Exploring herd-level perinatal calf mortality risk factors in eastern Canadian dairy farms

This closed cohort study aimed to identify the associations between dairy calf management practices and herd-level perinatal calf mortality risk. From February 2020 to June 2021, predominantly Holstein dairy farms in Québec (n = 1,832) and New Brunswick (n = 52), Canada, that were registered in the dairy herd improvement program were visited once. A questionnaire covering all aspects of precalving, calving, and colostrum management was administered. Data regarding perinatal mortality were retrieved from the dairy herd improvement program database for each farm for 2021. Perinatal mortality was calculated for each farm as the proportion of calves dead at birth or dying within 24 h after birth. A multivariable negative binomial model was used to assess herd-level factors associated with the risk of perinatal mortality. The final model included the lying surface in the calving area, the typical time to first colostrum intake, typical cow-calf contact time, the proportion of males born, the proportion of assisted calvings, and herd size. Herd-level perinatal mortality risk ranged from 0% to 38.1% (mean ± SE = 7.6% ± 0.1%). A greater proportion of males born, a higher proportion of assisted calvings, and delayed colostrum feeding were associated with increased herd-level perinatal mortality. Factors associated with a decreased herd-level perinatal mortality risk were having a typical cow-calf contact time between 7 and 12 h after calving compared with reduced cow-calf contact time, soft lying surfaces in the calving area compared with concrete and mat-lying surfaces, and an increased number of calvings per year. Our results show that although some of the significant risk factors are not well understood (i.e., calving area lying surface, typical cow-calf contact time), Canadian farmers could focus on the factors under their control (i.e., time to first colostrum feeding, proportion of difficult calvings, males born, and calvings per year) to reduce the risk of perinatal mortality. Future work should focus on qualitative research to understand the dairy farmer motivations and limitations to implementing practices identified in this and other studies to reduce perinatal mortality.

The factors contributing to better workplaces for farmers on pasture-based dairy farms

Herd size expansion, combined with the reduced availability of people to work on farms, has led to an increased focus on techniques that can improve dairy farm social sustainability. Effective work organization is one such entity, which could influence farm social sustainability; focusing on having a productive, flexible and standardized farm workload. The objective of this study was to examine the factors that contribute to better workplaces for the farmer using a survey of representative pasture-based dairy farms in Ireland. Potential contributing factors to better workplaces for farmers were identified, namely; farm and farmer characteristics, working day structure, farmer attitudes, farm facilities, labor efficient practices and human resource management practices. A survey was completed by 313 Irish dairy farmers between 20 November and 3 January 2019 to capture relevant information. One proxy indicator was selected to represent each of productivity, flexibility and standardization within the workplace, and each of the 313 farms were categorized into quartiles based on their ranking for these 3 indicators (1 = most effective quartile to 4 = least effective quartile). The average farmer that completed the survey was 51 years old, milked 125 cows, reported to work 69.6 h/ week, take 10.3 d of holidays/ year and had a finish time of 19:52 in spring. The quartile of farms with the most effective farmer workplace reported reduced hours worked per week (58.6 v 82.6 h per week), more holiday days (16.6 v 5.1 d) and weekends off (8.3 v 2.4) per year, and earlier finish times (18:41 v 21:14 in spring) compared with the least effective quartile. Similarly, the most effective farms reported better facilities, and greater implementation of labor efficient and human resource management practices compared with the least effective farms. The most effective quartile for farmer workplace effectiveness were more positive about the industry's potential to offer an effective work-life balance, would be more likely to encourage young people to pursue careers in dairy, and had more positive attitudes toward attracting and retaining workers compared with the least effective quartile. The study highlighted the range of factors contributing to more effective workplaces for farmers, indicating scope for improvement on many farms, and challenges across all farms when compared with other industries in the case of some indicators (e.g., time-off). The results can support the continued extension of concepts regarding work organization to assist farms in alleviating social sustainability challenges; highlighting the differentiating factors between the most and least effective farmer workplaces.

Checklist-based approach to measure milker behavior before and after training

So far, evaluation of training initiatives for dairy farm employees has been limited to the reaction and learning level. The effect of training on dairy farm employees' behavior has not been studied yet. The objective of this study was to determine the effectiveness of online training to change employee behavior toward best-practice routines. An interactive training course related to udder health was developed in 5 modules in Spanish and English: (1) collecting an aseptic milk sample, (2) administering intramammary treatment, (3) deciding on salable milk, (4) treating a cow at dry-off with antibiotics, and (5) administering teat sealants. Participants navigated the modules at their own pace or watched a narrated video. Employees were assessed performing 2 procedures related to dry cow treatment (i.e., treating a cow at dry-off with antibiotics, administering internal teat sealant) by using an objective structured clinical examination. If possible, all employees were scored performing the procedure on 2 cows before and within 2 to 3 wk after the training was applied.

