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This study investigated the effect of ambient temperature and humidity on milk urea nitrogen (MUN) concentration in Holstein cows. Meteorological data corresponding to the dates of milk sampling were collected over six years. A linear mixed-effects model including a random effect term for cow identification was used to assess whether temperature and humidity were predictive of MUN concentration. Age, days in milk, temperature humidity index (THI), ration, milk yield, parity and somatic cell count were also evaluated as main effects in the model. A general linear model including all variables as random effects was then fitted to assess the contribution of each variable towards the variability in MUN concentration. Maximum daily temperature and humidity on the sampling day were positively associated with MUN concentration, but their interaction term was negatively associated, indicating that their effects were not independent and additive. Variables that contributed the most to the variability of MUN concentration were dietary crude protein (21%), temperature (18%) and other factors (24%) that were not assessed in the model (error term). Temperature has a significant influence on urea nitrogen concentration and should therefore always be considered when urea nitrogen concentration data are used to make inferences about the dietary management of dairy cows.

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Cryopreservation and storage of semen for artificial insemination (AI) result in excessive accumulation of reactive oxygen species (ROS). This leads to a shortened life span and reduced motility of spermatozoa post-thawing, with consequent impairment of their function. However, certain levels of ROS are essential to facilitate the capacitation of spermatozoa required for successful fertilisation. Tannins, as well-known antioxidant compounds, may act as ROS binders/acceptors/scavengers to inhibit the damaging effects of ROS. This review comprises an analysis of the semen cryopreservation protocol and health functions of tannins, as well as the effects of ROS on fresh and cryopreserved semen's longevity and fertilisation. Additionally, we surveyed available evidence of the effects of tannin extract feed supplementation on male fertility. We furthermore interrogated existing theories on tannin use as a potential additive to semen extenders, its relationship with semen quality, and to what degree existing theories have been investigated to develop testable new hypotheses. Emphasis was placed on the effects of tannins on ROS, their involvement in regulating sperm structure and function during cryopreservation, and on post-thaw sperm motility, capacitation, and fertilising ability. The diverse effects of tannins on the reproductive system as a result of their potential metal ion chelation, protein precipitation, and biological antioxidant abilities have been identified. The current data are the first to support the further investigation of the incorporation of tannin-rich plant extracts into semen extenders to enhance the post-thaw survival, motility, and fertilising ability of cryopreserved spermatozoa.

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The unusual and tiring physical activity of bovine transrectal palpation (TRP) requires a novel approach to improve students' TRP and pregnancy diagnosis (PD) skills. It has been shown that students who participated in an exercise program and students who had a grip strength (GS) of more than 30 kilograms performed better in bovine PDs. Participation in the exercise program increased students' sensitivity (ability to identify pregnant cows) but did not increase total arm muscle strength. To identify which muscles are used during TRPs and to improve the exercise program, an electromyographic (EMG) analysis was used to identify muscle activation patterns and muscle activity levels during bovine TRPs. Eight subject matter experts (SMEs) each palpated two live cows and one Breed'n Betsy® rectal examination simulator while an EMG Triggered Stimulator recorded muscle activity. Muscle activation was higher for forearm muscles compared with all other examined muscle groups (p < .001); was higher during retraction of the uterus and palpation of left and right uterine horn, compared with palpation of cervix, uterine body, left ovary, and right ovary (p < .001); and showed an endurance pattern. Findings have been used to modify the previously developed exercise program in effort to improve students' TRP and PD skills. The Bovine PD Improvement Exercise Program is available to students through an online application (http://icarus.up.ac.za/vetmlp/) and aims to not only improve GS and TRP accuracy but also stamina and well-being while adding fun to busy study schedules.

