Effects of polyphenolic bioactive compounds (pterostilbene, resveratrol, curcuminoids, quercetin, and hydroxypterostilbene) on pro-inflammatory cytokine production in vitro

s / Journal of Equine Veterinary Science 33 (2013) 321-399 343 could be reduced. Furthermore, because growing horses use P differently than mature horses, there might be a difference in P digestibility due to age. This study was designed to examine the availability of dietary P in growing horses and mature horses. Four long yearling geldings (19 1 mo; 478 58.9 kg) and 4 mature geldings (10.5 7.5 yr; 541 45.9 kg) were fed a diet of timothy cubes, alfalfa cubes, and concentrate without added P. The diet contained 0.26% P (dry matter basis) and 29% of that P occurred as phytate-P. The diet was formulated to be close to each horse’s P requirement. The concentrate contributed 50% of the total P and the forage cubes contributed 50%. There was a 14 d diet adaptation period during which feed intake was adjusted to minimize orts and horses were accustomed to wearing fecal collection harnesses. Total fecal collections were then conducted for a 4 d period. Fecal and feed samples were used to determine P and dry matter digestibility. P was measured using a gravimetric assay. Dry matter digestibility for both age groups was 53.93 3.13% and was not different between ages (P > 0.05). Apparent P digestibility was not different (P > 0.05) between the two groups. True digestibility was calculated using published values for endogenous losses (NRC, 2007). Estimated true P digestibility (27.63 12.70%) was not different between the two groups (P > 0.05). One mature horse had a very low P digestibility, and the data were re-analyzed without the values from this horse. However, even without including this horse in the data set, age did not affect apparent or true P digestibility (P > 0.05). Long yearlings and mature horses have the same ability to digest P, thus a similar P digestibility can be used for both age groups when formulating diets. Effects of polyphenolic bioactive compounds (pterostilbene, resveratrol, curcuminoids, quercetin, and hydroxypterostilbene) on pro-inflammatory cytokine production in vitro M.H. Siard, K.E. McMurry, D.W. Horohov, and A.A. Adams M. H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington,