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Item Risk factors associated with tail damage in New Zealand dairy cattle(Elsevier B.V., 2025-12) Cuttance EL; Mason WA; Bryan MA; Laven RATail damage in dairy cattle is an increasingly recognised cause of poor welfare. However, there have been very few studies of the risk factors associated with the prevalence of tail damage. This analysis combined a 200-farm study of the prevalence of tail damage in New Zealand with a survey of farm management and handling practice with the aim of identifying the risk factors associated with tail damage (defined as either a deviated tail or one with evidence of other injury). Across the farms, the median herd level prevalence of tail damage was 11.5 %. The survey included 42 variables which were analysed at the univariable level. Factors which were identified as being potentially associated based on these univariable analyses included region, parlour type, milking frequency, use of automatic cup removers, use of coaxing to get cows to move and farmer's opinion of how many cows with tail damage they had. The final multivariable model had region, milking frequency (odds of tail damage 1.18 times higher for farms which always milked cows twice daily than for those which did not) and the use of coaxing (i.e. gentle persuasion) (odds of tail damage on farms which used coaxing was 0.83 times that on farms which did not). These results support the hypothesis that poor handling and/or interaction with infrastructure are important causes of tail damage on New Zealand dairy farms. More studies in more countries are needed to better understand the cause of tail damage in dairy cows. In addition, we need to standardise and optimise the repeatability of tail scoringItem The prevalence of damaged tails in beef cows, pregnant dairy heifers and weaned dairy calves(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-07-09) Cuttance EL; Mason WA; Bryan MA; Laven RAAims: To determine the prevalence of tail deviations, trauma and shortening in weaned dairy calves, pregnant dairy heifers and beef cows on a selection of New Zealand farms, and to compare results to those recorded in lactating dairy cows. Methods: This was a cross-sectional observational study. For beef cows, 25 farms were randomly selected from two veterinary practices. For dairy heifers and calves, data were collected from farms (70 and 76, respectively) previously involved in a study of tail damage in lactating cows. All cattle were tail scored using a modification of the New Zealand Veterinary Association Scoring System. Tails were palpated and lesions recorded as deviated (non-linear deformity), shortened, or traumatic (all other lesions). Cows could have more than one lesion, but for the prevalence calculations, only the presence/absence of a particular lesion was assessed. Descriptive herd-level prevalence data were reported for all farms/cattle types. For dairy heifers, the prevalence of tail deviation was compared to that in adult cows on the same farm. Results: For beef cattle, median prevalence of any tail damage was 4.0% (min 0.0, max 37.5%), and for deviations + trauma, it was 2.0% (min 0.0, max 16.7%). For dairy heifers, equivalent figures were 1.7% (min 0.0, max 17.8%) and 1.3% (min 0.0, max 17.8%). In weaned calves, the median prevalence of any damage was 0% (min 0.0, max 11.6%): almost all damage (61/64 cases) was deviation. Farms with a heifer prevalence of deviations > 2% had a mean cow prevalence of deviations 3.65 (95% CI = 0.7–6.6)% higher than herds with heifer prevalence ≤ 2%, but this explained only 9% of the variation in log percentage cow prevalence. Conclusions and clinical relevance: In all groups, median prevalence of tail damage was low (and lower than reported in dairy cows), but individual farms had high levels of damage. Beef cows were more likely to have shortened or traumatised tails than dairy heifers/calves, perhaps from an increased prevalence of faecal tail rings. Limited association between the prevalence of tail deviations in heifers and lactating cows on the same farm, and generally lower levels of tail damage in heifers, do not support the hypothesis that tail damage in cows principally results from damage earlier in life. This study adds support to our hypothesis that poor handling/infrastructure are responsible for most tail damage in dairy cows.Item Use of hormones on New Zealand dairy farms: an analysis of the results from a survey of farmers and a survey of veterinarians(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-07-09) Laven RA; Cuttance EL; Chambers GAims: To survey New Zealand dairy farmers and veterinarians on their attitude and use of reproductive hormones in treating cows identified as non-cyclers. Whilst hormones have been identified as effective tools in assisting reproduction in dairy cattle, there is widespread but anecdotal concern about their cost-effectiveness and a lack of high-quality information on the attitude and practices around hormone use on New Zealand dairy farms. Methods: Electronic links to separate farmer