Effects of energy supplementation on energy losses and nitrogen balance of steers fed green-chopped wheat pasture I: Calorimetry.

Cattle grazing wheat pasture in the southern Great Plains are sometimes fed an energy supplement; however, the benefits of supplementation on nutrient balance, energy metabolism, and greenhouse gas emissions have not been elucidated. Therefore, we used 10 British crossbred steers (206 ± 10.7 kg initial BW) in a respiration calorimetry study to evaluate the effects of energy supplementation on energy losses, N balance, and nutrient digestibility of steers fed green-chopped wheat forage. The study design was an incomplete replicated 4 × 4 Latin square with treatments in a 2 × 2 factorial arrangement. Steers ( = 8) were assigned to 1 of 2 BW blocks (4 steers per block) with dietary factors consisting of 1) no supplementation (CON) or supplemented with a steam-flaked corn-based energy supplement (that also contained monensin sodium) at 0.5% of BW daily (SUP) and 2) NEm intakes of 1 times (1x) or 1.5 times (1.5x) maintenance. Wheat forage was harvested daily and continuously fed as green-chop to steers during the 56-d study. There were no differences ( ≥ 0.32) between CON and SUP for OM (78.3 vs. 80.7%, respectively) or NDF (68.3 vs. 64.8%, respectively) digestibility. At the 1.5x level of intake, there was no difference ( ≥ 0.16) in energy lost in feces (4.27 vs. 3.92 Mcal/d) or urine (0.58 vs. 0.55 Mcal/d), heat production (8.69 vs. 8.44 Mcal/d), or retained energy (3.10 vs. 3.46 Mcal/d) between supplementation treatments. Oxygen consumption (1,777 vs. 1,731 L/d; = 0.67) and CO production (1,704 vs. 1,627 L/d; = 0.56) of CON and SUP steers, respectively, were not different; however, SUP steers tended to have ( = 0.06) lower CH production (115 vs 130 L/d) than CON steers. Methane, as a proportion of GE intake, was similar for CON (6.87%) and SUP (6.07%; = 0.18), as was the ME:DE ratio ( = 0.24; 86.3% for CON and 87.9% for SUP). Fractional N excretion in urine and feces, as a proportion of total N excreted ( ≥ 0.84) or N intake ( ≥ 0.63), was not different between treatments. Calculated NEm and NEg values for CON were 1.76 and 1.37 Mcal/kg DM, respectively, whereas the NEm and NEg values for the SUP treatment were 2.32 and 1.61 Mcal/kg DM, respectively. Calculated NE values for steers fed additional energy were approximately 17.5% greater than the expected difference in energy content. This was probably the result of the inconsistent response at the 1x DMI level. Under these circumstances, energy supplementation did appear to enhance NEm and NEg value of the supplemented wheat forage diet.

Effects of roughage inclusion and particle size on digestion and ruminal fermentation characteristics of beef steers.

Roughage is fed in finishing diets to promote ruminal health and decrease digestive upset, but the inclusion rate is limited because of the cost per unit of energy and feed management issues. Rumination behavior of cattle may be a means to standardize roughage in beef cattle finishing diets, and increasing the particle size of roughage could modulate the ruminal environment and aid in maintaining ruminal pH. Therefore, this experiment was conducted to determine the effects of corn stalk (CS) inclusion rate and particle size in finishing diets on digestibility, rumination, and ruminal fermentation characteristics of beef steers. Four ruminally cannulated steers were used in a 4 × 4 Latin square experiment. Treatments were arranged as a 2 × 2 factorial with treatments consisting of 5% inclusion of a short-grind roughage (5SG), 10% inclusion of a short-grind roughage (10SG), 5% inclusion of a long-grind roughage (5LG), and 10% inclusion of a long-grind roughage (10LG). Differences in particle size were obtained by grinding corn stalks once (LG) or twice (SG) using a commercial tub grinder equipped with a 7.6-cm screen and quantified using the Penn State Particle Separator (PSPS) to estimate physically effective NDF (peNDF). Each period included 14 d for adaptation and 4 d for diet, fecal, and ruminal fluid collections. Animals were outfitted with rumination monitoring collars to continuously measure rumination activity. The 10LG treatment had a greater ( < 0.01) percentage of large particles (retained on the top 3 sieves of the PSPS) compared to the other treatments. This resulted in a greater ( < 0.01) percentage of estimated peNDF for the 10LG diet compared to the others. Feeding diets containing 5% roughage tended to increase ( ≤ 0.09) DM, NDF, and starch total tract digestibility compared to diets containing 10% roughage. Cattle consuming LG treatments had greater ( < 0.01) rumination time and greater ( < 0.01) ruminal pH than cattle consuming diets containing SG roughage. Cattle receiving the 5% inclusion rate of roughage tended to have greater ( = 0.09) time (h/d) under a ruminal pH of 5.6 and a larger ( = 0.03) area under the threshold compared to cattle receiving the 10% roughage treatments. Overall, feeding a lower inclusion of roughage with a larger particle size may stimulate rumination and aid in ruminal buffering similar to that of a higher inclusion of roughage with a smaller particle size, without negatively impacting digestibility and fermentation.

