Introduction

Reproductive efficiency is critical to the profitability of all dairy operations. Each additional day required for a cow to conceive, after 90 days of lactation, costs between $0.50 and $4.00 (US$) per day (22). Improving reproductive efficiency can be difficult as it is influenced by many factors including plane of nutrition, rate of weight gain, level of stress and level of milk production. Improving zinc, manganese, copper and cobalt nutrition of dairy cattle is part of an effective program to improve reproductive performance, as these trace minerals play vital roles in reproduction (Table 1).

The objective of this paper is to review the role of trace minerals in fertility of dairy cattle. In addition, it will address the indirect effects of mastitis, immune function and laminitis on reproduction.