Impact of Mastitis on Reproductive Performance

Introduction On many dairy farms, reproductive failure and the occurrence of mastitis are two of the most common management problems. Risk factors for mastitis and reproductive disorders are similar and it can be difficult to determine the specific impact of mastitis on reproductive performance. Age of cow, heat stress, occurrence of metabolic diseases, immune suppression in early lactation and high milk yield are all associated with increased risk of mastitis and reduced fertility. However, the direct impact of mastitis on reducing reproductive performance was first noted more than 2 decades ago (Moore et al., 1991) and since that time researchers have consistently reported that mastitis can significantly reduce reproductive performance (Barker et al., 1998, Schrick et al., 2001; Santos et al., 2004a; Hertl et al., 2010). The occurrence of mastitis has been associated with reductions in the occurrence of natural estrus (Moore et al., 1991; Barker et al., 1981, Schrick et al., 20012, Santos et al., 2004a), the ability to conceive after breeding (Ahmadzadeh et al., 2009; Barker et al., 1981; Chebel et al., 2004; Santos et al., 2004a; Schrick et al., 20012) and increased pregnancy loss (Chebel et al., 2004; Hudson et al. 2012; Santos et al., 2004a).