Supplementation of Blackberry Pomace during the Transition Phase May Improve Health and Immune Function of Dairy Cows in the Week before Calving

Blackberry pomace, the waste from blackberry processing, is rich in polyphenolic compounds that have anti-inflammatory and anti-oxidative properties. More than 80% of dairy cows become sick after calving with diseases such as mastitis and ketosis, which in turn have a negative effect on their production and reproductive health. In this study the effectiveness of blackberry pomace as a natural supplement to improve the overall health of transition dairy cattle was assessed. We hypothesized that the addition of blackberry pomace would help improve metabolic status (lower free fatty acids (FFA), lower β-hydroxybutyrate (BHB), and increase glucose) and overall health around the time of calving. Using completely randomized block design, 24 cows were assigned to three groups and received between 4 weeks before and after calving either no supplement (Control), 57g/day of dried blackberry pomace (Low Blackberry), or 114g/day of dried blackberry pomace (High Blackberry) as top dressing to their standard total mixed ration (TMR). Blood samples were collected on approximately days 28, 21, 14, 9, 7, 5, 3, and 1 pre-partum, while both blood and milk samples were collected on days 0, 1, 3, 7, 14, 21, and 28 post-partum. Upon completion of the study, blood samples were analyzed for BHB, glucose, phosphorus, and FFA concentrations. In addition, we collected body condition scores (BCS) weekly and feed intake data daily. All data was analyzed using PROC MIXED and PROC GLIMMIX in SAS version 9.4. There was a significant decrease (p<0.05) in BHB for day -1 and BUN day -3 relative to calving in the Low Blackberry cows when compared with the Control cows. In addition, there was a significant increase (p<0.05) for glucose day 0 relative to calving for High Blackberry cows compared with Control cows. Serum phosphorus concentration at day -1 relative to calving significantly increased (p<0.05) for both Blackberry groups when compared with the Control group. The average BCS for the High Blackberry cows was significantly higher (p<0.05) than that of the Control cows in the week prior to calving. There were no differences observed in milk yield or feed intake when comparing the groups. In conclusion, the supplementation of blackberry pomace to multiparous transition cows helped to improve metabolic status and health in the week leading up to calving.