and veterinary survey forms were sent to all dairy clients and all veterinary employees of five, convenience-selected veterinary practices across New Zealand. Using closed, open, and Likert-style questions, the surveys covered cost-effectiveness of hormonal interventions, value judgements on their use, and impact on the public perception of dairy farming. Results: Usable surveys were returned by 424 farmers and 70 veterinarians. Response rates are not known as denominator data were not sought. Of the farmers, 253/424 (60%) reported using hormone treatments, with 153 (36%) primarily using them before mating started. However, only 163 (38%) thought treatment was cost-effective, compared to 65/70 (93%) veterinarians. Beliefs around cost-effectiveness affected use: 8/171 (5%) farmers who never used hormones believed they were cost-effective, compared to 38/94 (40%) who used hormones occasionally and 117/159 (74%) who used them routinely. Other reasons put forward by farmers for not using hormones included “breeding infertility”, “not natural”, and “not treating the cause”. Farmer and veterinary opinion also varied around the trajectory of hormone use. Amongst veterinarians, 12/70 (17%) thought use should decrease compared to 271/424 (64%) farmers, while 19/70 (27%) veterinarians thought use should increase compared to 21/424 (5%) of farmers. Conclusions: The results suggest a disconnect around hormone use between the participating veterinarians and farmers. Many farmers did not believe hormone use was cost-effective, despite strong evidence to the contrary. As other reasons for not using hormones were also cited, and as most farmers believed hormone use should decrease, it seems unlikely that further education on cost-effectiveness will change practice. Rather, it could increase the proportion who think veterinarians benefit financially more from hormone use. Clinical relevance: Veterinary focus on maximising synchronisation use and efficacy is bypassing a significant proportion of dairy farmers. There is an opportunity for veterinarians to focus on what their clients want and work with them to improve herd fertility without relying on hormones to fix management problems.Item Use of adjusted cut-off values for Neospora caninum antibody ELISA in calves after colostrum intake: on-farm evaluation as part of a neosporosis eradication programme(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-06-04) van Velsen CM; Laven LJ; Laven RA; Weston JFAims: To assess the effectiveness of testing young calves using an ELISA for antibodies to Neospora caninum with adjusted cut-off values to account for the presence of maternal antibodies, as an aid in decision-making during calf-rearing, with the purpose of eradicating neosporosis from endemically infected dairy herds. Methods: Replacement heifer calves on two dairy farms with endemic neosporosis were blood sampled at approximately 1–4 weeks of age. Sera were tested with an ELISA for antibodies to N. caninum, with the thresholds increased (based on unpublished data) to account for colostrum intake. The sample/positive (S/P) cut-off value for seronegative animals was increased from the manufacturer’s recommendation of S/P < 30 to < 70; the S/P value for seropositive was increased from ≥ 40 to ≥ 100; and S/P values 70–100 were considered inconclusive. Calves with inconclusive results were retested using standard thresholds at approximately 4 months of age (after colostral antibodies had waned). Seropositive calves were removed from the replacement herd. This protocol was first implemented in 2016. From 2018 onwards, parentage testing was carried out, and the calves’ results were extrapolated to their dams. Dams of seropositive calves were bred predominantly to beef semen. The proportion of seronegative calves in each cohort from 2016 to 2023 was calculated, and the reproductive performance of seronegative replacement calves (% producing a calf at approximately 24 months of age) was analysed. Results: The proportion of seropositive replacement calves peaked in 2017 (19.5%) and by 2023 had reduced to 1.2%. The odds of a heifer being seronegative in 2023 compared to 2016 were 14.0 (95% CI = 4.12–87.56) times higher. Compared to 2014/2015 when replacement heifers’ serostatus was unknown, after 2016 (the first year when replacement heifer serostatus was established) at least 12.9% more heifers produced a calf at approximately 24 months of age; compared to 2014 the odds were at least 2.88 (95% CI = 1.75–4.88) times higher. Conclusions and clinical relevance: Combining early testing of replacement heifers with the identification and breeding management of dams of seropositive replacement heifers reduced the proportion of seropositive heifer calves in subsequent years and improved the reproductive performance of heifer cohorts. Further research is required to establish optimal ELISA cut-off values, but this strategy is likely to be a useful tool to reduce the N. caninum seroprevalence in endemically infected dairy herds.Item Understanding the current evidence base for the commonly recommended