Colostrum Management for Dairy Calves Godden, Sandra M; Lombard, Jason E; Woolums, Amelia R
The Veterinary clinics of North America. Food animal practice,
11/2019, Letnik:
35, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Colostrum management is the single most important management factor in determining calf health and survival. Additional benefits of good colostrum management include improved rate of gain and future ...productivity. Successful colostrum management requires producers to provide calves with a sufficient volume of clean, high-quality colostrum within the first few hours of life. This article reviews the process of colostrogenesis and colostrum composition, and discusses key components in developing a successful colostrum management program. In addition, the article discusses approaches for monitoring and proposes new goals for passive immunity in dairy herds.
The selective treatment of clinical mastitis based on culture results can reduce antibiotic use by more than 50% without sacrificing treatment efficacy. Local laboratories reporting results in a ...24-hour period, or adoption of on-farm milk culture systems, allow producers to make strategic treatment decisions. On-farm culture systems are most reliable when used to classify infections in broad diagnostic categories such as no growth, gram-positive, or gram-negative growth. Diagnostic accuracy is crucial for on-farm culture systems to be efficacious and economically advantageous. Quality assurance is necessary for the success of on-farm culture systems.
Colonization of dairy cows by Staphylococcus aureus (S. aureus), especially those which are multi-drug resistant and toxin producing, is a concern for animal health and well-being as well as public ...health. The objective of this study was to investigate the prevalence, antibiotic resistance, gene content and virulence determinants of S. aureus in bulk tank milk samples (BTM) from U.S. dairy herds.
BTM samples were collected, once in winter and once in summer, from 189 U.S. dairy herds. Of 365 BTM samples cultured, the sample and herd prevalence of S. aureus in BTM was 46.6% (170 of 365 samples) and 62.4% (118 of 189 herds), respectively. Among a subset of 138 S. aureus isolates that were stored for further analysis, 124 were genome sequenced after being confirmed as S. aureus using phenotypic tests. The most commonly identified antimicrobial resistance-associated gene was norA (99.2%) and mecA gene responsible for methicillin resistance (MRSA) was identified in one isolate (0.8%). The most frequently detected putative virulence genes were aur (100%), hlgB (100%), hlgA, hlgC, hlb (99.2%), lukE (95.9%) and lukD (94.3%). In the 53 staphylococcal enterotoxin positive isolates, sen (37.9%), sem (35.5%), sei (35.5%) and seg (33.1%) were the most frequently detected enterotoxin genes. Among the 14 sequence types (ST) and 18 spa types identified, the most common was ST2187 (20.9%) and t529 (28.2%), respectively. The most predominant clone was CC97 (47.6%) followed by CC unknown (36.3%). The single MRSA isolate belonged to ST72-CC8, spa type t126 and was negative for the tst gene but harbored all the other virulence genes investigated.
Our findings indicated a high prevalence of S. aureus in BTM of U.S. dairy herds, with isolates showing little evidence of resistance to antibiotics commonly used to treat mastitis. However, isolates often carried genes for the various enterotoxins. This study identified predominant genetic clones. Despite lower prevalence, the presence of MRSA and multi-drug resistant strains in BTM poses a significant risk to animal and public health if their number were to increase in dairy environment. Therefore, it is necessary to continuously monitor the use of antibiotics in dairy cows.
