Five Angus (Bt) and 5 Brahman steers (Bi) fitted with ruminal and duodenal cannulas were used in concurrent 5 × 5 Latin squares to determine the effects of supplemental protein degradability and level of supplemental N on utilization of rice straw. Treatments consisted of a control (CON; no supplement) and two levels (50 and 100 mg N/kg BW) of an isonitrogenous supplement (27% CP), either high (H; 72%) or low (L; 28%) in DIP. Forage OM intake (FOMI) was greater for Bt than Bi (P = 0.05). Supplementation increased FOMI in both Bt and Bi (P < 0.05). Organic matter digestibility (OMD) was greater in Bi than Bt (P < 0.01). Supplementation increased OMD for Bi (P = 0.02) but not Bt. Total digestible OM intake (TDOMI) was similar between subspecies (P = 0.12). Bos indicus had greater ruminal NH3-N than Bt (P < 0.01). Plasma urea nitrogen (PUN) was greater for Bi than Bt (P < 0.01) for all treatments and at both 0 and 4 h after feeding. Supplementation tended (P = 0.06) to increase PUN versus CON in Bt, but not Bi (P = 0.82). Bos taurus had numerically (P = 0.19) greater total volatile fatty acids (VFA) across treatments than Bi. Total N intake increased versus CON (P < 0.01), and greater amounts of supplemental N increased total N intake within both subspecies (P < 0.01). Fecal N excretion was greater in Bt than Bi (P = 0.01). Supplementation increased (P < 0.01) fecal N versus CON for both subspecies. Urinary N tended to be higher for Bi than Bt (P = 0.10). Supplementation increased (P < 0.05) urinary N for both subspecies. Retained N was greater for Bt over Bi (P = 0.07). While Bt had greater FOMI, increased OMD for Bi with supplementation resulted in similar TDOMI between subspecies. Overall, Bi had higher NH3-N and PUN than Bt; which increased as level and degradability of supplements increased in both subspecies. Increased supplementation raised N excreted and N balance for both subspecies; fecal N was greater in Bt, while urinary N was greater in Bi.

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Revised; Originally Published: 2000 / 6 pp.

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Bermudagrass (Cynodon dactylon (L) Pers.), one of the predominant forages in the southeastern US, varies in nutritive value in response to management and environmental factors. Beef cattle supplementation decisions are complicated by this variability. Therefore, our objective was to determine the effect of four protein supplementation levels (0, 82, 119 and 155 mg N/kg BW) on the utilization of three bermudagrass hays (5.6, 6.3, and 8.1 percent CP).Thirteen ruminally fistulated Angus x Hereford steers (BW = 330 plus/minus 19 kg) were used in a 13 x 4 incomplete Latin square design with 13 treatments. Treatments were arranged as a 3 x 4 factorial plus a control bermudagrass hay (10.8 percent CP). Hay was provided ad libitum and protein supplements were offered as range cubes once daily. Periods were 15 d with intake determinations made on d 10 through d 13 to correspond with fecal grab samples collected from d 11 through d 14. Acid detergent insoluble ash was used as an internal marker for determination of fecal output. Hay OM intake of unsupplemented steers increased linearly (P < 0.01) as hay nutritive value increased from 75 to 77, 96 and 94 g/kg BW^0.75 for 5.6, 6.3, 8.1 and 10.8 percent CP hays, respectively. A cubic increase (P = 0.03) in OM digestibility for unsupplemented hays was observed with values ranging from 46 to 65 percent. This resulted in a linear increase (P < 0.01) in total digestible OM intake in response to hay nutritive value from 35 to 45, 51, and 60 g/kg BW^0.75 for 5.6, 6.3, 8.1, and 10.8 percent CP hays, respectively. No significant effects on total digestible OM intake were observed when hays were supplemented with protein. There was a tendency for forage OM intake of the 6.3 percent CP hay to increase linearly with supplemental protein (P = 0.08). Total OM intake increased linearly (P < 0.01) when CP was supplemented to the 6.3 percent CP hay from 77 to 88, 92, and 98 g/kg BW^0.75 for 0, 82, 119, and 155 mg N/kg BW, respectively. We conclude that forage CP content was the primary driver in determining total digestible OM intake, and the effects of protein supplementation on utilization of bermudagrass hay were varied.

This research synthesis evaluates the effectiveness of nutritional interventions on the improvement of expressive language abilities in children with Autism Spectrum Disorders (ASD). Three nutritional interventions are the focus of this synthesis: 1) Gluten-casein free diet, 2) Magnesium-vitamin B6 supplementation, and 3) Digestive enzyme supplementation. Although three of the six studies included in this synthesis reported positive results, the methodology used to obtain the results was flawed. The positive results cannot be attributed solely to the intervention. While the results achieved in the studies provide enough evidence to justify further research, currently there is not enough evidence to support the use of nutritional interventions to treat expressive language deficits in children with ASD. Additional research with fewer threats to validity is needed to determine the effectiveness of nutritional interventions. / text