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Bovine pregnancy diagnosis (PD) by transrectal palpation (TRP) is an important skill for veterinary graduates. Factors influencing students' PD accuracy were investigated to optimize bovine PD by TRP training without increasing live animal exposure. The objective was to determine whether arm length and strength, proprioception, and exposure to a 6-week exercise training program were significantly associated with students' PD accuracy. Veterinary students (n = 128) who had previously received formal theoretical and practical training in bovine TRP and PD (live cows and TRP simulators) were assessed for PD accuracy on live cows. Prior to assessment, arm muscle strength measurement, an exercise program, and additional TRP sessions on Breed'n Betsy® simulators and live cows were offered to the students. Seventy-eight students volunteered to participate in the arm length measurement, muscle strength, and proprioception testing. Of these, 35 randomly allocated students completed a 6-week exercise program, after which muscle strength was reassessed. Each student performed PDs on six cows of which the pregnancy status, ranging from 6 weeks to 9 months pregnant or not pregnant, was predetermined by an experienced veterinarian. PD accuracy was measured as sensitivity and specificity, being defined as the proportion of pregnant or nonpregnant cows, respectively, correctly identified by the student. It is concluded that hand grip strength and participation in an exercise program are significant predictors of veterinary students' PD accuracy. Implementation of an exercise program aimed at improving grip strength in the veterinary curriculum is a novel approach to improve bovine TRP and PD training.

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Mental health and wellness research continue to be a topic of importance among veterinary students in the United States of America (US). Limited peer reviewed literature focusing on South African veterinary students is available. South African veterinary medical students might benefit from approaches to improve mental health and wellness similar to those recommended in the US. However, these recommendations may not address the underlying risk factors for mental health and wellness concerns or mismatch resources available to South African veterinary medical students. The purpose of this collaborative study was to compare the mental health and wellness among veterinary students enrolled at the University of California, Davis (UCD), and the University of Pretoria (UP), the only veterinary school in South Africa. Our primary research question was; Are the measures of mental health and wellness for students at similar stages in the veterinary curriculum different between the two schools? We hypothesized that mental health and wellness as determined by assessment of anxiety, burnout, depression, and quality of life between the two schools is different. A cross-sectional study of 102 students from UCD and 74 students from UP, at similar preclinical stages (Year 2 for UCD and Year 4 for UP) of the veterinary curriculum was performed. Anxiety, burnout, depression, and quality of life were assessed using the Generalized Anxiety Disorder (GAD-7), Maslach Burnout Inventory (MBI), Patient Health Questionnaire (PHQ-9), and Short Form-8 (SF-8), respectively. Students from both schools had moderate levels of anxiety, high levels of burnout, mild to moderate levels of depression, poor mental health, and good physical health. Our results suggest that similar mental health and wellness concerns in South African veterinary students is comparable with concerns in veterinary medical students in the US. Recommendations and resources to improve mental health and wellness in US veterinary medical students might be applicable to South African veterinary medical students.

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BACKGROUND: There are challenges around the practicality of conventional standard setting methods for student assessment. Furthermore, accuracy of absolute methods of standard setting is difficult to achieve.The aim was to determine which group of judges is most accurate at establishing the minimum level required to pass questions in order to ensure an appropriate standard (cut-scores), and how the Bloom's level of each question affected the correlation of cut-scores to student performance. METHODS: The modifications to the classical Angoff method where a group of judges convene and discuss cut-scores was that, in this study, the judges set cut-scores independently and did not receive the answers to the questions that they were assessing. Computer-based multiple choice and multiple response type questions were compiled, and allocated Bloom's levels. Judges answered the questions, determined cut-scores and completed a questionnaire. Simple linear regression was used to determine whether number of years' experience, proportion of time spent in small ruminant practice or specialisation in the field resulted in the most accurate comparison to student performance. RESULTS: Individuals spending the greatest proportion of time in small ruminant practice demonstrated greater accuracy in determining cut-scores. The Bloom's level assigned to each question was reflected on student performance. CONCLUSION: This study supports that the time spent in a particular discipline must be taken into consideration when selecting judges for establishing cut-scores, and that the cognitive level of each exam question be considered to improve accuracy.

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BACKGROUND: To improve bovine transrectal palpation (TRP) and pregnancy diagnosis (PD) training, the effect of a high-intensity one-week training programme for veterinary elective students (N=59) with an interest in production animal practice was evaluated. METHODS: Training consisted of exposure to rectal examination simulators, abattoir organs, theory materials and live cow PDs supervised by experienced large animal practitioners. Palpation skills were assessed before and after training using a validated TRP Objective Structured Clinical Examination (OSCE) in non-pregnant cows. Each student then performed PDs (n=12) on cows of known pregnancy status. Students' PD accuracy was measured as sensitivity and specificity, being respectively defined as the proportion of pregnant and non-pregnant cows correctly identified. RESULTS: Students' scores improved from the first to the second OSCE (P=0.03), mostly as a result of improved ability to identify uterine symmetry/asymmetry and the presence/absence of a corpus luteum on the right ovary (P<0.01 and P=0.03, respectively). Overall student sensitivity and specificity of PD were 89.1 per cent (95 per cent CI 78.1-92.2 per cent) and 67.7 per cent (95 per cent CI 60.1-74.5 per cent), respectively. CONCLUSION: This prospective cohort study describes a strategy to improve students' TRP skills with the potential to reduce training time and animal use at teaching institutions by outsourcing student training to private practitioners.

