S. Bas

Assessment of calving progress and reference times for obstetric intervention during dystocia in Holstein dairy cows

The objectives of this observational study were (1) to assess the time from the appearance of the amniotic sac (AS) or feet outside the vulva to birth in Holstein cows (primiparous and multiparous) with (dystocia) or without assistance (eutocia) at calving, and (2) to estimate reference times to be used as guidelines for obstetric intervention in Holstein cows that need assistance during difficult births. Cows (n=92) from 1 commercial dairy operation were used in this study. Periparturient dairy cows (primiparous, n=58; multiparous, n=34) were placed in a maternity pen and constantly monitored until birth. The calving ease of cows, time from AS or feet appearance to birth, calving progress from a subset of 15 cows (frequency and duration of abdominal contractions during labor), calf birth weight, calf sex, and stillbirths (born dead or died within 24h after birth) were recorded. The reference times for obstetric intervention during dystocia were estimated based on values from unassisted births (normal). The normal range of times from the appearance of AS or feet outside the vulva to birth was estimated based on the mean+2 standard deviations (SD) of unassisted births. According to farm protocol, assistance was provided to cows without calving progress 80 min after AS appearance or earlier (e.g., to correct malpositions). Cows with dystocic births had a longer time from AS appearance to birth and increased incidence of stillbirth compared with cows with eutocic calvings. After the appearance of the AS, calving progress was evident every 15 min for eutocic births. The estimated reference times (mean+2 SD) from AS appearance to birth were 69.7 min and from feet appearance to birth were 64.6 min for eutocic births. Findings from this study suggested that calving personnel should start assisting cows 70 min after AS appearance (or 65 min after feet appearance) outside the vulva. The time spent in labor (straining) combined with the time from the appearance of the AS or feet to birth, and the assessment of calving progress (as described for eutocic births) should be used as guidelines for obstetric intervention during difficult births under field conditions. These reference times should be interpreted in combination with adequate obstetrical knowledge and examination.

Effect of intrauterine dextrose or antibiotic therapy on reproductive performance of lactating dairy cows diagnosed with clinical endometritis

The objectives of this study were to assess the responses to treatments (clinical cure and cow survival 14 d posttherapy) of cows with clinical endometritis (CE) that received intrauterine infusion of a hypertonic solution of 50% dextrose (DEX) or subcutaneous ceftiofur crystalline free acid (CCFA) and subsequent pregnancy per artificial insemination (P/AI) in cows with CE compared with cows without CE. Cows (n=760) from 2 dairy herds were screened for CE using vaginoscopy and measurement of cervix diameters [exam 1; 26±3 d in milk (DIM)]. Cows with vaginal discharge scores of 2 or 3 (scale 0-3) were stratified by parity and randomly allocated into 1 of 3 treatment groups: (1) intrauterine infusion (∼200 mL) of 50% DEX solution (n=79); (2) 6.6 mg/kg single-dose of subcutaneous administration of CCFA (n=75); or (3) untreated control animals (CON, n=83). Fourteen days posttherapy (at 40±3 DIM), cows with CE were re-examined (exam 2; 40±3 DIM) to assess the response to treatments. All cows were presynchronized with 2 injections of PGF(2α) given 14 d apart (starting at 26±3 DIM) followed by Ovsynch (OV; GnRH-7 d-PGF-56 h-GnRH 16 h-timed-AI) 12 to 14 d later. Cows displaying signs of standing estrus any time during the protocol were inseminated, whereas the remaining cows were subjected to timed AI 16 h after the second GnRH of OV. Pregnancy diagnosis was performed via transrectal ultrasonography at 39±3d post-AI followed by pregnancy reconfirmation 30 d after the first pregnancy diagnosis. Uterine swabs revealed that Arcanobacterium pyogenes and Escherichia coli were the most predominant bacteria isolated at the time of treatments. Mortality within 14 d posttherapy was not different among treatment groups. Cows with CE had greater cervical diameter at exam 1 and decreased P/AI compared with cows without CE. Treatment with CCFA or DEX increased the proportion of cows with clear vaginal discharge (score 0; clinical cure) 14 d posttherapy compared with CON cows. Pregnancy per AI from DEX (29.8±4%) cows tended to differ from that of CON (21.1±4%) or CCFA cows (19.7±4%), but it resulted in similar P/AI as those cows without CE (39.1±2%). The use of intrauterine DEX alone or as an adjunct of antibiotic therapy for the treatment of CE needs further investigation.

Dairy calving management: Description and assessment of a training program for dairy personnel

The objective of this study was to assess the effectiveness of a comprehensive calving management program designed to enhance the flow of applied, research-based, calving information to dairy personnel. Calving personnel (n=70), serving an estimated 18,100 cows from 18 Ohio dairies, attended the calving management program (∼1h of training and ∼2h of demonstration). Description of the birth canal, behavioral signs of normal parturition (stages I to III), dystocia (presentations, positions, and postures), hygiene practices during the assistance procedure, strategies for intervention (when and how to intervene), record-keeping, communication (when to call for help), and newborn care were discussed. Posttraining follow-ups (2/yr) were available for participating personnel. Educational materials were delivered through lectures followed by group discussions and hands-on demonstrations. Attendees were assessed using pre- and posttests of knowledge to determine the level of knowledge gained during the training program. Participants evaluated the program and provided feedback at the conclusion of the program. Dairy personnel reported that the overall program, presentations, and discussions were useful. The presented materials and demonstrations substantially increased the knowledge level of the attendees by 20.9 percentage points from pre- to posttest scores. Importance of open communication within the farm team, recognizing the landmarks for parturition, signs of calving progress, reference times for intervention, hygiene practices at calving, and strategies to correct abnormal presentation, position, or posture were listed as learned concepts with immediate field application. The follow-up assessment with participant personnel revealed that they were able to implement and apply their learned skills, communicate calving records with the farm team, and follow written calving protocols. Results indicated that the workshop was relevant and effective, offering information with immediate field application.

The use of plastic cover sheaths at the time of artificial insemination improved fertility of lactating dairy cows

An adequate and clean artificial insemination (AI) technique is recommended to improve reproductive outcomes in dairy cattle. The objective of this study was to evaluate the effectiveness of using protective plastic sheaths (PS) to minimize contamination of the AI catheter (AIC) on pregnancies per AI (PAI) in lactating dairy cattle. Lactating cows housed in freestall barns on a commercial dairy farm were presynchronized with 2 injections of PGF(2α) given 14 d apart (starting at 26±3 d postpartum) followed by Ovsynch (GnRH-7 d-PGF(2α)-56 h-GnRH-16 h-timed-AI; TAI) 12 d later. Cows presenting signs of standing heat any time during the protocol received AI, whereas the remaining animals were subjected to TAI 16h after second Ovsynch GnRH. At the time of AI (1 AI technician), 996 services from 773 lactating dairy cows were randomly assigned to 1 of the 2 groups; with (TRT, n=487) or without (CON, n=509) the use of disposable PS. In the TRT group, the AIC protected with a PS was introduced into the vagina; once in the cranial portion of the vagina adjacent to the cervical os, the PS was pulled back and only the AIC was manipulated through the cervix into the uterine body for semen deposition. In the CON group, cows were inseminated without the use of PS. Samples were taken with a sterile cotton swab from the tip of the AIC (n=51) after AI from both treatment groups. Pregnancy diagnosis was determined by ultrasonography 39±3 d after AI. Cultured swab samples revealed that the use of PS was effective in minimizing contamination of the AIC (positive bacterial growth: TRT=61.53% vs. CON=100%). Overall, the proportion of cows pregnant was greater for cows in TRT (42.7) compared with the CON group (36.1). For first services postpartum, PAI did not differ between CON (43.01%, n=194) and TRT (43.8%, n=182) groups. However, PAI for second or greater services were greater in TRT (43.8%, n=305) than in CON cows (32.3%, n=315). Results from this study provided evidence that the use of PS during AI improved PAI for second or greater services in lactating dairy cows. Performing a clean AI technique through the use of PS may be an effective strategy to improve reproductive outcomes in dairy cattle.