Effect of condensed tannin extract supplementation on growth performance, nitrogen balance, gas emissions, and energetic losses of beef steers.

Condensed tannins (CT) may decrease greenhouse gas emissions and alter the site of N excreted by ruminants. We evaluated the effect of top-dressing a steam-flaked corn-based finishing diet (14.4% CP and NEg 1.47 Mcal/kg) for beef cattle with a commercially available CT extract at 3 levels (0, 0.5, and 1.0% of diet, DM basis). Angus-crossbred steers ( = 27; 350 ± 32 kg initial BW) were individually fed via Calan gates for 126 d. Diet digestibility and N balance were estimated after 34 and 95 d on feed (Phase 1 and Phase 2, respectively) using titanium dioxide as a marker of fecal output and the creatinine:BW ratio as a marker for urine output. Ruminal CH and metabolic CO fluxes were measured using a GreenFeed system (C-Lock Inc., Rapid City, SD) for 2 sampling periods that coincided with fecal and urine sampling. Urine energy loss was estimated from urine N excretion, assuming all excreted N was urea. Oxygen consumption was estimated from CO production assuming a respiratory quotient of 1.05. Average daily gain (2.08, 2.14, and 2.08 kg/d for 0, 0.5, and 1.0% CT, respectively) and G:F did not differ ( = 0.88) among treatments. Starch intake and OM intake did not differ ( ≥ 0.42) among treatments during each phase. Apparent total tract starch digestibility during Phase 1 linearly decreased ( = 0.04) with inclusion of CT. Apparent total tract digestibility of OM and starch were not different among treatments ( ≥ 0.13) during Phase 2. Nitrogen intake did not differ ( ≥ 0.16) among treatments during each phase, but fecal N excretion linearly increased ( = 0.05) with inclusion of CT during Phase 1. Urinary N excretion was not different ( ≥ 0.39) among treatments during both phases, but urinary N as a proportion of total N excretion linearly decreased ( = 0.01) when CT was included in the diet during Phase 1. Retained N was not different ( ≥ 0.27) among treatments during each phase. Fluxes of CO were similar ( ≥ 0.37) among treatments during both phases. No differences ( ≥ 0.23) were observed for percentage of GE intake lost as CH (2.99, 3.12, and 3.09% in Phase 1 and 3.54, 3.55, and 4.35% in Phase 2) for 0, 0.5, and 1.0% CT, respectively. No difference ( ≥ 0.42) was observed for heat production lost as a percent of GE intake during both phases. Growth performance, gas emissions, and energetic losses were not affected by the inclusion CT in a steam-flaked corn-based finishing diet.

Effects of feeding condensed distiller's solubles and crude glycerin alone or in combination on finishing beef cattle performance, carcass characteristics, and in vitro fermentation.

