Measuring the torque required to cause vertebral dislocation in cattle tails.

Aim: To estimate, ex vivo, the torque required to cause vertebral dislocation of cattle tails.Methods: Five tails from dairy cows, severed at the junction between the sacrum and the first caudal vertebra, were sourced from a slaughterhouse. Within 2 hours of slaughter, the severed end of each tail was clamped in a vice and a steel collar was placed halfway along the tail. A torque wrench was attached to the steel collar, which was then rotated to produce an audible and palpable vertebral dislocation, and the torque at the time of the break was recorded.Results: The maximum torque required to break a tail was 20 Nm, the minimum was 9.8 Nm, and the uncertainty was 4.9 Nm.Conclusion: The torque required to break a cow's tail is unlikely to be applied accidentally if cattle are handled following recommended best practice. Thus if cattle on a farm can be shown to have broken tails due to manipulation by farm staff, cattle handling is not meeting the recommended best practice of the New Zealand Dairy Cattle Code of Welfare.

Sampling strategies for assessing lameness, injuries, and body condition score on dairy farms.

Our objective was to evaluate how sampling strategies (i.e., how many cows to sample and which animals to include) used in 4 dairy cattle welfare assessment programs affect the classification of dairy farms relative to thresholds of acceptability for animal-based measures. We predicted that classification performance would improve when more cows were sampled and when selecting from all lactating cows versus when some pens were excluded. On 38 freestall farms, we assessed all 12,375 cows for lameness, injuries on the tarsal (hock) and carpal joints, and body condition score and calculated the farm-level prevalence for each measure. Based on approaches used in the industry, we evaluated 6 sampling strategies generated using formulas with precision (d) of 15, 10, or 5% applied to either a single high-producing pen or all lactating cows; an additional sample was included with d = 10% applied to the entire herd, selecting lactating cows in proportion to their representation in the herd. For each sampling strategy, cow records were selected randomly (in 10,000 replicates) to calculate prevalence. The strategy of assessing all cows in the high-producing pen was also compared. Farms were classified as meeting (below) or failing to meet (above) thresholds of ≤15% moderate lameness; ≤20% moderate carpal or hock injuries; <10, <5, and ≤1% severe lameness; or injuries on the carpus or hock; and <5, <3, <1, or 0% thin cows. For each measure and threshold, we calculated pooled percent agreement, kappa, sensitivity, specificity, and positive and negative predictive value for each sampling strategy using true prevalence as the gold standard for herd classification. Across measures and thresholds, classification performance increased with the number of cows sampled [i.e., when narrower precision values (d = 5 vs. 10 vs. 15%) were used in the sample size calculation]. Because narrower precision values can dramatically increase sample size, assessment programs may need to consider both feasibility and the degree of misclassification they will accept. Applying the formula directly to lactating cows performed better than applying it to the entire herd and then selecting lactating cows in proportion to their representation in the herd. Farm classifications were similar whether cows in the hospital pen were included or excluded from the sample. Selecting all cows from the high-producing pen resulted in classifications similar to when including all lactating cows, suggesting that assessing cows from the high-producing pen may serve as an acceptable proxy for all lactating cows on the farm.

Thermographic evaluation of primary closure and second intention healing in dairy calves.

OBJECTIVE: To evaluate the suitability of infrared thermography in assessing healing of surgically created wounds that are managed by primary closure or second intention in neonatal dairy calves during a 3-week period. STUDY DESIGN: Randomized clinical trial. ANIMALS: Six Jersey bull calves. METHODS: Two skin patches approximately 10 cm2 were shaved on each hind limb of all calves. The dorsal patch was designated the wound creation site, and the ventral patch was the control. The wound creation sites were randomly assigned for either primary closure or healing by second intention. Wounds were created by using an 8-mm biopsy punch. Thermographic imaging was performed prior to wound creation and at 0 minutes; 15 minutes; 2, 4, 8, 12, and 24 hours; and 2, 3, 4, 7, 10, 14, and 21 days postwounding. RESULTS: There were no differences in skin temperature changes observed between wounds that were managed by primary closure or second intention (P = .9934) at any time. Time after wound creation had an effect on the skin temperature (P < .0001), with skin temperature consistently warmer (P < .05) 2, 4, and 8 hours after creation of wounds compared with subsequent times. CONCLUSION: Infrared thermography was unable to detect differences in wound healing by primary closure or second intention in this model. CLINICAL SIGNIFICANCE: Thermographic monitoring to detect differences in wound healing was not evident in this model. This model might be useful in monitoring temporal changes during early wound repair.

