Effects of treatment with propylene glycol and cyanocobalamin on disease, milk production and reproductive outcomes of dairy cows diagnosed with hyperketonemia and hypoglycemia

Almost all periparturient dairy cows experience a period of negative energy balance, and despite improvements to fresh cow management, some dairy cows still experience clinical dis­ease associated with the periparturient period (Duffield et al., 2009; Taylor et al., 2004). Hyperketonemia (HK) remains an im­portant production and animal welfare concern (McArt et al., 2012; Tatone, Duffield, Capel, et al., 2016; Tatone, Duffield, LeB­lanc, et al., 2016), and recently several handheld meters which measure beta-hydroxybutyric acid (BHBA) have been validated in dairy cows and can be used to detect pre-clinical HK (Bach et al., 2016; Tatone et al., 2015). Several studies have explored the screening of post-parturient cows to detect HK and adminis­ter treatment in order to ward off clinical disease and increase milk production (Capel et al., 2021; Gordon et al., 2017; McArt et al., 2012). However, these studies have been inconsistent in their findings, and treatment may not be economically beneficial for farms with a relatively low incidence of HK (McArt et al., 2014). A 2017 study indicated that cows may have variable production responses to HK treatment based on blood glucose concentra­tion (Gordon et al., 2017). Because blood glucose can also be mea­sured cow-side, measurement of blood glucose concurrent with measurement of blood BHBA may be a means to target treatment to cows that will respond to current treatments. Therefore, our objective was to explore the effects of treatment with propylene glycol and cyanocobalamin in early post-partum cows based on both HK and glycemic status. We hypothesized that improve­ments to health, milk production, and reproduction would be greatest among cows that were hypoglycemic.