Two experiments were conducted to evaluate the effects of feeding condensed distiller's solubles (DS) and crude glycerin alone or in combination on performance of finishing beef cattle and in vitro fermentation. In both experiments, dietary treatments consisted of a steam-flaked corn-based diet with 0% DS or crude glycerin (CON), 10% DS (CDS), 10% crude glycerin (GLY), or a combination of 5% DS and 5% crude glycerin (C+G) included on a DM basis. All treatment diets contained 15% (DM basis) wet distiller's grains plus solubles. In Exp. 1, crossbred steers ( = 256; 322 ± 15 kg initial BW) were used in a randomized complete block finishing trial. Growth performance and gain efficiency were not different ( > 0.10) across all treatments. Treatment had no effect ( > 0.10) on carcass weight, marbling score, yield grade, LM area, or percent grading USDA choice. In Exp. 2, ruminal fluid was collected from 2 ruminally cannulated steers to evaluate in vitro fermentation characteristics. No differences ( = 0.43) were observed for DM disappearance across all treatments. The GLY and C+G treatments had decreased ( = 0.02 and = 0.05, respectively) NDF disappearance (NDFD), whereas the CDS treatment tended to have decreased ( = 0.06) NDFD compared with CON. Concentrations of NH decreased ( < 0.04) with GLY and C+G treatments compared with CON. Total gas production decreased ( < 0.01) for the C+G treatment compared with other treatments. The CDS treatment had increased ( < 0.02) total VFA compared with the CON or C+G treatments. Treatments had no effect ( > 0.17) on concentrations of acetate, propionate, and butyrate, but valerate concentrations were the greatest ( < 0.04) for the CON treatment. Concentrations of isobutyrate increased ( < 0.05) for the CON and C+G treatments compared with the GLY treatment and tended to increase ( < 0.10) compared with the CDS treatment. Including DS or glycerin in the substrates decreased ( < 0.08) isovalerate compared with CON. Feeding additional byproducts such as DS and crude glycerin alone or in combination in a finishing diet did not alter live animal performance or carcass characteristics; however, feeding a combination of the 2 byproducts may alter in vitro fermentation.

The effect of zilpaterol hydrochloride supplementation on energy metabolism and nitrogen and carbon retention of steers fed at maintenance and fasting intake levels.

An indirect calorimetry trial examined energy metabolism, apparent nutrient digestibility, C retention (CR), and N retention (NR) of cattle supplemented with zilpaterol hydrochloride (ZH). Beef steers ( = 20; 463 ± 14 kg) blocked ( = 5) by weight and source were individually fed and adapted to maintenance energy intake for 21 d before allotment to ZH (90 mg/steer∙d) or no ß-adrenergic agonist treatment (control [CONT]) for 20 d (455 ± 14 kg at the start of treatment). Respiration chambers = 4 were used to quantify heat production (HP) during maintenance (d 12 to 16 of the ZH period) and fasting heat production (FHP; d 19 to 20 of ZH period; total 4 d of fast). Steers were harvested after a 6-d ZH withdrawal and carcasses were graded 24 h after harvest. Control cattle lost more BW ( < 0.01; 9 kg for CONT and 2 kg for ZH-treated) during maintenance whereas the BW loss of ZH-treated steers was greater ( < 0.01; 9 kg for ZH-treated and vs. 4 kg, for CONT) during FHP; no differences ( ≥ 0.76) were detected for G:F, ADG, and end BW. No differences in DMI, apparent nutrient digestibility, O consumption, or CH production ( ≥ 0.12) were detected; however, ZH-treated cattle had greater CO production during maintenance ( = 0.04; 23.6 L/kgBW for ZH-treated and 22.4 L/kg BW for CONT). Digestible energy and ME did not differ ( ≥ 0.19); however, urinary energy was greater ( = 0.05; 0.091 Mcal for CONT and 0.074 Mcal for ZH-treated) in CONT cattle. Steers treated with ZH tended to have greater HP ( = 0.09; 12.44 Mcal for ZH-treated and 11.69 Mcal for CONT), but the effect was reduced on a BW basis ( = 0.12; 0.126 Mcal/kg BW0.75 for ZH-treated and 0.120 Mcal/kg BW0.75 for CONT vs. 0.120 Mcal/kg BW). No treatment difference in FHP was observed ( ≥ 0.32) although CO production (L/steer) increased with ZH treatment ( = 0.04; 1,423 L/steer for ZH-treated and 1,338 L/steer for CONT). Control cattle excreted more ( = 0.05) N in urine (39.8 g/d for CONT and 32.4 g/d for ZH-treated); therefore, NR ( = 0.07; 22.14 g/d for ZH-treated and 14.12 g/d for CONT steers) tended to be greater for ZH-fed steers. Steers treated with ZH lost more C via CO ( = 0.04; 1,036.9 g/d for ZH-treated and 974.3 g/d for CONT) although total CR did not differ ( ≥ 0.23). Empty BW, HCW, and harvest yields (g/kg empty BW) were not different ( ≥ 0.13), whereas ZH increased dressed yield ( = 0.02; 62.12 % for ZH-treated and 60.65% for CONT) and LM area ( = 0.02; 77.81 cm for ZH-treated and vs. 70.90 cm for CONT). Separable carcass lean and actual skeletal muscle protein (SMP) were increased with ZH ( ≤ 0.04; 201.6 and 41.2 kg, respectively for ZH-treated and 196.0 and 38.4 kg, respectively for CONT). Results from this trial indicate that ZH treatment increased ( = 0.03) SMP and tended ( ≥ 0.07) to increase NR and modify HP during maintenance by increasing CO production.

