segments, and only the V segment was recognized in the context of a III7-15 FN. Such recognition was mediated via a "second" arginine-glycine-aspartic acid (RGD) sequence that is present in the V95 subsegment in rat, but not human, FN. CONCLUSION The chondrocyte lineage-committed C5.18 cell line, similar to its multipotential chondroprogenitor, RCJ 3.1, recognizes the "cartilage-restricted" EIIIA and V segments of FN with cation, integrin, and molecular context requirements that are specific to each of these segments.
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McDougall S, Bryan MA, Tiddy RM. Effect of treatment with the nonsteroidal antiinflammatory meloxicam on milk production, somatic cell count, probability of re-treatment, and culling of dairy cows with mild clinical mastitis. J Dairy Sci 2009; 92:4421-31. [PMID: 19700702 DOI: 10.3168/jds.2009-2284] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It was hypothesized that treatment of clinical mastitis with a combination of a nonsteroidal antiinflammatory treatment (meloxicam) and a parenteral antibiotic (penethamate hydriodide) would result in lower somatic cell counts (SCC), reduced milk yield losses, improved clinical outcomes, and reduced culling rates compared with antibiotic therapy alone. Cows in 15 herds with clinical mastitis during the first 200 d of lactation (median = 13 d) were treated with 5 g of penethamate hydriodide daily for 3 d, and one-half these cows were treated with 250 mg of the nonsteroidal antiinflammatory drug meloxicam (n = 361 cows), whereas the other half (n = 366 cows) were treated with the vehicle (control group). Milk samples for bacteriology were collected from clinically affected glands before treatment, and samples were collected at 7 (+/-3), 14 (+/-3), and 21 (+/-3) d after commencement of treatment for SCC determination. Additionally, the rectal temperature, udder edema score, California Mastitis Test score, and milk clot score were determined before treatment and daily milk yield data were collected across the lactation. There were no differences between the treatment groups in calving date, days in milk, age, breed, rectal temperature, California Mastitis Test score, clot score, udder edema score, or bacterial pathogens isolated before treatment. There was no difference between treatment groups in the number of cows that were defined as treatment failures (i.e., re-treated within 24 d of initial treatment, died, or the treated gland stopped producing milk); 79 (21.9%) vs. 92 (25.1%) cows in the meloxicam and control groups failed, respectively. The SCC was lower in the meloxicam-treated group compared with the control group after treatment [550 +/- 48 vs. 711 +/- 62 geometric mean (x1,000/mL) +/- standard error of the mean SCC for quarters after treatment with meloxicam vs. control, respectively]. There was no difference in milk yield for the cows treated with meloxicam compared with the control cows within 28 or 200 d after treatment. Fewer meloxicam-treated than control cows were removed (culled) from the herds [39/237 (16.4%) vs. 67/237 (28.2%) for meloxicam vs. control cows, respectively; odds ratio = 0.42, 95% confidence interval = 0.26 to 0.68]. It was concluded that treatment of cows with clinical mastitis with a combination of meloxicam and penethamate resulted in a lower SCC and a reduced risk of removal from the herd (culling) compared with treatment with penethamate alone.
