scholarly journals Trace mineral source impacts rumen trace mineral metabolism and fiber digestion in steers fed a medium-quality grass hay diet

2021 ◽  
Vol 99 (9) ◽  
Author(s):  
Octavio Guimaraes ◽  
Sam Jalali ◽  
John J Wagner ◽  
Jerry W Spears ◽  
Terry Eugene Engle
Keyword(s):  
Mineral Metabolism ◽  
Neutral Detergent Fiber ◽  
Adaptation Period ◽  
Trace Mineral ◽  
Time Interaction ◽  
Grass Hay ◽  
Medium Quality ◽  
Mineral Concentrations ◽  
The Impact ◽  
Cu And Zn

Abstract Twelve Angus steers (BW 452.8 ± 6.1 kg) fitted with ruminal cannulae were used to determine the impact of trace mineral (TM) source on digestibility, ruminal volatile fatty acid (VFA) composition, ruminal soluble concentrations of Cu, Zn, and Mn, and relative binding strength of trace minerals located in the rumen insoluble digesta fraction. Steers were fed a medium-quality grass hay diet (DM basis: 10.8% CP, 63.1% neutral detergent fiber [NDF], 6.9 mg Cu/kg, 65.5 mg Mn/kg, and 39.4 mg Zn/kg) supplemented with protein for 21 d. Treatments consisted of either sulfate (STM) or hydroxy (HTM) sources (n = 6 steers/treatment) to provide 20, 40, and 60 mg supplemental Cu, Mn, and Zn/kg DM, respectively. Following a 21-d adaptation period, total fecal output was collected for 5 d. Dry matter (P < 0.07) and CP (P < 0.06) digestibility tended to be reduced, and NDF (P < 0.04) and acid detergent fiber (ADF) (P < 0.05) digestibility were reduced in STM- vs. HTM-supplemented steers. On day 6, ruminal fluid was collected at 0, 2, and 4 h post-feeding and analyzed for VFA. There were no treatment x time interactions for VFA. Steers receiving HTM had less (P < 0.02) molar proportions of butyric acid and greater (P < 0.05) total VFA concentrations than STM-supplemented steers. Steers were then fed the same diet without supplemental Cu, Zn, or Mn for 14 d. On day 15 steers received a pulse dose of 20 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either STM or HTM (n = 6 steers/treatment). Ruminal samples were obtained at 2-h intervals starting at −4 and ending at 24 h relative to dosing. There was a treatment x time interaction (P < 0.03) for ruminal soluble Cu, Mn, and Zn concentrations. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, 10, 12, and 14 h; for Mn at 4 and 6 h; and for Zn at 4, 6, and 8 h post-dosing in STM compared with HTM-supplemented steers. Copper concentrations were greater (P < 0.05) at 12 and 24 h and Zn concentrations in ruminal solid digesta were greater at 24 h in HTM-supplemented steers. Upon dialysis against Tris-EDTA, the percent Zn released from digesta was greater (P < 0.05) at 12 h (P < 0.03) and 24 h (P < 0.05), and the percent Cu released was greater (P < 0.02) at 24 h post-dosing in HTM steers when compared with STM-supplemented steers. Results indicate that Cu and Zn from HTM have low solubility in the rumen and appear to be less tightly bound to ruminal solid digesta than Cu and Zn from STM. The lower ruminal soluble concentrations of Cu and Zn in steers given HTM were associated with greater fiber digestibility.

scholarly journals 414 The influence of trace mineral source on fiber digestion, rumen fermentation characteristics, and mineral solubility in beef cattle fed a low-quality forage diet

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 167-167 ◽  
Author(s):  
Octavio Guimaraes ◽  
Sam Jalali ◽  
John Wagner ◽  
Jerry Spears ◽  
Terry Engle
Keyword(s):  
Rumen Fluid ◽  
Neutral Detergent Fiber ◽  
Adaptation Period ◽  
Ruminal Fermentation ◽  
Trace Mineral ◽  
Mineral Solubility ◽  
Dry Matter Digestibility ◽  
Grass Hay ◽  
Mineral Concentrations ◽  
The Impact

Abstract Twelve Angus steers (BW 452.8 ±21.8 kg) fitted with ruminal cannulae were used to determine the impact of trace mineral source on neutral detergent fiber (NDF) digestibility, short chain fatty acid (SCFA) production, and ruminal solubility of Cu, Mn, and Zn. Steers were fed a low-quality grass hay diet (10.8% CP, 63.1% NDF, 6.9 mg Cu/kg, 65.5 mg Mn/kg, and 39.4 mg Zn/kg) supplemented with protein for 21 d. Treatments consisted of 20, 40, and 60 mg supplemental Cu, Mn, and Zn/kg DM, respectively from either sulfate (STM) or hydroxy (HTM) sources (n = 6 steers/treatment). Following a 21-d adaptation period total fecal output was collected for 5 d. Dry matter digestibility tended (P < 0.07) to be reduced (51.9 vs. 53.4 ±0.52%) and NDF digestibility was reduced (P < 0.04; 40.4 vs. 42.7 ±0.67%) in STM vs. HTM steers. On d 6, rumen fluid was collected at 0, 2, and 4h post feeding. Steers receiving HTM had lesser (P < 0.02) butyric acid and greater (P < 0.05) total SCFA than STM steers. Steers were then fed the same grass hay diet without supplemental Cu, Zn, or Mn for 14 d. On d 15 steers received a pulse dose of 20, 40, and 60 mg Cu, Mn, and Zn/kg DM, respectively from either STM or HTM. Ruminal samples were obtained at 2h intervals starting at -4 and ending at 24h relative to dosing. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, 10, 12, and 14h; for Mn at 4 and 6h; and for Zn at 4, 6, and 8h post dosing in STM compared to HTM steers. Results indicate that ruminal solubility of Cu, Mn, and Zn differs between STM and HTM sources and rumen Cu, Mn, and Zn solubility may impact ruminal fermentation.

scholarly journals 226 Influence of trace mineral source on digestion, ruminal volatile fatty acid and soluble mineral on steers fed a dairy type diet balanced to meet requirements for a high producing lactating dairy cow

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 133-134
Author(s):  
Octavio Guimaraes ◽  
John Wagner ◽  
Jerry Spears ◽  
Terry Engle
Keyword(s):  
Dairy Cow ◽  
Rumen Fluid ◽  
Adaptation Period ◽  
Trace Mineral ◽  
Specific Amino Acid ◽  
Fiber Digestion ◽  
Post Feeding ◽  
Pulse Dose ◽  
The Impact ◽  
Cu And Zn

Abstract Twelve Angus steers (BW 530.9 ± 22.7kg) fitted with ruminal cannulae were used to determine the impact of trace mineral source on digestibility, ruminal VFA, and soluble concentrations of Cu, Zn, and Mn. Steers were fed a dairy type diet balanced to meet requirements for a high producing lactating dairy cow (DM basis: 16.8% CP, 29.2 Mcal NEm, 30.3 Mcal NEl, 33.6% NDF) for 21 d. Treatments consisted of 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either sulfate (STM), hydroxy (HTM; IntelliBond) or organic (ORG; metal specific amino acid complexes) sources (n=4 steers/treatment). Following a 21-d adaptation period, total fecal output was collected for 5 d. On d 6, rumen fluid was collected at 0, 2, and 4 h post feeding and analyzed for VFA. Steers were then fed the same diet without supplemental Cu, Zn, or Mn for 14 d. On d 15 steers received a pulse dose (cannulae) of 100 mg Cu, 400 mg Mn, and 60 mg Zn from either STM, HTM, or ORG. Ruminal samples were obtained at 2-h intervals starting at -4 and ending at 24 h post dosing and analyzed for soluble Cu, Mn, and Zn. Digestibility of NDF and ADF were lesser (P < 0.05) in STM vs. HTM and ORG supplemented steers. Steers receiving HTM and ORG had greater (P < 0.05) total VFA concentrations than STM supplemented steers at 2 and 4h post feeding. Ruminal soluble Cu and Zn concentrations were greater (P < 0.001) post dosing in STM and ORG supplemented steers at 2, 4, and 6 h for Cu and 4, 6, 8, 10 and 12 h for Zn when compared to HTM supplemented steers. Results indicate that ruminal solubility of Cu and Zn differs between STM, HTM and ORG sources and trace mineral source impacts fiber digestion and ruminal VFA concentrations.

scholarly journals The influence of xylanase on the fermentability, digestibility, and physiochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