Effects of roughage inclusion and particle size on performance and rumination behavior of finishing beef steers.

Roughage is typically mechanically processed to increase digestibility and improve handling and mixing characteristics in beef cattle finishing diets. Roughage is fed to promote ruminal health and decrease digestive upset, but inclusion in finishing diets is limited due to the cost per unit of energy. Rumination behavior may be a means to standardize roughage in beef cattle finishing diets, and increasing particle size of roughage may allow a decrease in roughage inclusion without sacrificing animal performance. Therefore, the objectives of this study were to quantify rumination time for a finishing beef animal and to evaluate the effects of corn stalk (CS) inclusion rate and particle size on rumination behavior, animal performance, and carcass characteristics. Fifty-one individually fed steers (385 ± 3.6 kg initial BW) were used in a randomized complete block design feeding study. Corn stalks were passed through a tub grinder equipped with a 7.62-cm screen once to generate long-grind CS (LG-CS) or twice to generate short-grind CS (SG-CS). Dietary treatments were based on steam-flaked corn and included, on a DM basis, 30% wet corn gluten feed (WCGF) with 5% SG-CS (5SG), 30% WCGF with 5% LG-CS (5LG), and 25% WCGF with 10% SG-CS (10SG). The Penn State Particle Separator was used to separate ingredients and treatment diets and to estimate physically effective NDF (peNDF). On d 70, each steer was fitted with a collar (HR Tag; SCR Dairy, Netanya, Isreal), which continuously measured rumination minutes via a sensory microphone. Long-grind CS contained more ( < 0.01) peNDF than SG-CS, and the 10SG diet contained more ( = 0.03) peNDF than the 5LG and 5SG diets. Dry matter intake was greatest ( = 0.03) for steers consuming 5LG and least for steers consuming 10SG, with cattle consuming 5SG being intermediate. Carcass-adjusted ADG and G:F were greatest ( ≤ 0.03) for steers consuming 5LG and 5SG compared with steers consuming 10SG. Hot carcass weight tended ( = 0.10) to be greatest for steers consuming 5LG and least for steers consuming 10SG, with steers consuming 5SG being intermediate. Dressing percent was greater ( = 0.01) for steers consuming 5LG and 5SG than for steers consuming 10SG. A significant interaction ( < 0.01) occurred for rumination minutes × day. Rumination (min/day) were greatest ( = 0.01) for steers consuming 10SG followed by steers consuming 5LG and was lowest for steers consuming 5SG. Increasing particle size of roughage may be a means to decrease roughage inclusion rate while maintaining rumination and performance.

In vivo ruminal degradation characteristics and apparent digestibility of low-quality prairie hay for steers consuming monensin and Optimase.