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McDougall S, Bryan M, Tiddy R. Erratum to “Effect of treatment with the nonsteroidal antiinflammatory meloxicam on milk production, somatic cell count, probability of re-treatment, and culling of dairy cows with mild clinical mastitis” (J. Dairy Sci. 92:4421–4431). J Dairy Sci 2009. [DOI: 10.3168/jds.2009-92-11-5765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Hunnam JC, Parkinson TJ, Lopez-Villalobos N, McDougall S. Association between gestational age and bovine fetal characteristics measured by transcutaneous ultrasound over the right flank of the dairy cow. Aust Vet J 2009; 87:379-83. [DOI: 10.1111/j.1751-0813.2009.00468.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hunnam JC, Parkinson TJ, Lopez-Villalobos N, McDougall S. Comparison of transcutaneous ultrasound over the right flank with transrectal ultrasound for pregnancy diagnosis in the dairy cow. Aust Vet J 2009; 87:318-22. [DOI: 10.1111/j.1751-0813.2009.00459.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hunnam JC, Parkinson TJ, McDougall S. Transcutaneous ultrasound over the right flank to diagnose mid- to late-pregnancy in the dairy cow. Aust Vet J 2009; 87:313-7. [DOI: 10.1111/j.1751-0813.2009.00458.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fitzmaurice J, Sewell M, King CM, McDougall S, McDonald WL, O'Keefe JS. A real-time polymerase chain reaction assay for the detection of Mycoplasma agalactiae. N Z Vet J 2009; 56:233-6. [PMID: 18836504 DOI: 10.1080/00480169.2008.36839] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIM To develop a real-time PCR for the detection of Mycoplasma agalactiae, using PCR primers targeting the ma-mp81 gene. METHODS A group of 15 M. agalactiae isolates, 21 other Mycoplasma spp. isolates and 21 other bacterial isolates was used in evaluation of the assay. RESULTS All M. agalactiae isolates were detected by the assay and none of the non-target isolates was amplified. The analytical detection limit of the assay was 10 fg of purified genomic DNA and 104 cfu/ml milk inoculated with M. agalactiae. When applied to goat-milk samples collected from three herds free of M. agalactiae infection, the assay had a specificity of 100%. CONCLUSIONS The assay would be useful in a diagnostic laboratory, providing specific, sensitive and rapid detection of M. agalactiae.
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McDougall S, Parker KI, Weir AM, Compton CWR. Effect of application of an external teat sealant and/or oral treatment with a monensin capsule pre-calving on the prevalence and incidence of subclinical and clinical mastitis in dairy heifers. N Z Vet J 2008; 56:120-9. [DOI: 10.1080/00480169.2008.36820] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Parker K, Compton C, Anniss F, Heuer C, McDougall S. Quarter-Level Analysis of Subclinical and Clinical Mastitis in Primiparous Heifers Following the Use of a Teat Sealant or an Injectable Antibiotic, or Both, Precalving. J Dairy Sci 2008; 91:169-81. [DOI: 10.3168/jds.2007-0212] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Compton CWR, Heuer C, Parker K, McDougall S. Epidemiology of mastitis in pasture-grazed peripartum dairy heifers and its effects on productivity. J Dairy Sci 2007; 90:4157-70. [PMID: 17699034 DOI: 10.3168/jds.2006-880] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An observational field study was conducted on 708 heifers in 30 spring-calving dairy herds in the Waikato region of New Zealand. The aim of the study was to describe patterns and effects of intramammary infection (IMI) and clinical mastitis (CM) in the peripartum period. Mammary secretion samples for bacteriological testing were taken from all quarters approximately 3 wk before the planned start of the calving period and within 5 d following calving, in addition to quarters diagnosed with CM within 14 d of calving. Precalving IMI was diagnosed in 18.5% of quarters, and of these, coagulase-negative staphylococci were the predominant isolate (13.5% of quarters). Streptococcus uberis prevalence increased 4-fold to 10.0% of quarters on the day of calving compared with the precalving period. Prevalence of all pathogens decreased rapidly following calving. Clinical mastitis cases were predominantly associated with Strep. uberis (64%). The daily hazard of diagnosis was higher in heifers than in cows (0.06 vs. 0.02/d on d 1 postcalving, respectively), but was not different by d 5 (0.005 vs. 0.002, respectively) of lactation. Intramammary infection with a major pathogen was associated with an increased risk of removal from the herd (15 vs. 10% for infected and noninfected heifers, respectively) and somatic cell count >200,000 cells/mL at subsequent herd tests (15 vs. 8%), but neither CM nor IMI were associated with reduced milk yield or milk solids production. Results suggest that bacterial species involved and the pattern of IMI prevalence in pasture-grazed peripartum heifers differ from those in other production systems. Further, mastitis control programs need to target major environmental pathogens causing precalving IMI, because new infections are likely before the onset of lactation, whereas existing detection and control measures are generally implemented after calving. Novel control programs that reduce new infections due to Strep. uberis immediately before calving are required to reduce the incidence of CM in pasture-grazed dairy heifers.
