Use of hormones on New Zealand dairy farms: an analysis of the results from a survey of farmers and a survey of veterinarians.

Abstract

Aims: 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.