Free ferulic acid uptake in lactating cows.

Ferulic acid (FRA), a phenolic compound with antioxidant and anticancer activities, naturally occurs in plants as a lignin precursor. Many veins of research have been devoted to releasing FRA from the lignin complex to improve digestibility of ruminant feeds. Thus, the objective of this research was to investigate the transfer of a given dosage of the free form of FRA into the milk of dairy cattle. Six mid- to late-lactation Holstein cows at the Cornell Research Farm (Harford, NY) were given 14-d adaptation to diet and stall position. Ad libitum access to a total mixed ration based on haylage and maize silage (31.1% neutral detergent fiber containing 5.52 mg of FRA/g) was provided during the study. A crossover design was implemented so that each cow alternated weekly between FRA-dosed and control. On d 1, jugular cannulas and urine catheters were placed in all cows. On d 2, FRA-dosed cows received a single dosage of 150 g of pure FRA powder at 0830 h via their fistula (n=4) or a balling gun for nonfistulated cows (n=2). Plasma, urine, feces, feed, orts, milk, and rumen fluid were sampled intensively for the next 36 h and analyzed for FRA concentration. On d 8, the cows crossed over and the experiment was repeated. When compared with the control, FRA administration did not have an effect on dry matter intake, milk yield, milk fat yield, milk protein yield, somatic cell count, or neutral detergent fiber content of orts and feces. The concentration of FRA in the feces did not change as a result of FRA dosage. As expected, FRA concentration increased dramatically upon FRA dosage and decreased over time until returning to basal levels in rumen fluid (4 h after dosage), plasma (5.5 h after dosage), urine (10 h after dosage), and milk (14 h after dosage). Baseline values for FRA in urine and rumen fluid were variable among cows and had an effect on FRA concentration in FRA-dosed cows. From this study, it is observed that orally ingested FRA can be transported into the milk and that the physiological transfer of FRA occurs from rumen to milk within 6.5 h or the first milking after dosage. Ferulic acid may affect the functionality of milk due to its antioxidant, anticancer, and antibacterial activities. Future research will be required to elucidate whether FRA in milk is bioavailable and bioactive, and to evaluate the complete sensory and microbiological effects of increased FRA and FRA degradation products in milk.

Short communication: Antioxidant activity of calf milk replacers.

A calf milk replacer (CMR) is designed to replace whole, saleable milk as a lower cost nutrient source for calves while striving to nourish a newborn calf, reduce calf mortality, strengthen immunity, and increase animal life span and productivity. Antioxidants (AO) can enhance immune defense by reducing oxidative damage, but CMR are traditionally not formulated for AO activity. The objective of this study was to compare total AO activities of bovine milk and 6 CMR (A to F) that vary in the amount and source of fat and protein. Calf milk replacers were donated by Milk Products LLC (Chilton, WI). Milk was obtained from the Cornell Dairy Research Farm bulk tank, representing milk produced within 24h by 455 cows. Milk replacers were mixed to 150 g/L with 40°C purified water. All samples were extracted in triplicate. Following hexane lipid extraction, both milk and CMR samples were extracted 5 times with ethyl acetate and then evaporated and reconstituted with 70% methanol:water. Samples were assessed for total AO activity using the peroxyl radical scavenging capacity assay where each sample was diluted to 5 descending concentrations, plated in triplicate. Ascorbic and gallic acids were standards for each plate. Type of protein (soy) had a positive effect on AO activity for CMR A, which exhibited the highest total AO activity. Natural bovine milk had the second highest AO activity. Many factors may explain the difference in AO activity between natural milk and formulated CMR, including fat, vitamin, and mineral contents, enzymatic AO, phenolics, flavonoids, fatty acid profile, and AA composition. When comparing AO activity of CMR, it is important to consider the diversity in feeding recommendations, which will alter the vitamin and mineral content, thus influencing AO activity. The opportunity exists to enhance AO activity of CMR to more closely mimic that of bovine milk. Future research is warranted to compare a broader range of CMR using methods that account for total lipophilic and hydrophilic AO activities, as well as to investigate the effect of additional compounds in milk that may affect AO activity.

Free ferulic acid uptake in ram lambs.

The objective of this research was to investigate the fate of free ferulic acid (FA) in sheep. Ferulic acid is normally present in plants, bound to the indigestible cell wall. If the FA present in a ruminant diet is released from the cell wall with feed pretreatment methods, FA may be released into the rumen for digestion or absorption into the bloodstream or both. Eight male Dorset × Finn lambs were randomly assigned to 1 of 4 treatment (trt) concentrations, 0 (control), 3, 6, or 9 g/d free FA as part of a replicated 4 × 4 Latin square design. Lambs were housed individually and consumed chopped alfalfa hay (Medicago sativa; 22.8% CP, 39.3% NDF, 0.73 Mcal/kg NE(g)) ad libitum and 350 g corn grain (Zea mays L.; 9.1% CP, 11.2% NDF, 1.52 Mcal/kg NE(g)) once daily at 0800 h. Basal concentrations of FA in hay, grain, blood, feces, and urine were established following a 14-d adjustment to diet and housing. An oral dose of free FA was administered for 5 d via bolus after each morning feeding, after which hay, grain, blood, feces, and urine were sampled. Body weights were recorded at the beginning and end of each trt, and DMI was measured daily during trt periods. In addition to trt, each lamb ingested a daily average of 3.78 g FA in its bound form via the offered hay (2.67 mg/g FA; 1.0 kg/d DMI) and corn (3.17 mg/g FA; 0.35 kg/d DMI). The FA administered had a quadratic effect on average hay DMI (1.25, 1.41, 1.41, and 1.29 kg/d for 0, 3, 6, or 9 g/d FA trt; P < 0.01; SE = 58.9 g), but lamb BW did not change as a result of FA trt (P = 0.28). The NDF content and amount of FA in refusals were not affected by trt, (P = 0.30; P = 0.82, respectively). Fecal FA did not differ among trt or when compared with basal FA (P = 0.53), while urine FA increased as FA dose increased (P < 0.01), indicating that free FA was absorbed and transferred into urine. No free FA was found in the plasma analyzed, suggesting that disappearance from the blood of absorbed free FA occurred within the 5 h that passed between bolus dosage and blood collection. An in vitro analysis was conducted to assess the degree of inhibition of microbial NDF digestion caused by FA supplementation. In vitro, NDF disappearance was not inhibited as a result of FA treatment (P = 0.80). These data in combination with the results of the lamb study indicate that free FA as 0.24, 0.43, and 0.70% of DMI in lambs is absorbed and excreted in the urine as opposed to the feces with no apparent effects on rumen microbial NDF digestion.