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Compton CWR, Heuer C, Parker K, McDougall S. Risk Factors for Peripartum Mastitis in Pasture-Grazed Dairy Heifers. J Dairy Sci 2007; 90:4171-80. [PMID: 17699035 DOI: 10.3168/jds.2006-882] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A longitudinal observational field study was conducted using 708 heifers in 30 spring-calving dairy herds in the Waikato region of New Zealand. The aim of the study was to investigate risk factors for subclinical and clinical mastitis (CM) in the peripartum period using path analysis methods and to find the factors most important at the population level as a basis for potential control programs. Body condition and udder hygiene scores, blood samples, and quarter mammary secretion samples for bacteriology were collected approximately 3 wk before the planned start of the seasonal calving period and again within 5 d following calving. Additionally, milk samples were collected from quarters diagnosed with CM within 14 d of calving. Significant risk factors for subclinical mastitis postcalving were precalving subclinical mastitis (3.32 incidence risk ratio; IRR), low minimum teat height above the ground (1.32 IRR), and unhygienic udder postcalving (1.32 IRR). Significant risk factors for clinical mastitis postcalving were precalving subclinical mastitis (2.14 IRR), Friesian breed (1.94 IRR), low minimum teat height above the ground (2.05 IRR), udder edema (1.81 IRR), and low postcalving nonesterified fatty acid serum concentration (1.55 IRR). Control of precalving subclinical mastitis and udder edema by producers, and enhancement of breed immunity by geneticists were important factors at a population level, and hence, are likely the most rewarding areas to target in any heifer mastitis management program.
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McDougall S, Arthur DG, Bryan MA, Vermunt JJ, Weir AM. Clinical and bacteriological response to treatment of clinical mastitis with one of three intramammary antibiotics. N Z Vet J 2007; 55:161-70. [PMID: 17676080 DOI: 10.1080/00480169.2007.36762] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIM To compare the proportions of clinical and bacteriological cure of glands of dairy cows diagnosed with clinical mastitis, following treatment with one of three different intramammary antibiotic preparations. METHODS Cows from dairy cow herds (n=28) across New Zealand which were diagnosed with clinical mastitis in one or more glands at any stage of lactation were randomly assigned at the cow level within sequentially presented groups of three animals to be treated with one of three intramammary antibiotics. The treatments were 1 g procaine penicillin, 0.25 g cefuroxime, and a combination of 1 g procaine penicillin and 0.5 g dihydrostreptomycin (DHS). All treatments were infused on three occasions at 12-hourly intervals. Duplicate milk samples were collected for bacteriology before initial treatment, and 21-42 days later. Logistic regression or generalised linear mixed models were used to analyse the proportion of cows or quarters retreated for mastitis within 30 days of initial treatment ('clinical treatment failure'), and the proportion of glands from which bacteria were isolated initially but from which the same bacterial species was not re-isolated ('bacteriological cure'). RESULTS The annual herd average cumulative incidence rate of clinical mastitis was 12.7 cases/100 cows. The incidence rate was higher in young (2-year-old) and old (> or = 9-year-old) cows relative to 3- and 4-year-old cows, and was higher in Friesian than Jersey or crossbred cows. Streptococcus uberis was the pathogen most commonly isolated, and its relative prevalence declined with time postpartum. Cows treated with cefuroxime were more likely (p<0.01) to be re-treated for clinical mastitis in the 30 days after initial treatment than cows treated with procaine penicillin or procaine penicillin and DHS. Bacteriological cure occurred in 74% of treated glands and there was no difference in the proportion of cures among the treatments (p=0.4). The proportion of cures was lower when treatment occurred 28-72 days after calving (p<0.01) and if a major pathogen was isolated (p<0.001). CONCLUSIONS AND CLINICAL RELEVANCE There was no benefit in terms of clinical or bacteriological cure rate in treating clinical mastitis cases with the combination of procaine penicillin and DHS compared to treatment with procaine penicillin alone. The proportion of clinical mastitis cases re-treated differed among herds, and more cows treated with cefuroxime were retreated within 30 days of initial treatment. However, the bacteriological cure proportion was the same among the treatments. Cure proportions were lower in cows from which major mastitis pathogens were isolated and when treatment commenced 28-72 days after calving.