2021 ◽  
Author(s):  
Amy L Petry ◽  
Nichole F Huntley ◽  
Michael R Bedford ◽  
John F Patience
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Nutrient Digestibility ◽  
Growing Pigs ◽  
Neutral Detergent Fiber ◽  
Adaptation Period ◽  
High Fiber ◽  
Gross Energy ◽  
Digesta Viscosity ◽  
The Impact

Abstract In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. Three replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF+100 mg xylanase/kg [HF+XY, (Econase XT 25P; AB Vista, Marlborough, UK)] providing 16,000 birch xylan units/kg; and HF+50 mg arabinoxylan-oligosaccharide (AXOS) product/kg [HF+AX, (XOS 35A; Shandong Longlive Biotechnology, Shandong, China)] providing AXOS with 3-7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P<0.01). Relative to HF, HF+XY improved the AID of GE, CP, and NDF (P<0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P<0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P=0.031). Relative to HF, HF+XY improved cecal disappearance of DM (162 vs. 98g; P=0.008) and NDF (44 vs. 13g; P<0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P<0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF+XY decreased ileal viscosity compared with HF (P<0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.

scholarly journals PSXII-13 The influence of trace mineral source on copper, manganese, and zinc binding strength to rumen digesta in cattle fed a high forage-based diet

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 443-443
Author(s):  
Octavio Guimaraes ◽  
Huey Yi Loh ◽  
Meghan P Thorndyke ◽  
Nicole M Tillquist ◽  
Jerry W Spears ◽  
...  
Keyword(s):  
Insoluble Fraction ◽  
Trace Minerals ◽  
Trace Mineral ◽  
Binding Strength ◽  
Pulse Dose ◽  
Copper Manganese ◽  
High Forage ◽  
Mineral Concentrations ◽  
Cu And Zn ◽  
Mn Concentrations

Abstract Twelve crossbred Angus steers fitted with rumen cannulae were used to determine the influence of trace mineral source on ruminal soluble mineral concentrations and relative binding strength of trace minerals in the ruminal insoluble digesta fraction. Steers were adjusted to a low-quality hay (chopped) diet balanced to meet the nutrient requirements for growing steers. For 7 d prior to initiation of the study, steers were fed the diet without supplemental Cu, Mn, and Zn. On day 8 steers received a pulse dose (2 x NRC requirement) of Cu, Mn, and, Zn from sulfate (STM) or hydroxy trace minerals (HTM; Micronutrients LLC, USA). Ruminal samples were obtained at 2 h intervals until 24 h post-dosing for soluble (fraction obtained after centrifugation) Cu, Mn, and Zn concentrations. Binding strength of Cu, Mn, and Zn to ruminal solid digesta (post centrifugation) was estimated at 0, 12, and 24h post-dosing using dialysis against 0.05 M Tris-EDTA. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, 10, 12, and 16 h; for Mn at 4 and 6 h; and for Zn at 4, 6, and 8 h post dosing in STM compared to HTM steers. Concentration of Cu, Mn, and Zn remaining in the insoluble fraction were greater (P < 0.05) at 12 h post dosing in HTM vs STM supplemented steers. At 24 h post dosing, Mn concentrations were lesser (P < 0.03) and Zn concentrations were greater (P < 0.001) in HTM vs STM supplemented steers. Following dialysis, the % Cu, and Zn released from the insoluble fraction was greater (P < 0.001) at 12 h and 24h in HTM vs. STM supplemented steers. Results indicate that a greater proportion of Cu and Zn HTM remained loosely bound to the insoluble fraction within the rumen.

scholarly journals 186 Hormone content of anabolic implants differentially affects plasma and liver trace mineral concentrations

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 154-155
Author(s):  
Elizabeth M Messersmith ◽  
Caleb C Reichhardt ◽  
Kara J Thornton ◽  
Stephanie L Hansen
Keyword(s):  
Repeated Measures ◽  
Mineral Metabolism ◽  
Animal Health ◽  
Sampling Period ◽  
Trace Mineral ◽  
Trenbolone Acetate ◽  
Feedlot Steers ◽  
Diet Formulation ◽  
Liver Biopsies ◽  
Mineral Concentrations

