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BACKGROUND While previous research has examined components of professionalism that veterinary employers and clients expect in veterinarians, little attention has been paid to practising clinical veterinarians' opinions on important professional competencies that help to enhance the veterinarian-client relationship. This study used a phenomenological approach and critical incident technique to gather the narratives of practising veterinarians in New Zealand about positive and negative veterinarian-client interactions. The intention was to identify the underlying principles of professionalism that resulted in the positive/negative outcomes of those interactions. METHODS Twenty-two practising veterinarians were interviewed, and each respondent was asked to recollect and narrate a significant positive and a significant negative critical incident in their career that involved a veterinarian-client interaction within a clinical setting. The professional competencies that the veterinarian believed contributed to a successful or an unsuccessful outcome were elucidated using thematic analysis. RESULTS Thematic analysis of the critical incident narratives revealed four major themes under the overarching theme of 'building a relationship between the veterinarian and the client': 'accountability and integrity', 'effective communication skills', 'personal wellbeing' and 'quality of care'. CONCLUSION The description of the important professional competencies that helped to enhance the veterinarian-client relationship provides a reference for the practising profession to help improve the likelihood of veterinarians enjoying satisfied and successful careers.

To provide a descriptive analysis of all notifications and complaints received by the Veterinary Council of New Zealand (VCNZ) during 1992-2016 and to use a thematic analysis of complaints made by clients to the VCNZ during 2013-2015 to determine the underlying reasons for their complaints.A mixed methods approach was used. Notifications and complaints against veterinarians between 1992-2016 (n=1218) were summarised based on complaint categories and by gender of the veterinarian respondents, the number of years registered with the VCNZ and the animal species to which the complaint related. In-depth thematic analysis was made of the content of clients' complaints between 2013-2015 (n=141) to identify details of the key themes and subthemes underlying the complaints.The VCNZ categorised 595/959 (62.0%) of the complaints made between 1992-2016 as related to technical competency, and 308/959 (32%) to professional behaviour. Of the 1,218 complaints, 818 (67.2%) were not investigated or were dismissed, and 18 (1.5%) cases were upheld due to technical competency concerns. Of the complaints in which animal species was identified, 623/738 (84.4%) involved companion animals and 104/738 (14.1%) involved large animals. Male veterinarians were the subject of 855/1,218 (70.2%) complaints. Of the complaints that recorded the number of years the respondent had been registered, 488/1,121 (43.5%) involved veterinarians who had been registered ≥21 years. Thematic analysis identified client expectations as the one overarching theme, within which were four subthemes; a veterinarian would be trustworthy and honest, provide good quality care, communicate in a way that the client finds acceptable, and charge fairly.Notifications and complaints against male practitioners outnumbered those against female practitioners, and companion animal practitioners were over-represented. Many complaints that were ostensibly related to technical failures, were shown by thematic analysis to also represent underlying failures of professional behaviour. Key issues included lack of trustworthiness, honesty, good quality care and acceptable communication with the client. These data should not be interpreted as an accurate indicator of the prevalence of misconduct in practice, as the proportion of dissatisfied clients who did not raise a notification or complaint is unknown. Accurate classification of complaints will enable veterinary regulators and educators to identify competencies that could be developed or improved through training and experience.

To describe the ethnicity of domestic applicants for selection into the professional phase of veterinary education in Aotearoa New Zealand from 2003 to 2019, and to compare this with the ethnic composition of New Zealand society. This study also aims to explore whether there are differences in the demographic features and educational background of Māori applicants compared to non-Māori applicants that may be relevant to widening access to veterinary education.This study was conducted with a Kaupapa Māori research methodology. Data for all applicants to the Bachelor of Veterinary Science programme at Massey University (Palmerston North, NZ) from 2003 to 2019 were retrieved from the university's Student Management System and the School of Veterinary Science selection application databases. Self-identified ethnicity was analysed in four time periods (2003-2006, 2007-2012, 2013-2016, 2017-2019) defined by factors that might influence whether an individual chose to apply for selection into the veterinary programme. Gender, age, previous university experience, decile and type of high school, and being first in family to attend university were compared between Māori and non-Māori.From 2003 to 2019, 3,819 individuals submitted 4,802 applications for selection into the veterinary programme. Across all time periods, applicants who identified as Māori (274/4,802; 5.7%) or Pacific (56/4,802; 1.2%) were underrepresented compared to the New Zealand population (Māori 16.5%; Pacific 8.1%), while applicants who identified as European (4,035/4,802; 84%) were over-represented (70.2% of the New Zealand population). The proportion of Māori (p = 0.82) and Pacific (p = 0.31) applicants did not change over time, while the proportion of European applicants decreased from 853/968 (88.1%) to 823/977 (84.2%; p 0.001). Compared to non-Māori, Māori applicants were more likely to have attended a lower decile school (p 0.001), have attended a state rather than private or overseas school (p = 0.003) and to have been the first in their family to attend university (p = 0.001).Māori are underrepresented in the veterinary applicant pool and veterinary profession in comparison to the New Zealand population. Additionally, Māori applicants differed from non-Māori applicants in pre-university factors that are barriers to university attendance. Implementing activities and processes aimed at widening veterinary programme access with the eventual goal of improving the ethnic representation of the veterinary workforce needs to be a priority for the university and profession.