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McDougall S, Agnew KE, Cursons R, Hou XX, Compton CRW. Parenteral Treatment of Clinical Mastitis with Tylosin Base or Penethamate Hydriodide in Dairy Cattle. J Dairy Sci 2007; 90:779-89. [PMID: 17235155 DOI: 10.3168/jds.s0022-0302(07)71562-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objective of this study was to compare the clinical and bacteriological cure rates of cows with clinical mastitis following treatment with either tylosin base (5 g injected 3 times at 24-h intervals; n = 306) or penethamate hydriodide (5 g injected 3 times at 24-h intervals; n = 289). Duplicate milk samples were collected before treatment and again 14 +/- 3 and 21 +/- 3 d later for microbiological analysis. Only those quarters from which gram-positive mastitis pathogens were isolated before treatment were included in the analyses. Streptococcus uberis was the most prevalent isolate. The number of cows with clinical failure (i.e., retreated within 21 d of enrollment) did not differ between treatments (64 vs. 63, respectively). At the quarter level, there was no difference in the proportion of bacteriological cure between treatments (81.2 vs. 83.8% for penethamate hydriodide or tylosin, respectively). The proportions of clinical and bacteriological cure were influenced by age, herd, severity of mastitis, number of glands within the cow with clinical mastitis, bacterial species, and days postpartum at enrollment. There was no difference between treatment groups for SCC (4.46 vs. 4.44 +/- 0.08, mean +/- standard error of the difference in ln SCC for cows treated with penethamate hydriodide or tylosin, respectively) or production of milk solids (1.45 vs. 1.48 +/- 0.02 kg/d of milk fat + protein, for the penethamate hydriodide or tylosin treatment, respectively). Overall, there was no difference in the proportions of clinical failure (17.3 vs. 16.5% of cows treated with penethamate hydriodide or tylosin, respectively) or bacteriological cure (79.8 vs. 82.0% of cows treated with penethamate hydriodide or tylosin, respectively), or in SCC or milk production between dairy cows with clinical mastitis and those treated for clinical mastitis with 1 of 2 parenteral antibiotic therapies.
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Parker KI, Compton C, Anniss FM, Weir A, Heuer C, McDougall S. Subclinical and Clinical Mastitis in Heifers Following the Use of a Teat Sealant Precalving. J Dairy Sci 2007; 90:207-18. [PMID: 17183089 DOI: 10.3168/jds.s0022-0302(07)72622-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study investigated the effect in heifers of infusion of a bismuth subnitrate teat-canal sealant and bacterial intramammary infection (IMI) precalving on prevalence of postcalving IMI and incidence of clinical mastitis in the first 2 wk postcalving. Glands (n = 1,020) from heifers (n = 255) in 5 seasonally calving, pasture-fed dairy herds were randomly assigned within heifer to 1 of 4 treatment groups (no treatment; mammary gland secretion collection; infusion of a teat sealant; or sample collection with infusion of teat sealant). Heifers within a herd were enrolled on one calendar day, 31 d on average before the planned start of the seasonal calving period. Duplicate milk samples were collected from each gland within 4 d after calving for bacterial culture. Herd owners collected duplicate milk samples, before treatment, for bacterial culture from glands they defined as having clinical mastitis. The gland prevalence of IMI precalving was 15.5% and did not differ between herds. Bacteria isolated precalving included coagulase-negative staphylococci (76.9% of all bacteriologically positive samples), Streptococcus uberis (14.1%), Staphylococcus aureus (5.1%), Corynebacterium spp. (3.8%), and others (0.1%). The presence of an IMI precalving increased the risk of an IMI postcalving 3.6-fold and the risk of clinical mastitis 4-fold, relative to no IMI precalving. Infusion of the teat sealant reduced the risk of postcalving IMI due to Strep. uberis by 84%, and of clinical mastitis by 68%. Sampling the glands precalving had no effect on postcalving IMI or on clinical mastitis incidence. Use of an internal teat canal sealant in heifers precalving may be a useful tool for reducing the risk of subclinical and clinical mastitis in heifers.
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McDougall S, Compton C. Reproductive performance in the subsequent lactation of dairy cows previously treated for failure to be detected in oestrus. N Z Vet J 2006; 54:132-40. [PMID: 16751844 DOI: 10.1080/00480169.2006.36625] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIM To describe the effect of treatment of cows not detected in oestrus (NDO) with progesterone (P4) and oestradiol benzoate (ODB) in one lactation, on the reproductive and productive performance in the subsequent lactation. METHODS Cows (n=770 from nine herds) which were NDO 10 days before the planned start of the seasonal breeding programme (PSM) were blocked by herd, age (2 or >2 years old) and ovarian status (i.e. with or without a palpable corpus luteum; CL), and treated either with an intravaginal progesterone-releasing device and ODB and resynchrony, or were left as untreated controls. In the following lactation, data were collected on the occurrence of endometritis, NDO, breeding dates, pregnancy test results and milk production. The effect of treatment and ovarian status in the previous lactation on the incidence of disease, and the proportions submitted for service, conceived and pregnant in the subsequent lactation were analysed. Calving dates and intervals from start of breeding to first insemination and conception were analysed using Kaplan Meier survival analysis. Additional multivariate analyses were undertaken to include known confounders such as age, breed, herd, calving date and milk production, as well as the cyclic status (i.e. previously cycling, NDO, or "late-calving") in the previous lactation, to examine the potential "carryover" effects of previous status on the reproductive performance in the subsequent lactation. RESULTS Treatment of NDO cows resulted in an earlier calving date (Julian calving date 214, 95% CI=207-221, vs 224, 95% CI=220-228; p=0.005), more female calves reared (31.4% vs 23.3%; p=0.01), and reduced risk of being NDO (33.9% vs 46.1%; p=0.002) in the subsequent lactation compared with controls. There were no differences in the incidence of peripartum disease, or the proportion of cows submitted, conceived or pregnant between the Treatment and Control groups in the subsequent lactation (p>0.2). Previously CL-positive (+ve) NDO cows were less likely to produce a female calf that was reared (19.0% vs 29.9%; p=0.005), more likely to be treated as NDO (26.4% vs 18.6%; p=0.02), less likely to conceive by the end of the subsequent lactation's breeding programme (82.2% vs 87.8%; p=0.09), and took longer to conceive (41 vs 33 days from the PSM to conception) than cows that were NDO-CL-negative (-ve) in the previous lactation. There was no interaction between ovarian status and treatment for any of the outcome variables (p>0.05). Cows that were NDO or late-calving in the previous lactation were more likely to be NDO (p<0.005), treated as NDO (p<0.005), and have longer PSM to conception intervals (p<0.005) in the subsequent lactation than cycling herdmates, despite inclusion of factors known to confound reproductive performance in analyses. CONCLUSIONS Treatment of NDO cows resulted in more female calves reared, earlier calving and a reduced risk of being NDO in the subsequent lactation. Status (i.e. NDO-CL+ve or NDO-CL-ve) affected some reproductive measures in the subsequent lactation, and the effect of treatment in the subsequent lactation differed between the two groups for some measures. Reproductive performance in the subsequent lactation was not improved despite the earlier calving date and longer calving to PSM intervals. Additionally, the previous season's status was still important in the subsequent season's reproductive performance, despite adjusting for known confounders of fertility. CLINICAL RELEVANCE The economic benefits from treatment of NDO cows are likely limited to effects of an earlier calving date and potential for longer lactation and increased milk yield, increased number of calves derived from artificial insemination and from a reduced number of NDO cows in the subsequent lactation. Effects of improved reproductive performance in the subsequent lactation were not demonstrated and hence should not be included in any economic analysis of therapy of NDO cows.
