|Abstract or Summary
- The transition period is a time of increased nutritional demands and risk to metabolic and infectious diseases in dairy cows due to a suppressed immune system. These problems lead to reproductive challenges, increased culling rates, and decreased milk production postpartum, which leads to decreased profits. Feeding yeast (Saccharomyces cerevisiae) or its fermentation product during the transition period may counteract some of those challenges by improving appetite, nutrient utilization, and immune function. The objective of this study was to evaluate the effects of a single and a double dose of Saccharomyces cerevisiae fermentation product (Diamond V Original XP™; XP) on the risk of metabolic and infectious diseases, reproductive function, and variable net gain in multiparous Holstein dairy cows on a commercial dairy.
A total of 160 multiparous Holstein cows, housed in the same pen, were fed a supplementation mixture of 0 (n = 54), 56 (n = 52), or 112 g/d (n = 54) of XP, corn, and molasses, provided as a top dressing starting 28 d before the expected calving date and ending 28 d postpartum. The supplement consisted of 0, 56, or 112 g of XP mixed with 84 g of molasses and 168, 112, or 56 g of corn
meal, respectively. The incidence and duration of retained placenta, metritis, mastitis, ketosis, laminitis, udder edema, spent time in the hospital pen, or was sold or died in the first 100 d postpartum were recorded. Somatic cell count was analyzed from DHIA records. Body condition scores (BCS) were recorded weekly -28 to 28 d with relation to calving, plus at 7 and 14 wk postpartum. To indicate ovarian activity, serum progesterone concentrations were determined at 28, 35, 42, and 49 d postpartum. Conception rates, number of services, and days open were recorded as indicators of reproductive success. Variable net gain was defined as the difference between total costs/losses and total income. Total costs/losses included expenses for XP, medical treatment, and milk profit lost due to discarded milk and culling, whereas total income was calculated from milk and cow cull sales.
Feeding XP improved supplement intake at parturition (P = 0.02) and decreased the incidence and treatment length of clinical mastitis (P = 0.02 and P = 0.08) and somatic cell scores in milk (P = 0.08). Feeding a double dose of XP additionally tended to decrease the incidence and duration of udder edema (P = 0.09 and P = 0.07) and days lost due to early culling or death (P = 0.05). Serum progesterone concentrations were higher at d 42 and 49 postpartum in cows fed XP (both P = 0.04), whereas indicators of reproductive success were not significantly altered. A double dose compared with a single dose of yeast fermentation product increased variable net gain during the supplementation period in 2nd lactation cows by decreasing costs (both P = 0.05). Our results suggest that feeding Saccharomyces cerevisiae fermentation product during the
transition period may improve appetite, mammary health, ovarian activity and, ultimately, profit margins in multiparous dairy cows.