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1.
J Dairy Sci ; 107(8): 6211-6224, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38460879

RESUMO

Selenium is an essential trace mineral for dairy cattle and can be provided in the diet in various forms that may differ in bioavailability. The objective of this study was to determine how source of Se affects animal performance, Se status, retention, and apparent and true absorption. Multiparous Holstein cows (n = 24; 597 ± 49 kg of BW) were blocked by DIM (161 ± 18) and randomly assigned to receive 0.3 mg Se/kg of DM (100% of National Academies of Sciences, Engineering, and Medicine requirements) of either organic Se (ORG; selenized yeast) or inorganic Se (INO; sodium selenite). The Se premix was top dressed on a common TMR fed daily and mixed into the top 15 cm directly before feeding. Following an 11-wk adaptation period, cows received simultaneous infusions of an intraruminal isotope dose of 77Se in the same chemical form as the premix, and an intravenous dose of 82Se in an inorganic form. Infusions were followed by a 4-d period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Daily DMI (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period, but milk Se concentrations were greater for ORG compared with INO. Serum 77Se maximum concentration and area under the curve (AUC) were not different between treatments for 72 h following infusion, but rumen fluid 77Se AUC was higher for ORG than INO. Apparent absorption (64% ± 1.4%), and retention (44% ± 1.5%) of the 77Se dose did not differ between treatments. True absorption was calculated using 82Se enrichment in serum and feces and was determined to be 69% ± 1.3% and did not differ between treatments. Fecal excretion of the 77Se dose was not different between treatments (36% ± 1.4%), but ORG had lower urinary excretion and higher milk excretion compared with INO. These results indicate that organic Se resulted in greater Se concentration of milk and lower urinary Se excretion into the environment, but absorption, Se status, and performance of the cow were not affected by Se source at this supplementation level.


Assuntos
Dieta , Suplementos Nutricionais , Lactação , Leite , Selênio , Animais , Bovinos , Selênio/farmacocinética , Feminino , Leite/química , Leite/metabolismo , Dieta/veterinária , Ração Animal
2.
J Anim Sci ; 95(8): 3700-3711, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28805908

RESUMO

A long-term experiment was conducted to examine the effects of feeding encapsulated nitrate (EN) on growth, enteric methane production, and nitrate (NO) toxicity in beef cattle fed a backgrounding diet. A total of 108 crossbred steers (292 ± 18 kg) were blocked by BW and randomly assigned to 18 pens. The pens (experimental unit; 6 animals per pen) received 3 dietary treatments: Control, a backgrounding diet supplemented with urea; 1.25% EN, control diet supplemented with 1.25% encapsulated calcium ammonium NO (i.e., EN) in dietary DM, which partially replaced urea; or 2.5% EN, control diet supplemented with 2.5% EN (DM basis) fully replacing urea. Additionally, 24 steers were located in 4 pens and randomly assigned to 1 of the above 3 dietary treatments plus a fourth treatment: 2.3% UEN, control diet supplemented with 2.3% unencapsulated calcium ammonium NO (UEN) fully replacing urea. Animals in the additional 4 pens were used for methane measurement in respiratory chambers, and the pens (except UEN) were also part of the performance study (i.e., = 7 pens/treatment). The experiment was conducted for 91 d in a randomized complete block design. During the experiment, DMI was not affected by inclusion of EN in the diet. Feeding EN had no effect on BW, ADG, and G:F ( ≥ 0.57). Methane production (g/d) tended to decrease ( = 0.099) with EN and UEN, but yield (g/kg DMI) did not differ ( = 0.56) among treatments. Inclusion of EN in the diet increased ( ≤ 0.02) sorting of the diets in favor of large and medium particles and against small and fine particles, resulting in considerable increases in NO concentrations of orts without affecting DMI. Plasma NO-N and NO-N concentrations increased ( ≤ 0.05) for EN compared with Control in a dose response manner, but blood methemoglobin levels were below the detection limit. Nitrate concentration in fecal samples slightly increased (from 0.01% to 0.14% DM; < 0.01) with increasing levels of EN in the diet. In conclusion, EN can be used as a feed additive replacing urea in beef cattle during a backgrounding phase in the long term without NO intoxication or any negative effects on growth performance. In addition, the study confirmed that feeding EN tended to decrease enteric methane production in the long term.


Assuntos
Bovinos/fisiologia , Suplementos Nutricionais , Metano/metabolismo , Nitratos/administração & dosagem , Ureia/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Cápsulas , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Fezes/química , Masculino , Metemoglobina/análise , Nitratos/toxicidade , Distribuição Aleatória
3.
J Anim Sci ; 95(8): 3712-3726, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28805918