Tibial fracture repair with angle-stable interlocking nailing in 2 calves.

OBJECTIVE: To report tibial fracture repairs with I-Loc angle-stable interlocking nails (AS-ILN) in 2 calves. STUDY DESIGN: Clinical case reports. ANIMALS: One 5-day-old Holstein calf and one 3-month-old beefalo calf. METHODS: In a 50-kg Holstein calf, a proximal juxtametaphyseal comminuted tibial fracture with tibial tuberosity slab fracture was repaired with an 8-160-mm I-Loc nail and 2 cortical lag screws. In an 89-kg beefalo calf, a long oblique middiaphyseal tibial fracture was repaired with an 8-185-mm I-Loc nail and 5 double loop cerclage wires. In each case, an I-Loc AS-ILN was selected because unique biomechanical challenges precluded treatment with traditional osteosynthesis methods, such as external coaptation or plate fixation. RESULTS: No complications were diagnosed, and clinical union was documented 4 weeks after surgery in both cases. Axial growth continued in both calves, with no evidence of angular limb deformity at 7- and 6-month follow-up. CONCLUSION: This is the first report describing the use of the I-Loc nail in a bovine species. This application led to uncomplicated healing of tibial fractures and continued growth in both young calves described here. CLINICAL SIGNIFICANCE: Interlocking nailing may provide an effective and safe alternative for osteosynthesis of tibial fractures in young calves. Insertion of the AS-ILN across the center of the proximal tibial physis of a rapidly growing calf does not seem to alter its growth potential.

Clinical and laboratory findings in 503 cattle with traumatic reticuloperitonitis.

BACKGROUND: The study evaluated the results of clinical examination and haematological and serum biochemical analyses in 503 cattle with traumatic reticuloperitonitis (TRP). RESULTS: The most common clinical findings were abnormal demeanour and general condition (87%), decreased rumen motility (72%), poorly digested faeces (57%), decreased rumen fill (49%), fever (43%) and tachycardia (26%). In 58% of the cattle, at least one of three tests for reticular foreign bodies (pinching of the withers, pressure on the xiphoid and percussion of the abdominal wall) was positive, and in 42% all three tests were negative. The most common haematological findings were decreased haematocrit in 45% of cattle and leukocytosis in 42%. An increase in the concentration of fibrinogen in 69% of cattle and total protein in 64% were the main biochemical findings. The glutaraldehyde test time was decreased with coagulation occurring within 6 min in 75% of cattle. CONCLUSIONS: In many cases, a diagnosis of TRP is not possible based on individual clinical or laboratory findings because even the most common abnormalities are not seen in all cattle with TRP.

Use of on-farm emergency slaughter for dairy cows in British Columbia.

On-farm emergency slaughter (OFES), whereby inspection, stunning, and bleeding occur on the farm before the carcass is transported to a slaughterhouse, is permitted in some jurisdictions as a means to avoid inhumane transportation while salvaging meat from injured animals. However, OFES is controversial and its use for dairy cows has been little studied. Inspection documents for 812 dairy cows were examined to identify how OFES was used for dairy cows in British Columbia, Canada, over 16.5 mo. Producers used OFES for dairy cows aged 1 to 13 yr (median of 4 yr). Leg, hip, nerve, spinal, foot, and hind-end injuries or conditions (in that order) were the most common reasons for OFES, and some cases may have been a consequence of calving. Foot conditions were disproportionately common among cows 5 yr and older, and hind-end conditions were disproportionately common among cows 6 yr and older. Producers used OFES promptly after traumatic injury (within 1 d) for some cows, but OFES was delayed for others, sometimes until cows had been nonambulatory for 2 to 6 d. In some cases, OFES was used for nontraumatic chronic conditions, such as lameness and hind-end weakness, rather than traumatic injuries such as fractures and dislocated hips. Use of OFES appears to conform to the purpose of the program when used promptly after traumatic injuries, but clear guidelines are needed to avoid inappropriate use and delays that may prolong animal suffering.