management strategies for recurrent feline idiopathic cystitis: a systematic review(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-03-27) Macleod B; Laven LJ; Laven RA; Hill KEObjectives: This systematic review aims to describe and understand the evidence available for commonly recommended management strategies for feline idiopathic cystitis (FIC) to provide guidance for clinicians in their treatment of this condition. A subsequent objective was to identify gaps in the literature and areas where future research may be directed. Methods: A computerised search of three electronic databases (Discover, Scopus and PubMed) was performed. Results were imported into a single EndNote library and duplicates were removed. Remaining records underwent a two-stage screening process with the aim to identify peer-reviewed primary literature on therapeutic strategies for FIC. Studies were categorised according to one of seven management strategies: environmental modification, dietary manipulation, anti-inflammatory drugs, amitriptyline, glycosaminoglycans, prazosin, and intravesical lidocaine. Results: Twenty-two studies were included in the final review, with one study providing evidence in two categories. Two studies assessed environmental manipulation, with results showing encouraging evidence for multimodal environmental modification but little evidence to support the use of feline facial pheromone. Five papers examined dietary manipulation, with good evidence for the use of therapeutic urinary diets, and for increasing the moisture content of a cat’s diet. Anti-inflammatory drugs were the focus of four studies, with none providing evidence to support their use. Four papers indicated that the evidence to support glycosaminoglycans is lacking. The antispasmodic drug prazosin was purported to be useful in one retrospective paper, while three papers comparing it to a placebo showed no evidence for its use. Three studies assessed amitriptyline, with two indicating that short-term use is not supported, and one long-term study suggesting it may be useful in some refractory cases. One study on intravesical instillation of lidocaine concluded that it was not a useful treatment strategy. Conclusions: Multimodal environmental modification to reduce stress/conflict and therapeutic urinary foods (particularly if combined with an increase in moisture content of the diet) currently have the strongest evidence to support their use in managing FIC, and should, together, be considered the primary treatment approach. The evidence for other modalities, is currently insufficient to support their use. The overall lack of high quality studies emphasises the need for clinicians to be critical in their evaluation of the published literature on the management of this perplexing condition.Item Dynamics of Porcine Circovirus Type 3 Detection in Pre-Weaning Piglets: Insight From Multiple Sampling Methods(John Wiley and Sons Ltd, 2025-01-24) Yang DA; Li M; Wang Y; Zhao K; Zhang Q; Laven RA; Yang Z; Chen N-HPorcine circovirus type 3 (PCV3) has been identified worldwide and is associated with reproductive and systemic diseases, yet the dynamics of PCV3 within pig farms remain unclear. Building upon our previous study, which initialised comparisons of different sample types for the detection of PCV3 in a sow farm, this study expanded both the range of sample types and the timeline of sampling in piglets and sows to better understand the PCV3 dynamics. This study collected two additional sample types—oropharyngeal swab (OS) and oral fluid (OF) along with placental umbilical cord (PUC) blood and processing fluid (PF) that were used in the previous study. Data were collected from July to August and October 2022; the aforementioned four sample types from 51 litters were collected, and additional OS samples were collected from two to three identified piglets per litter on days 1, 7, 14, and 21 post-farrowing. Besides, blood swabs were taken from 135 sows subject to both PCR test and oestrogen measurement. PF showed the highest detection rates (50/51), while OS and OF revealed 33/51 (95% confidence interval [CI]: 51.2%–76.8%) and 37/51 (95% CI: 59.5%–83.5%) detection rates; both were higher than that of PUC blood (22/51, 95% CI: 30.2%–56.8%). Despite the similarity between OS and OF samples, they did not identify the same population as infected, as the agreement between the samples was only fair at 90% level. The Bayesian generalised linear mixed model suggested PCV3 was more likely to be detected in both OS and OF compared to PUC blood, and PCV3 was present in the farrowing room throughout the pre-weaning period using an OS. Finally, we observed higher PCV3 detection rates in sows after farrowing; however, no evidence was found that such a pattern was associated with the decreased concentration of oestrogen.Item Can we estimate herd-level prevalence of lameness in dairy cow herds kept at pasture by sampling part of the herd?