Academics meet practitioners: Interactive exchange instead of consuming knowledge on dairy calving management

Consensus on optimal calving management is difficult to achieve among veterinarians. Some of this discordance may stem from asymmetry between the literature written by subject matter experts (SME) and the knowledge, attitude and practice (KAP) of non-SMEs and veterinary practitioners. Hence, the objective of this study was to assess how veterinary practitioners KAPs in calving management compared with the findings in the literature. An online questionnaire survey was conducted prior to a World Buiatrics Congress by delegates (n = 80) who attended a workshop on calving management at which the outcomes of the latter were recorded. The responses from the questionnaire and the consensus from the workshop were compared and these were compared with the literature on calving management, specifically, prediction of calving, assistance at calving and farmer training in calving management. In general, there was good agreement between the aggregated individual responses to the questionnaire and the consensuses from the workshop. The suggested methods of predicting calving were well aligned between practitioners and those researched in the literature but practitioners tended to emphasize more practical aspects of prediction while the literature tends to focus more on the effectiveness of various predictor devices. Practitioners tended to recommend a later time of calving assistance than that recommended in the recent literature though they did also emphasize the importance of calving progress. The majority of practitioners conducted informal (at calving) calving training focusing on time of intervention, welfare-friendly intervention and delivery of a live healthy calf. However, the educational literature recommends a formal training approach as being more effective. These findings indicate that practitioners may benefit from continuing professional education on the scientific merits/demerits of calving prediction devices, current best practice on intervention timing during calving and formal methods of farmer training on calving management.

Graduate Student Literature Review: The problem of calf mortality on dairy farms

Calf mortality can be used as an indicator of animal health and welfare on dairy farms. However, several challenges surround the estimation and reporting of this metric, specifically: (1) lack of records or reliable data, (2) methods of data collection, and (3) inconsistencies in calculation and definitions used. Therefore, despite its importance, the lack of consensus on a definition of calf mortality makes it difficult to compare mortality rates between dairy farms or studies. Monitoring factors associated with calf mortality is vital to create preventative strategies. Although common strategies have been set about how to raise dairy calves and manage dairy calves, discrepancies among studies evaluating factors associated with calf mortality still exist. This review summarizes research on the evaluation of calf mortality and associated risk factors, specifically, the lack of reliable data and standardization of the definition of calf mortality. In addition, current strategies to monitor and prevent calf mortality will be presented in this review.

Antimicrobial stewardship on the dairy: Evaluating an on-farm framework for training farmworkers

Dairy farmworkers are commonly responsible for disease diagnosis and routine treatment decisions for cattle. This highlights the importance of farmworkers' knowledge and skills to successfully implement judicious use of antimicrobials in livestock production systems. The main objectives of this project were to develop and evaluate an on-farm educational program for farmworkers in antimicrobial stewardship in adult dairy cattle. A longitudinal quasi-experimental study design was used, by enrolling 12 conventional dairy farms in the United States (6 in California and 6 in Ohio). Farmworkers responsible for treatment decisions on the farm (n = 25) participated in a didactic and hands-on 12-wk antimicrobial stewardship training program led by the investigators. All antimicrobial stewardship training materials were available in Spanish and English. Interactive short videos with audio were developed to cover the learning objectives for each of the 6 teaching modules: antimicrobial resistance, treatment protocols, visual identification of sick animals, clinical mastitis, puerperal metritis, and lameness. Pre- and post-training assessments were administered using an online training assessment tool to evaluate changes in knowledge and attitudes about antimicrobial stewardship practices. Cluster analysis and multiple correspondence analyses were conducted to evaluate the association among categorical variables for participants' level of change in knowledge and its association with language, farm size, and state. A 32% average increase in knowledge was observed through an assessment conducted after completing the antimicrobial stewardship training, compared with the pre-training assessment. A significant improvement in 7 of 13 attitude questions related to antimicrobial stewardship practices on the farm was observed. Knowledge and attitude scores of participants on antimicrobial stewardship and identification of sick animals significantly improved after completing the antimicrobial stewardship training. The results observed in this study support the relevance of antimicrobial stewardship training programs targeting farmworkers to improve antimicrobial drug use knowledge and skills.

Role of Genital Tract Bacteria in Promoting Endometrial Health in Cattle

Microbiota regulate endometrial health in cattle. It is important to know what a ‘good’ microbiome is, in order to understand pathogeneses of uterine disease. Given that microbial influx into the genital tract of cows at calving is unavoidable, exploring the involvement of genital tract bacteria in promoting endometrial health is warranted. The dysbiosis of endometrial microbiota is associated with benign and malign uterine diseases. The present review discusses current knowledge about the altered endometrial microbiome and the implications of this modulation on endometrial inflammation, ovarian activity, fecundation, pregnancy, and postpartum complications. Intravaginal administration of symbiotic microbes in cattle is a realistic alternative to antibiotic and hormone therapy to treat uterine disease. Genital microbial diversity can be modeled by nutrition, as the energy balance would improve the growth of specific microbial populations. It may be that probiotics that alter the endometrial microbiome could provide viable alternatives to existing therapies for uterine disease in cattle.

Dairy farm worker milking equipment training with an E-learning system

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Milking equipment malfunctions, which milkers could detect, are common on dairy farms.