The primary objective of this cross-sectional observational study was to determine whether bulk tank milk quality, udder health, udder hygiene and milk production outcomes were associated with ...facility type on organic dairies. A secondary objective was to identify other management-related risk factors associated with bulk tank milk quality, udder health, udder hygiene, and milk production on organic dairy herds in Vermont. We aimed to enroll 40 farms, to compare herds using the 2 most common systems (freestalls, tiestalls) for housing organic dairy cattle in the state with those using a bedded pack during the non-grazing season (typically November–May). Two general styles of bedded packs were observed: cultivated bedded packs and untilled deep bedded packs. Due to the limited number of herds using bedded packs to house lactating dairy cattle in Vermont, we combined untilled and cultivated bedded packs to describe udder hygiene, milk quality, and udder health on these loose-housing systems deeply-bedded with organic material. The study was completed on 21 farms (5 bedded packs, 6 freestalls, 10 tiestalls) before interruption due to the COVID-19 pandemic. Data captured from Dairy Herd Improvement Association records from the test closest to the date of the farm visit included average somatic cell score (SCS), standardized 150-d milk (pounds), % cows with current high SCS (SCS ≥ 4.0), % cows with newly elevated SCS (previous SCS < 4.0 to current ≥ 4.0), and % cows with chronically elevated SCS (SCS ≥ 4.0 last 2 tests). Multivariable linear regression models were used to describe outcomes by facility type, but suffered from limited statistical power due to small group sample sizes. Unconditional comparisons failed to find statistically significant differences between farms grouped by facility type in metrics captured from Dairy Herd Improvement Association test data, bulk tank milk somatic cell count (BTSCC) and aerobic culture data, or udder hygiene scores. A secondary analysis was conducted using univariate linear regression to identify associations between herd management factors and outcomes for all 21 farms combined. Although not all differences found were statistically significant in this secondary analysis combining all farms, numeric differences that may be biologically important are reported showing farms with deeper bedding had a lower BTSCC, lower newly elevated SCS, lower chronically elevated SCS, lower elevated current SCS, lower average SCS, and better udder hygiene metrics. Farms with lower mean udder hygiene scores had numerically lower chronically elevated SCS, lower elevated current SCS, and lower average SCS. We could not reject the null hypothesis that milk quality and udder health outcomes did not differ by facility type, and this does not preclude the existence of biological differences in these outcomes between facility types. The current study provides insight on factors affecting bulk tank milk quality, udder health and hygiene measures on organic dairy farms in Vermont. Bedded packs may be a viable option for confinement housing during the winter non-grazing season for pasture-based herds interested in a loose-housing system in the Northeastern US, but more research such as longitudinal studies with a larger sample size is needed to test this hypothesis.
Treatment of clinical mastitis (CM) and use of antimicrobials for dry cow therapy are responsible for the majority of animal-defined daily doses of antimicrobial use (AMU) on dairy farms. However, ...advancements made in the last decade have enabled excluding nonsevere CM cases from antimicrobial treatment that have a high probability of cure without antimicrobials (no bacterial causes or gram-negative, excluding Klebsiella spp.) and cases with a low bacteriological cure rate (chronic cases). These advancements include availability of rapid diagnostic tests and improved udder health management practices, which reduced the incidence and infection pressure of contagious CM pathogens. This review informed an evidence-based protocol for selective CM treatment decisions based on a combination of rapid diagnostic test results, review of somatic cell count and CM records, and elucidated consequences in terms of udder health, AMU, and farm economics. Relatively fast identification of the causative agent is the most important factor in selective CM treatment protocols. Many reported studies did not indicate detrimental udder health consequences (e.g., reduced clinical or bacteriological cures, increased somatic cell count, increased culling rate, or increased recurrence of CM later in lactation) after initiating selective CM treatment protocols using on-farm testing. The magnitude of AMU reduction following a selective CM treatment protocol implementation depended on the causal pathogen distribution and protocol characteristics. Uptake of selective treatment of nonsevere CM cases differs across regions and is dependent on management systems and adoption of udder health programs. No economic losses or animal welfare issues are expected when adopting a selective versus blanket CM treatment protocol. Therefore, selective CM treatment of nonsevere cases can be a practical tool to aid AMU reduction on dairy farms.
Treatment of clinical mastitis (CM) contributes to antimicrobial use on dairy farms. Selective treatment of CM based on bacterial diagnosis can reduce antimicrobial use, as not all cases of CM will ...benefit from antimicrobial treatment, e.g., mild and moderate gram-negative infections. However, impacts of selective CM treatment on udder health and culling are not fully understood. A systematic search identified 13 studies that compared selective versus blanket CM treatment protocols. Reported outcomes were synthesized with random-effects models and presented as risk ratios or mean differences. Selective CM treatment protocol was not inferior to blanket CM treatment protocol for the outcome bacteriological cure. Noninferiority margins could not be established for the outcomes clinical cure, new intramammary infection, somatic cell count, milk yield, recurrence, or culling. However, no differences were detected between selective and blanket CM treatment protocols using traditional analyses, apart from a not clinically relevant increase in interval from treatment to clinical cure (0.4 d) in the selective group and higher proportion of clinical cure at 14 d in the selective group. The latter occurred in studies co-administering nonsteroidal anti-inflammatories only in the selective group. Bias could not be ruled out in most studies due to suboptimal randomization, although this would likely only affect subjective outcomes such as clinical cure. Hence, findings were supported by a high or moderate certainty of evidence for all outcome measures except clinical cure. In conclusion, this review supported the assertion that a selective CM treatment protocol can be adopted without adversely influencing bacteriological and clinical cure, somatic cell count, milk yield, and incidence of recurrence or culling.