Seven ruminally cannulated crossbred steers (BW = 720 ± 62 kg) were used in a randomized crossover design (4 periods, each 18 d) to evaluate in vivo rumen characteristics and apparent digestibility of steers consuming low-quality prairie hay and 1 of 4 isonitrogenous protein supplements. Treatments included 1) 40% CP (DM basis) cottonseed meal and wheat middlings-based supplement (Control), 2) a cottonseed meal and wheat middlings-based supplement with slow-release urea and a fibrolytic feed enzyme (Optimase; Alltech, Inc., Nicholasville, KY) designed to replace 30% of plant-based CP provided in the Control (OPT), 3) the Control plus 0.40 mg∙kg BW∙d monensin (Rumensin 90; Elanco Animal Health, Greenfield, IN; MON), and 4) the OPT plus 0.40 mg∙kg BW∙d monensin (COMBO). Steers were allowed ad libitum access to prairie hay (5.0% CP and 76% NDF) and were provided each respective supplement at 0800 h daily at a rate of 1.0 g/kg of BW. Steers were adapted to diets for 10 d before sample collection. Beginning on d 11, DMI was measured and samples were collected to determine apparent digestibility. On d 15 of the 18-d period, rumen fluid was collected 10 times over a 24-h period. Forage DMI was greater ( ≤ 0.02) for steers consuming the OPT compared with steers consuming the MON or COMBO, although forage DMI was not different ( = 0.10) among steers consuming the Control compared with steers consuming the OPT, MON, or COMBO. Steers fed the MON and COMBO had lower ( ≤ 0.05) passage rate compared with steers fed the Control and the OPT. The MON-fed steers had lower ( = 0.01) ruminal pH and increased ( = 0.03) propionate as a percentage of total VFA production. A time × treatment ( = 0.01) interaction was observed for ruminal NH-N due to a rapid (0 to 1 h after feeding) increase followed by a quick (1 to 4 h after feeding) decline in NH-N by steers consuming the OPT and COMBO that was not observed for steers consuming all other treatments. Apparent digestibility of DM ( = 0.01) and NDF ( = 0.03) were improved for steers fed the COMBO supplement compared with steers consuming all other experimental supplements. This work suggests that the OPT may be an effective replacement for a portion of supplemental degradable intake protein in low-quality forage. Further research is necessary to determine if the combination of monensin and the Optimase consistently improves low-quality forage utilization.

Supplementation of monensin and Optimase to beef cows consuming low-quality forage during late gestation and early lactation.

Two experiments were designed to investigate the effects of feeding monensin and/or slow release urea with a fibrolytic feed enzyme (Optimase; Alltech, Inc., Nicholasville, KY) on performance, milk production, calf growth performance, and blood metabolites in beef cows. Spring-calving cows and heifers were used in a completely randomized design in Exp. 1 (N = 84; 534 ± 68 kg initial BW) and Exp. 2 (N = 107; 508 ± 72 kg initial BW). Exp. 1 supplements were formulated to meet cow protein requirements and fed daily and included 1) cottonseed meal with no monensin (control); or 2) monensin added to control to supply 200 mg per head per d (MON). In Exp. 2, experimental supplements included 1) cottonseed meal/wheat middlings (CS) fed at a rate to provide adequate DIP and CP according to , 2) the CS plus soybean hulls and 61 g per cow per d Optimase (OPT), 3) the CS plus monensin to supply 200 mg per cow per d (MON2), and 4) OPT plus MON2 (Combo). Cows were fed in last trimester through early lactation in Exp. 1 and during 2nd trimester in Exp. 2. Data were analyzed using the Mixed procedure in SAS with animal as the experimental unit. In Exp. 1, treatment did not affect cow BW or BCS change (P > 0.19). Calf birth BW was not affected by dam treatment (P = 0.24); however, calves from dams consuming MON weighed more (P < 0.04) at d 45 and at trial end. Calves also had greater (P = 0.04) ADG from birth to trial end. Milk production did not significantly differ among treatments (P > 0.41). In Exp. 2, mean cow BW and BCS were similar (P > 0.35) among treatments on d 90. However, from d 0 to 54, cows assigned to the OPT supplement gained less BCS (P = 0.02) compared with cows assigned to the CS supplement. Cumulative BCS gain was greater (P < 0.01) for CS-fed cows than for cows fed the OPT and MON2 supplements, although it was not significantly different for cows fed the Combo supplement. These studies indicate that the influence of monensin on cow BW and BCS change is inconsistent. The potential for monensin supplementation to positively impact calf performance during early lactation seems to be clearer. Replacing a portion of oilseed N in the supplement with Optimase may marginally reduce cow performance. Further research is needed to determine both the effects of monensin and the implications of combining monensin with Optimase on forage intake and cow performance at various stages of production.

Effects of the Programmed Nutrition Beef Program on feedlot performance and carcass characteristics.