RESUMO

A finishing feedlot study was conducted with beef steers to determine effects of encapsulated nitrate (EN) on growth performance, carcass characteristics, methane production, and nitrate (NO) residues in tissues. The 132 crossbred steers were backgrounded in a feedlot for 91 d and transitioned for 28 days to the high-concentrate diets evaluated in the present study, maintaining the treatment and pen assignments designated at the start of the backgrounding period. The steers were initially assigned to 22 pens (6 animals per pen) in a randomized complete block design with BW (18 pens) and animals designated for methane measurement (4 pens) as blocking factors. Five animals in each pen designated for methane measurement (total of 20 animals) were monitored for methane emissions in respiratory chambers twice during the experiment. Pens received 3 dietary treatments (7 pens each): Control, a finishing diet supplemented with urea; 1.25% EN, control diet supplemented with 1.25% encapsulated NO in dietary DM that partially replaced urea; and 2.5% EN, control diet supplemented with 2.5% EN (DM basis) fully replacing urea. The final pen designated only for methane measurement received a fourth dietary treatment, 2.3% UEN, the control diet supplemented with unencapsulated NO (UEN) fully replacing urea. The cattle weighed 449 ± SD 32 kg at the start of the 150-d finishing period. The 2.5% EN diet decreased ( < 0.01) DMI compared with Control and 1.25% EN diets. Feeding EN tended to increase ( = 0.092) ADG compared with Control, and G:F was improved ( < 0.01) for EN compared with Control. No differences in methane production (g/d) and yield (g/kg DMI) were observed among treatments. Inclusion of EN in the diets increased ( ≤ 0.03) sorting in favor of large and medium particles and against small and fine particles. Plasma NO and NO concentrations were elevated ( < 0.01) with EN in a dose-response manner, but total blood methemoglobin levels for all treatments were low, below the detection limit. Feeding EN increased ( < 0.01) NO concentrations of samples from muscle, fat, liver, and kidney; NO concentrations of these tissues were similar between 1.25% EN and 2.3% UEN. In conclusion, inclusion of 2.5% EN in a finishing diet (DM basis; about 2% NO) did not cause NO toxicity or any health problems in the long term. In comparison with supplemental urea, feeding EN improved feed efficiency despite increases in sorting against dietary EN.


Assuntos
Bovinos/fisiologia , Suplementos Nutricionais , Metano/metabolismo , Nitratos/administração & dosagem , Carne Vermelha/análise , Ureia/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Cápsulas , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Masculino , Nitratos/análise , Distribuição Aleatória
4.
J Anim Sci ; 93(10): 4956-66, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26523588

RESUMO

The objective of the study was to investigate the effects of feed consumption rate on potential toxicity, rumen fermentation, and eating behavior when beef heifers were fed a diet supplemented with nitrate (NI). Twelve ruminally cannulated heifers (827 ± 65.5 kg BW) were used in a randomized complete block design. The experiment consisted of 10-d adaptation, 8-d urea-feeding, and 3-d nitrate-feeding periods. All heifers were fed a diet supplemented with urea (UR) during the adaptation and urea-feeding periods, whereas the NI diet (1.09% NO in dietary DM) was fed during the nitrate-feeding period. After adaptation, heifers were randomly assigned to ad libitum or restrictive feeding (about 80% of ad libitum intake) for the urea- and nitrate-feeding periods. Ad libitum DMI decreased (14.1 vs. 15.1 kg/d; < 0.01) when heifers were fed the NI diet compared with the UR diet. The amount of feed consumed increased ( < 0.01) at 0 to 3 h and decreased ( ≤ 0.03) at 3 to 24 h for restrictive vs. ad libitum feeding of both the UR and NI diets. Compared to the UR diet, the NI diet decreased ( < 0.01) feed consumption at 0 to 3 h and increased ( < 0.02) feed consumption at 3 to 24 h (except feed consumption at 9 to 12 h; = 0.90), indicating nitrate feeding changed the consumption pattern (a more even distribution of feed intake over the day). The increased feed consumption from 0 to 3 h after feeding the NI diet restrictively vs. ad libitum numerically decreased ( = 0.11) rumen pH and numerically or significantly increased ( = 0.01 to 0.28) rumen ammonia, NO, and NO; blood methemoglobin; and plasma NO and NO at 3 h. Regression analysis indicated that increased feed consumption (0 to 3 h) exponentially elevated ( < 0.01; = 0.75) blood methemoglobin, and plasma NO + NO among other rumen and blood variables had the greatest correlation (sigmoid response; < 0.01, = 0.47) with feed consumption (0 to 3 h). Particle size distribution of orts was partially altered ( = 0.02 to 0.40) when the NI diet was fed compared with the UR diet. During the nitrate-feeding period, the nitrate content of orts on d 2 and 3 was greater ( = 0.02) than that on d 1. In conclusion, the increased consumption rate of a diet supplemented with nitrate was an important factor influencing risk of nitrate toxicity based on blood methemoglobin and plasma NO. In addition, the pattern of daily feed consumption was altered by nitrate (creating a "nibbling" pattern of eating) in beef heifers.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Suplementos Nutricionais , Comportamento Alimentar/efeitos dos fármacos , Nitratos/farmacologia , Amônia/metabolismo , Animais , Dieta/veterinária , Ingestão de Alimentos/fisiologia , Feminino , Fermentação , Privação de Alimentos , Concentração de Íons de Hidrogênio , Nitratos/administração & dosagem , Nitratos/efeitos adversos , Nitratos/sangue , Rúmen/metabolismo , Ureia/administração & dosagem , Ureia/farmacologia
5.
J Anim Sci ; 93(8): 3950-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26440175