Objective The aim of this research was to study the roles of the day 0 energy balance and gonadotrophin-releasing hormone (GnRH) and progesterone levels on dominant follicle (DF) and corpus luteum (CL) development during the first 7 days of a gonadotrophin–prostaglandin–gonadotrophin (GPG) + progesterone (P4) program in anoestrous dairy cows. Methods Cows (n = 81) were allocated to one of the three treatments: (1) GPG + P4 (days 0 and 9, 100 µg GnRH; day 0–7, intravaginal P4 device; day 7, 500 µg PGF2α); (2) GPG (as for treatment 1 but excluding the P4 device) and (3) prostaglandin + GnRH + P4 (as for treatment 1, but excluding day 0 GnRH). DF and CL size, plasma concentrations of insulin, insulin-like growth factor-I (IGF-I) and non-esterified fatty acid (NEFA) were measured on days 0 and 7. Results The proportion of cows with a CL on day 7 was significantly different between groups (GPG: 78%, GPG+P4: 69%, PGF2α + GnRH + P4: 42%, P = 0.02). The CL volume on day 7 was significantly associated with treatment, treatment by time postpartum and plasma concentrations of insulin, IGF-I and NEFA. Conclusion In cows without a CL present on day 0 of an oestrus synchronisation program, removal of the day 0 GnRH treatment led to reduced CL development; however, no effect of adding progesterone was found. In contrast, in cows with a CL present on day 0 inclusion of a progesterone device led to a higher CL volume, but removal of the first GnRH injection had no effect. Response to the treatment was affected by plasma concentrations of insulin, IGF-I and NEFA.

The aim of this study was to evaluate how the addition of a progesterone device to a gonadotropin-prostaglandin-gonadotropin (GPG) programme in dairy cows with postpartum anovulatory anoestrus affected ovarian follicular dynamics and the synchronisation of ovulation. Twenty-two dairy cows were randomly assigned to either GPG (Day 0: 100 μg GnRH, Day 7: 500 μg PGF2α, Day 9: 100 μg GnRH, Day 0-7: Day 10) or GPG with a progesterone device from Day 0 to 7 (GPG+P4). Ovarian follicular dynamics and ovulation synchronisation were studied using transrectal ultrasonography. Compared to the GPG+P4, GPG alone resulted in a relatively larger mean dominant follicle size and a higher mean peripheral oestradiol concentration (74.9 pg ∗ day vs. 60.6 pg ∗ day; P=0.002); however, there was much greater variation in follicle diameter in the group treated with GPG (7.8-22 mm vs. 10.8-17.5mm in GPG+P4) and this may, at least partly explain why only 7/11 cows in this group ovulated within 48 h of the Day 9 GnRH injection compared to 10/10 of the cows in the GPG+P4 group. These results suggest that differences in follicular dynamics between GPG and GPG+P4 programmes are not a key driver of the difference in conception rate, but further studies are required to better assess the role of ovulation synchronisation.

To compare the antimicrobial susceptibility patterns of three common mastitis pathogens (Staphylococcus aureus, Streptococcus uberis and Str. dysgalactiae) isolated from milk samples from New Zealand and the USA.A total of 182 S. aureus, 126 Str. uberis and 89 Str. dysgalactiae isolates from New Zealand (107, 106 and 41, respectively) and the USA (75, 20 and 48, respectively) were assessed using the disk diffusion test.Susceptibility varied among the bacterial species. All isolates were susceptible to the amoxicillin-clavulanic acid combination. Resistance to lincomycin was most frequent (susceptibility of 8.6%) across all species. Non-susceptible (i.e. resistant or intermediate) isolates of S. aureus were identified for the three non-isoxazolyl penicillins (amoxicillin, ampicillin and penicillin: 20.6% and 36.0%) and lincomycin (99.9% and 94.6%) for NZ and the USA, respectively. Resistance to erythromycin (5.3%) and tetracyclines (6.7%) was detected only in isolates from the USA. There were differences in susceptibility between Str. uberis and Str. dysgalactiae; all streptococcal isolates demonstrated resistance to aminoglycosides (neomycin 52.4% and streptomycin 27.9%) and enrofloxacin (28%). Resistance of Str. dysgalactiae to tetracycline was almost 100.0% and to oxytetracycline 89.9%.Most of the isolates tested were susceptible to most of the antimicrobials commonly used for treatment of bovine mastitis, with the exception of the lincosamides. Susceptibility to a selected class-representative antimicrobial and at the genus level should be interpreted with caution. Differences between NZ and the USA confirm the value of national surveys to determine the susceptibility patterns of mastitis pathogens.