Corrective Osteotomy of a Metacarpal Deviation Caused by Fracture in a 9-Month-Old German Fleckvieh Heifer.

OBJECTIVE: To describe the surgical treatment of a metacarpal deviation caused by an untreated Salter-Harris type I fracture in a heifer. STUDY DESIGN: Case report. ANIMAL: 9-month-old German Fleckvieh heifer. METHODS: A closing wedge osteotomy was performed to correct deviation of fused metacarpal III and IV. A triangular bone wedge was removed and the proximal and distal fragments of the bone were brought into apposition and stabilized with an 11-hole T-plate. A full-limb cast was applied postoperative. RESULTS: Radiographs were taken at 2, 4, and 6 weeks postoperative. No postoperative complications occurred and the heifer was discharged from the clinic 51 days after surgery. Radiographs taken 6 months after discharge showed periosteal callus formation around the closing wedge osteotomy. At 24 months postoperative, implants were intact and the heifer was in good general condition. CONCLUSION: Closing wedge osteotomy was successfully performed in a heifer with a metacarpal deviation, correcting the malunion after a untreated Salter-Harris type I fracture. Radiographs showed evidence of osteotomy healing and the heifer had full use of the affected leg at 24 months postoperative.

Surgical Correction of Traumatic Lateral Patellar Luxation.

OBJECTIVE: To report successful surgical repair of a grade IV lateral patellar luxation in a 437-kg heifer. STUDY DESIGN: Case report. ANIMAL: Seventeen-month-old Holstein heifer (437 kg). METHODS: Diagnosis of traumatic lateral patellar luxation was made based on physical examination, and confirmed on radiographs. Arthroscopic examination of the stifle assessed joint changes. Lateral patellar luxation was surgically repaired using lateral release of the patella and medial imbrication of the joint capsule. RESULTS: The heifer presented nonweight-bearing lameness of the left hind limb (5/5 lameness score). Unilateral grade IV lateral patellar luxation was diagnosed based on physical examination and radiography. Arthroscopic examination of the stifle showed synovitis and cartilage eburnation of the medial articular surface of the patella and of the lateral trochlear ridge of the femur. Lateral release of the patella and medial imbrication of the joint capsule was performed. The heifer remained lame (4.5/5 lameness score) and developed severe disuse muscle atrophy after surgery. By day 112, the heifer was walking easily and was completely weight bearing on the left hindlimb but did have a gait alteration (2/5 lameness score). On day 229, the heifer calved for the first time and lameness was no longer evident. CONCLUSION: This report documents successful surgical treatment of traumatic lateral patellar luxation in a large heifer but additional case evaluation is required to provide an accurate prognosis for this condition and treatment in large cattle.

Pathophysiology of humeral fractures in a sample of dairy heifers.