RESUMO

The objective of this study was to determine whether supplementing organic acids can prevent incidences of subacute ruminal acidosis (SARA) in beef heifers fed a diet consisting of 8% barley silage and 92% barley grain-based concentrate (DM basis). Ten ruminally cannulated Hereford crossbred heifers (484 ± 25 kg BW) were used in a replicated 5 × 5 Latin square design with 14-d periods including 10 d for dietary adaptation and 4 d for measurements. Dietary treatments included no supplementation (Control), low fumaric acid (61 g/d), high fumaric acid (125 g/d), low malic acid (59 g/d), and high malic acid (134 g/d). Organic acid supplementation had no effect on DMI ( = 0.77). Similarly, no effects were observed on mean ( = 0.74), minimum ( = 0.64), and maximum ( = 0.27) ruminal pH measured continuously for 48 h. Moreover, area under the curve for pH thresholds 6.2 ( = 0.97), 5.8 ( = 0.66), 5.5 ( = 0.55), and 5.2 ( = 0.93) was similar for all treatments. However, malic acid supplementation lowered the amount of time that ruminal pH was <6.2 compared with the Control ( = 0.02) and fumaric acid treatments ( < 0.01). No effects were observed on total VFA concentrations with organic acid supplementation ( = 0.98) compared with the Control, but greater total VFA concentrations were observed with fumaric acid compared with the malic acid treatments ( = 0.02). The population of total culturable bacteria 3 h after feeding was reduced with supplemental malic acid compared with the Control ( = 0.03) and fumaric acid treatments ( = 0.03). However, no effects were observed with organic acid supplementation on lactic acid-utilizing bacteria ( = 0.59). In conclusion, under the conditions of the present study, organic acid supplementation did not have any significant effects on ruminal fermentation parameters compared with the Control and were not effective in preventing SARA in beef cattle fed high-grain diets.


Assuntos
Acidose/veterinária , Doenças dos Bovinos/prevenção & controle , Dieta/veterinária , Grão Comestível , Rúmen/metabolismo , Silagem/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Suplementos Nutricionais , Feminino , Fermentação
6.
J Anim Sci ; 93(5): 2391-404, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26020335

RESUMO

UNLABELLED: The objective of this study was to investigate effects of encapsulated nitrate (EN) on enteric methane emission and N and energy utilization in beef heifers. Eight ruminally-cannulated beef heifers (451 ± 21 kg BW) were used in a replicated 4 × 4 Latin square design. Four experimental diets were prepared and fed once daily for ad libitum intake: control, 1%, 2%, and 3% EN (0.15, 0.9, 1.5, and 2.5% NO3(-) in dietary DM, respectively). The control diet (55% forage and 45% concentrate) included encapsulated urea, which was gradually replaced with EN for the EN diets (iso-nitrogenous; 12.5% CP). In each period, EN was increased stepwise by 1% every 4 d during adaptation. A 7-d washout period (control diet offered to all heifers) was provided between experimental periods. Dry matter intake tended to decrease (10.4 to 10.1 kg/d; linear, P = 0.06) with EN levels. Enteric methane yield was linearly decreased (21.3 to 17.4 g/kg DMI; P < 0.01) by EN, and methane production (g/d) recovered to the level from heifers fed the control diet on the first day when EN was withdrawn from the diet. Apparent total-tract digestibility of DM and OM increased (P = 0.03) or tended to increase (P = 0.06), respectively, with EN levels. Starch digestibility tended to be greater (P = 0.07) for EN vs. CONTROL: The concentrations of rumen ammonia-N and plasma urea-N decreased linearly (P < 0.01) with EN. Total urinary N and urea-N excretion as proportions of N intake were linearly decreased (46.3 to 41.4%, = 0.09 and 37.1 to 29.9%, P = 0.01, respectively) with EN addition. However, NO3(-)-N excretion in urine increased linearly (P < 0.01) with EN levels. Fecal N excretion was not affected (P = 0.47) by EN, although fecal NO-N excretion increased linearly (P < 0.01) with inclusion of EN (0.09 to 0.88% of total N, P < 0.01). Retained N tended to be increased (percentage of N intake; 16.6 to 21.4%, = 0.08) by the EN. Supplementary EN lowered (6.64 to 5.46% of GE intake [GEI], P < 0.01) energy losses by enteric methane mitigation, which increased ME supply (calculated; 56.5 to 58.8% of GEI, P = 0.01) without changes in calculated heat production (P = 0.24). As a result, retained energy tended to increase (P = 0.07) with EN levels. In conclusion, feeding EN to beef heifers lowered enteric methane production in a dose-response manner, which slightly increased energy supply. Total urinary N excretion was lowered for EN due to lower urinary urea-N excretion.


Assuntos
Bovinos/metabolismo , Sistema Digestório/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Metano/metabolismo , Nitratos/farmacologia , Nitrogênio/metabolismo , Amônia/metabolismo , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Peso Corporal/fisiologia , Cápsulas , Suplementos Nutricionais , Sistema Digestório/metabolismo , Ingestão de Alimentos/fisiologia , Metabolismo Energético/fisiologia , Feminino , Nitratos/administração & dosagem , Rúmen/metabolismo , Ureia/metabolismo
7.
J Anim Sci ; 93(5): 2405-18, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26020336