To evaluate the conception rate to fixed-time artificial insemination (FTAI) of two oestrus synchronisation programmes in dairy heifers on eight farms over 2 years.The study was conducted in 2008 and 2010 on eight farms near Palmerston North, New Zealand. Nulliparous Friesian and Friesian×Jersey heifers (13-15 months of age) were randomly allocated to one of two oestrus synchronisation programmes. Group 1 (GPG+P4; n=330), received gonadotrophin-releasing hormone (GnRH) I/M on Day 0, a progesterone (P4)-releasing intravaginal device from Days 0-7, prostaglandin F2α (PGF) I/M on Day 7 and a second dose of GnRH at the time of FTAI on Day 9. The second group (P4+PGF; n=343) received a P4-releasing intravaginal device from Days 0-7, PGF on Day 6 and FTAI on Day 9. Pregnancy was diagnosed from Days 42-52 by transrectal ultrasonography.The overall conception rate was 52.4% and 54.8% for the GPG+P4 and P4+PGF groups, respectively. The odds of conception for the two treatments were not different (OR=0.90; 95% CI=0.67-1.23), nor was there any difference between groups in different years (p=0.58). Farm affected conception rate (p=0.002), but there was no interaction with treatment (p=0.92) .This study has shown that an alternative synchronisation programme can produce similar results in terms of conception rate to the GPG+P4 treatment, currently commonly used in heifers. More research is required to establish whether other modifications to the GPG+P4 programme can produce similar results at lower costs, and to identify and quantify farm factors which affect the economic benefit of heifer synchronisation.This study indicated that synchronising heifers with P4 and PGF resulted in conception rates equivalent to those resulting from a GPG+P4 treatment, but with reduced drug costs. However, because heifers in the GPG+P4 group received the second GnRH injection at the time of AI, they needed only three yardings as opposed to the four required for the heifers treated with P4 and PGF. Thus, the choice of programme for an individual farm will depend on that farm's circumstances, in particular the cost of yarding the heifers.

The aim of this study was to estimate whether fetal age could be accurately estimated using placentome size.Fifty-eight cows with confirmed conception dates in two herds were used for the study. The length of the long axis and cross-sectional area of placentomes close to the cervix were measured once every 10 days between approximately 60-130 days of gestation and once every 15 days between 130-160 days of gestation. Four to six placentomes were measured using transrectal ultrasonography in each uterine horn. A linear mixed model was used to establish the factors that were significantly associated with log mean placentome length and to create an equation to predict gestational age from mean placentome length. Limits of agreement analysis was then used to evaluate whether the predictions were sufficiently accurate for mean placentome length to be used, in practice, as a method of determining gestational age.Only age of gestation (p0.001) and uterine horn (p=0.048) were found to have a significant effect on log mean placentome length. From the three models used to predict gestational age the one that used log mean placentome length of all placentomes, adjusting for the effect of horn, had the smallest 95% limits of agreement; ±33 days. That is, predicted gestational age had a 95% chance of being between 33 days greater and 33.7 days less than actual age. This is approximately twice that reported in studies using measurement of fetal size.Measurement of placentomes near to the cervix using transrectal ultrasonography was easily achieved. There was a significant association between placentome size and gestational age, but between-cow variation in placentome size and growth resulted in poor agreement between placentome size and gestational age.Although placentomes can be easily visualised during diagnosis of pregnancy using transrectal ultrasonography, mean placentome size should not be used to estimate gestational age.

