The association between fluoride concentrations and spontaneous humeral fracture in first-lactation dairy cows: results from two New Zealand studies.

Aim: To assess whether the fluoride concentration in the humeri of first-lactation, 2-year-old dairy cows with a spontaneous humeral fracture is significantly different from that of first-lactation, 2-year-old dairy cows without a humeral fracture.

Methods: Two studies were conducted, the first with nine bone samples from 2-year-old, first-calving dairy cows with a humeral fracture (all from the Waikato region) age-matched with seven control bone samples from the Waikato, Bay of Plenty and Manawatū-Whanganui regions. The second study used 26 bone samples from 2-year-old, first-lactation dairy cows with a humeral fracture (from the Otago, Canterbury, Southland, West Coast, Waikato and Manawatū-Whanganui regions) age-matched with 14 control bone samples (all from the Manawatū-Whanganui region or unknown).

An Assessment of the Epidemiology and Herd-Level Impact of the Fractured Humerus Epidemic in New Zealand Dairy Cattle, 2007-2015: Results from Four Studies.

A multi-method approach integrating data from four independent sources was used to describe some key features of the epidemiology and estimate the herd and within-herd incidence of fractured humeri in New Zealand dairy cattle for the period 2007-2015. The first dataset was from a national case series where cases of humeral fractures in dairy cattle were identified by veterinarians across New Zealand between the 2007/2008 and 2011/2012 lactation seasons. The second dataset was from a pet food company based in the Waikato region, which collated the number of casualty first- and second-lactation cows found to have a fractured humerus post-slaughter in the 2014/2015 lactation season, and the third dataset was a case series conducted by veterinarians employed in a Waikato veterinary business, also from the 2014/2015 lactation season.

Farm management and husbandry practices associated with spontaneous humeral fractures in New Zealand dairy heifers.

Aims: To use a farm-based survey to identify characteristics of the New Zealand dairy system associated with the risk of spontaneous humeral fracture in dairy heifers.

Methods: A questionnaire was designed and made available in print and online to collect information from dairy farmers and/or veterinarians, across New Zealand, about the management and nutrition of cows from birth to first lactation. Data were collected from July 2019 to March 2020 from farms that either had recorded (case farms) or not recorded (control farms) cases of humeral fractures in dairy heifers.

Bone quality changes as measured by Raman and FTIR spectroscopy in primiparous cows with humeral fracture from New Zealand.

The occurrence of spontaneous humeral fractures in primiparous dairy cows from New Zealand prompted the study of bone material from affected cows to further characterize this condition and to outline a likely pathogenesis. Previous studies indicate that these cows developed osteoporosis due to periods of suboptimal bone formation followed by increased bone resorption during the period of lactation complicated by copper deficiency. We hypothesized that there are significant differences in the chemical composition/bone quality in bones from cows with spontaneous humeral fracture compared to cows without humeral fractures.