RESUMO

A slow-release form of nitrate (encapsulated nitrate [EN]) was investigated for effects on risk of toxicity, feed consumption rates, and feed sorting behavior in 2 experiments. In Exp. 1, 5 beef heifers (806 ± 72 kg BW) were fed once daily at 75% of ad libitum intake. Supplementary EN (85.6% DM; 71.4% NO3(-) on a DM basis) was increased by 1% every 4 d from 0 to 1.0, 2.0, 2.9, 3.9, 4.8, and 5.8% of dietary DM (from 10.3 to 15.6% CP and 0.11 to 4.8% total NO3(-)). During the study, a heifer was removed due to nitrate poisoning with 59% blood methemoglobin (MetHb; % of total hemoglobin) at 2.9% EN and another due to refusal to eat the 2% EN diet. When dietary EN increased from 0 to 5.8%, DMI (8.8 to 7.6 kg/d; P < 0.001) and feed consumption from 0 to 3 h were decreased (70.3 to 48.6% of total feed offered on an as-is basis; P = 0.001) and feed consumption from 12 to 24 h was increased (0.6 to 22.6%; P < 0.001). Blood MetHb at 1% EN was negligible (<1.5% of total hemoglobin). However, MetHb levels were greater (average 9.8 vs. 3.1% and maximum 23.6 vs. 13.6% at 3 h) at 2.0 and 2.9% EN than at 3.9, 4.8, and 5.8% EN. In Exp. 2, 8 beef heifers (451 ± 21 kg BW) were used in a replicated 4 × 4 Latin square design and fed for ad libitum intake, once daily, diets containing 0, 1, 2, and 3% EN (isonitrogenous, 12.7% CP, and 0.15 to 2.5% total NO3(-) in dietary DM). Each period consisted of 14 d for adaption and 14 d for sampling followed by a 7-d washout. During adaptation, EN was provided to heifers in a stepwise manner (an increase by 1% every 4 d). In Exp. 2 with ad libitum feeding, feed consumption rates were not different (41.8% of total feed consumed from 0 to 3 h; P = 0.56) among EN levels, but DMI tended to decrease linearly (0 to 3% EN; 10.4 to 10.1 kg/d; P = 0.06) and feed was sorted (linear, P < 0.05) against concentrates (containing EN) with EN inclusion. Potential toxicity of nitrate based on blood MetHb was not observed (all samples <2.0% of total hemoglobin). In both studies, ruminal pH increased numerically (Exp. 1) and significantly (Exp. 2; linear, P = 0.04) with EN. In conclusion, studies indicated that the organoleptic properties of diets containing >3% EN may have caused lower feed intake, reduced feed consumption rates, and feed sorting. In addition, feed consumption rate, which was altered by restrictive or ad libitum feeding, was an important factor affecting the potential toxicity of nitrate (e.g., MetHb). Ad libitum feeding minimized risks of nitrate toxicity.


Assuntos
Bovinos/metabolismo , Comportamento Alimentar/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Metemoglobina/metabolismo , Nitratos/farmacologia , Rúmen/metabolismo , Ração Animal , Animais , Cápsulas , Dieta/veterinária , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Feminino , Fermentação/fisiologia , Concentração de Íons de Hidrogênio , Nitratos/administração & dosagem , Rúmen/efeitos dos fármacos , Fatores de Tempo
8.
J Anim Sci ; 91(5): 2310-20, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23478813

RESUMO

The objectives were to characterize the effects of supplemental CP concentration and ruminal degradability in barley-based finishing diets on microbial protein synthesis, ruminal fermentation and nutrient digestion, and route and chemical form of N excretion in beef cattle. Four Angus heifers (564 ± 18 kg BW) with ruminal and duodenal cannulas were used in an experiment designed as a 4 × 4 Latin square with four 28-d periods (9 d for diet adaptation and 19 d for measurements). The basal diet consisted of 9% barley silage and 91% barley-based concentrate (DM basis). Dietary treatments included the basal diet with no added protein (13% CP) or diets containing 14.5% CP by supplementation with urea (UREA), urea and canola meal (UREA+CM), or urea, corn gluten meal, and xylose-treated soybean meal (UREA+CGM+xSBM). Nutrient digestion was determined using Yb as a digesta flow marker and purine N as a microbial marker with the collection of ruminal, duodenal, and fecal samples over 5 d. The next week, total collections of feces and urine were performed for 5 d to quantify route and chemical form of N excretion. Feed offered was restricted (95% of ad libitum) and there was no effect of the dietary treatments on DMI (P = 0.55); therefore, N intake was less (P < 0.05) in heifers fed the 13% CP diets than the 14.5% CP diets. Supplemental RDP and RUP had no effect on ruminal NH3-N (P = 0.17), peptide N (P = 0.46), and VFA (P = 0.62) concentrations, flow of microbial (P = 0.69) and feed (P = 0.22) N, and ruminal and total tract nutrient digestibility (P ≥ 0.18). Nutrient digestion in the rumen and total tract averaged 75.4 ± 3.8% and 84.6 ± 0.9% for OM, 80.8 ± 3.6% and 95.8 ± 0.8% for starch, and 41.2 ± 7.9% and 60.4 ± 3.3% of intake for NDF, respectively. Daily output of N in feces (P = 0.91) and urine (P = 0.14) were not affected by the dietary treatments. Fecal N output averaged 19.9 ± 1.9% (P = 0.30) and urine N output averaged 44.1 ± 2.8% (P = 0.63) of N intake. Urea N output, however, was greater (P < 0.05) in heifers fed the 14.5% CP than the 13% CP diets and was the major form of N in urine (68.3% in heifers fed the 13% CP diet and 78.7 ± 2.9% in heifers fed the 14.5% CP diets; P < 0.10). Beef cattle fed barley-based finishing diets containing 13% CP do not require additional RDP or RUP to meet microbial or host N requirements. Barley-based finishing diets with no supplemental CP minimized urea N excretion and the potential loss of N from the system.