AIMS: To investigate the pathophysiology of humeral fractures in first-lactation dairy heifers in the North Island of New Zealand. METHODS: Ten 2-year-old dairy heifers with humeral fractures were subject to euthanasia and the fractured and non-fractured contralateral humeri were collected. Humeri were also collected from 10 unaffected 2-year-old dairy heifers sent for slaughter. Humeri from heifers with and without fractures were examined using computed tomography (CT), and four slices of the diaphysis and lower metaphysis (D1-4) were analysed using the Bone J plug-in for Image J. The humeri were sectioned sagittally and 5 mm bone slabs were processed for histopathology. RESULTS: There were no differences in bone length between the humeri from heifers with or without fractures (p=0.31). Median cortical bone mineral density at D1 was increased in humeri from affected compared with unaffected heifers (810 vs. 783 mg/cm(3); p=0.03), cortical area at D1 was reduced (816 vs. 1,037 mm(2); p=0.04), the median stress strain index, a calculated theoretical measure of bone strength, at D1 was decreased (7,288 vs. 9,072 mm(3); p<0.01), and the median ratio of overall bone volume (BV) to total volume (TV) was decreased (0.32 vs. 0.38; p<0.01). The median periosteal circumference at D1 was also reduced in humeri from affected compared with unaffected heifers (151 vs. 173 mm; p<0.01). Using a binary logistic regression model, BV/TV was the only variable associated with humeral fractures (p=0.03).In nine of 10 fractured humeri the fracture appeared to have started just distal to the head of the humerus and spiralled distally down the diaphysis to end just above the humeral condyles. Histopathological findings included a reduction in the number, and thickness, of trabeculae in the metaphysis; metaphyseal growth arrest lines, and osteoclastic resorption in fractured humeri. Concentrations of copper in serum from four of five animals with fractures were within, and one was below, normal reference ranges, while concentration of copper in the livers of three heifers with fractures were below adequate ranges. CONCLUSIONS: The CT and histological findings were consistent with a diagnosis of osteoporosis. We propose that humeral fractures in dairy heifers are associated with osteoporosis, possibly as a result of insufficient deposition of bone during growth because of protein-calorie malnutrition. Increased osteoclastic resorption of bone associated with calcium mobilisation for lactation, and periods of copper deficiency may contribute to bone weakening.

IMAGING DIAGNOSIS-TRAUMATIC ABOMASITIS CAUSED BY FOREIGN BODIES IN A COW.

A 2-year-old Holstein cow presented with a history of colic signs of 3 days' duration that had not responded to routine medical therapy. Physical examination findings were consistent with tachycardia and colic. Ultrasonographic examination of the abomasum revealed a thin hyperechoic line producing a cone shadow. Radiography of the cranial abdomen revealed two radiopaque objects within the abomasum. Right paracostal laparotomy and abomasotomy permitted palpation and manual removal of two metallic foreign bodies and a small quantity of gravel. The animal recovered well after surgery and no signs of colic were observed. Her appetite and rumination were also improved.

[Intermittent upward fixation of the patella in 12 cows: A retrospective study of treatment and long-term prognosis]. / Patella-Fixation nach proximal bei 12 Kühen: Eine retrospektive Untersuchung zu Therapie und Langzeitprognose.

This retrospective study investigated possible risk factors for intermittent upward fixation of the patella and the outcome of medial patellar desmotomy in 12 cows. All but one young cow had distinctive clinical signs, which usually started in the periparturient period. Medial patellar desmotomy led to normalisation of the stride in 10 cows but did not improve the condition of the young cow. Another cow developed instability and signs of lateral patellar luxation in the affected stifle and was euthanized. The 10 cows that were operated successfully remained in the long term free of symptoms. Medial patellar desmotomy is a suitable treatment for upward patellar fixation in cattle but should be reserved for cows with typical clinical signs. The medial patellar ligament should be cut 4 to 6 cm proximal to its insertion on the tibia to minimise the risk of injury to the middle patellar ligament.

Transfixation pinning and casting of a comminuted metacarpal fracture in a 870 kg bull.

OBJECTIVE: To report metacarpal fracture repair in a bull. STUDY DESIGN: Clinical report. ANIMALS: Simmental bull (n = 1; 870 kg). METHODS: A comminuted right metacarpal fracture was repaired using 2 transfixation pins (6 mm diameter) through the distal metaphysis and diaphysis of the radius and a full limb synthetic resin cast. RESULTS: Slight bending of both pins occurred 1 day after surgery. Both pins were loose and removed at 31 days and a full-limb cast reapplied. The cast was changed at approximately -4 week intervals. On day 50, the right carpus had moderate overextension and a valgus deformity. An exercise program was started on day 62, and on day 110, the cast was replaced with a Robert-Jones-bandage. At 130 days there was circumferential callus formation and the bull was discharged. At 6.5 months, overextension of the right carpus had resolved and carpal valgus had improved. The bull returned to at 7.5 months after surgery, and was successfully used for 4 years. CONCLUSION: For highly valuable cattle like this breeding bull, a surgical treatment of such a fracture should be attempted despite a primarily poor prognosis.

Necropsy as a means to gain additional information about causes of dairy cow deaths.

High mortality among dairy cows constitutes a problem both financially and in relation to animal welfare. Knowledge about causes of death is a fundamental step toward reducing cow mortality. Several studies have evaluated causes of dairy cow deaths. However, the vast majority of studies describing causes of death are based on questionnaires with farmers or veterinarians. It is uncertain to what degree such information is sufficient and reflects the true cause of death or euthanasia. In this study, proximate causes of death were evaluated based on a thorough necropsy of a random sample of 79 Danish dairy cows at an incineration plant. The necropsy was combined with information about the farmer's perception regarding the cause of death and information about disease treatments from the Danish Cattle Database. Pneumonia and locomotor disorders were found to be the most predominant proximate causes of death. Often the death occurred after a prolonged period during which the cow suffered several different disorders, even though this was often not noticed by the farmer. Causes of death stated by the farmers agreed with the necropsy results in 50 to 64% of cases. Information about disease treatments from the Danish Cattle Database agreed with the necropsy results in 34 to 39% of cases. All 3 sources of information about cause of death agreed in only 1 out of 4 cases, and even when the farmer and the disease recordings did agree with the necropsy results, the latter often gave additional information about the cause of death. In many situations, therefore, a necropsy may be a valuable tool when trying to control excessive cow mortality in a herd.

A finite element model to simulate femoral fractures in calves: testing different polymers for intramedullary interlocking nails.

OBJECTIVE: To verify if the finite element method can correctly estimate the performance of polyacetal and polyamide 6 intramedullary nails in stabilizing a femoral fracture in calves and to estimate the performance of a polypropylene nail in same conditions. STUDY DESIGN: Computational and experimental study. SAMPLE POPULATION: Finite element models (FEMs). METHODS: Based on a 3-dimensional finite element method (FEM) of the femoral diaphysis, 3 models were constructed to simulate an oblique simple fracture stabilized by an intramedullary nail composed of 1 of 3 distinct polymers. Models were tested under 6 loading conditions that simulated a static calf or a calf in different walking phases. Maximum bone and implant stresses were compared to yield and rupture stresses of specific materials. RESULTS: Under static conditions, all polymers were resistant to critical deformation and rupture because maximum von Mises stresses were lower than the respective yield and rupture stresses. However, during walking, maximum stresses exceeded the yield and rupture limits of the polymers, in agreement with a previous in vivo study, which used polyacetal and polyamide nails. CONCLUSIONS: FEM correctly estimated that polyacetal and polyamide 6 nails would fail to immobilize an oblique femoral diaphyseal fracture in calves that were allowed to walk freely during the early postoperative period. FEM can be useful in the development of new bovine orthopedic devices.

Repair of transverse process fractures of multiple lumbar vertebrae in an adult dairy cow.

OBJECTIVE: To report lumbar vertebrae transverse process fracture repair using a narrow 3.5 mm limited contact dynamic compression plate (LC-DCP) in an adult dairy cow. STUDY DESIGN: Case report. ANIMALS: A 3-year-old Holstein cow. METHODS: Under general anesthesia, fractured left transverse processes of lumbar vertebrae 2-4 were repaired using internal fixation. A narrow 3.5 mm LC-DCP was contoured and secured to the spinous process and the transverse process of each fractured vertebra. RESULTS: Fractured transverse processes of the lumbar vertebrae were successfully repaired and the cow discharged 10 days after surgery. At 10 months after surgery, the cow was declared reserved champion at a regional show. CONCLUSION: A paramedian approach and muscle splitting can be used to repair multiple lumbar transverse process fractures using internal fixation with an excellent cosmetic outcome.

[Life-threatening injuries of the subcutaneous ventral abdominal veins in dairy cows]. / Lebensbedrohliche Verletzungen der Bauchwandvenen bei Milchkühen.