Blanket dry cow therapy (DCT) is a major contributor to overall antibiotic usage on dairy farms in the United States. With low prevalence of intramammary infections at dry-off in US herds today, ...alternative DCT approaches have been the focus of much research. We hypothesized that complete cessation of DCT i.e., use of internal teat sealants (ITS) only at dry-off could be a practical alternative to blanket DCT in well-managed herds. The objective of this negatively controlled clinical trial was to determine the effects of DCT on clinical mastitis (CM) and removal from the herd during the dry period and the first 200 d of the subsequent lactation in multiparous dairy cows treated with only ITS at dry-off. As a secondary objective, we conducted exploratory analysis to identify subpopulations in the herd (based on parity, previous CM history, and dry-period length) where DCT would not affect postcalving udder health, to generate hypotheses about potential alternative selective DCT programs. The study was conducted in a commercial dairy herd in South Dakota from June 2020 to January 2021. Dry-off sessions (n = 43) were scheduled such that all cows at a given session were dried off using ITS alone (ITS only, n = 20 sessions, n = 1,108 cows) or an intramammary DCT product containing 500 mg of cloxacillin (Dry-Clox, Boehringer Ingelheim) followed by ITS (ITS+ABX, n = 23 sessions, n = 1,331 cows). Culling and CM events were recorded by farm workers who were blinded to the treatment status of cows. Hazard ratios (HR) for the effects of the treatment group on CM and removal from the herd were estimated using multivariable Cox proportional hazards, adjusting for the clustered treatment allocation strategy. Risk of removal from the herd during the dry period was lower in ITS+ABX than ITS-only cows (1.1 vs. 2.7%; HR = 0.45; 95% CI: 0.25 to 0.81). Risk of removal from the herd during the first 200 d of lactation was similar in ITS+ABX and ITS-only cows (17.3 vs. 18.0%; HR = 0.98; 95% CI: 0.82 to 1.18). Risk of CM during the first 200 d of lactation was lower in ITS+ABX cows (6.9%; HR = 0.56; 95% CI: 0.41 to 0.76) compared with ITS-only cows (13.4%). The beneficial effects of DCT on CM and removal from the herd were consistently observed across strata of parity, previous CM history, and dry-period length, indicating that no subpopulations could be identified to withhold DCT. The findings from this study indicate that the omission of DCT from the dry-off procedure, when udder health is not taken into consideration, in multiparous cows can have a negative effect on cow health and welfare. Findings from previous research suggest that culture- or algorithm-guided selective dry cow therapy are likely to be safer approaches to improving antibiotic stewardship.