Assuntos
Bovinos/fisiologia , Proteínas Alimentares/metabolismo , Hordeum/química , Nitrogênio/metabolismo , Rúmen/metabolismo , Amônia/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais/análise , Digestão , Fezes/química , Feminino , Fermentação , Nitrogênio/química , Distribuição Aleatória
9.
J Anim Sci ; 91(5): 2278-94, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23478824

RESUMO

Crossbred beef steers (n = 312) were used in an experiment with a completely randomized design during the growing (235 ± 1.6 kg initial BW) and finishing (363 ± 2.7 kg) phase to determine the effects of dietary CP concentration and rumen degradability on NH3-N emissions, growth performance, and carcass traits. Diets were barley based and consisted of 55% silage and 45% concentrate in the backgrounding phase and 9% silage and 91% concentrate in the finishing phase. For each phase, there were 4 dietary treatments (6 pens of 13 cattle per diet): the basal diet with no protein supplementation (12% CP backgrounding and 12.6% CP finishing) or supplemented (14% CP) with urea (UREA), urea and canola meal (UREA+CM), or urea, corn gluten meal, and xylose-treated soybean meal (UREA+CGM+xSBM). Feed intake and BW of cattle were measured at 3-wk intervals. One pen of steers fed the 12 or 12.6% CP and 1 pen fed 1 of the 14% CP diets were housed in 2 isolated pens to quantify NH3-N emissions using the integrated horizontal flux technique with passive NH3 samplers. In the backgrounding phase final BW, ADG, and G:F were less (P < 0.05) in cattle fed the 12% CP and UREA compared with the UREA+CM and UREA+CGM+xSBM diets. Nitrogen-use efficiency of cattle fed UREA+CM and UREA+CGM+xSBM was equal to that of cattle fed 12% CP and averaged 19.8%. In the finishing phase, there was no effect (P > 0.10) of CP supplementation on BW, DMI, ADG, G:F, N-use efficiency, and carcass traits. The NH3-N emissions from December to February during the backgrounding phase ranged from 4.3 to 25.6 g N/(steer•d) and 3.8 to 16.3% of N intake and from April to July during the finishing phase ranged from 9.7 to 76.4 g N/(steer•d) and 4.4 to 26.7% of N intake. Differences in NH3-N emissions between the pens of cattle fed the backgrounding diets with 12 and 14% CP were not detected. For cattle fed the 12.6 and 14% CP finishing diets, NH3-N emissions tended (P ≤ 0.16) to be less for 2 of the 5 periods and averaged 14.4 and 28.1 g N/(steer•d) and 7.7 and 12.7% of N intake, respectively. The NH3-N emitted as a % of N intake averaged 42% less for cattle fed 12.6% compared with 14% CP. Feeding the barley-based concentrate diet to finishing cattle with 12.6% compared with 14% CP diets reduced NH3-N emissions with no effect on performance. Feeding the barley-based forage diet to backgrounding cattle with 12% CP, however, reduced performance compared with growing cattle fed supplementary degradable and undegradable true protein.


Assuntos
Composição Corporal , Bovinos/fisiologia , Proteínas Alimentares/metabolismo , Hordeum/química , Nitrogênio/metabolismo , Amônia/metabolismo , Ração Animal/análise , Animais , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais/análise , Masculino , Rúmen/metabolismo
10.
J Anim Sci ; 91(5): 2295-309, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23478832

RESUMO

The objectives of the study were to characterize the effects of CP concentration and ruminal degradability of barley-based backgrounding diets on route and chemical form of N excretion, ruminal fermentation, microbial protein synthesis, and nutrient digestion in beef cattle. Four Angus heifers (479 ± 14.6 kg average BW) with ruminal and duodenal cannulas were used in an experiment designed as a 4 × 4 Latin square. The basal diet consisted of 54% barley silage and 46% barley grain-based concentrate (DM basis). Dietary treatments included the basal diet with no added protein (12% CP) or diets formulated to contain 14% CP by supplementation with urea (UREA), urea and canola meal (UREA+CM), or urea, corn gluten meal, and xylose-treated soybean meal (UREA+CGM+xSBM). The amount of feed offered was restricted to 95% of ad libitum intake. There was no effect of the diets on DMI (P = 0.38), and therefore, N intake was less (P < 0.05) in heifers fed the 12% CP diets than the 14% CP diets. Fecal N output was not affected by the diet (P = 0.15), but urine N (P < 0.10) and urea N output were greater (P < 0.05) in heifers fed the 14% CP than the 12% CP diets. There was no effect of CP degradability (P > 0.10) on the amount of urine N output. Urine N output was 38.9 and 45.1 ± 5.50% of N intake in heifers fed the 12% CP and 14% CP diets (P < 0.05), respectively. Urea N, the form of N most susceptible to NH3-N volatilization and loss, was the major form of N in urine (75.5% in heifers fed the 12% CP diet and 81.4 ± 1.7% in heifers fed the 14% CP diets; P < 0.05). Supplemental RDP (UREA+CM) and RUP combined with urea (UREA+CGM+xSBM) to provide 14% CP increased (P < 0.05) ruminal NH3-N but had no effect on ruminal peptide N (P = 0.62) and free AA N (P = 0.18) concentration, the flow of microbial (P = 0.34) and feed (P = 0.55) N, and ruminal (starch, P = 0.11; NDF, P = 0.78) and total tract nutrient digestibility (OM, P = 0.21; starch, P = 0.16). Supplementation of barley-based backgrounding diets containing 12% CP with NPN alone or combined with ruminally degradable and undegradable true protein to attain 14% CP had no effect on fecal N output, but urine N and urea N increased irrespective of protein source. In addition, the ruminal degradability of the protein sources did not influence the composition of protein flowing to the intestine and site and extent of nutrient digestibility.