The incidence of clinical mastitis and infection status at calving was assessed in quarters treated with 1 of 2 internal teat sealants at the time of dry off. Two contralateral quarters per cow (n=63 cows) were treated with a sealant that contained 0.5% chlorhexidine; the other quarters were treated with a commercial teat sealant. Ten cows were untreated (controls). On d 2, 4, and 16 after dry off, cows were challenged with Streptococcus uberis S210 strain. Cows were examined daily for 34 d after drying off and cases of clinical mastitis were recorded. Milk samples were collected for culture from any quarters that developed clinical mastitis during the first 34 d after drying-off and from all quarters on d −5 and 0 relative to treatment and at the first and twentieth milking after calving. The incidence of clinical mastitis during the examination period was lower in treated quarters (n=7/252; 1.5%; lower incidence for those treated with chlorhexidine-containing teat sealant n=3/126; 1.2%) than in untreated quarters (n=13/40; 26.8%). The protection against intramammary infection after calving, adjusted for the effect of cow, was higher in quarters treated with the novel teat sealant (89/105; 15.2%; 95% CI=9.6–23.4) than in those treated with the commercial teat sealant (71/104; 31.7%; 95% CI=23.5–41.3) and untreated controls (6/28; 78.6%; 95% CI=59.8–90.0), respectively. Quarters treated with teat sealants were less likely to have an intramammary infection after calving and had a lower incidence of clinical mastitis during the early dry period than did untreated controls in this challenge study.

Summary Reasons for performing study: There is little information on age, weight and time of year of puberty in Thoroughbred horses, and the interpretation of such data is difficult due to the wide variety of descriptions of the onset of puberty. Objectives: To examine the age, bodyweight and date of onset of puberty in Thoroughbreds born in spring and autumn. Methods: Bodyweight data and blood samples were collected in 59 pasture-raised Thoroughbred horses. Five autumn-born and 18 spring-born colts and 3 autumn-born and 33 spring-born fillies were examined from birth to age 13 and 17 months. A testosterone concentration >2 s.d. above the baseline concentration was indicative of onset of puberty in colts; and progesterone concentration >2 ng/ml and at least 3 times greater than the previous progesterone concentration was indicative of a first ovulation in fillies. Results: Spring-born fillies and colts were older and heavier than autumn-born fillies and colts at puberty. The age at onset of puberty in spring- and autumn-born foals was 291-408 days and 212-270 days, respectively. The weight at puberty in spring-born foals was 302-409 kg, and in autumn-born foals was 277-344 kg. However, the mean date at onset of puberty was not significantly different between spring- and autumn-born horses, with puberty occurring in October (New Zealand spring). Conclusions and potential relevance: Seasonal changes in photoperiod affect the timing of onset of puberty, provided a minimum threshold bodyweight has been reached. Springborn horses reached this threshold weight during the winter months and remained reproductively inactive until after the stimulus of increasing day-length occurred. The autumn-born horses reached the threshold weight to support puberty at the same time as stimulatory photoperiod and, therefore, reached puberty significantly younger and lighter than the spring-born horses.

To determine bovine fetal characteristics significantly associated with increasing gestational age as measured via transcutaneous ultrasonography over the right flank.The length of gestation at date of pregnancy diagnosis via transcutaneous and transrectal ultrasonography was determined for 224 dairy cattle by estimation from subsequent calving dates. A separate dataset was created for each measurable fetal characteristic (i.e. thoracic diameter, abdominal diameter, umbilical diameter, placentome length and placentome height) and risk factors significantly associated with gestational age at pregnancy diagnosis within each dataset, including the fetal characteristic, were identified.Abdominal diameter was the most frequently observed fetal characteristic and thoracic diameter was the least. Gestational age at pregnancy diagnosis (d) was significantly associated with fetal thoracic diameter (P0.01), abdominal diameter (P0.01) and umbilical diameter (P = 0.02) when measured via transcutaneous ultrasound. Within each model, sire breed, dam breed, dam age and/or calf sex were also significantly associated with gestational age. Gestational age at pregnancy diagnosis was not significantly associated with either placentome height or length (P0.05).Fetal thoracic diameter, abdominal diameter and umbilical diameter were found to be significantly associated with gestational age between approximate days 73 to 190 of gestation. Transcutaneous ultrasonography may prove a useful method of estimating gestational age in the absence of accurate breeding records.

