The Uptake Of Ferulic Acid In Ruminants And The Antioxidant Capacity Of Milk And Milk Replacers
Ferulic acid (FA) is a phenolic compound with antioxidant and anti-cancer properties that naturally occurs in forages. Bound FA is not typically available for ruminant absorption and is excreted primarily in the feces as a component of lignin. However, FA can be released from the lignin complex to increase digestibility in vitro using enzymatic pretreatments. The first objective of this research was to investigate the likelihood of free FA uptake in sheep and the impact of increasing dosages of free FA on DMI and rumen microbes in vitro. There were no negative repercussions on microbial in vitro digestion of alfalfa NDF or on lamb DMI as a result of FA administration. Moreover, the dose dependent presence of FA in the urine of lambs confirmed FA uptake in the blood. Thus, the second objective was to determine if orally dosed free FA could be transferred into the milk of lactating cows. It was observed that free FA could be transferred into milk, and is also present at basal levels of 4.1 [MICRO SIGN]g/L in cows fed maize silage. Given the peak concentration of FA in bovine milk of cows receiving 121% of the FA present in their diet (1500 [MICRO SIGN]g/L), the amount of FA that could potentially be released from feeds using enzymatic pretreatments would still be far below the reported sensory detection threshold of 62 mg FA/L. The primary benefit of increased FA in milk is its effects on antioxidant activity (AOA). However, the benefit of studying one compound‟s contribution to total AOA in milk is limited due to the potential effects of many compounds and their synergies. Therefore, the final objective was to describe the AOA of bovine milk, compared to six calf milk replacers (CMR), varying in fat and protein. Although 69% of calves in the U.S. are raised on CMR, CMR are not formulated for AOA. Five of the 6 CMR analyzed were significantly lower in AOA than milk (52.7 [MICRO SIGN]mol vitamin C equivalent/mL). This research revealed opportunity to better meet the needs of calves in a critical stage of life when AO can enhance immune defense.
ferulic acid; antioxidant; milk replacer
Cherney, Debbie Jeannine
Overton, Thomas R; Barbano, David Mark; Cherney, Jerome Henry
Ph.D. of Animal Science
Doctor of Philosophy
dissertation or thesis