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The objective of this randomized clinical trial was to evaluate the effect of selenium and vitamin E supplementation by systemic injection on dairy calf health and growth during the pre-weaning period. The study was conducted at 39 dairy farms in Ontario, selected through a convenience sample of farms in close proximity to either Guelph or Kemptville. A total of 835 Holstein heifer calves were enrolled in this study. At birth, calves were randomly allocated to receive selenium and vitamin E supplementation by injection (3 mg sodium selenite and 136 IU dl-a-tocopherol acetate) or a placebo solution. At enrollment, producers recorded time of birth, calving ease, and colostrum feeding status. At weekly visits to the individual dairy farms, trained technicians collected measurements and samples from enrolled calves. Blood was collected from calves that were up to 8 d of age to assess the concentration of serum total protein and selenium. Between 8 and 15 d of age, fecal samples were collected to identify the presence of rotavirus and Cryptosporidium parvum (C. parvum) using a commercially +available lateral immuno-chromatography antigen detection kit. Each enrolled calf was also weighed and assessed for health scores during the first, second, and seventh weeks of life. The average serum selenium concentration (SD) in treated calves was 0.08 μg/mL (0.02), versus 0.06 μg/mL (0.01) in control calves. The incidence of failure of passive transfer (FPT) among study calves was 21%, and did not differ between treatment groups. The mean average daily gain (ADG) for the study period was 1.43 lb (0.65 kg)/day and was not associated with selenium and vitamin E supplement injection. Of the 761 fecal samples tested, 272 (36%) and 118 (16%) tested positive for C. parvum and rotavirus antigen, respectively. Selenium and vitamin E treatment had a protective effect against rotavirus infection. However, there was no effect of experimental treatment on C. parvum infection status. Reduced odds of treatment for diarrhea was also seen in the selenium and vitamin E treatment group. This study suggests that selenium and vitamin E injection at birth could improve pre-weaning health by reducing rotavirus infection and diarrhea., The Bovine Practitioner, Vol. 53, No. 1 (2019 Spring)

A partial budget model was developed to evaluate the economic value of Rumensin Controlled Release Capsule (CRC) boluses when administered before calving to reduce disease and increase milk production. After accounting for disease incidences in a herd and the percentage by which Rumensin CRC can reduce them, and the increase in milk production attributable to administration of Rumensin CRC, the return on investment (ROI) per lactation was 4:1. Another partial budget model was developed to estimate the economic value of propylene glycol (PG) to treat ketosis when diagnosed by 3 different cow-side tests or when administered to all cows without using any cow-side testing. After accounting for the sensitivity and specificity of each test, ROI per lactation ranged from 2:1 to 4:1. The ROI was 2:1 when no cow-side testing was used. In conclusion, prevention of diseases that occur in the postpartum period and treatment of ketosis after calving yielded a positive ROI that varies based on disease incidence and method of diagnosis.

The objective of this study was to develop a model to estimate the cost of a case of subclinical ketosis (SCK) in Canadian dairy herds. Costs were derived from the default inputs, and included increased clinical disease incidence attributable to SCK, $76; longer time to pregnancy, $57; culling and death in early lactation attributable to SCK, $26; milk production loss, $44. Given these figures, the cost of 1 case of SCK was estimated to be $203. Sensitivity analysis showed that the estimated cost of a case of SCK was most sensitive to the herd-level incidence of SCK and the cost of 1 day open. In conclusion, SCK negatively impacts dairy herds and losses are dependent on the herd-level incidence and factors included in the calculation.

The objective of this research was to evaluate the usefulness of a novel calf VIGOR assessment tool to measure birth trauma and associations with future health and growth. In addition, pain management therapy using meloxicam injectable solution was evaluated for calves suffering from birth trauma and reduced vigor. A total of 842 heifer and bull calves from 10 commercial dairy herds were enrolled in a randomized, double-blind clinical field trial. At birth, newborn VIGOR was evaluated by the dairy producer to assess the Visual appearance, Initiation of movement, General responsiveness, Oxygenation, as well as heart and respiration Rate of the calf. Subsequently, calves were administered either a 1.0 mL subcutaneous injection of meloxicam or placebo solution. Each calf was measured for growth and assessed using a standardized clinical score for health at 1, 2, 3, and 6 weeks of age. Compared to unassisted calvings, calves born with assistance had lower vigor. Assisted calves treated with meloxicam had improved weight gain in the first week compared to placebo-treated calves. In contrast, treatment with meloxicam resulted in lower gains in observed but unassisted calves. Calves with improved newborn vigor and better health had significantly greater weight gain up to 6 weeks of age. Meloxicam-treated calves had better health from birth to 6 weeks of age. Overall, the calf VIGOR score is a good indicator of trauma at calving. Meloxicam therapy shows promise for improving health and growth, particularly for calves born with assistance., The Bovine Practitioner, Vol. 49, No. 1 (2015 Spring)

Serum and milk samples from 1229 cows on 22 Ontario dairy farms were individually tested for antibodies specific for bovine leukosis virus (BLV) and Neospora caninum by enzyme-linked immunosorbent assay (ELISA). Antibodies against BLV were present in 361 serum samples (29.4%) and 369 milk samples (30.0%). Comparing the 2 tests, agreement was almost perfect (k = 0.86; 95% CI = 0.83 to 0.90) and the proportions of samples positive were not significantly different (P = 0.56). Both tests identified the same 3 herds free of bovine leukosis virus. Antibodies against N. caninum were detected in 138 serum samples (11.2%), and 111 milk samples (9.0%). Agreement between the 2 tests was moderate (k = 0.52; 95% CI = 0.43 to 0.59). Four herds were free of neosporosis by the serum test, while 10 herds were negative by the milk test. The ELISA on milk samples facilitates sample collection to classify herds free of BLV; the milk N. caninum ELISA was less reliable in predicting herd-level infection.