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Our results reaffirm the lack of communication between managers and employees, which restate the necessity to state objectives and goals on every training.

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Practical logistics of on-farm training are a limiting factor, so the use of online training is a reasonable alternative for dairy farms, increasing employees' confidence by providing more detailed training content.

In many farms, the logistics of on-farm training are a limiting factor due to communication challenges in the workplace (i.e., cultural differences, language barriers, impaired listening skills) and limited access to industry professionals. The use of E-learning systems may help to improve communication and can be sensitive to cultural challenges. The objectives of this study were to (1) identify how many of the high-priority problems in the milking parlor relate to milker training in the areas of milking equipment and milking routine, (2) design and test an E-learning training system for dairy farm milkers related to milking equipment, and (3) gain feedback targeted to improve subsequent E-learning training modules. An interactive online training course on basic checks of the milking equipment was developed with a cloud-based authoring software. A total of 95 dairy farm workers on 15 commercial dairy farms in northern New York State (USA) were trained and participated in the study. Milk quality professionals performed an initial evaluation of 3 main areas: equipment analysis, milker assessment, and cow assessment. The 3 most important risk factors for mastitis were summarized for each farm. A training event was scheduled with milkers guided by a bilingual (English and Spanish) professional in milk quality. Over 50% of the farms (8/15) had one or more of the top 3 priorities involving problems with milking equipment, which milkers could have detected and reported to management. All participants completed the module, 95% stated that they felt capable of checking the equipment before milking, and 86% felt more confident in reporting equipment problems to the manager after having taken the course. There were also differences between managers' and milkers' statements on how and whether milking equipment training was offered or not on the farm. This can be explained due to the lack of or secondary to poor communication between managers and employees on training objectives and goals on the farm. Our results also show that milking equipment issues which milkers could detect and report are common on dairy farms and reinforces the need for additional milker training in this area.

Identification of cow-level risk factors and associations of selected blood macro-minerals at parturition with dystocia and stillbirth in Holstein dairy cows

A deeper understanding of the risk factors for dystocia and stillbirth could help farmers make decisions about dairy cow management. The objectives of this study were to investigate cow-level risk factors associated with dystocia and stillbirth in a relatively large sample of dairy cows using multivariable linear regression models. The data consisted of 51,405 calving records of 14,546 Holstein cows from 3 dairy herds in Isfahan Province, Iran, collected between April 2011 and September 2017. To investigate the association between selected blood macro-minerals and the incidence of dystocia and stillbirth, blood samples were collected at the time of parturition from a random subset of these cows, which included 1311 animals. The incidence of dystocia and stillbirths averaged 14.7% and 4.3%, respectively. Results showed that calving year, calving season, dry period length, BCS, parity, calf sex, calf birth weight, twin status, and stillbirth were significantly associated with the incidence of dystocia. According to the Random Forest (RF) classifier, we found that dry period length, calf birth weight, and parity were the most important cow-level risk factors for the incidence of dystocia. Calving year, calving season, parity, twin status, dry period length, calf birth weight, calf sex, and dystocia were significantly associated with the incidence of stillbirths. The most important risk factors identified by the RF classifier for stillbirths were twin status, parity, dry period length, and calf birth weight. Also, interactions between the cow-level risk factors associated with dystocia and stillbirth were identified. The incidence of dystocia was associated with the interactions of twin status × calf birth weight and twin status × stillbirth. According to our analysis, the incidence of stillbirth is caused by interactions among several factors, such as twin status × length of dry period, twin status × calving season, and twin status × parity. The highest incidence of dystocia (21.3%) and stillbirths (5.4%) was observed in hypo-calcemic cows. In conclusion, twin status seems to be a determining factor for the incidence of stillbirths but not for dystocia. Finally, the results of this study may help the dairy industry make management decisions aimed at reducing dystocia and stillbirth rates.

Calving Management: A Questionnaire Survey of Veterinary Subject Matter Experts and Non-Experts

Simple Summary

We designed a questionnaire and asked two groups of veterinarians: (1) subject matter experts, who had published on calving management and (2) veterinary practitioners) for their opinion about aspects of calving management. Participants recommended to differentiate between the two stages of parturition and emphasized signs of imminent parturition, such as “restlessness” and “visibility of fetal parts”. There was no consensus on the right time to move the cow to the maternity pen. Almost half of the respondents recommended a 6-h observation interval for prepartum cows in the maternity pen. The two veterinary groups differed little in their knowledge of calving management.