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Pelvis size plays an important role to prevent dystocia in cattle caused by the foeto-maternal disproportion in commonly primiparous females. The reproducibility and repeatability are two important aspects for the reliability of the measurements to use in the selection of cattle for culling. Pelvic measures were taken with a Rice pelvimeter from 224 young cattle (180 females and 44 males) of four beef breeds in South Africa. One experienced and two inexperienced observers each measured pelvic height and width twice. The proportion measurements with a maximum difference of 0.5 cm within animal compared with the first measurement by the experienced observer are around 80% and by the inexperienced observers around 50% for pelvic height and around 60% for pelvic width. Breed and sex do not affect the reliability of pelvimetry by an experienced observer. Under- and overestimation of pelvis size were observed in inexperienced observers, which seems to be unrelated to breed and sex.

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Although theoretical training of veterinary students is uncomplicated even for larger groups, practical training remains a challenge. Much has been said about the value of practical training in curriculum design. Yet, the impact of practical training on theoretical knowledge needs further research. A cohort of 89 students with very limited clinical practical experience completed an assessment at the end of their theoretical training in small ruminants. The scores obtained by the students were compared with those obtained by a group of 35 veterinarians who volunteered to participate in the study. In addition to comparing the scores between students and practitioners, the cognitive level of each of the questions was considered. Overall, veterinarians achieved higher test scores than did the students. The veterinarians outperformed the students in all cognitive levels except for 'applying' type questions where there was no difference. Different levels of experience, namely young veterinarians (n = 11), established veterinarians (n = 13) and veterinarians approaching retirement (n = 11), were evaluated against the revised Bloom's cognitive levels. When modelling congress attendance frequency, years' experience, proportion of time spent with ruminants and revised Bloom's levels, congress attendance was not a significant variable, and thus, only the other three variables remained. This investigation found that practical experience has a positive effect on theoretical knowledge. The type of practical experience and where such practical experience is included in a curriculum need further research. Working for a number of years in a specific discipline will provide the best support for theoretical knowledge.

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Bovine pregnancy diagnosis (PD) by transrectal palpation (TRP) is one of the most frequently performed procedures in bovine practice, and an important competency for veterinary graduates. It is currently not known if pre-existing TRP skills on non-pregnant cows can be used to predict students' future PD accuracy. The study objective was to evaluate if TRP objective structured clinical examination (OSCE) scores can predict students' future PD accuracy.Fourth year (of a six-year programme) veterinary students (n=128) received TRP and PD training on Breed'n Betsy (BB) simulators and live cows. Students' TRP skills were assessed using a live cow TRP OSCE after completion of the fourth year training. The same students received additional TRP (BB and live cows) and PD (BB) training sessions in the first semester of their fifth year. PD accuracy was assessed after the additional TRP and PD training, five months after the TRP OSCE assessment and measured as sensitivity and specificity (the ability to correctly identify the presence and absence of pregnancy, respectively). Each student palpated six cows transrectally to diagnose pregnancy status and stage for the PD assessment. The TRP OSCE results were analysed as predictors for students' PD accuracy.Students with 'competent palpation skills' on the TRP OSCE had higher PD specificity. The individual OSCE components that were predictive of higher PD accuracy were students' ability to estimate ovarian size, identify uterine position and exclude intrauterine fluid. It was concluded that a TRP OSCE has the ability to predict students' future PD accuracy.

