Invited Review: Unique reproductive challenges for certified organic dairy herds

Because dairy production under organic regulations is unique in multiple aspects, reproductive management in these systems is performed under specific conditions. The purpose of this review was to highlight some particular reproductive challenges associated with organic certified dairy production in the United States. Refereed scientific journals and books available in online databases were consulted in this review. Only peer-reviewed articles published in English were selected. Over the past decade, the demand for organically produced food has increased in the United States, with the emergence of organic milk production as one of the fastest growing segments of organic agriculture in the country. Among many specific requirements, regulations for organic dairies in the United States mandate minimum grazing times, together with sufficient levels of DMI coming from pasture. In addition, the use of antibiotics and hormones (excluding oxytocin for postpartum disorders) is prohibited. This scenario results in particular reproductive challenges with specific implications. Although this review centers on reproduction, it also attempts to discuss other areas that indirectly affect the approach to reproductive management and the subsequent fertility outcomes. Multiple interrelated factors are unique to organic dairy production, and they influence fertility. Lower levels of milk production, use of heterosis, smaller herd sizes, unavailability of reproductive hormones to manage estrous and ovulation and antimicrobials to treat reproductive disease are elements that should be considered when analyzing fertility in organic certified dairies.