(Taylor and Francis Group on behalf of the New Zealand Veterinary Association, 2025-03-26) Sapkota S; Laven RA; Müller KR; Yang DAAims: To assess whether herd-level lameness prevalence can be estimated on New Zealand dairy farms, by scoring the first, middle, or last 100 cows in the milking order. In pasture-based herds, whole herd locomotion scoring requires an assessor outside the milking parlour throughout milking. If sufficiently predictive, sampling a proportion of the herd based on milking order, could reduce the costs and time of welfare assessments. Methods: Six pasture-based, spring-calving, dairy farms in the Manawatū region of New Zealand were conveniently selected. Visits occurred at approximately 6-week intervals between October 2021 and May 2022. Cows were scored using the DairyNZ lameness score (0–3). The assessor tallied cows as they left the parlour and recorded the milking order of those with a lameness score ≥ 2. Data were analysed to determine the association between farm, visit and the proportion of lame cows in the first, middle, and last 100 cows, and the agreement between the prevalence of lame cows in those groups and from whole herd scoring. Results: Across all visits, 263 lame cows were recorded. Of these, 40.7% were in the last 100, 25.9% in the middle 100, and 14.4% in the first 100. Farm, visit and their interactions with group were all statistically significant (p < 0.001). While, overall, the last 100 cows had the highest proportion of lame cows, this pattern varied across farms and visits, Limits-of-agreement plots showed that as herd prevalence increased, agreement between the prevalence in each sample group and herd prevalence worsened. When herd prevalence exceeded 5%, only the middle 100 sampling group had a limits-of-agreement < 5%. Conclusions: Variations across farms and seasons in the proportion of lame cows in each part of the milking order lead to variations in the accuracy of predicting overall lameness from such samples. Based on limits-of-agreement, observing the middle 100 cows is likely to be the most accurate sample, but is still likely to be of limited value on New Zealand dairy farms, especially as a single, one-off measurement. Clinical relevance: On New Zealand dairy farms, locomotion scoring the middle 100 cows in the milking order as part of a welfare assessment would reduce costs and time but would not produce an accurate estimate of whole-herd lameness prevalence. However, it may be useful as a screening tool in herds routinely locomotion scoring throughout the year.Item Teat and udder morphology and pathology of New Zealand dairy ewes.(Taylor and Francis Group, 2025-02-12) Chambers G; Lawrence KE; Ridler AL; Laven RAAIMS: To describe the morphology and prevalence of teat and udder pathology of New Zealand dairy ewes. METHODS: A repeated cross-sectional study was conducted on 20 commercial New Zealand dairy sheep farms over the 2022-2023 season. Approximately 15 randomly selected ewes were examined on each farm in early, mid, and late lactation. Four udder morphology measures were scored on a 5-point scale: depth (1 = pendulous, 5 = compact udder), suspension (ratio of width at abdominal attachment to height, 1 = low, 5 = high), gland separation (1 = zero, 5 = maximum separation), and teat placement (1 = distally located, vertically oriented, 5 = laterally located, horizontally oriented teats). Teat length and width were measured, and the presence of supernumerary teats, asymmetry, visible teat/udder inflammation, and lesions were recorded. Teats and glands were palpated for consistency, gland-nodules, teat canal thickening, and patency, and teat ends scored for hyperkeratosis. Teat and gland-level pathological variables were converted to ewe-level scores. The presence of involuted, non- or minimally lactating glands was recorded. Data were analysed using descriptive statistics. RESULTS: Across the three visits, 893 observations were made on 882 unique ewes. Mean teat length and width were 27.5 (95% CI = 27.2-27.7) and 15.8 (95% CI = 15.7-15.9) mm. Udder depth, separation, suspension, and teat placement had modal scores of 4, 3, 3, and 3 respectively, and varied across visits and age groups. Asymmetrical udder prevalence was 39% (95% CI = 35.5-42%) overall and increased with age (27% for 1-year-olds, 38% for two-year-olds, 43% for mixed age ewes). Supernumerary teats were observed in 15% (95% CI = 13-17.9%) of ewes. There was between-farm variation in all udder morphology variables. Ewe-level prevalences of teat end hyperkeratosis (any degree of severity), gland/teat inflammation, lesions, palpable defects, and involuted glands were all < 6%. CONCLUSIONS: Morphological observations resembled those from overseas dairy sheep. Teat dimensions, udder depth, separation, suspension, teat placement, and presence of supernumerary teats varied between farms. Udder depth, separation, and suspension scores decreased with age, while teat placement score and the prevalence of asymmetry increased with age. Teat and udder pathology were rare. CLINICAL RELEVANCE: This is the first systematic study of teat and udder morphology and pathology in New Zealand dairy ewes. The data will be useful for farmers and industry partners, providing a comparison with their own flocks, identifying areas for improvement, and informing and contrasting with future studies.Item Effect of a pre-calving injectable trace mineral supplement on white blood cell function in seasonally calving pastoral dairy cows.