Objective Evaluate the sensitivity and specificity of transrectal ultrasound and transcutaneous ultrasonography across the right flank between days 31 and 196 of pregnancy in the dairy cow. Procedure Pregnancy status and stage of gestation at date of pregnancy diagnosis by transcutaneous and transrectal ultrasonography were determined for 1570 dairy cattle. Sensitivity and specificity values and probabilities of a correct diagnosis for both techniques were determined and compared. Possible effects of gestational age, herd, method of transcutaneous ultrasound diagnosis, cow age, cow and bull breed, and calf sex on the determination of a correct diagnosis of pregnancy status were evaluated for both techniques. Results The overall sensitivity and probability of a correct diagnosis of pregnancy status from days 31 to 196 of gestation were significantly higher when using transrectal ultrasound relative to transcutaneous ultrasound over the right flank. However, the sensitivity of transcutaneous ultrasound changed over the course of pregnancy: it was low (7–8%) before day 84, increased to 89% between days 141 and 154, and was close to 100% thereafter. The specificity of both methods did not differ significantly. Herd and gestational age at date of pregnancy diagnosis were significantly associated with making a correct test result using transcutaneous ultrasound, although only the latter predictor was significantly associated with making a correct test result using transrectal ultrasound. Conclusion Transcutaneous ultrasound can not be recommended as an accurate method for early pregnancy diagnosis in the dairy cow, particularly on a whole-herd basis. However, if pregnancy testing is undertaken in mid to late gestation, this technique could provide an accurate and rapid alternative to transrectal ultrasound or manual palpation per rectum.

To investigate ovarian follicular and luteal activity during the postpartum period of cows genetically selected for high or low mature bodyweight, in relation to metabolic and reproductive endocrine parameters, to determine whether there are differences between strains that could affect fertility outcomes.The presence of folliclesor =5 mm diameter and luteal structures was mapped in the ovaries of 12 high (heavy-strain) and 12 low (light-strain) mature bodyweight cows by daily trans-rectal ultrasonography from Day 7 postpartum until the end of their first normal oestrous cycle. Blood samples were collected daily, for measurement of concentrations of follicle stimulating hormone (FSH), progesterone, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin. Intervals to first ovulation were calculated from ultrasonography data.Heavy-strain cows had shorter intervals than light-strain cows from calving to the emergence of the first (9.0 (SE 0.9) vs 12.4 (SE 1.3) days) and second (16.4 (SE 1.8) vs 20.6 (SE 1.6) days) dominant follicles (p0.05). Concentrations of FSH in heavy-strain cows prior to the emergence of the second, third and fourth dominant follicles were higher than in light-strain cows (p0.05). Heavy-strain cows were more likely to have a large (15 mm diameter) follicle earlier than light-strain cows (p0.01). Concentrations of insulin and IGF-1, but not those of GH, were higher in heavy- than light-strain cows during the postpartum period (p=0.01 and p=0.02, respectively), and concentrations of both on Day 6 were inversely related to the time of emergence of the first dominant follicle (p0.01). Concentrations of progesterone were similar in both strains of cow until Day 10 of the first oestrous cycle, but thereafter were higher in light- than heavy-strain cows until Day 16. Progesterone concentrations in heavy-strain cows declined earlier and more rapidly than in their lighter counterparts.These results indicate that there is a rapid postpartum resumption of follicular activity in both heavy- and light-strain cows, but that there is an earlier emergence of dominant follicles and ovulation in the former. Differences in luteal function, in terms of lower dioestrus progesterone concentrations and an earlier onset of luteolysis, in heavy- than light-strain cows might be sufficient to impair the fertility of the former.

To assess if raising concentrations of crude protein (CP) in pasture in spring by the frequent application of urea fertiliser would affect ovarian follicular dynamics, luteal function, onset of oestrus and reproductive performance of dairy cows under farming conditions in New Zealand.Spring-calved dairy cows were grazed for 101 days in paddocks that were either not fertilised (Control; n=20) during the course of the study, or were fertilised with 40-50 kg nitrogen (N)/ha every 4-6 weeks (High-N; n=20). Similar generous pasture allowances were offered to both groups. Concentrations of CP in pasture, urea in serum and progesterone in milk were measured. Ovarian follicular and luteal dynamics were determined using ultrasonography. Oestrous behaviour and the number, time and outcome of inseminations were also recorded.Mean concentrations of CP in pasture and urea in serum was higher in the High-N than the Control group (25.2 vs 21.6 and 8.3 vs 5.4 mmol/L for CP and urea, respectively; p0.001). Intervals between calving and first oestrus, first insemination and conception, the time of first emergence of a dominant follicle, milk progesterone concentration, and the diameter of the corpus luteum (CL) in the first luteal phase did not differ significantly between groups. The interval from calving to first ovulation tended (p=0.10) to be lower and the diameter of the dominant follicle of the oestrous cycle at which cows conceived was greater (p=0.02) in Control than High-N cows.The use of large amounts of urea fertiliser during spring and the consequent increases in concentrations of CP in pasture and urea in serum did not negatively affect any of the parameters of reproductive performance of pasture-fed dairy cows that were assessed in this study.