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McDougall S, Macaulay R, Compton C. Association between endometritis diagnosis using a novel intravaginal device and reproductive performance in dairy cattle. Anim Reprod Sci 2006; 99:9-23. [PMID: 16630700 DOI: 10.1016/j.anireprosci.2006.03.017] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 03/16/2006] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
Endometritis reduces reproductive performance in dairy cattle. Diagnosis of endometritis is undertaken using a variety of techniques including vaginoscopy, manual examination, cytology and ultrasonography. The current studies compared a novel test device ("metricheck") that is inserted into the vagina with vaginoscopy and then examined the relationship between the metricheck test score at 35 days before the start of the seasonal breeding programme and subsequent reproductive performance. Cows (n = 191; Study 1) with a history of a peripartum disease were examined by both vaginoscopy and the metricheck device and any material viewed within the vagina (using vaginoscopy) or retrieved (by the metricheck device) was scored on a 0 (no material) to 5 (grossly purulent and with an odour) scale. Within each herd the order of examination was randomized with sequentially presented pairs of cows. All cows (n = 2793; Study 2) from nine herds were examined and scored using the metricheck device 35 days before the start of the seasonal breeding programme. All cows were pregnancy tested to determine date of conception. In Study 1, more cows were defined as infected (i.e. score > 1) following metricheck than vaginoscopic examination (60% versus 43%, respectively; P < 0.05) and the level of agreement between the two tests was moderate (kappa = 0.45). The metricheck device had a higher sensitivity, but lower specificity, than vaginoscopy. Endometritis (i.e. score > 1) was detected in 21.2% of cows examined in Study 2. The prevalence of endometritis varied among herds, declined with time postpartum (P < 0.05) and was higher in cows recorded as having a peripartum disease (P < 0.01). Cows diagnosed with endometritis were at higher risk of not being detected in oestrus before the start of breeding (P < 0.01), took longer to be inseminated after the start of the seasonal breeding programme (P < 0.01), had a lower first service conception rate (P < 0.01), had lower 56-day and final pregnancy rates (P < 0.05) and took longer to conceive than cows without endometritis (P < 0.05). It is concluded that examination with the metricheck device is more sensitive in detecting endometritis than vaginoscopy. Diagnosis of endometritis with the metricheck device was associated with poorer subsequent reproductive performance.
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McDougall S, Blache D, Rhodes FM. Factors affecting conception and expression of oestrus in anoestrous cows treated with progesterone and oestradiol benzoate. Anim Reprod Sci 2005; 88:203-14. [PMID: 16143212 DOI: 10.1016/j.anireprosci.2005.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Revised: 12/13/2004] [Accepted: 01/27/2005] [Indexed: 11/25/2022]
Abstract
Nutrient balance affects the resumption of ovarian cyclic activity following calving in dairy cattle. However, few data are available about the relationships between nutrient balance and expression of oestrus or conception. It was hypothesised that previously anoestrous cows that conceived to first insemination and cows that expressed oestrus at the subsequent expected return to oestrus would be less likely to be in negative energy balance (i.e. would have higher body condition score, higher glucose, insulin-like growth factor (IGF), leptin or insulin concentrations, and lower non-esterified fatty acids (NEFA), blood urea nitrogen (BUN), beta hydroxy butyrate (BOH) concentrations 12-15 days after insemination) than herd mates not conceiving or expressing oestrus. Anoestrous cows were treated with progesterone and oestradiol benzoate (Day 0 = end of treatment period) and retrospectively categorised as conceiving (n = 108) or not conceiving (n = 108) to insemination. A subset of cows not conceiving to insemination were categorised as expressing (n = 44) or not expressing (n = 44) oestrus between Days 14 and 28 after initial insemination. Cows conceiving had a lower NEFA concentration (P = 0.014) than non-conceiving cows. Cows subsequently detected in oestrus had higher body condition scores (P = 0.016), IGF concentrations (P = 0.008) and milk protein percentages (P = 0.038), and lower BOH concentrations (P = 0.018) than cows not expressing oestrus. No difference in concentrations of leptin, insulin, glucose, blood urea nitrogen or milk yield were found between cows conceiving or not conceiving and those detected in oestrus or not detected in oestrus (P > 0.1). It is concluded that some measures of metabolic status at the time of pregnancy recognition affects the probability of pregnancy and of subsequent expression of oestrus in those treated, anoestrous cows not conceiving.
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