The objective of this study was to examine the effects of alternative finishing strategies on feedlot performance and carcass characteristics. Beef steers (64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement. Factor 1 consisted of diet, with cattle fed a conventional (CON) diet or a diet consisting of Programmed Nutrition Beef Program (PN) supplements. The PN treatment included Programmed Nutrition Beef Receiver fed from d 1 through 20 of feeding and Programmed Nutrition Beef Finisher fed from d 21 to harvest. Factor 2 evaluated the presence (EGP+) or absence (EGP-) of exogenous growth promotants (ExGP) in the production system. Steers in the EGP+ treatments were initially implanted with Component E-S, reimplanted with Component TE-IS, and fed 400 mg·animal·dof ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175, and strip loins were removed from 2 carcasses selected at random from each pen for transport to Kansas State University. One 1.27-cm-thick steak was removed from the anterior face for proximate and long-chain fatty acid analysis. There were no diet × ExGP interactions ( > 0.10) for feedlot performance except for DMI ( = 0.02). Steers in the PN/EGP+ treatment consumed more feed than all other treatments ( < 0.05). Both diet and ExGP affected DMI ( < 0.05), with PN and EGP+ steers consuming more feed than their contemporaries. Gain:feed and ADG were unaffected ( > 0.10) by diet, but ExGP improved these measures ( < 0.01). There were no diet × ExGP interactions for carcass characteristics except KPH fat and percentages of yield grade 3 and 4 carcasses ( < 0.05). Diet affected total incidence of liver abscesses because PN steers had a greater ( = 0.05) incidence of liver abscesses than steers in the CON treatment. Diet did not affect the other carcass characteristics ( > 0.10). Use of ExGP increased ( < 0.05) HCW, LM area, and 12th-rib fat but did not affect ( > 0.10) marbling score. Using ExGP reduced the percentage carcasses grading Premium Choice ( < 0.05). No diet × ExGP interactions or diet effects were detected for long-chain fatty acid profiles ( > 0.10). Use of ExGP increased ( < 0.05) the ratio of saturated:unsaturated fatty acids. In summary, the alternative feeding strategy presented in this study produced similar feedlot performance and carcass characteristics compared with a conventional feedlot system.

Effects of the Programmed Nutrition Beef Program on meat quality characteristics.

The objective of this study was to examine the effects of alternative finishing strategies on beef steak color and cooked meat characteristics. Beef steers (n = 64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 × 2 factorial treatment arrangement and initial body weight serving as the blocking factor. Factor 1 consisted of dietary treatment with cattle either being fed a conventional feedlot diet (CON) or a diet that included Programmed Nutrition Beef Program supplements. Cattle in the Programmed Nutrition (PN) treatments were fed in two-stages: 1) the basal diet with Programmed Nutrition Beef Receiver from d 1 to 20 and the basal diet with Programmed Nutrition Beef Finisher from d 21 to harvest. Factor 2 consisted of the inclusion (EGP+) or absence (EGP-) of an exogenous growth promoting program. Steers in the EGP+ treatments were implanted initially with Component E-S, reimplanted with Component TE-IS, and fed 400 mg · d(-1) · steer(-1) of ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175 of feeding and 1 strip loin was removed from 2 carcasses selected at random from each pen for transport to Kansas State University. After 14 d of aging, loins were fabricated into 2.54-cm thick steaks for objective and trained sensory panel measurement of cooked meat characteristics and objective color measurements during 7 d retail display. There were no interactions (P > 0.10) between feeding strategy and exogenous growth promotants for all objective measures of color and cooked meat characteristics. Throughout the display period, PN steaks were darker (P = 0.02) than CON steaks, but surface percentages of oxymyoglobin and metmyoglobin and metmyoglobin reducing ability were unaffected by feeding strategy (P > 0.10). Loins and steaks from PN cattle possessed decreased moisture loss during aging and cooking (P < 0.01). Trained sensory panel evaluation of cooked meat revealed a dietary program × growth promotant interaction for myofibrillar tenderness, connective tissue amount, and overall tenderness (P = 0.01). Compared to the CON/EGP- and PN/EGP- treatments, steaks from the CON/EGP+ and PN/EGP+ treatments were evaluated by panelists as being less myofibrillar and overall tender (P < 0.05). The alternative feeding strategies presented in this study can favorably impact water-holding capacity without negatively compromising retail display discoloration.

Influence of nitrogen and sulfur intake on bovine uterine pH throughout the luteal phase.