Abstract Forty-eight commercial Angus steers (327 ± 25 kg) were utilized to determine effects of varying implant hormone composition on liver and plasma trace mineral concentrations. Implant (IMP) treatments (n = 12/treatment) included: no implant (CON), estradiol (E2; Compudose; 25.7 mg estradiol; Elanco Animal Health; Greenfield, IN), trenbolone acetate (TBA; Finaplix H; 200 mg trenbolone acetate; Merck Animal Health; Madison, NJ), and a combination of estradiol and trenbolone acetate (ETBA Revalor-S; 24 mg estradiol + 120 mg trenbolone acetate; Merck Animal Health). Cattle were fed forage-based step up rations throughout the sampling period. Plasma samples were collected on d 0, 2, 10 and 30, with liver biopsies collected on d 2 and 10. Data were analyzed with ProcMixed of SAS with fixed effect of IMP. Contrast statements for each treatment vs CON were developed. Plasma trace mineral analysis utilized repeated measures (repeated effect = day). No IMP × Day effects (P ≥ 0.18) on plasma trace mineral were observed. Day 2 liver Zn and Cu and d 10 liver Mn were lesser (P ≤ 0.04) for TBA implanted steers than CON and d 2 liver Mn tended to be lesser (P = 0.06). The Mn response may reflect changes in protein metabolism due to TBA. However, E2 and ETBA tended to have greater (P ≤ 0.07) d 10 liver Fe concentrations than CON while plasma Fe was unaffected (P ≥ 0.75) by E2, TBA, or ETBA. Both d 2 liver and plasma Zn were lesser for ETBA than CON (P ≤ 0.04) likely driven by the TBA in the implant. Implant contrasts did not affect (P ≥ 0.13) other plasma or liver trace mineral concentrations. These data indicate implant strategies, and thus hormones differentially influence trace mineral metabolism in feedlot steers, which may have implications for diet formulation.

scholarly journals The use of live yeast to increase intake and performance of cattle receiving low-quality tropical forages

2021 ◽  
Vol 99 (2) ◽  
Author(s):  
Mariano C Parra ◽  
Diogo F A Costa ◽  
Andre S V Palma ◽  
Karine D V Camargo ◽  
Lais O Lima ◽  
...  
Keyword(s):  
Growth Performance ◽  
Feed Efficiency ◽  
Average Daily Gain ◽  
Neutral Detergent Fiber ◽  
Control Group ◽  
Adaptation Period ◽  
Rhodes Grass ◽  
Growing Cattle ◽  
Grass Hay ◽  
Live Yeast

Abstract The objective was to evaluate the effects of a specific strain of live yeast (LY) on growth performance, fermentation parameters, feed efficiency, and bacterial communities in the rumen of growing cattle fed low-quality hay. In experiment (exp.) 1, 12 Droughtmaster bull calves (270 ± 7.6 kg initial body weight [BW]) were blocked by BW into two groups, allocated individually in pens, and fed ad libitum Rhodes grass hay (8.4% of crude protein [CP]) and 300 g/bull of supplement (52% CP) without (Control) or with LY (8 × 109 colony-forming unit [CFU]/d Saccharomyces cerevisiae CNCM I-1077; Lallemand Inc., Montreal, Canada) for 28 d, followed by 7 d in metabolism crates. Blood and rumen fluid were collected before feeding and 4 h after feeding. In exp. 2, for assessment of growth performance, 48 Charbray steers (329 ± 20.2 kg initial BW) were separated into two blocks by initial BW and randomly allocated into 12 pens. The steers were fed Rhodes grass hay (7.3% CP) and 220 g/steer of supplement (60% CP) without or with LY (8 × 109 CFU/d) for 42 d, after a 2-wk adaptation period. In exp. 1, fiber digestibility was calculated from total fecal collection, and, in exp 2, indigestible neutral detergent fiber (NDF) was used as a marker. Inclusion of LY increased (P = 0.03) NDF intake by 8.3% in exp. 1, without affecting total tract digestibility. No changes were observed in microbial yield or in the efficiency of microbial production. There was a Treatment × Time interaction (P < 0.01) for the molar proportion of short-chain fatty acids, with LY increasing propionate before feeding. Inclusion of LY decreased rumen ammonia 4 h after feeding (P = 0.03). The addition of LY reduced rumen bacterial diversity and the intraday variation in bacterial populations. Relative populations of Firmicutes and Verrucomicrobia varied over time (P < 0.05) only within the Control group. At the genus level, the relative abundance of an unclassified bacterial genus within the order Clostridiales, a group of cellulolytic bacteria, was reduced from 0 to 4 h after feeding in the Control group (P = 0.02) but not in the LY group (P = 1.00). During exp. 2, LY tended to increase average daily gain (ADG) (P = 0.08) and feed efficiency (P = 0.10), with no effect on NDF intake or digestibility. In conclusion, S. cerevisiae CNCM I-1077 reduced the intraday variation of rumen bacteria and increased the amount of NDF digested per day. These observations could be associated with the tendency of increased ADG and feed efficiency in growing cattle fed a low-quality forage.