(Taylor and Francis Group, 2024-10-30) Bates AJ; Wells M; Fitzpatrick C; Laven RAAims To investigate the effect of injection of trace mineral supplement (TMS) 14–28 days before calving on white blood cell count (WBCC) and function, serum antioxidant capacity (SAC) and reactive oxygen species (ROS) in pasture-fed cattle after calving. Methods On each of two South Island, seasonally calving, pastoral dairy farms,1 month before dry-off, a random sample of 150 multiparous cows predicted to calve within 7 days of the herd’s planned start of calving (PSC) were stratified on individual somatic cell count, age, breed and expected calving date. On each farm, 14–24 days before PSC, 60 selected cows were randomly assigned for TMS (Zn, Mn, Se, Cu) injection, and 60 were controls. All 240 cows were contemporaneously injected with hydroxocobalamin, and controls with Se. Blood samples were collected pre-injection and 3, 12 and 40 days after calving. Phagocytic activity, count and proportion of neutrophils, lymphocytes and monocytes, WBCC, ROS, SAC were measured. Plasma concentrations of Se, Cu and glutathione peroxidase (GPx) were monitored from a random subset of animals. Differences attributable to TMS were estimated using mixed-multivariable Bayesian analysis, expressed as mean and highest density interval (HDI). Results Three and 40 days after calving, TMS-treated cows had 0.36 (90% HDI = 0.00–0.77) x 109 and 0.25 (90% HDI = 0.00–0.55) x 109 fewer neutrophils/L. Neutrophils comprised 6 (90% HDI = 0–11)% and 4 (90% HDI = 0–8)% less of the WBCC, and the neutrophil count was 14 (90% HDI = 0–27)% and 9 (90% HDI = 0–18)% less than controls. However, 3 days after calving, there were 7 (95% HDI = 2–12)% more cells phagocytosing and 2,900 (95% HDI = 2,600–3,200) more bacteria ingested/cell. Twelve and 40 days after calving, TMS-treated cows had 0.65 (95% HDI = 0.17–1.17) x 109 and 0.28 (95% HDI = 0.00–0.59) x 109 more lymphocytes/L. Lymphocytes comprised 10 (95% HDI = 3–18)% and 5 (95% HDI = 0–9)% more of the WBCC, and the lymphocyte count was 30 (95% HDI = 11–51)% and 9 (95% HDI = 0–9)% more than controls. There were no meaningful differences in ROS, SAC, ROS/SAC, other white blood cells, or WBCC. Plasma Cu, Se and GPx concentrations were above recommended thresholds. Conclusions Pre-calving TMS injection was associated with differences in white blood cell population and function that may reduce the risk of disease. Abbreviations BHOB: Beta-hydroxybutyrate; GPx: Glutathione peroxidase; HDI: Highest density interval; MESF: Molecules of equivalent soluble fluorophore; OSi: Oxidative stress index; PSC: Planned start of calving; ROPE: Region of probable equivalence; ROS: Reactive oxygen species; SAC: Serum antioxidant capacity; THI: Temperature humidity index; TMS: Trace mineral supplement; WAIC: Widely applicable information criterion; WBCC: White blood cell count.Item Repeatability of whole herd lameness scoring: an analysis of a New Zealand dataset(Taylor and Francis Group, 2024-09-03) Laven RA; Mason WA; Laven LJ; Müller KRAIMS: To assess whether a whole-herd lameness score on a New Zealand dairy farm in spring could predict lameness prevalence on the same farm in summer (and vice versa) and whether a single-herd lameness score could be used to determine whether herd lameness prevalence was < 5% in both spring and summer. METHODS: Prevalence data (proportion of the herd with lameness score ≥ 2 and with score 3; 0-3 scale) from a study where 120 dairy farms across New Zealand were scored in spring and in the following summer were analysed using limits-of-agreement analysis. In addition, farms were categorised as having either acceptable welfare (lameness prevalence < 5% in both spring and summer) or not (lameness prevalence ≥ 5% in either spring or summer or both). The accuracy and specificity of a single, whole-herd lameness score at identifying herds with acceptable welfare were then calculated. RESULTS: The limits-of-agreement analysis suggests that 95% of the time, the prevalence of lameness in summer would be expected to be between 0.23 and 4.3 times that of the prevalence in spring. The specificity and accuracy of identifying a farm as acceptable on both occasions from a single observation were, respectively, 74% and 92% in spring, and 59% and 87% in summer. CONCLUSIONS: A single, one-off, whole-herd lameness score does not accurately predict future lameness prevalence. Similarly, acceptable status (lameness prevalence < 5%) in one season is not sufficiently specific to be used to predict welfare status in subsequent seasons. CLINICAL RELEVANCE: Whole-herd lameness scoring should be used principally as a means of detecting lame cows for treatment. A single whole-herd lameness score by an independent assessor should not be used to determine a herd's welfare status.