Previous research has reported that diets high in protein and sulfur decreased uterine pH in cattle. The objective of this study was to determine the effect of high N and high S intake on uterine pH. Holstein (n = 15) and Angus-cross (n = 5) heifers (337.5 ± 8.4 kg of BW) were randomly assigned to 1 of 4 diets: control (CON; 13.4% CP and 0.17% S); high nitrogen (HN; CON plus urea supplement); high sulfur (HS; CON plus calcium sulfate); or both high nitrogen and sulfur (HNS). Diets were individually fed at 2.6% of BW on a DM basis using Calan gates and estrus was synchronized to occur on d 13 (d 0 = start of dietary treatment). Blood samples were collected on d -2 and daily (d 1 to 28) at 1400 h to determine concentrations of plasma urea nitrogen (PUN), sulfate (d 1, 4, 8, 12, 16, 20, 24, and 28), and progesterone. Uterine pH was measured on d 16, 20, 24, and 28 (d 3, 7, 11, and 15 of the estrous cycle). There was a treatment, time, and treatment by time interaction (P < 0.01) on concentrations of PUN. There was an effect of treatment (P < 0.01) on concentrations of sulfate, with concentrations being increased in HS compared with CON, HN, and HNS (P < 0.01), and HNS increased compared with CON (P < 0.01) and HN (P < 0.01). Uterine pH was increased in HN and HNS compared with CON (P < 0.02), whereas HS was not different from any treatment (P > 0.11). There was no effect of time (P = 0.26) or treatment by time interaction (P = 0.71) on uterine pH. In summary, uterine pH was increased in HN and HNS compared with CON, whereas HS was intermediate and was associated with increased concentrations of PUN.

Circulating ghrelin and leptin concentrations and growth hormone secretagogue receptor abundance in liver, muscle, and adipose tissue of beef cattle exhibiting differences in composition of gain.

Data from species other than cattle indicate that ghrelin and GH secretagogue receptor (GHS-R) could play a key role in fat deposition, energy homeostasis, or glucose metabolism by directly affecting liver and adipose tissue metabolism. Beef steers (n = 72) were used to test the hypothesis that plasma ghrelin and leptin concentrations and abundance of the GHS-R in liver, muscle, and adipose tissues differ in steers exhibiting differences in composition of gain. At trial initiation (d 0), 8 steers were slaughtered for initial carcass composition. The remaining 64 steers were stratified by BW, allotted to pen, and treatment was assigned randomly to pen. Steers were not implanted with anabolic steroids. Treatments were 1) a low-energy (LE) diet fed during the growing period (0 to 111 d) followed by a high-energy (HE) diet during the finishing period (112 to 209 d; LE-HE) or 2) the HE diet for the duration of the trial (1 to 209 d; HE-HE). Eight steers per treatment were slaughtered on d 88, 111, 160, and 209. Carcass ninth, tenth, and eleventh rib sections were dissected for chemical composition and regression equations were developed to predict compositional gain. Liver, muscle, and subcutaneous adipose tissues were frozen in liquid nitrogen for subsequent Western blotting for GHS-R. Replicate blood samples collected before each slaughter were assayed for ghrelin and leptin concentrations. When compared at a common compositional fat end-point, the rate of carcass fat accretion (g·kg of shrunk BW(-1)) was greater (P < 0.001) in HE-HE steers whereas the rate of carcass protein accretion (g·kg of shrunk BW(-1)) was less (P < 0.001) compared with LE-HE steers. When compared at a common compositional fat end-point, plasma leptin, ghrelin, and insulin concentrations were greater (P < 0.05) for HE-HE compared with LE-HE steers. Abundance of the GHS-R, to which ghrelin binds, increased over time in liver and adipose tissue but did not differ as a result of treatment. Plasma ghrelin concentrations were increased for cattle continuously fed the HE diet as they became increasingly fatter; however, abundance of the GHS-R in liver, muscle, and subcutaneous adipose tissue was not different between treatment groups. The role of ghrelin in cattle metabolism warrants further investigation as it could have a significant effect on composition of BW gain, feed efficiency, and metabolic disorders such as ketosis and fatty liver.

Costs of care for Crohn's disease following the introduction of infliximab: a single-centre UK experience.