scholarly journals The Impact of Nordic Walking on Bone Properties in Postmenopausal Women with Pre-Diabetes and Non-Alcohol Fatty Liver Disease

2021 ◽  
Vol 18 (14) ◽  
pp. 7570
Author(s):  
Xiaming Du ◽  
Chao Zhang ◽  
Xiangqi Zhang ◽  
Zhen Qi ◽  
Sulin Cheng ◽  
...  
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Postmenopausal Women ◽  
Fatty Liver Disease ◽  
Whole Body ◽  
Nordic Walking ◽  
Significant Group ◽  
Time Interaction ◽  
Bone Properties ◽  
The Impact

This study investigated the impact of Nordic walking on bone properties in postmenopausal women with pre-diabetes and non-alcohol fatty liver disease (NAFLD). A total of 63 eligible women randomly participated in the Nordic walking training (AEx, n = 33), or maintained their daily lifestyle (Con, n = 30) during intervention. Bone mineral content (BMC) and density (BMD) of whole body (WB), total femur (TF), femoral neck (FN), and lumbar spine (L2-4) were assessed by dual-energy X-ray absorptiometry. Serum osteocalcin, pentosidine, receptor activator of nuclear factor kappa-B ligand (RANKL) levels were analyzed by ELISA assay. After an 8.6-month intervention, the AEx group maintained their BMCTF, BMDTF, BMCL2−4, and BMDL2−4, and increased their BMCFN (p = 0.016), while the Con group decreased their BMCTF (p = 0.008), BMDTF (p = 0.001), and BMDL2−4 (p = 0.002). However, no significant group × time interaction was observed, except for BMDL2−4 (p = 0.013). Decreased pentosidine was correlated with increased BMCWB(r = −0.352, p = 0.019). The intervention has no significant effect on osteocalcin and RANKL. Changing of bone mass was associated with changing of pentosidine, but not with osteocalcin and RANKL. Our results suggest that Nordic walking is effective in preventing bone loss among postmenopausal women with pre-diabetes and NAFLD.

Evaluation of iron, copper and zinc concentrations in commercial foods formulated for healthy cats

2021 ◽  
pp. 1098612X2110262
Author(s):  
Stacie Summers ◽  
Jonathan Stockman ◽  
Jennifer A Larsen
Keyword(s):  
Food Products ◽  
Metabolizable Energy ◽  
Life Stages ◽  
Trace Mineral ◽  
Iron Copper ◽  
Copper And Zinc ◽  
Zinc Concentrations ◽  
Dry Food ◽  
Raw Foods ◽  
Mineral Concentrations

Objectives The aim of this study was to analyze iron, copper and zinc concentrations in commercial foods and compare among food formats (dry, canned, raw), foods marketed by age category (adult 1+ years and senior 7+ years) and foods intended for adult maintenance vs all life stages. Methods In total, 112 commercial non-therapeutic food products marketed for healthy adult and senior cats were purchased in the USA. Foods were analyzed for their proximate composition. Trace mineral concentrations were measured using inductively coupled argon plasma–optical emission spectroscopy and described on a calculated metabolizable energy basis using standard modified Atwater values. Results Measured iron (median 58.4 mg/1000 kcal [range 15.7–379.0]), copper (median 5.6 mg/1000 kcal [range 0.8–13.3]) and zinc (median 47.6 mg/1000 kcal [range 7.6–128.1]) concentrations were highly variable among cat foods. When all food products – regardless of their nutritional adequacy substantiation method – were compared with the Association of American Feed Control Officials regulatory minimums, 13/112 food products had a mineral deficiency, of which a majority (n = 11/13) were raw food products. Raw foods had significantly lower trace mineral concentrations compared with dry food products and, except for copper, canned food products. Cat foods marketed for senior cats had higher iron ( P = 0.019) and zinc ( P <0.0001) concentrations than foods marketed for adult cats. Foods intended for adult maintenance had higher iron ( P = 0.003) and zinc concentrations than foods intended for all life stages ( P <0.0001). Conclusions and relevance Iron, copper and zinc concentrations in commercial non-therapeutic foods for adult and senior cats are highly variable. A minority of foods – mainly raw food products – were deficient in these minerals. It is unknown if some foods with high trace mineral concentrations could have adverse effects as studies are needed to establish safe upper limits for dietary intake of trace minerals in healthy cats.