Injuries of the superficial veins on the ventral abdomen of dairy cows can result in life-threatening haemorrhage. Treatment of these injuries can be difficult because of the characteristics of the veins. Five cows aged 6.5 to 12 years were referred to the Animal Hospitale Zurich, because of intermittent haemorrhage from a ventral abdominal vein. Four of the cows were near term and one had calved two weeks before referral. Intermittent bleeding was seen from the highly convoluted and dilated subcutaneous tributaries to the cranial superficial epigastric vein (milk vein). The haematocrit of 2 cows was markedly lower than normal. Emergency slaughter of one of the cows was carried out because of advanced age. The other 4 cows were sedated and after application of local anaesthetic, the wounds were debrided and sutured. Two of the cows required a blood transfusion before being operated. There were no postoperative complications. This type of injury seems to occur predominantly in pluriparous dairy cows close to term, in which the tributaries to the milk vein have undergone varicose changes. Treatment should consist of surgical resection of the injured tissue and suturing of the venous wall, subcutaneous tissues and skin.

[Treatment of long bone fractures in 125 newborn calves. A retrospective study]. / Behandlung von Frakturen der langen Röhrenknochen bei 125 neugeborenen Kälbern. Eine retrospektive Untersuchung.

OBJECTIVES: Retrospective study of the causes, location, configuration, treatment and outcome of long bone fractures in newborn calves. MATERIAL AND METHODS: The medical records of 125 calves presented during a 16-year period because of fracture of the humerus (3 calves), radius/ulna (14), femur (50) or tibia (58) were evaluated. The majority of calves (61.6%) sustained the fractures during assisted delivery. Of 125 calves, 107 were treated and 18 were euthanized because of concurrent diseases. Conservative treatment was used in 16 calves and surgical treatment in 91. Four of the latter were euthanized because of muscle contraction which prevented fracture reduction, and five others died in surgery. RESULTS: Fracture healing occurred after conservative treatment in 10 of 16 calves and after surgical treatment in 44 of 82 calves. The outcome was better in calves with plate and clamp-rod internal fixation (37/58 healed) than with intramedullary pinning (4/16 healed) or external fixation (3/8 healed). There were significant associations (chi2-test, p<0.01) between concurrent diseases and choice of therapy and fracture healing. Of 67 calves that developed complications, only 26 could be cured. Common complications were implant loosening and instability, which were often followed by osteomyelitis and sepsis. Implants were removed in 39 of 44 surgically treated calves that survived up to 6 months postoperatively. Long-term follow up (> 6 months postoperatively) by clinical and radiographic re-examination (25 calves) or telephone inquiry (29 calves) revealed that 54 animals were sound and had returned to their intended use. CONCLUSIONS AND CLINICAL RELEVANCE: The treatment of long bone fractures in newborn calves remains difficult because of a high incidence of complications. These are most likely attributable to trauma during delivery, which results in insufficient colostrum intake and predisposes to concurrent diseases. In addition, the characteristics of juvenile bones do not provide sufficient physical strength for implants. Therefore, professional and diligent assistance during forced extraction, particularly in presentations with "stifle lock" or "hip lock", is required to minimize the incidence of long bone fractures in newborn calves. Most cases require surgical fixation, which is time consuming, expensive and carries a guarded prognosis.

Associations between On-farm Welfare, Milk Production, and Reproductive Performance in Dairy Herds in Northwestern Spain.

This study was conducted to evaluate the relationship between on-farm welfare, milk production, and reproductive performance in dairy herds in northwestern Spain. Data on the welfare status from 31 herds were collected using the Welfare Quality® protocol. Linear regression was applied to assess associations between WQ criteria/principle scores on farm average 305-d milk production and calving to conception interval (CCI). Results indicated that milk production was associated with the absence of prolonged hunger criterion (average increase of 22.33kg per unit score). Each one unit increase in the score for good feeding was also associated with a26.49kg increase in milk production. A10 unit increase in the scores for the absence of pain (by management procedures), expression of social behaviors, and absence of injuries was associated with reductions in CCI by 1.77, 0.8, and 0.29 days. CCI also decreased by 1.08 and 0.53 days when the principles of good health and appropriate behavior increased by 10 units. This study points out associations which can help encourage the dairy cattle sector to adopt practices that promote animal welfare.