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The objective of this study was to determine if individual beef cows in a herd have an inherent ability to maintain their blood urea nitrogen (BUN) concentration when exposed to different levels of dietary nitrogen supplementation. Ten Hereford and 12 Nguni cows, aged between 2 and 16 years, were utilized in two crossover experiments. In the first experiment, cows were exposed to two diets: a balanced diet with a crude protein (CP) level of 7.9% and a modified diet with a CP level of 14%, formulated by adding 20 kg of feed grade urea per ton of the balanced diet. At the end of the first crossover experiment, cows received the balanced diet for 1 week. The second component utilized the same cows wherein they were fed the balanced diet in addition to another modified diet containing only 4.4% CP. Blood urea nitrogen concentration was measured 22 times (twice weekly) from each cow during both components of the study. A linear mixed-effects model was used to assess whether baseline BUN concentration (measured 1 week before onset of the study) was predictive of subsequent BUN concentration in individual cows. Breed, cow age, body condition score, and body mass were also evaluated for their effects on BUN concentrations. Albumin, beta hydroxybutyric acid (BHBA), glucose, and total serum protein (TSP) were compared between diets within each breed. Baseline BUN concentration was a significant predictor of subsequent BUN concentration in individual cows (P = 0.004) when evaluated over both components of the study. Breed (P = 0.033), the preceding diet (P < 0.001), current diet (P < 0.001), and the week during which sampling was performed (P < 0.001) were also associated with BUN concentration. Results suggest that beef cattle (within a herd) have an inherent ability to maintain their BUN concentration despite fluctuations in levels of available dietary nitrogen.

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Adequate nutrition is required for maintenance of normal reproduction in cattle. Albumin, the best marker and fundamental part of nutrition, most abundant plasma protein and major component of fetal bovine serum, is the best predictor of malnourishment in South African cattle. The aim of this study was to determine if serum albumin concentrations of donor cows predict the developmental competence of oocytes, and if additional protein supplementation of the in vitro culture media improves embryo outcomes in oocytes from cows with inadequate serum albumin concentrations. Oocytes (n = 1024) were recovered from donors with inadequate (≤35.9 g/L), or adequate serum albumin concentrations (≥36.0 g/L). Four hundred and sixty oocytes originated from cows with inadequate serum albumin and 564 from cows with adequate serum albumin. Oocytes of these cohorts were randomly allocated to a control and supplemented fetal bovine serum in vitro embryo culture protocol. Multiple linear, logistic and Poisson regression analyses were performed to estimate the effects of different covariates on linear, binary and count data respectively. Mixed effects Poisson regression was performed for the number of oocytes that developed into blastocysts by the seventh day of culture. Adequate serum albumin concentration of donor cows independently resulted in 46% increased blastocyst formation in the control protocol (P = 0.02). Although fetal bovine serum supplementation of the culture protocol did not affect blastocyst formation in oocytes originating from cows with inadequate serum albumin, it independently reduced blastocyst formation by 30% in oocytes originating from cows with adequate serum albumin (P = 0.02). Other independent predictors of blastocyst outcome included higher serum urea nitrogen, lower beta (ß)-hydroxybutyric acid concentrations and lower fat classification of donor cows. It is concluded that adequate serum albumin of donor cows is a significant predictor of developmental competence of oocytes, and that in vitro supplementation of fetal bovine serum does not improve developmental competence of oocytes and can lead to negative blastocyst outcomes. Further research is required to determine optimal protein supplementation for oocytes originating from inadequately nourished cows.

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To optimize bovine pregnancy diagnosis (PD) training, factors influencing student performance were investigated. The objective was to determine whether training method, gender, background (farm, urban, or mixed), previous experience in bovine PD, and current career interest influenced the accuracy of bovine PD by trans-rectal palpation (TRP). Fourth-year (of a 6-year program) veterinary students (n=138) received one PD training session in groups using either simulator training on Breed'n Betsy (BB) or training on live cows (C). Students completed a questionnaire on gender, background, and career interest. Students' PD accuracy (pregnancy status and stage) was determined after training when each student palpated six cows with known pregnancy status. Students' accuracy in determining pregnancy status was measured as sensitivity and specificity (the ability to correctly identify the presence and absence of pregnancy respectively). Factors that influenced overall accuracy with a higher student sensitivity of bovine PD by TRP were training method, farming background, an interest in a mixed animal career, and stage of gestation. Gender of students and previous experience in bovine PD did not have an influence. Training on BB simulators was associated with lower student sensitivity for pregnancy detection in cows <6 months pregnant. Student sensitivity for pregnancy detection in cows >6 months pregnant was similar for training on BB simulators and live cows. No evaluated factors were significantly associated with specificity of PD. Teaching efforts focusing on specificity of PD and repeated simulator-based training in conjunction with live cow exposure are recommended.

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Four years after the institution of a new curriculum at the University of Pretoria's Faculty of Veterinary Science, a second major curricular renewal was initiated as a result of several pressing drivers, many of which were unique to the national and institutional context. During the project, South African higher education was disrupted by student protests prompted by financial pressures on students, the overt colonial structure of higher education, and the need to accelerate transformation of the sector. A structured curricular renewal process was followed, including the laying down of the principles, the structuring the macro-curriculum as a story, the design of a meso- and micro-curriculum, and the mapping of the curriculum to Day One outcomes. The resulting program is a 6-year bachelor's degree with a blend of discipline and species modules, with the first cohort graduating in 2016. There is a strong focus on skills embodied in a 62-week experiential component, managed using a unique custom-designed online platform for booking placements, documenting exposure, assessing competency, and providing feedback to students. The experiential training includes a large elective component. Several causes of loss of impetus during the process are discussed and proposals are made for avoiding these. The value of accreditation as a driver and a source of inputs is evident. The process has succeeded in producing a significantly reshaped curriculum that has been well received by external stakeholders.

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Previous reports have shown that reproductive tract score (RTS) can predict reproduction outcomes in seasonally bred beef heifers, although the accuracy can vary. Some ultrasonographic measures of the female reproductive tract and pelvis area have also been associated with reproductive outcome in young heifers. The objectives of this study were to determine which transrectal ultrasound or pelvis measures taken at a single examination are independent predictors of reproductive failure and whether the RTS system can be optimized with this information. In this observational study, year-old beef heifers (n = 488) in 2 birth cohorts were followed from just before the first breeding until confirmation of pregnancy. A single pre-breeding examination included body condition score, RTS, ultrasound measures of the reproductive tract (length and diameter of the left and right ovaries, presence and diameter of a CL, largest follicle diameter and left uterus horn diameter) and transverse and vertical diameters of the pelvis. Additional farm records including dam parity, sire, birth weight and birth date, weaning weight, weaning date, prebreeding body weight, AI dates, and semen used were available. Breeding consisted of 50 days of AI, followed 5 to 7 days later by a 42-day bull breeding period. Pregnancy failure was defined as the failure to become pregnant after the AI and bull breeding periods, while anestrus was defined as the failure to be detected in estrus during the 50-day AI period. From the prebreeding data and farm records, independent predictors of pregnancy failure and anestrus were identified using stepwise reduction in multiple logistic regression models. Age at the onset of breeding was the only consistent independent predictor of pregnancy failure and anestrus in both cohorts of this study (P < 0.05). Body condition score, uterus horn diameter, absence of a CL, largest follicle of less than 13 mm, and pelvis area (PA) were the prebreeding examination variables that remained in prognostic models (P < 0.1). Combining either the model based on the 3 remaining ultrasound measures or RTS with PA provided more accurate prognostic models for pregnancy failure and anestrus than using RTS alone (P < 0.05). It is concluded that ultrasound measures have prognostic value for pregnancy failure in restricted bred yearling heifers as a result of their association with anestrus, and that smaller PA has additional prognostic value for poorly performing heifers.

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This study investigated the association between pre-breeding blood urea nitrogen (BUN) concentration and reproductive performance of beef heifers within different management systems in South Africa. Bonsmara heifers (n = 369) from five herds with different estimated levels of nitrogen intake during the month prior to the commencement of the breeding season were sampled in November and December 2010 to determine BUN concentrations. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at study enrolment. Trans-rectal ultrasound and/or palpation was performed 4-8 weeks after a 3-month breeding season to estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until the estimated conception date. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the association of pre-breeding BUN concentration with subsequent pregnancy and DTP, respectively. After stratifying for herd and adjusting for age, heifers with relatively higher pre-breeding BUN concentration took longer to become pregnant when compared to those with relatively lower BUN concentration (P = 0.011). In the herd with the highest estimated nitrogen intake (n = 143), heifers with relatively higher BUN were less likely to become pregnant (P = 0.013) and if they did, it was only later during the breeding season (P = 0.017), after adjusting for body mass. These associations were not present in the herd (n = 106) with the lowest estimated nitrogen intake (P > 0.500). It is concluded that Bonsmara heifers with relatively higher pre-breeding BUN concentration, might be at a disadvantage because of this negative impact on reproductive performance, particularly when the production system includes high levels of nitrogen intake.

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