4,7,10,13,16,19,22,25,28,31-Decaoxatetratriaconta-1,33-diyne

We report structure determination of an octaene fatty acid, 4,7,10, 13,16,19,22,25-octacosaoctaenoic acid (28:8n-3). The molecular weight and double bond locations were determined using acetonitrile chemical ionization mass spectrometry (MS) and MS/MS and were confirmed by MS of hydrogenated and deuterogenated 28:8 and by argentation thin-layer chromatography. 28:8n-3 was 1.2 +/- 0.1%, in oil derived from the heterotrophic dinoflagellate Crypthecodinium cohnii and a commercial polyunsaturated fatty acid concentrate derived from fish oils (0.16 +/- 0.01%), both components of human dietary supplements. It was not found in whole bovine retina, cultured Y79 human retinoblastoma cells, or neonate baboon cerebral cortex. The long chain polyunsaturates present in the C. cohnii oil suggest a possible route for 28:8n-3 biosynthesis similar to that for biosynthesis of 22:6n-3.

Auction-derived steers (n = 36; initial BW = 284 ± 11 kg) were received to compare performance, rumination characteristics, and rumen pH differences due to alternative ration energy densities and feed management strategies during a 56 d receiving study. Cattle were weighed on day -1 and randomized to 1 of 3 treatments. Time spent ruminating was quantified with a three-axis accelerometer ear-tag. Rumen pH and temperature were logged in a random subset (n = 6 per treatment) by a ruminal bolus. Cattle were processed identically and housed in individual pens. The modified-live virus respiratory vaccination was delayed until day 28. The finisher (FIN) cattle were provided their daily feed as a high energy density (1.39 Mcal NEg/kg) diet. The finisher + hay (FIN+H) cattle were provided the same diet but were also offered 0.5% BW DM as coastal Bermudagrass hay on days 1, 4, 7, 10, 13, 16, 19, 22, 25, and 28. The control (CON) cattle were fed a low energy density (0.93 Mcal NEg/kg) diet from day 0 to 7, then transitioned to the FIN diet by replacing an additional 25% of the daily feed call with FIN every 7 d until 100% of the diet was FIN on day 29. Feed offering for CON was increased more aggressively (0.45 kg DM daily for days 1 to 7, every other day for day 8 to 14) than FIN and FIN+H (0.45 kg DM every other day for days 1 to 7, daily for days 8 to 14). Performance and DMI were analyzed using PROC MIXED in SAS with treatment as a fixed effect. Rumination, pH, and temperature models included repeated measures. There was no treatment difference observed for BW, average daily gain (ADG), or G:F (P ≥ 0.12). There was a treatment × day interaction (P = 0.06) for rumen temperature, where FIN increased more rapidly following vaccination on day 28 compared to CON (P ≤ 0.04). Daily rumination minutes were greater (P < 0.01) for CON than FIN from days 7 to 22. Additionally, CON had the greatest (P < 0.01) hourly rumination from 2000 to 0800 hours. Lower minimum daily rumen pH occurred in FIN+H (P ≤ 0.06) on weeks 1, 2 and 6 to 8 compared to CON. There were minimal statistical differences in area under the curve or time below pH thresholds, probably due to large animal-to-animal variation. Hourly rumen pH was reduced (P ≤ 0.05) for FIN vs. FIN+H and CON during the initial 28 d, but greater (P = 0.05) for FIN and FIN+H during the final 28 d. When cattle are individually fed, greater energy density rations can be fed initially without compromising performance, but this needs to be evaluated in group pens where greater DMI variation is probable.

Several previous investigations have employed betaine supplementation in randomized controlled crossover designs to assess its ostensible ergogenic potential. Nevertheless, prior methodology is predicated on limited pharmacokinetic data and an appropriate betaine-specific washout period is hitherto undescribed. The purpose of the present pilot investigation was therein to determine whether a 28 day washout period was sufficient to return serum betaine concentrations to baseline following a supplementation protocol. Five resistance-trained men (26 ± 6 y) supplemented with 6 g/day betaine anhydrous for 14 days and subsequently visited the lab 10 additional times during a 28 day washout period. Participants underwent venipuncture to assess serum betaine and several other parameters before (PRE) and periodically throughout the washout timeframe (POST0, -4, -7, -10, -13, -16, -19, -22, -25 and -28). All analyses were performed at a significance level of p < 0.05. While analyses failed to detect any differences in any other serum biomarker (p > 0.05), serum betaine was significantly elevated from PRE-to-POST0 (p = 0.047; 2.31 ± 1.05 to 11.1 ± 4.91 µg·mL-1) and was statistically indistinguishable from baseline at POST4 (p = 1.00). Nevertheless, visual data assessment and an inability to assess skeletal muscle concentrations would otherwise suggest that a more conservative 7 day washout period is sufficient to truly return both serum-and-skeletal muscle betaine content to pre-supplementation levels.