Abstract

Accurate detection of the onset of parturition is a key factor in the prevention of dystocia. In order to establish current best practice recommendations for calving management, we asked subject matter experts (SME) who had published on calving management (by online survey, n = 80) and non-SMEs, veterinary practitioners (by workshop survey, n = 24) for their opinions. For this, we designed a questionnaire on the significance of signs of imminent parturition (SIP), the frequency of calving observation, and influencing factors for the timing of cow movement to a maternity pen. The response rate was 67.5% in the online survey and 100% in the workshop survey. The majority (89.7%) of all respondents agreed that it is beneficial for successful calving management to differentiate between stage I and II of parturition. Of 12 signs of imminent parturition (for stage I and II), “restlessness” and “visibility of fetal parts in vulva” were cited by 56.5% and 73.3% of SME and non-SME respondents, respectively. There was no consensus on the right time to move the cow to the maternity pen; recommendations varied from one to over 21 days. Almost half of the respondents (45.7%) recommended a 6-h observation interval for prepartum cows in the maternity pen. This study identified a strong consensus on the SIP and how and when to observe cows prior to parturition. SMEs and non-SMEs provided broadly similar recommendations, while the SMEs and the non-SMEs differed significantly in the number of publications on calving they authored, they differed little in their knowledge of calving management.

Treatment practices after calving-related events on 45 dairy farms in California

Retained fetal membranes (RFM), dystocia, and twinning are common postpartum events that increase the risk of metritis, impair reproductive performance, and contribute to antimicrobial use on dairies. The overall objective of this study was to describe treatment decisions after RFM, severe dystocia (cesarean section and fetotomy), nonsevere dystocia (nonmechanical and mechanical assistance to extract the calf), and twinning. A total of 44 dairies from California's San Joaquin Valley (39 Holstein and 6 Jersey or crossbreed herds) with 450 to 9,500 lactating cows were enrolled in this study. Researchers visited each dairy once to observe cow-side fresh cow health evaluations and to interview health evaluators and maternity workers, using a standardized survey tool. The survey included questions about antimicrobial (class, dose, and duration) and nonantimicrobial therapies for calving-related events. Antimicrobial therapy was used in all 44 dairies to treat RFM at 24 (n = 23), 48 (n = 10), or 72 h (n = 5) after calving, or when puerperal metritis signs were observed (n = 6). Antimicrobial therapy was used after all severe dystocia cases, and after nonsevere dystocia (n = 27) and twinning (n = 15). Ceftiofur products were the most common antimicrobial class; they were used to treat RFM cases (n = 29), nonsevere dystocia (n = 13), and twinning (n = 10). Supportive therapy for calving-related events included nonantimicrobial intrauterine treatments, nonsteroidal antiinflammatory drugs, oxytocin, i.v. calcium, or oral drenches. Our study highlights opportunities to reduce extra-label use of antimicrobials in postpartum cows affected with RFM, and the need for education and outreach efforts on judicious use of antimicrobials. Furthermore, antimicrobial treatment choices differed largely across dairies, indicating a need to reach consensus and promote standardized practices within the industry.

Administration of ketoprofen affects post-partum lying behaviours of Holstein dairy cows regardless of whether parturition is assisted

BACKGROUND

Assistance at parturition in cattle is common. Although analgesia is commonly provided, its value in terms of welfare improvement is not known. Few previous studies include both parturition assistance and analgesic treatment status as well as appropriate control groups in a factorial design.

METHODS

Seventy-two Holstein cattle (37 assisted and 35 unassisted) were randomly allocated to receive a single dose of the NSAID ketoprofen or a saline placebo within 3 h of parturition. Detailed behavioural observations allowed a time budget to be constructed for each cow for 48 h post-partum.

RESULTS

Cows experiencing assisted parturition spent more time in lateral recumbency (overall and with the head rested) (p < 0.05) - an infrequently adopted posture suggestive of illness or pain. Cows treated with ketoprofen spent less time in lateral recumbency (p < 0.05) (overall and with the head rested); this was independent of assistance status, and lateral recumbency was not affected by the interaction between assistance and treatment status. Additionally, cows treated with ketoprofen spent more time with the head rested when in sternal recumbency (p = 0.009) - a behaviour associated with comfortable resting.

CONCLUSION

These differences in lying postures exhibited by cows receiving ketoprofen analgesia suggest that, regardless of whether parturition is assisted, a single dose of ketoprofen in the immediate post-partum period has the potential to improve cow comfort in the first 48 h post-partum.

Artificial insemination of cattle: Description and assessment of a training program for veterinary students

The objective was to assess the effectiveness of a comprehensive artificial insemination (AI) training program designed to facilitate an understanding of the breadth of the AI process, including AI skill acquisition, for preclinical veterinary students. Participants (n = 303) were enrolled at the Ross University School of Veterinary Medicine (Basseterre, St. Kitts, West Indies). The 2-d AI training program (n = 20) consisted of ∼8 h of instruction and ∼8 h of demonstration and hands-on activity. Oral presentations were used to deliver educational content, followed by video clips, discussion, demonstrations, and hands-on activity. Reproductive anatomy and physiology of the estrous cycle, AI sire acquisition, collection, evaluation, cryopreservation and distribution of conventional and sexed semen, storage and handling of frozen semen, use of synchronization protocols, accurate and efficient detection of estrus, and correct AI technique were discussed. True or false pre- and posttests were used to determine the level of knowledge gained by participants during the AI training program. Preclinical veterinary students were required to complete a semen handling and AI technique practical exam to achieve a certificate of completion. Participant program evaluations conducted at the conclusion of the program indicated that veterinary students found the content, structure, discussion, demonstrations, and hands-on activities to be appropriate and useful. No negative comments were offered about the training program, instructor, or activity coinstructors. The AI training program increased the posttest knowledge scores of veterinary students by 22 percentage points. Only 1 participant was unable to achieve a certificate of completion due to failure of the semen handling and AI technique practical exam. These results provide evidence that the AI training program was relevant and effective and that it offered information and skill acquisition with immediate field application.

