ABSTRACT
Ruminal acidosis is arguably the most common digestive disorder in conventional dairy production (Penner and Beauchemin, 2010). Data obtained, using ruminocentesis, in lactating dairy cattle in the United States suggest that prevalence rates range between 19 and 40%, depending on the stage of lactation (Krause and Oetzel, 2006). More recent data using continuous ruminal pH measurement have indicated that the prevalence may be higher than those previously reported. In fact, during the post-partum phase of the transition period prevalence rates may exceed 60% (Penner et al., 2007, 2009). While intensive feeding management is often implicated with ruminal acidosis, there is considerable evidence to suggest that ruminal acidosis can occur on pasture when cattle are fed high-quality fresh forages, especially when supplemental silage or grain is provided (Bargo et al., 2002; Kolver and de Veth, 2002; O’Grady et al., 2008). Moreover, Holstein calves at the time of weaning also have ruminal pH profiles indicative of ruminal acidosis (Suarez et al., 2006; Laarman et al., 2012; Wood et al., 2015), suggesting that ruminal acidosis is not limited to lactating cows.