Antibiotic stewardship on dairy farms can be heightened through the implementation of selective dry-cow therapy (SDCT). However, some producers are concerned that this practice may be related to poor ...udder health outcomes in cows with high milk production at the time of dry-off. The objective of this study was to evaluate if the effect of culture-guided SDCT (Cult-SDCT) and algorithm-guided SDCT (Alg-SDCT) on dry-period intramammary infection (IMI) dynamics and postcalving udder health and performance when compared with blanket dry-cow therapy (BDCT) varied according to milk production level before dry-off. Data were compiled from clinical trials conducted in the United States and Canada that compared Cult-SDCT and Alg-SDCT to a positive control, i.e., BDCT. In those trials, cows were enrolled 1–2 d before dry-off, randomized to their dry-cow therapy strategy and followed until 120 d in milk of the subsequent lactation. The number of cows and quarters in the final data set were 1,485 and 5,097, respectively. Measured outcomes included quarter-level antibiotic use at dry-off, quarter-level IMI prevalence after calving, quarter-level dry-period IMI cure risk, quarter-level dry-period new IMI risk, cow-level clinical mastitis and removal from the herd during 1–120 d in milk, and somatic cell count and milk yield during 1–120 DIM. The primary objective of analysis was to investigate if the effect of Cult-SDCT and Alg-SDCT on these outcomes, when compared with BDCT, varied according to milk production level before dry-off. To do this, each cow was classified as having low, mid or high production, based on her milk yield tertile group at the most recent herd test before enrollment (low: <23.7 kg/d, mid: 23.7 to 30.4 kg/d, and high >30.4 kg/d). Multivariable generalized estimating equations were used to estimate risk differences and differences in means, and Cox regression was used to estimate hazard ratios. For Cult-SDCT, the proportion of quarters treated with dry-cow antibiotics within each milk production level were 40.7% (low), 41.7% (mid) and 47.2% (high). For Alg-SDCT, the proportions were 60.6% (low), 38.7% (mid), and 35.1% (high). Measures of udder health were not markedly different when comparing Cult-SDCT to BDCT and Alg-SDCT to BDCT. This was consistently observed in low, mid and high producing cows. In conclusion, the findings from this study indicate that Cult-SDCT and Alg-SDCT can be successfully implemented in cows of all milk production levels.
Colostrum management for dairy calves Godden, Sandra
The Veterinary clinics of North America. Food animal practice,
03/2008, Letnik:
24, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Colostrum management is the single most important management factor in determining calf health and survival. Unfortunately, a significant proportion of North American dairy calves suffer from failure ...of passive transfer of antibodies from colostrum, contributing to excessively high preweaning mortality rates and other short- and long-term losses associated with animal health, welfare, and productivity. A successful colostrum management program requires producers to consistently provide calves with a sufficient volume of clean, high-quality colostrum within the first few hours of life. This article reviews the process of colostrogenesis and discusses important components of colostrum. The key components of delivering and monitoring a successful colostrum management program are discussed.
MALDI-TOF is a chemistry analytical tool that has recently been deployed in the identification of microorganisms isolated from nosocomial environments. Its use in diagnostics has been extremely ...advantageous in terms of cost effectiveness, sample preparation easiness, turn-around time and result analysis accessibility. In the dairy industry, where mastitis causes great financial losses, a rapid diagnostic method such as MALDI-TOF could assist in the control and prevention program of mastitis, in addition to the sanitation and safety level of the dairy farms and processing facility. However, the diagnostic strengths and limitations of this test method require further understanding. In the present study, we prospectively compared MALDI-TOF MS to conventional 16S rDNA sequencing method for the identification of pathogens recovered from milk associated with clinical and subclinical bovine mastitis cases. Initially, 810 bacterial isolates were collected from raw milk samples over a period of three months. However, only the isolates (481) having both 16S rDNA sequencing and MALDI-TOF identification were included in the final phase of the study. Among the 481 milk isolates, a total of 26 genera (12 g-postive and 14 g-negative), including 71 different species, were taxonomically charecterized by 16S rDNA at the species level. Comparatively, MALDI-TOF identified 17 genera (9 g-positive and 8 g-negative) and 33 differernt species. Overall, 445 (93%) were putatively identified to the genus level by MALDI-TOF MS and 355 (74%) were identified to the species level, but no reliable identification was obtained for 16 (3.3%), and 20 (4.2%) discordant results were identified. Future studies may help to overcome the limitations of the MALDI database and additional sample preparation steps might help to reduce the number of discordances in identification. In conclusion, our results show that MALDI-TOF MS is a fast and reliable technique which has the potential to replace conventional identification methods for common mastitis pathogens, routinely isolated from raw milk. Thus it's adoption will strengthen the capacity, quality, and possibly the scope of diagnostic services to support the dairy industry.
•The objective was to test the accuracy of MALDI-TOF MS.•16S rDNA sequencing was used for field validation of MALDI-TOF MS.•MALDI-TOF MS proved to be a reliable identification tool at the genus level for bovine mastitis isolates.•Discordance between MALDI-TOF and 16S rDNA sequencing identification were low.•Expansion and continuous update of MALDI-TOF reference database is recommended for better identification at species level.
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