Sensitivity and specificity of a tail-activity measuring device for calving prediction in dairy cattle

Efficient calving surveillance is essential for avoiding stillbirth due to unattended dystocia. Calving sensors can help detect the onset of parturition and thus ensure timely calving assistance if necessary. Tail-raising is an indicator of imminent calving. The objective of this study was to evaluate a tail-mounted inclinometer sensor (Moocall Ltd., Dublin, Ireland) and to monitor skin integrity after sensor attachment. Cows (n = 157) and heifers (n = 23) were enrolled at 275 d post insemination, and a sensor was attached to each cow's tail. Investigators checked for signs indicating the onset of stage II of parturition, verified the position of the sensor, and evaluated the skin integrity of the tail above and below the sensor hourly for 24 h/d. We used 5 different intervals (i.e., 1, 2, 4, 12, and 24 h until calving) to calculate sensitivity and specificity. Sensors continuously remained on the tail (i.e., within 3 cm of the initial attachment position) after initial attachment until the onset of calving in only 13.9% of animals (n = 25). Sensors were reattached until a calving event occurred (51.6%) or the animal was excluded for other reasons (34.4%). In 31 animals the sensor was removed because the tail was swollen or painful. Heifers were significantly less likely than cows to lose a sensor but more likely to experience tail swelling or pain. Depending on the interval preceding the onset of parturition, sensitivity varied from 19 to 75% and specificity from 63 to 96%.

A survey of management practices that influence calf welfare and an estimation of the annual calf mortality risk in pastured dairy herds in Uruguay

Despite the importance of dairy farming in Uruguay, little information on dairy systems in this country is available in the scientific literature, and management practices that influence calf welfare at the herd level have not been explored. The aims of this study were to (1) describe the prepartum and calf-rearing systems, as well as the management practices that may influence calf welfare in pastured dairy herds in Uruguay, (2) estimate the annual calf mortality risk from birth to weaning, and (3) identify the primary clinical disease syndromes shown by the calves before death. A survey comprising a farm visit and a questionnaire was conducted on 225 randomly selected dairies with >30 milking cows, in 3 strata (31-99, 100-299, and ≥300 milking cows) of 6 Uruguayan departments where dairies are concentrated. Retrospective information from July 2013 to June 2014 was collected. A descriptive analysis was performed and results were inferred into the national dairy cattle population. Several management practices that could contribute to poor calf welfare were identified in a large proportion of farms. The annual calf mortality risk (calves that died between birth and weaning/calves born death or alive × 100, n = 149 farms) was 15.2%. Age at weaning averaged 75 d. Farmers reported that the most common clinical syndromes were diarrhea and respiratory disease in 85.2% and 47.5% of the farms, respectively. There was no continuous veterinary advice in 61.3% of the farms, 20.0% lacked data records, 38.5% had poor drainage in the prepartum area with waterlogging after rainfall, 52.1% monitored the prepartum area ≤2 times per day during the calving season, 65.1% did not perform navel antisepsis on newborns, 62.3% separated the calves from their dams at >24 h postpartum, 95.2% did not have a colostrum management program, 72.4% did not rotate the calf-rearing areas, 59.0% did not disinfect the calf feeders, 85.7% did not have staff dedicated exclusively to calf rearing, and 39.8% did not separate sick from healthy calves. The average volume of milk or milk replacer offered per calf was 4.5 L/day. Several of the identified management practices that affect calf welfare in the prepartum and calf-rearing periods could explain the high mortality risk. An effort should be made to conduct extension work focusing on the dissemination of good management practices to improve calf welfare and reduce calf mortality in Uruguayan dairy farms.

Quantifying the Forces Applied During Manually and Mechanically Assisted Calvings in Beef Cattle