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.

Effect of intrauterine administration of gonadotropin releasing hormone on serum LH concentrations in lactating dairy cows

The objectives were to compare: (1) preovulatory serum LH concentrations, and (2) synchronization of ovulation, after im or iu administration of the second GnRH treatment of Ovsynch in lactating dairy cows. Lactating cows (N = 23) were presynchronized with two injections of PGF(2α) given 14 days apart (starting at 34 ± 3 days in milk), followed by Ovsynch (GnRH-7 d-PGF(2α)-56 h-GnRH) 12 days later. At the time of the second GnRH of Ovsynch (Hour 0), cows were blocked by parity and randomly assigned to 1 of 3 groups: (1) control group (CON; N = 7) were given 2 mL sterile water im; (2) intramuscular group (IM; N = 8) received 100 μg of GnRH im; and (3) intrauterine group (IU; N = 8) had 100 μg GnRH infused in the uterus (2 mL). Blood samples for serum LH concentrations were collected at Hours 0, 0.5, 1, 1.5, 2, 3, and 4. Furthermore, ultrasonography was performed twice daily (12-h intervals) from Hours 0 to 60 to confirm ovulation. The LH concentrations were greater (P < 0.05) in the IM than IU and CON groups at Hours 0, 0.5, 1, 1.5, 2, 3, and 4. Although LH concentrations were numerically higher in the IU group, LH concentrations within the IU and CON groups did not change over time. More cows ovulated in the IM (8/8) and IU (7/8) groups within 60 h after the second GnRH administration compared with the CON (2/7) group. In summary, serum LH concentrations were lower in the IU versus IM group, but the proportion of cows that ovulated within 60 h was similar between these two groups. Therefore, iu administration of GnRH may be an alternative route of delivery to synchronize ovulation in beef and dairy cattle.

Assessment of an application for touchscreen devices to record calving-related events in dairy herds and monitor personnel performance

The objectives of the present study were to assess (1) the effectiveness of a calving training workshop and an application (app) for touchscreen devices to capture calving-related events, and (2) personnel compliance with calving protocols (time from birth to feeding of first colostrum and time that cows spent in labor). Calving personnel (n=23) from 5 large dairy farms (range: 800-10,000 cows) participated in the study. Participants received training through an on-farm workshop regarding calving management practices and functioning of the app before recording calving-related events. Pre- and posttest evaluations were administered to each participant to measure their knowledge gain and satisfaction with the workshop. Calving personnel recorded calving-related events (n=323) using the app for 7 d following training. Furthermore, the records collected with the app were used to assess missing and incorrect data and calving personnel compliance with calving management protocols (recording time that cows spent in labor and timing of feeding first colostrum to calves). Calving personnel reported that the information provided during the training was relevant (agree=14.3% and strongly agree=85.7%) and of great immediate use (agree=33.3% and strongly agree=66.7%). The presented materials and hands-on demonstrations substantially increased the knowledge level of the attendees (by 23.7 percentage points from pre- to posttest scores). The follow-up assessment with participants revealed that the app was easy to use (91.3%) and that they would continue to use it (100%). Frequency of incorrect (r=0.77) or missing (r=0.76) data was positively correlated with calving:personnel ratio. Furthermore, calving personnel compliance with calving protocols was significantly different within and between herds. These results substantiated the great variation in compliance with calving management protocols within and between dairy farms. Furthermore, the app may serve as a tool to monitor personnel compliance with first feeding of colostrum to calves and their awareness and recognition of amount of time that each cow spent in labor. This would allow decision-makers to adjust, reassign tasks, or plan the management according to actual calving rate to improve the overall quality of data (frequency of incorrect and missing data) and calf welfare (survival and performance).