scholarly journals Firefighter hemodynamic responses to different fire training environments

2021 ◽  
pp. 1358863X2098760
Author(s):  
Elizabeth C Lefferts ◽  
Alexander J Rosenberg ◽  
Georgios Grigoriadis ◽  
Sang Ouk Wee ◽  
Stephen Kerber ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Oriented Strand Board ◽  
Hemodynamic Response ◽  
Strenuous Exercise ◽  
Training Environment ◽  
Time Interaction ◽  
Increased Risk ◽  
Fire Smoke ◽  
System Activation ◽  
The Impact

Firefighting is associated with an increased risk for a cardiovascular (CV) event, likely due to increased CV strain. The increase in CV strain during firefighting can be attributed to the interaction of several factors such as the strenuous physical demand, sympathetic nervous system activation, increased thermal burden, and the environmental exposure to smoke pollutants. Characterizing the impact of varying thermal burden and pollutant exposure on hemodynamics may help understand the CV burden experienced during firefighting. The purpose of this study was to examine the hemodynamic response of firefighters to training environments created by pallets and straw; oriented strand board (OSB); or simulated fire/smoke (fog). Twenty-three firefighters had brachial blood pressure measured and central blood pressure and hemodynamics estimated from the pressure waveform at baseline, and immediately and 30 minutes after each scenario. The training environment did not influence the hemodynamic response over time (interaction, p > 0.05); however, OSB scenarios resulted in higher pulse wave velocity and blood pressure (environment, p < 0.05). In conclusion, conducting OSB training scenarios appears to create the largest arterial burden in firefighters compared to other scenarios in this study. Environmental thermal burden in combination with the strenuous exercise, and psychological and environmental stress placed on firefighters should be considered when designing fire training scenarios and evaluating CV risk.

A survey of variation in the chemical composition of commercial canola meal produced in Western Canadian crushing plants

1991 ◽  
Vol 71 (2) ◽  
pp. 469-480 ◽  
Author(s):  
J. M. Bell ◽  
M. O. Keith
Keyword(s):  
Press Cake ◽  
Neutral Detergent Fiber ◽  
Canola Meal ◽  
Glucosinolate Content ◽  
Western Canada ◽  
Composition Variation ◽  
Gross Energy ◽  
The Mean ◽  
Whole Seed ◽  
Mineral Concentrations

Canola samples of whole seed, press cake and commercial meal (CM) were collected from seven canola-crushing plants in Western Canada over 4 successive weeks to assess nutrient and glucosinolate content and variability. The CM data are described in this report. The mean concentrations in CM (dry matter (DM) basis) were: in %, crude protein (N × 6.25) 41.85; ether extract 3.92; crude fiber 13.13; neutral detergent fiber 23.54; acid detergent fiber 19.09; and in MJ kg−1, gross energy 20.36. The mean mineral concentrations were, in percent, calcium 0.70; magnesium 0.57; phosphorus 1.13; potassium 1.35; sulfur 0.94; and in μg g−1, copper 6.34; iron 157; manganese 54.7; molybdenum 1.5; selenium 1.22; zinc 75.8. Total aliphatic glucosinolate concentrations (oil-free DM basis) ranged from 6.26 to 28.42 μmol g−1 for different plants, mean 16.20; indolyl glucosinolate concentrations were from 0.56 to 9.49 μmol g−1. Small and variable amounts of allyl and hydroxybenzyl glucosinolates due to weed seed contamination were found. Myrosinase activity (thioglucoside glucohydrolase EC 3.2.3.1) averaged 0.15% of that in the corresponding canola seed. Differences among crushing plants were due mainly to regional environmental factors, cultivars used and, for lysine and glucosinolates, processing conditions mainly in the desolventizer toaster stage. Key words: Canola, meal, composition, variation, regional, Western Canada

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