Dystocia is a leading cause of calf mortality, yet there is little available information quantifying the duration and forces applied to assisted deliveries. Objectives of this study were to: (1) develop a method to measure the magnitude and duration of various forces applied to a calf during calving assistance, and (2) quantify the forces applied to beef calves during manual or mechanical calving assistance. Twenty-five primiparous dams requiring calving assistance were enrolled. Calvings were assisted by manual (1 or 2 people pulling) or mechanical (calf extractor) delivery. A set of modified obstetric chains with integrated force measuring devices (Calving Assistance Force Logger; CAF-Log) were applied to the calf for delivery. The CAF-Log system was calibrated using known masses ranging from 25 to 200 kg in increasing increments of 25 kg. Duration of the assisted delivery and force parameters (peak force applied to one leg, peak force applied to both legs, cumulative force, and maximum jerk force) were described and assessed for their associations with method of delivery and ranch. Median duration was 112.6 s (IQR: 88.4–149.7) for manual and 312.6 s (IQR: 221.6–462.3) for mechanical deliveries. Mean peak force applied to one leg was 56.9 kg (SD: 22.9) for manual and 126.8 kg (SD: 48.2) for mechanical deliveries. Mean peak force applied to both legs was 95.4 kg (SD: 34.1) for manual and 188.6 kg (SD: 83.9) for mechanical deliveries. Median cumulative force was 178.3 kg min (IQR: 21.1–38.8) for manual and 380.6 kg min (IQR: 252.1–581.3) for mechanical deliveries. The maximum jerk force for manual deliveries was 36.6 kg/s (IQR: 21.1–38.8) and 77.2 kg/s (IQR: 60.9–97.1) for mechanical deliveries. An interaction occurred between ranch and method of delivery for peak force applied to one leg, peak force applied to both legs, and cumulative force. The CAF-Log system demonstrated that significantly greater forces were applied to mechanically delivered calves compared to manually delivered calves and could be used in future studies to investigate forces applied to a calf during calving assistance and their impacts on cow and calf well-being.

Primiparous and multiparous Friesland, Jersey, and crossbred cows' behavior around parturition time at the pasture-based system in South Africa

OBJECTIVE

The objective of the study was to assess the behavioral attributes of primiparous and multiparous Friesland, Jersey, and Crossbred cows around calving time in a pasture-based dairy system.

MATERIAL AND METHODS

A total of 120 pregnant cows were used in the study, comprising of 40 cows per genotype in different parities [A-primiparous (n = 10), B-2 to 4 (n = 10), C-5 and 6 (n = 10), and D-7 and 8 (n = 10)] and kept in a maternity paddock. Five observers monitored cows from the onset of parturition until the calves were fully expelled, recording the frequency and duration of lying, standing, and walking bouts, calf licking, and suckling.

RESULTS

There were differences (p < 0.05) observed in the behavioral patterns around the time of calving. Jersey multiparous cows spent (p < 0.05) significantly most of their time (20.50 ± 3.10) in lying position as compared to the other genotypes. The Jersey cows also spent most (p < 0.05) of their time (48.00 ± 0.34) in a standing position during the calving period. Friesland cows spent (p < 0.05) most of their time (12.00 ± 1.19) exhibiting either stepping or walking attributes as compared to Jersey and Crossbred cows. The Jersey genotype spent significantly (p < 0.05) more time (123.00 ± 10.43) in expelling their calves compared to the other genotypes. There was a significant (p < 0.05) interaction between genotypes and parity on time spent by cows on licking their calves. There was a significant difference (p < 0.05) observed between the genotypes of the primiparous cow.

CONCLUSION

The primiparous cows spent most of their time in standing and the least amount of time in other activities throughout the trial due to the lack of maternal experience. The current study revealed that behavioral activities differ according to genotype and parity.

Evaluation of an investigative model in dairy herds with high calf perinatal mortality rates in Switzerland

The objective of this study was to evaluate an investigative model which encompassed the risk factors, incidence, timing and causes of perinatal mortality (PM) (0-48 h) on high risk dairy farms (PM of >5% in the previous year) in Switzerland. This pilot-study was carried out on 47 predominantly Holstein PM calves from 21 dairy farms, between September 2016 and January 2018. Gross pathological examinations of calves and placentae as well as histopathological examinations of internal organs and placental tissue were performed. Further investigations included microbiological examinations: broad-spectrum bacterial and fungal culture, detection of Chlamydia abortus, Coxiella burnetii, pathogenic Leptospira spp. and Neospora caninum by real-time PCR (qPCR) and of bovine viral diarrhoea virus (BVDV) by Ag-ELISA. Maternal blood samples were used for serology of bovine herpesvirus 1 (BHV-1), Brucella abortus, Chlamydia abortus, Coxiella burnetii and nine pathogenic leptospiral serovars and the evaluation of trace element status. A questionnaire was completed with the farmer, which included general farm characteristics and case-related data. Inbreeding coefficients (IC) were calculated for pure-bred matings. At the farm-level, the PM rate was 10.0% (5.3-28.2%) and at the cow-level, 11.5%. These values, from high-risk farms, were approximately five-times higher than the contemporary national bovine PM rate (2.3%) in Switzerland. The risk factors associated with these high PM rates were the self-selection of high risk herds, the high proportion of primiparae in these herds (45%) and the evidence of widespread pathogenic infections on these farms (exposure: 67% of herds, 53% of dams; infection: 57% of herds, 45% of calves). The majority (68.1%) of calves died intrapartum. The most commonly diagnosed initiating/ultimate cause of death (UCOD) was infection (34%) of which Coxiella burnetii was the most frequently detected pathogen, by antigen. The most frequently diagnosed proximate cause of death (PCOD) was asphyxia (44.7%), though multiple PCOD was also common (21.3%). This study was the first detailed investigation of bovine PM in Switzerland. Infectious causes were diagnosed more frequently than expected. While the findings from these high PM Swiss herds may have limited external validity, the investigative model adopted and the detailed research methodologies employed can be replicated and re-evaluated, respectively, in future studies on PM internationally.

The Bos taurus maternal microbiome: Role in determining the progeny early-life upper respiratory tract microbiome and health

Natural transference of maternal microbes to the neonate, especially at birth via the vaginal canal, has recently been recognized in humans and cows; however, its microbial influence on calf health has not yet been documented. We compared the bacterial communities in vaginal and fecal samples from 81 pregnant dairy cows versus those in nasopharyngeal and fecal samples collected at 3, 14 and 35 days of life from their respective progeny. The microbiota of the calf upper respiratory tract (URT), regardless of calf age, was found to be highly similar to the maternal vaginal microbiota. Calf fecal microbiota clustered closely to the maternal fecal microbiota, progressing toward an adult-like state over the first 35 days when relative abundances of taxa were considered. Sixty-four, 65 and 87% of the detected OTUs were shared between cow and calf fecal microbiota at days 3, 14 and 35 respectively, whereas 73, 76 and 87% were shared between maternal vaginal microbiome and calf URT microbiota at days 3, 14 and 35, respectively. Bacteroidetes, Ruminococcus, Clostridium, and Blautia were the top four genera identified in maternal and calf fecal samples. Mannheimia, Moraxella, Bacteroides, Streptococcus and Pseudomonas were the top five genera identified in maternal vaginal and calf URT samples. Mannheimia was relatively more abundant in the vaginal microbiota of cows whose progeny were diagnosed with respiratory and middle ear disease. Our results indicate that maternal vaginal microbiota potentially influences the initial bacterial colonization of the calf URT, and that might have an important impact on the health of the calf respiratory tract and middle ear.

Dynamics of the microbiota found in the vaginas of dairy cows during the transition period: Associations with uterine diseases and reproductive outcome

We investigated the microbiota found in the vaginas of Holstein dairy cows during the transition period and described the differences in bacterial composition and total bacterial load (TBL) associated with disease and fertility. Vaginal swabs were collected at -7, 0, 3, and 7 d relative to parturition from 111 dairy cows housed on a commercial dairy farm near Ithaca, New York. Microbiota were characterized by next-generation DNA sequencing of the bacterial 16S rRNA gene, and TBL was determined by real-time quantitative PCR. We applied repeated-measures ANOVA to evaluate the associations of uterine disease and related risk factors with the microbiota and TBL. We estimated phylum-specific bacterial load by multiplying the TBL by the relative abundance of each phylum observed in the metagenomics results. We confirmed the validity of this approach for estimating bacterial load by enumerating the number of bacteria in an artificial sample mixed in vitro and in clinical and healthy vaginal samples. Phyla associated with uterine disease and related risk factors were Proteobacteria, Fusobacteria, and Bacteroidetes. Cows with retained placenta and healthy cows had similar TBL at the day of parturition, but at d 7 postpartum, cows with retained placenta showed a significantly higher TBL, mainly driven by higher estimated loads of Fusobacteria and Bacteroidetes. Cows diagnosed with metritis had a significantly higher estimated load of Proteobacteria at d -7 and at calving and higher estimated loads of Fusobacteria in the postpartum samples. Additionally, the estimated load of Bacteroidetes at d 7 postpartum was higher for cows diagnosed with endometritis at 35 days in milk. Higher estimated loads of Fusobacteria and Bacteroidetes were also evident in cows with postpartum fever, in primiparous cows, in cows with assisted parturition, and in cows that gave birth to twins. Our findings demonstrated that microbiota composition and TBL were associated with known periparturient risk factors of uterine diseases and reproductive failure, including parity, assisted parturition, and retained fetal membranes.

Effect of serum calcium status at calving on survival, health, and performance of postpartum Holstein cows and calves under certified organic management