Assuntos
Bovinos/fisiologia , Proteínas Alimentares/metabolismo , Hordeum/química , Nitrogênio/metabolismo , Rúmen/metabolismo , Amônia/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais/análise , Digestão , Fezes/química , Fermentação , Masculino , Nitrogênio/química , Distribuição Aleatória
11.
Aliment Pharmacol Ther ; 29(1): 126-34, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18945261

RESUMO

BACKGROUND: Patients with functional chest pain (FCP) represent a therapeutic challenge for practising physicians. AIM: To determine the efficacy of Johrei as compared to wait-list in improving symptoms of FCP patients. METHODS: Patients with chest pain of noncardiac origin for at least 3 months were enrolled into the study. All patients had to have negative upper endoscopy, pH testing and oesophageal manometry prior to randomization. Subsequently, patients were randomized to either Johrei or wait-list control. Patients received 18 Johrei sessions from a Johrei practitioner for 6 weeks. RESULTS: A total of 21 FCP patients enrolled into the Johrei group and 18 into the wait-list group. There was no difference in symptom intensity score between Johrei group and wait-list group at baseline (20.28 vs. 23.06, P = N.S.). However, there was a significant pre- and post-treatment reduction in symptom intensity in the Johrei group (20.28 vs. 7.0, P = 0.0023). There was no significant reduction in symptom intensity score between baseline and at the end of the study in the wait-list group (23.06 vs. 20.69, P = N.S.). CONCLUSION: This pilot study shows that Johrei may have a role in improving FCP symptoms; however, future studies are needed to compare Johrei treatment with sham Johrei or supportive care.


Assuntos
Dor no Peito/terapia , Terapias Espirituais/métodos , Adulto , Idoso , Algoritmos , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
12.
Br J Nutr ; 98(3): 504-16, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17459191

RESUMO

Three groups of five wethers with ruminal and duodenal cannulas and maintained as either fauna-free (FF) or inoculated with total mixed fauna (TF) or Entodinium caudatum as a single-species monofauna (EN) were used in an experiment with two 28 d periods. In the first period, the sheep were fed a control barley-based diet (40:60 concentrate to silage DM) and in the second period the diet was supplemented with 187 g DM of Enterolobium cyclocarpum for the last 12 d of the period. The diets of period 1 and 2 were isonitrogenous. There was no effect of fauna on apparent ruminal and total tract organic matter and fibre digestion, but bacterial and microbial N flow and efficiency were improved in FF sheep compared to TF sheep. In period 2, protozoal numbers were reduced between 31 and 88 % 2 h after feeding E. cyclocarpum for the third to twelfth day of supplementation and by an average of 25 % in samples collected over the 24 h feeding cycle. Supplementation of the diet with E. cyclocarpum and the consequent protozoal reduction in TF and EN sheep improved the flow of non-ammonia N and bacterial N to the small intestine and the efficiency of microbial synthesis. However, E. cyclocarpum reduced ruminal organic matter digestion, especially in faunated sheep, and total tract organic matter, N and fibre digestion. Thus, a reduction in the protozoal cell numbers of 25 % was sufficient to achieve the beneficial effects of reduced fauna on the bacterial protein supply, but diet digestibility was reduced.


Assuntos
Proteínas de Bactérias/metabolismo , Cilióforos/fisiologia , Digestão/fisiologia , Fabaceae/fisiologia , Rúmen/microbiologia , Ração Animal , Animais , Cilióforos/isolamento & purificação , Fibras na Dieta/metabolismo , Proteínas Alimentares/metabolismo , Suplementos Nutricionais , Duodeno/fisiologia , Ácidos Graxos Voláteis/análise , Fermentação/fisiologia , Trânsito Gastrointestinal/fisiologia , Nitrogênio/metabolismo , Proteínas de Protozoários/metabolismo , Rúmen/metabolismo , Rúmen/parasitologia , Ovinos
14.
J Dairy Sci ; 85(4): 930-8, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12018438

RESUMO

Ruminal escape of various amounts of methionine hydroxy analog [D,L-2-hydroxy-4-(methylthio)-butanoic acid (HMB)] was measured in an experiment designed as a 4 x 4 Latin square using four lactating dairy cows with cannula in the rumen and duodenum. The cows were fed a diet composed of corn silage, alfalfa haylage, rolled barley grain, canola meal, and blood meal, three times per day. The cows were fed the liquid analog each day for 1 wk before the experiment was started. On the day of the experiment, each cow received an intraruminal bolus dose of 0, 25, or 50 g of the liquid analog (Alimet feed supplement, 88% HMB) or 51.2 g of a dry calcium salt of the analog (86% HMB; MHA) mixed with 0.5 kg of ground barley grain. A liquid phase marker (Co-EDTA) was administered as a bolus dose into the rumen at the time of administration of the methionine hydroxy analogs. Rumen and duodenal contents, and blood serum were collected at 0, 1, 3, 6, 9, 12, and 24 h relative to the time of dosing. Rumen and duodenal samples were analyzed for Co and HMB, and serum was analyzed for free methionine. Fractional rate constants for the passage of the liquid marker (k(p)) and the decline of HMB concentration in the rumen (k(rHMB)) were determined by nonlinear regression. Liquid passage from the rumen was similar among the four analog treatments (0.136 +/- 0.012/h; mean +/- SEM). Ruminal escape of HMB as a percentage of the dose (100% x k(p)/k(rHMB)) did not differ between cows receiving 25, 50, and 51.2 g of the methionine analogs (42.5, 41.0, and 34.9 +/- 9.0%, respectively) and averaged 39.5%. Duodenal appearance of HMB as a percentage also did not differ between cows receiving 25, 50, and 51.2 g of the methionine analogs (16.2, 26.8, and 22.7%, respectively) and averaged 22%. Omasal absorption of HMB was variable ranging from 12.3 to 26.3% and averaged 17.6%. Serum methionine concentration peaked at 3 and 6 h after dosing and increased in proportion to the amount of the analog administered. It was concluded that 39.5% of the methionine hydroxy analog escaped rumen degradation, the percentage of the dose that escaped the rumen was not affected by the amount or form of the methionine analog fed, and the analog that escaped ruminal degradation was likely absorbed and metabolized to methionine.