Gonadotropin releasing-hormone analogue (buserelin) challenges were carried out every 8 weeks from 4 to 14 months of age on thoroughbred colts born in the spring (n = 6) or autumn (n = 5) to define the onset of puberty. In all colts, luteinizing hormone (LH) secretion followed a seasonal pattern, with high baseline and maximal concentrations in the spring and summer and low concentrations in the winter. Testosterone concentrations were undetectable before spring and, thus, autumn-born colts were younger than spring-born colts when a testosterone response to buserelin was first observed. Mean weights of the autumn-born colts were 300 kg (282–327 kg) at the time of the first detectable testosterone response in the following spring (October). Spring-born colts had reached this weight in the winter (May and June, before day length had increased) but did not exhibit a significant testosterone response until the spring at a mean weight of 352 kg (327–403 kg). It is proposed that colts must achieve a threshold body weight concurrently with stimulatory photoperiod for onset of puberty to occur.

To describe the reproductive performance of beef cow herds in New Zealand and to develop reference ranges for assessing the reproductive performance of individual herds from in-calf rates, that take into account variation in the length of mating periods.Veterinary practices throughout New Zealand involved in beef cattle work were asked to collect reproductive data from seasonally calving beef cow herds mated in the spring of 2001 through to the end of summer of 2002. An estimate of conception rate (termed calculated conception rate: CCR) was determined for each herd, assuming that the conception rate was constant for each 21-day interval of the mating period. The algebraic relationship between CCR and in-calf rate at pregnancy testing was defined for mating periods of different durations and, therefore, given the in-calf rate and the duration of the mating period, a CCR could be determined for each herd. Expected pregnancy rates were recalculated from CCR data for a range of mating period durations to produce a look-up table for assessing herd reproductive performance. Reproductive data describing regional differences in in-calf rates and CCRs, bull:cow ratios, breed characteristics, start dates of mating and durations of mating periods were summarised. The effect of study variables in explaining CCRs was examined using a general linear model (GLM).Data were collected from 1,005 beef cow herds distributed throughout New Zealand. The median in-calf rate for all herds was 91%, the lower quartile wasor =88% and the upper quartileor =94%. The mean CCR for herds with complete reproductive data (862) was 55% (SD 11), the lower quartile wasor =48% and upper quartileor =61%. Median in-calf rates for 2-year-old heifers (mated at approximately 15 months of age), 3-year-old heifers (mated at approximately 27 months of age), and mixed-age cows were 90%, 91% and 92%, respectively. The study variables that accounted for significant variation in breeding group CCR in a multivariate GLM were 'region' (p0.01) and 'date mating commenced' (0.01). The adjusted R2 for the model was 0.055.The reproductive reference range produced provides veterinarians and herd managers with a quantitative method for assessing reproductive performance of beef cow herds compared with industry averages, from in-calf rates at the time of pregnancy testing and durations of mating periods.

To determine regional prevalences of beef cow herds in New Zealand positive for Campylobacter fetus subsp venerealis antibodies in samples of vaginal mucus tested using an immunoglobulin (Ig) A enzyme-linked immunosorbent assay (ELISA), and to examine the suitability of the IgA ELISA for detecting infection with C. fetus subsp venerealis under field conditions in New Zealand.Vaginal mucus samples (n=1,230) collected from beef cow herds (n=125) throughout New Zealand (approximately 10 samples/herd) were tested for antibodies to C. fetus subsp venerealis using an IgA ELISA. Test results were compared between herds classified as having low, medium and high fertility based on pregnancy test results interpreted in relation to the duration of the mating period used. In addition, a small number of samples were collected from dairy cows that were mated using artificial insemination (AI) and had no contact with breeding bulls. The influence of putative risk factors for the spread of venereal disease and the effect of sample quality on the status of herds according to test results was assessed using multivariate logistical regression. Preputial washings from 54 bulls from nine herds classified as low fertility in which mucus samples fromor =3 cows were IgA antibody-positive were cultured for the presence of Campylobacter spp, and isolates of C. fetus subspecies were characterised using a polymerase chain reaction (PCR) test.One or more mucus samples was positive to the IgA ELISA in 70% of all herds tested. The prevalence of IgA antibody- positive individuals was20% in most regions of New Zealand and did not differ significantly for cows from herds classified as high, medium or low fertility (28%, 26% and 23%, respectively; p=0.39). No relationship was found between mucus antibody status and age of breeding group, herd size, herd fertility, number of herds that female replacements or breeding bulls were sourced from, whether a serving ability test (SAT) was used to assess bulls, or the quality of samples submitted to the laboratory. Campylobacter fetus subsp venerealis was not cultured from any of the 54 bulls sampled. Four other species of Campylobacter and related organisms were cultured, viz Arcobacter cryaerophilus, Campylobacter jejuni, Campylobacter fetus subsp fetus and Helicobacter cinaedi.The specificity of the IgA ELISA as a diagnostic test for C. fetus subsp venerealis was found to be unsatisfactory under New Zealand conditions. It is possible that an immunological response by cows to Campylobacter species other than C. fetus subsp venerealis caused cross-reactivity in the IgA ELISA. The results do not support the hypothesis that C. fetus subsp venerealis is widespread in New Zealand.