The rumen microbiome is a dynamic environment consisting of bacteria, protist, and fungi responsible for fiber degradation. Advances in molecular techniques have enabled description of bacterial microbiome via pyrosequencing. Cattle consuming low-quality forage are often supplemented with protein to increase forage intake and digestion, but effect on the rumen bacterial community is unknown. Thus, increasing post-extraction algal residue (PEAR) and cottonseed meal (CSM) supplementation was provided to steers consuming oat straw to observe the rumen microbiome within the liquid and solid fraction. Weighted UniFrac analysis indicated different fraction-associated communities with greater similarity across treatments in the solid fraction. Bacteroidetes was the predominant phyla detected in all samples (>65%). Within Bacteroidetes, Prevotella was the most abundant genus. In the liquid fraction, Lachnospiraceae, Ruminococcaceae, and Clostridiaceae increased with PEAR provision (P < 0.05). Similar proportions of bacteria between unsupplemented control and CSM supplemented steers indicate factors other than N supply may impact ruminal bacteria populations. A second experiment evaluated the effect of supplemental CSM or dried distillers’ grain (DDG) for Brahman steers consuming rice straw. Total digestible OM intake and total tract OM digestion increased linearly with additional CSM and DDG provision (P < 0.01). Provision of CSM increased ruminal ammonia linearly (P < 0.01), but DDG supplementation resulted in a quadratic response (P = 0.02). Overall, protein supplementation may increase LQF utilization via changes in the rumen microbiome.

Beta-alanine supplementation has been shown to increase skeletal muscle carnosine concentration resulting in the delay of neuromuscular fatigue and an increased aerobic and anaerobic capacity. The current study investigated the effects of beta-alanine supplementation on aerobic and anaerobic capacity in trained cyclists. Fourteen highly-competitive (sprint, endurance, road and track) cyclists underwent an 8 week 6.4g/day protocol (beta-alanine and maltodextrin). Pre and post supplementation testing included a VO₂max test (familiarization and characterization), maximum aerobic power test (aerobic capacity), and 30s wingate anaerobic test (anaerobic capacity). Aerobic capacity parameter measures included aerobic and anaerobic thresholds, and maximum aerobic power, while anaerobic capacity parameters included fatigue index, average power, peak power, watts per kilogram, and final lactate concentration. There was a lack of change in aerobic and anaerobic capacity parameters post supplementation for both groups. Assuming an increase in skeletal muscle carnosine concentration, results suggest 8 weeks 6.4g/day beta-alanine does not increase aerobic and anaerobic capacity in trained cyclists. This lack of change has 3 potential explanations; carnosines’ physicochemical H⁺ buffering ability was not substantially elevated to prevent muscular fatigue via acidosis, pH decrease is only one limiting factor in aerobic and anaerobic capacity, or other factors (neuromuscular junction failure, contractile failure, substrate depletion, metabolite accumulation, oxidative stress) influence muscular fatigue.

The objectives of this study were to evaluate nutrient digestibility and CP retention of steers fed ryegrass baleage supplemented with hay or soybean hull pellets. Crossbred steers (n=12, BW 247 plus or minus 20.8 kg) were halter broken, and placed into individual metabolism crates for a total of 10 days. All 12 steers had ad libitum access to ryegrass baleage and were allotted to 3 supplements 1) no supplement; 2) soybean hull pellets; 3) hay, with 4 steers per treatment group. Supplements were fed at 0.25% of steer body weight. Sample collections were for 7 days following a 3 day adaptation to crates. Results collected indicated there was no effect of supplementing a fiber source to cattle consuming ryegrass baleage on nutrient digestibility or CP retention. This may be attributed to maturity of ryegrass at harvest.

The effects of vitamin E supplementation during late gestation were evaluated in dairy or beef cattle in three experiments. Dairy cows were injected with vitamin E and selenium (Se) in one study; beef cows were offered oral vitamin E supplementation via a free-choice vitamin-mineral mix in two studies. Breed-related effects were also evaluated. Jerseys had higher blood Se and lower serum vitamin E concentrations than Holsteins at dry-off and higher blood Se concentrations than Holsteins 3-4 weeks pre-calving and at calving. Selenium supplementation increased blood Se concentrations at calving. Treatment did not affect serum vitamin E concentrations at calving or post-calving, nor blood Se concentrations post-calving. Beef cattle consuming supplemental vitamin E (treatment) had greater responses to treatment when calving in late winter than when calving in late summer. Treated multiparous cows calving in winter had increased serum and colostral vitamin E concentrations but treatment did not affect colostral or serum immunoglobulin G (IgG) concentrations of their calves. Calves from treated, multiparous cows calving in winter had increased 205-day adjusted weaning weights (AWWs). Treatment did not affect colostral vitamin E or IgG concentrations of nulliparous heifers calving in winter, nor serum vitamin E or IgG concentrations, or AWWs of their calves. Six hundred IU supplemental vitamin E/head/day did not affect serum vitamin E concentrations of dams, colostral vitamin E or IgG concentrations, serum vitamin E or IgG concentrations, or growth of calves in the summer-calving herd. Breed-related differences in vitamin E concentrations and AWW occurred in both herds. Consumption of 600-1000 IU vitamin E/cow/day (treatment) during late gestation via a free-choice vitamin-mineral mix increased vitamin E concentrations in serum and the lipoprotein fraction containing no apolipoprotein B (non-ApoB) from 1-2 weeks pre-calving to calving. Treatment group calves had higher vitamin E concentrations in serum and non-ApoB than control group calves. Treatment did not affect cholesterol or phospholipid concentrations in serum or the lipoprotein fractions of either cows or calves. Treatment increased vitamin E cholesterol (VEC) and vitamin E phospholipid (VEPL) ratios in the serum and non-ApoB of cows and calves. Various breed-related differences also occurred. / Ph. D.