Assuntos
Ração Animal , Bovinos/fisiologia , Lactação/metabolismo , Metionina/análogos & derivados , Metionina/farmacocinética , Rúmen/metabolismo , Animais , Disponibilidade Biológica , Bovinos/metabolismo , Relação Dose-Resposta a Droga , Duodeno/metabolismo , Feminino , Conteúdo Gastrointestinal/química , Absorção Intestinal , Cinética , Metionina/administração & dosagem , Metionina/sangue , Omaso/metabolismo
15.
Atherosclerosis ; 154(2): 387-98, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11166771

RESUMO

The oxidation hypothesis of atherosclerosis implies that antioxidants are able to inhibit lipoprotein oxidation in the arterial wall and thereby retard atherogenesis. Since most of the animal studies performed have used very high doses of antioxidants, it is to date unknown whether antioxidants are effective antiatherosclerotic agents when given in pharmacological doses. Here we addressed this question using homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits as an animal model of atherosclerosis. The rabbits were divided into four groups, each consisting of ten animals. They received either a standard diet or a diet containing 4.3 mg ubiquinone-10, or 4.3 mg vitamin E or 15 mg probucol/kg body weight daily. After 12 months, the extent of aortic atherosclerosis was assessed as the intima thickness, media thickness and intima-to-media ratio in 14 cross sections equally distributed over the whole aorta. To evaluate the antioxidant effects of the diet, lipophilic and hydrophilic antioxidants, lipids, fatty acids and plasma oxidizability were measured after 0, 3 and 6 months of feeding. We found that supplementation with probucol significantly decreased aortic intima-to-media ratio compared to controls. The antiatherosclerotic action of probucol was accompanied by its beneficial action on plasma oxidizability and some plasma antioxidants. No decrease in aortic atherosclerosis was measured in ubiquinone-10- and vitamin E-supplemented rabbits, despite the fact that both antioxidants decreased plasma oxidizability and ubiquinone-10 increased the plasma levels of antioxidants. Taken together, these data suggest that pharmacological doses of probucol retard atherogenesis in WHHL rabbits by an antioxidant mechanism, while ubiquinone-10 and vitamin E at these dosages are ineffective in this highly hyperlipidaemic model. The measurement of some oxidation-related parameters in plasma, such as lipophilic antioxidants, polyunsaturated fatty acids and lipoprotein oxidizability, may be useful in assessing the risk of atherogenesis in humans.


Assuntos
Antioxidantes/administração & dosagem , Arteriosclerose/prevenção & controle , Hiperlipidemias/terapia , Oxirredução/efeitos dos fármacos , Administração Oral , Animais , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/farmacocinética , Antídotos/administração & dosagem , Antídotos/farmacocinética , Antioxidantes/farmacocinética , Aorta/efeitos dos fármacos , Aorta/patologia , Arteriosclerose/sangue , Arteriosclerose/etiologia , Arteriosclerose/patologia , Dieta , Relação Dose-Resposta a Droga , Ácidos Graxos Insaturados/sangue , Hiperlipidemias/sangue , Hiperlipidemias/complicações , Lipoproteínas/sangue , Probucol/administração & dosagem , Probucol/farmacocinética , Coelhos , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologia , Ubiquinona/administração & dosagem , Ubiquinona/farmacocinética , Vitamina E/administração & dosagem , Vitamina E/farmacocinética
16.
Int J Vitam Nutr Res ; 70(3): 119-25, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10883405

RESUMO

Iron overload, expressed as increased body iron stores, has been recognized as a potential hazard because it promotes the generation of oxygen radicals. We analyzed factors associated with serum ferritin levels (an indicator of body iron stores) among middle-aged women with a high prevalence of nutrient supplement use. Serum ferritin concentrations were determined on automated immunoassay for 487 healthy women with the mean age of 57 years who participated in the New York University Women's Health Study. The mean serum ferritin concentration in postmenopausal women was more than twice that in premenopausal women. Serum ferritin concentrations progressively increased with advancing age, but adjustment for menopausal status considerably weakened this association. Among non-dietary factors, nonwhite ethnicity, obesity and cigarette smoking were positively associated with serum ferritin concentrations. After adjustment for these factors and for menopausal status, serum ferritin levels were positively associated with meat intake and multivitamin use and inversely associated with breakfast cereal consumption. However, none of these lifestyle factors positively associated with serum ferritin levels had a significant impact on serum ferritin levels above 100 ng/ml (approximately equal to median concentration). Our results suggest that iron overload seems unlikely among middle aged women through their diet and nutritional supplements.


Assuntos
Dieta , Suplementos Nutricionais , Ferritinas/sangue , Sobrecarga de Ferro/diagnóstico , Ferro/administração & dosagem , Adulto , Idoso , Estudos de Coortes , Estudos Transversais , Grão Comestível , Feminino , Humanos , Ferro/sangue , Sobrecarga de Ferro/prevenção & controle , Ferro da Dieta/administração & dosagem , Estilo de Vida , Carne , Menopausa/sangue , Menopausa/metabolismo , Pessoa de Meia-Idade , Estado Nutricional , Estudos Prospectivos , Fatores de Risco
17.
Int J Vitam Nutr Res ; 69(5): 322-9, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10526776