The potential fertility of bulls can be evaluated in the field by assessment of mating ability and physical examination. Both methods are useful for screening out low fertility bulls, although neither allows precise determination of the pregnancy rates that bulls actually achieve. Observations of coitus, libido testing and service capacity testing are the main methods of assessing mating ability in the field and, although not reliable for virgin bulls, are widely used for older bulls. Of the traits that are assessed during physical examination, those most closely correlated with fertility are scrotal circumference and the semen quality parameters of motility and morphology. Whilst these methods allow reasonable accuracy in determining the fertility potential of an individual bull, they do not take into account other managemental constraint to bulls' fertility. Although these are reasonable well understood for beef herds, the managemental factors that affect the performance of natural service sires in dairy herds are poorly understood.

This study evaluated the effect of removing the GnRH injection on Day 0 or the progesterone (P4) device from a GnRH, PGF2α, GnRH (GPG) + P4 program on follicular dynamics and synchronization of ovulation in dairy heifers. Friesian and Friesian × Jersey heifers, in autumn 2009 (n = 35) and spring 2010 (n = 38), were randomly allocated to one of three estrus synchronization programs. The first group (GPG + P4) received 100 μg GnRH on Day 0, a P4-releasing intravaginal device from Days 0 to 7, 500 μg PGF2α on Day 7, and 100 μg GnRH on Day 9, followed by fixed-time artificial insemination 16 to 20 hours later. The program for group 2 (GPG) was the same as group 1 with the exclusion of the P4 device. Group 3 (P + G + P4) was treated the same as group 1, except for the absence of the GnRH treatment on Day 0. Ultrasonography was performed on Days 0, 1, 2, 3, and 7 and then at 12 hourly intervals on Days 9 to 11. Dominant follicle size was affected by both treatment and day, and there was also a significant interaction (P

Thin soles are a significant cause of lameness in dairy cattle but in most cases the diagnosis is based on subjective assessment. Ultrasonography has been used to more directly estimate sole thickness, but mostly on a one-off basis or over a short period of time. Data over a longer period of time (such as a lactation period) are lacking and there are no descriptions of the normal changes that occur over time and to show how sole thickness at calving relates to thickness later in lactation. This study measured the distance between the external sole surface and the distal phalanx (DP) in 25 mixed breed (Jersey cross Friesian and Friesian) heifers on five occasions over their first lactation (approximately 10, 60, 110, 160 and 220 days post calving). There was a significant effect of claw (medial/lateral) and of time after calving on DP. Mean DP was highest on day 10 and was lowest on day 110 at the tip of the distal phalanx (S1) and on day 160 25 mm towards the heel from the tip (S2). DP was greater at S1 in medial claws and S2 in lateral claws. Although mean DP decreased between days 10 and 110, this change was correlated to DP at day 10. At S1 claws with a DP of7.5mm tended to increase in thickness between day 10 and 110. Claws which were ≤ 8.25 mm at day 10 were 2.43 (95% CI 0.86-6.89) times more likely to be thin (7.0mm) at day 110, but of the 12 thin claws at day 110, six had had an adequate DP (8.25 mm) at day 10. A single measurement of DP at calving was not an effective method for predicting which claws would became thin during lactation.