Dairy nutrition management: Assessing a comprehensive continuing education program for veterinary practitioners

The purpose of this study was to assess the effectiveness of a team-based educational program designed to enhance the flow of applied, research-based, nutrition information to dairy veterinarians. A comprehensive dairy cattle nutrition curriculum was developed and participants from 11 veterinary practices located in 5 states (IN, NY, PA, NM, and OH), serving an estimated 186,150 dairy cattle in 469 herds, attended the 2 advanced nutrition modules (∼2.5 d each and ∼40 h of learning) held in 2009. Nutrients, feeding transition cows, calves, and heifers, dry matter intake, feed storage, metabolic diseases, evaluating cows (scoring body condition, manure, and lameness), metabolic blood profiles, and feeding behavior were discussed. Educational materials were delivered through in-class lectures, followed by case-based learning and group discussions. A farm visit and out-of-class assignments were also implemented. Attendees were assessed using pre- and post-tests of knowledge to determine the level of knowledge gained in both nutrition modules. Participants evaluated the program and provided feedback at the conclusion of each module. Veterinarians (100%) reported that the overall program, presentations, and discussions were useful. Attendees found the presented information relevant for their work (agree=60% and strongly agree=40%) and of great immediate use to them (neutral=6.5%, agree=56%, and strongly agree=37.5%). The presented materials and the implemented educational delivery methods substantially increased the knowledge level of the attendees (16.9% points increase from pre-test to post-test scores). Importance of feed particle size, ration evaluation, interpreting feed analysis, balancing carbohydrate components, and metabolic profiling in fresh cows were listed as learned concepts that participants could apply in their practices. Results suggested that both nutrition modules were relevant and effective, offering new information with immediate field application. This program has important implications for dairy veterinarians because they serve as a vital source of information for dairy producers.

Assessment of daily activity patterns and biomarkers of pain, inflammation, and stress in lactating dairy cows diagnosed with clinical metritis

The objectives of the present case-control study were to assess (1) daily activity patterns (lying time, number of steps, number of lying bouts, and lying bout duration), and (2) circulating concentrations of biomarkers of pain (substance P), inflammation (haptoglobin), and stress (cortisol) in lactating dairy cows diagnosed with clinical metritis. Lactating dairy cows (n = 200) from 2 commercial dairy herds were enrolled in the present study. Cows diagnosed with clinical metritis (n = 100) at 7 ± 3 d in milk were matched according to lactation and days in milk to cows without clinical metritis (NO-CM; n = 100). On study d 1, clinical metritis was diagnosed (using a Metricheck device, Simcro Tech Ltd., Hamilton, New Zealand) by the presence of watery, reddish, or brownish foul-smelling vaginal discharge, and blood samples were collected for assessment of circulating concentration of substance P, haptoglobin, cortisol, total calcium, β-hydroxybutyrate, and blood cells. In addition, on study d 1 body condition of cows was visually assessed, and activity monitors were placed on the hind leg of a subset of cows (CM, n = 56; CON, n = 56) and were kept until study d 7. Cows showing any other signs of other diseases were not included in the study. Cows with clinical metritis tended to spend more time lying (CM = 628.92 min/d; NO-CM = 591.23 min/d) compared with NO-CM cows. Activity analysis by parity revealed that primiparous cows with clinical metritis spent more time lying compared with primiparous cows without clinical metritis. However, no differences in daily lying time were observed between multiparous cows with and without clinical metritis. Furthermore, cows in the CM group had a higher circulating concentration of substance P (CM = 47.15 pg/mL; NO-CM = 37.73 pg/mL) and haptoglobin (CM = 233.00 µg/mL; NO-CM = 99.98 µg/mL) when compared with NO-CM cows. Cows with clinical metritis had lower body condition score, and a greater proportion of cows in this group had hypocalcemia when compared with cows without clinical metritis. The circulating concentration of leukocytes and erythrocytes were decreased in cows with clinical metritis compared with cows without clinical metritis. Results from this study showed that concentrations of markers of inflammation, stress, pain, and activity were affected in cows diagnosed with clinical metritis; thus, strategies aimed to minimize the negative effects associated with clinical metritis may be required to improve the welfare of dairy cows.