RESUMO

Lower serum folate and higher serum homocysteine levels are known risk factors for various conditions. Thus, epidemiologic correlates with these measurements were studied for 256 multivitamin users and 230 non-users who were middle-aged women. Both serum folate and homocysteine levels increased with advancing age in both multivitamin users (P < 0.01 and P < 0.01) and non-users (P = 0.08 and P < 0.01). Among non-users, higher intake of vegetables, fruits, cold cereals and total protein were associated positively with serum folate and inversely with homocysteine levels. There were 25-74% increases in serum folate and 10-15% decreases in serum homocysteine between 1st and 4th quartiles of intake of these food/nutrients. In addition, 26% lower serum folate and 18% higher serum homocysteine were observed for those smoking 20 or more cigarettes per day compared with non-smokers. Among multivitamin users, body weight was correlated inversely with serum folate (P < 0.01) and positively with serum homocysteine levels (P = 0.04), while no correlates were found among lifestyle factors. Regular use of multivitamins increased serum folate about fourfold and decreased homocysteine twofold. These results suggest that multivitamin use can offset the effects of an unhealthy lifestyle on these serum markers, and that levels of serum folate and homocysteine can also be favorably influenced by healthier diet and abstinence from smoking.


Assuntos
Suplementos Nutricionais , Ácido Fólico/sangue , Homocisteína/sangue , Vitaminas , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Estado Nutricional , Estudos Prospectivos
18.
J Dairy Sci ; 82(2): 355-61, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10068957

RESUMO

Availability of liquid methionine hydroxy analog [D,L-2-hydroxy-4-(methylthio)-butanoic acid] was evaluated in two experiments using four cannulated lactating dairy cows. The first experiment was designed as a 4 x 4 Latin square. Each cow received a pulse dose of 0, 30, 60, or 90 g of the methionine analog in the rumen each day for 10 d. Duodenal samples were collected at 16, 20, and 24 h after dosing for the last 5 d and pooled. The methionine analog was not detected in duodenal contents because it passed rapidly from the rumen relative to the sampling protocol. In the second experiment, cows were offered 90 g of the methionine analog and 600 ml of Cr-EDTA (3.5 g of Cr) mixed with ground corn for a period of 20 min after which any remains of the treatment were placed in the rumen. The concentration of the analog peaked in ruminal and duodenal fluid at 1 and 3 h, respectively. Based on the fractional rate constants for ruminal and duodenal disappearance of the methionine analog and passage of the liquid, it was determined that 50.0 +/- 2.8% of the methionine analog escaped ruminal degradation and became available for intestinal absorption (44.6 +/- 5.7%) or was absorbed from the omasum (5.4 +/- 3.3%). Serum methionine concentration peaked 6 h after analog dosing at a level that was three times the predose level, indicating that the methionine analog that escaped ruminal degradation was absorbed and metabolized to methionine.


Assuntos
Bovinos/fisiologia , Absorção Intestinal , Metionina/análogos & derivados , Metionina/sangue , Rúmen/metabolismo , Animais , Disponibilidade Biológica , Suplementos Nutricionais , Feminino , Cinética , Lactação , Metionina/farmacocinética , Metionina/farmacologia , Omaso/metabolismo
19.
Int J Cancer ; 80(5): 693-8, 1999 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10048969

RESUMO

Accumulated evidence suggests that increased body iron stores may increase the risk of colorectal cancer, possibly via catalyzing oxidation reactions. We examined the relationship between iron status and colorectal cancer in a case-control study nested within the New York University Women's Health Study cohort. For 105 incident cases of colorectal cancer with an average follow-up of 4.7 years and 523 individually matched controls, baseline levels of serum iron, ferritin, total iron binding capacity (TIBC) and transferrin saturation were determined as indicators of body iron stores, and total iron intake was assessed based on their diet and supplement intake. Overall, there were no associations between the risk of colorectal cancer and any of these indices except for serum ferritin, which showed a significant inverse association. When analyzed by subsite, there was an increasing trend in risk of cancer of the proximal colon with increasing total iron intake (p-value for trend = 0.04). In addition, a significantly increased risk of colorectal cancer associated with higher total iron intake [odds ratio (OR) = 2.50; 95% confidence interval (CI): 1.06-5.87] was observed among subjects with higher intake of total fat. Our results do not support a role of increased body iron stores in the development of colorectal cancer, but suggest that luminal exposure to excessive iron may possibly increase the risk in combination with a high fat diet.


Assuntos
Neoplasias do Colo/epidemiologia , Neoplasias Colorretais/epidemiologia , Dieta , Ferro/metabolismo , Neoplasias Retais/epidemiologia , Adulto , Idoso , Estudos de Casos e Controles , Neoplasias Colorretais/etiologia , Gorduras na Dieta , Feminino , Ferritinas/sangue , Seguimentos , Humanos , Ferro/sangue , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Fatores de Risco , Inquéritos e Questionários , Transferrina/metabolismo
20.
Prehosp Emerg Care ; 2(1): 67-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9737411

RESUMO

Emergency medical services systems and MCOs must cooperate and educate each other in order to effect delivery of reliable, high-quality emergency health care to the entire community. Shared goals are rapid access, medically appropriate care, and operational efficiency. An integrated approach is necessary in order to maintain the integrity of EMS systems. EMS systems serve as a safety net for patients with perceived emergencies. Changes in form and function should be guided by outcome studies that ensure the continued delivery of quality emergency health care services.


Assuntos
Prestação Integrada de Cuidados de Saúde/normas , Serviços Médicos de Emergência/organização & administração , Programas de Assistência Gerenciada/organização & administração , Comportamento Cooperativo , Sistemas de Comunicação entre Serviços de Emergência/organização & administração , Sistemas de Comunicação entre Serviços de Emergência/normas , Serviços Médicos de Emergência/normas , Humanos , Relações Interinstitucionais , Programas de Assistência Gerenciada/normas , Política Organizacional , Estados Unidos
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