To determine the pattern of isolation of major mastitis-causing organisms isolated from milk samples submitted to five veterinary diagnostic laboratories in New Zealand.The culture results of 25,288 milk samples that were collected from dairy cows throughout New Zealand from August 2003 to December 2006 and submitted to a group of veterinary diagnostic laboratories were assembled, reviewed and summarised. Logistic regression was used to analyse the effect of year, region (i.e. North vs South Island), and season on the probability of isolating the two most common organisms.The most commonly isolated mastitis causing organisms from all samples were: Streptococcus uberis (23.6%), Staphylococcus aureus (23.5%), coagulase-negative staphylococci (CNS; 7.2%), Strep. dysgalactiae (6.2%), Bacillus spp. (4.0%), and coliforms (3.7%). The percentage of samples with isolates of Strep. uberis or Staph. aureus was affected by island, year and season (p0.001). For most of the year, except in late winter and early spring when Strep. uberis was much more common, the percentage of isolates of Strep. uberis and Staph. aureus were not apparently different despite the former being an environmental pathogen and the other a contagious one.The pattern of isolation of major mastitis-causing organisms, as determined from culture of milk samples submitted to diagnostic laboratories in New Zealand, has changed significantly over the last 40 years, with a substantial increase in the percentage of isolates that are Strep. uberis and a decrease in isolates of Strep. agalactiae. There is a clear seasonal pattern to the isolation of both Strep. uberis and Staph. aureus, particularly the former.Knowledge of the aetiological agents causing bovine mastitis on a farm is of value in determining the choice of treatment. This dataset shows that, although there is seasonal pattern to the isolation of mastitis-causing organisms in New Zealand, both Strep. uberis and Staph. aureus are isolated throughout the year, so bacteriology is of value in determining aetiology even in late winter/early spring.

To estimate the incidence of clinical mastitis and the frequency of isolation of mastitis-causing organisms from clinical cases in one lactation season (July 2005 to May 2006) on 14 dairy farms from the Northland region of New Zealand.Cases of clinical mastitis were determined by trained farm personnel who recorded the identity of affected cows. Pooled milk samples from affected quarter(s) were aseptically collected by the farm personnel, for microbiology. Mean numbers of affected cows and quarters were compared at the population and farm level per 305 cow-days-at-risk (DAR).One or more cases of clinical mastitis occurred in 559/3,765 (14.8%) lactating cows. The average incidence of clinical mastitis was 0.19 cases per 305 DAR. The incidence in rear quarters (56.2%) was 1.3 times (p=0.027) that of front quarters (43.8%). The incidence of clinical mastitis and numbers of affected quarters were significantly influenced by the stage of lactation (higher in early lactation), age (higher in older cows) and farm. At the cow level, the most common isolates were Staphylococcus aureus (23.7%) and Streptococcus uberis (23.3%). No causative organisms were identified in 19.9% of the samples. Each cow had an average of 1.8 quarters affected during a case of clinical mastitis.This study demonstrated a higher incidence of staphylococcal clinical mastitis on dairy farms from Northland than has been reported in other regions of New Zealand.

High concentrations of dietary nitrogen have been associated with reductions in the fertility of dairy cows, but the evidence is not conclusive and many studies have shown little or no effect. This paper reviews recent investigations of the effect of rapidly degradable sources of nitrogen on parameters of fertility, and concludes that high levels of dietary nitrogen do not routinely reduce fertility, even at intakes above those in normal dairy cow diets. It also concludes that cows may be able to adapt to high nitrogen diets so that diets that may reduce their fertility when introduced at critical periods, for example, when they are inseminated, do not reduce it when introduced at an earlier stage.

To determine the responsiveness of the pituitary-gonadal axis of peri-pubertal colts to GnRH, buserelin (0.5, 1, 5, 10 and 40 microg) was given to 13 male Thoroughbred yearlings ( n=3-8 colts per dose). Jugular venous blood samples were taken at -10, 0, 10, 20, 30, 40, 60, 120 and 180 min relative to buserelin administration. Increases (P0.05) in LH concentrations occurred in colts that received 5, 10, or 40 microg buserelin, but not in those that received 0.5 or 1 microg. Peak LH concentrations and mean area under the curve were higher (P0.05) in colts receiving 40 microg buserelin than in those that received 0.5 or 1 microg. Increases ( P0.05) in testosterone concentrations occurred in some, but not all, colts that received 1, 5, 10, or 40 microg buserelin. Neither peak concentration nor area under the curve of testosterone differed significantly among doses of buserelin. The percentage of horses that responded to the buserelin increased with increasing dose, with only the highest dose eliciting LH and testosterone responses in all colts. In conclusion, peri-pubertal colts exhibited a dose-response release of LH following buserelin treatment, but individual colts responded in an "all or nothing" manner, such that each either had an LH response or did not. Some colts that exhibited a significant LH response had no subsequent increase in plasma testosterone concentrations; perhaps the pituitary LH response may not have been great enough to stimulate the Leydig cells in these individuals.