The study objective was to assess the effect of hypocalcemia (HYPO; ≤2.0 mmol/L) of the dam at calving on survival, health, and performance of lactating dairy cows and their calves under certified organic management. Prepartum dairy cows (primiparous, n = 445; multiparous, n = 328) from 1 dairy herd were monitored (prepartum pen) for imminent signs of parturition (appearance of amniotic sac outside the vulva) until birth. All calves were subject to the same newborn care, colostrum management, and failure of passive transfer assessment (serum total protein ≤5.5 mg/dL). Serum total calcium of cows was determined in samples taken within 2 h after calving. To define HYPO cows after calving, a cut-point of total serum Ca concentration with optimal sensitivity and specificity to predict metritis or calf diarrhea was established by using the receiver operator characteristic. The effect of HYPO on survival (died or culled within 60 DIM), health status, and pregnancy per artificial insemination (PAI) for first services of lactating cows were analyzed using the GLIMMIX procedure of SAS. Additionally, the effect of HYPO at calving on days in milk (DIM) at first service (DIMFS), milk yield (kg), milk components (percent fat and protein), and somatic cell count were analyzed for the first 3 Dairy Herd Improvement Association (DHIA) tests using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The effect of parity (primiparous and multiparous), body condition score at calving, and manure hygiene score at calving were also included in the statistical models. The effect of HYPO at calving on calf survival, serum total protein, and diarrhea within 10 d of age were assessed using GLIMMIX procedure of SAS. The overall prevalence of HYPO was 14.6% (2.7% for primiparous and 30.8% for multiparous cows). Cows experiencing HYPO at calving had greater proportion of metritis (25.1 vs. 14.7%) and culling within 60 DIM (15.9 vs. 6.8%) compared with non-HYPO cows, respectively. For the first 3 DHIA tests, milk yield and components did not differ between HYPO and non-HYPO cows. The DIMFS as well as proportion of cows with dystocia, births of twins, mastitis, and PAI at first service were not different between HYPO and non-HYPO cows. The proportion of stillbirth, weaned calves, and serum total protein did not differ between calves born from HYPO or non-HYPO cows. However, calves born from HYPO cows had greater incidence of diarrhea (49%) than calves born (33.3%) from non-HYPO cows. Findings from the present study showed that HYPO at calving had significant health implications for both dams and calves under certified organic management.

Invited review: Changes in the dairy industry affecting dairy cattle health and welfare

The dairy industry in the developed world has undergone profound changes over recent decades. In this paper, we present an overview of some of the most important recent changes in the dairy industry that affect health and welfare of dairy cows, as well as the science associated with these changes. Additionally, knowledge gaps are identified where research is needed to guide the dairy industry through changes that are occurring now or that we expect will occur in the future. The number of farms has decreased considerably, whereas herd size has increased. As a result, an increasing number of dairy farms depend on hired (nonfamily) labor. Regular professional communication and establishment of farm-specific protocols are essential to minimize human errors and ensure consistency of practices. Average milk production per cow has increased, partly because of improvements in nutrition and management but also because of genetic selection for milk production. Adoption of new technologies (e.g., automated calf feeders, cow activity monitors, and automated milking systems) is accelerating. However, utilization of the data and action lists that these systems generate for health and welfare of livestock is still largely unrealized, and more training of dairy farmers, their employees, and their advisors is necessary. Concurrently, to remain competitive and to preserve their social license to operate, farmers are increasingly required to adopt increased standards for food safety and biosecurity, become less reliant on the use of antimicrobials and hormones, and provide assurances regarding animal welfare. Partly because of increasing herd size but also in response to animal welfare regulations in some countries, the proportion of dairy herds housed in tiestalls has decreased considerably. Although in some countries access to pasture is regulated, in countries that traditionally practiced seasonal grazing, fewer farmers let their dairy cows graze in the summer. The proportion of organic dairy farms has increased globally and, given the pressure to decrease the use of antimicrobials and hormones, conventional farms may be able to learn from well-managed organic farms. The possibilities of using milk for disease diagnostics and monitoring are considerable, and dairy herd improvement associations will continue to expand the number of tests offered to diagnose diseases and pregnancy. Genetic and genomic selection for increased resistance to disease offers substantial potential but requires collection of additional phenotypic data. There is every expectation that changes in the dairy industry will be further accentuated and additional novel technologies and different management practices will be adopted in the future.

Short communication: Decrease in rumination time as an indicator of the onset of calving

The aim of this study was to investigate whether rumination time (RT) is affected by the onset of calving. The relationship between both feeding time and dry matter intake (DMI) to the onset of calving was also examined. In addition, the correlation between feeding behavior characteristics, described here as RT, feeding time, and DMI, was evaluated. Under test conditions, the feeding behavior of pregnant Holstein cows was recorded from the time when they were moved into calving pens (usually 7 to 5d prepartum) until the onset of calving. Feeding time and DMI were recorded by automatic feed bins; RT was measured continuously by a measuring halter based on electromyography (DairyCheck; BITSz Engineering GmbH, Zwickau, Germany), which constitutes a new approach regarding feeding behavior detection. Data analysis related to the final 72 h, before the onset of calving, which were divided into twelve 6-h blocks. The last 6h (one 6-h block) before calving were compared with the 72- to 7-h time frame (11 times 6-h blocks) before calving, which was defined as the reference period. For this time period, feeding behavior data for 17 cows was fully available, which was the precondition for data analysis. In the final 6h before imminent birth, RT was significantly reduced. During this time, it was found that the mean minimum RT was 69.9 ± 28.5 min/6h compared with the mean RT of 95.5 ± 30.8 min/6h in the reference period. The average decrease in RT was 27% (25.6 min/6h). In addition, feeding time and DMI were significantly reduced. The average decrease in feeding time was 57% (20.8 min/6h), and in DMI it was 56% (1.9 kg/6h). High correlation coefficients between feeding behavior characteristics were only found between feeding time and DMI. Values of feeding behavior among cows were characterized by high variability. Recording RT can serve as a useful tool for predicting the timing of birth for dairy cows, but further research is necessary.