BACKGROUND: Infliximab is effective for induction and maintenance of remission in patients with Crohn's disease. There are few data, however, examining effect of infliximab therapy on management costs of Crohn's disease. AIM: To assess Crohn's disease-related costs of care and resource use in a single-centre cohort of patients with Crohn's disease 12 months pre- and post-infliximab therapy. METHODS: Data on 100 consecutive patients receiving infliximab were collected. Crohn's disease-related resource use was collected 12 months pre- and post-infliximab. National Health Service reference costs were applied to these data and the total Crohn's disease-related health service costs per patient were calculated (£UK). The cost of infliximab therapy was not included in our analysis. RESULTS: Cost savings were demonstrated in all areas of Crohn's disease-related resource use following infliximab therapy. Mean total Crohn's disease-related cost reduction, 12 months following commencement of infliximab therapy, was £2750 per patient. Mean costs at 12 months post-infliximab in responders were lower than in nonresponders (£1656 vs. £3608, P = 0.02). The number of hospitalizations was reduced. Requirements for examination under anaesthesia were also significantly decreased. CONCLUSION: Infliximab use resulted in Crohn's disease-related cost savings and hospital resource use, although this was not sufficient to cover the cost of therapy.

Plasma ghrelin concentrations of beef cattle consuming a similar amount of dietary energy supplied by different ingredients.

Previous research demonstrated increased plasma ghrelin concentrations in beef cattle when intake of a high-grain diet was restricted. Two experiments were conducted to determine whether differences in DMI influenced plasma ghrelin concentrations when energy intake was similar but cattle were in either an anabolic or a catabolic state. In Exp. 1, five steers (BW = 592.6 +/- 9.3 kg) were offered dietary treatments of 1) 50:50 hay:concentrate (HY) to meet the NE(m) requirement and were supplied an additional 3.4 Mcal of NE(g) daily, 2) or a diet composed of 10:90 hay:concentrate but were limit-fed to achieve an energy intake similar to that of the HY steers (LFC). The LFC treatment met the NE(m) requirement of each steer and supplied 3.6 Mcal of NE(g) daily. The experiment was conducted as a crossover design composed of 2 21-d periods. In the first period, 2 steers were assigned to the HY treatment and 3 steers were assigned to the LFC treatment. On d 21 after initiation of the dietary treatment, serial blood samples were collected via indwelling jugular catheter, using periods of frequent sampling in which samples were collected at 15-min intervals. The periods of frequent sampling were spread throughout the beginning, middle, and end of the 12-h feeding interval. After the first period, steers were weighed, dietary treatments were switched between steer groups, and intake amounts were recalculated on the basis of the first-period ending BW. The second-period adaptation and sampling were repeated as described for the first period. Plasma samples were assayed for ghrelin, insulin, GH, and NEFA concentrations. Experiment 2 was conducted using the same methodology as Exp. 1, except that steers were in a catabolic state. Five steers (BW = 718.3 +/- 12.8 kg) were offered the HY or LFC diet at an amount that would supply 80% of the NE(m) required to maintain BW. For Exp. 1, energy intake was sufficient to result in similar (P = 0.14) BW gains between treatment groups. Experiment 2 energy intake resulted in a loss of BW that was similar (P = 0.66) between treatment groups. In both experiments, the decreased energy density of the HY diet resulted in greater (P < or = 0.001) DMI for HY steers compared with LFC steers. Regardless of catabolic or anabolic state, plasma ghrelin, GH, and insulin were similar (P > or = 0.44) when energy intakes were similar despite differences in DMI between HY and LFC steers. Plasma NEFA concentrations were similar (P > or = 0.45) between treatment groups in an anabolic state but tended to differ (P = 0.09) as a result of treatment for cattle in the catabolic state. These data are consistent with the hypothesis that quantity of DMI does not influence plasma ghrelin concentrations of steers when energy intake is similar.

Pharmacological strategies for neuroprotection in traumatic brain injury.

Traumatic brain injury affects over a million Americans annually, but pharmacological therapy remains limited. Current standards of care in acute, subacute and chronic phases of injury are primarily supportive. This review discusses pharmacological strategies and future directions in patient treatment emphasizing pleiotropic agents targeting inflammation, oxidative damage, and glutamate excitotoxicity.

Significantly increased lifespan and improved behavioral performances by rAAV gene delivery in adult mucopolysaccharidosis IIIB mice.

Mucopolysaccharidosis (MPS) IIIB is an inherited lysosomal storage disease, caused by the deficiency of alpha-N-acetylglucosaminidase (NaGlu), resulting in severe global neurological involvement with high mortality. One major hurdle in therapeutic development for MPS IIIB is the presence of the blood-brain barrier, which impedes the global central nervous system (CNS) delivery of therapeutic materials. In this study, we used a minimal invasive strategy, combining an intravenous (i.v.) and an intracisternal (i.c.) injection, following an i.v. infusion of mannitol, to complement the CNS delivery of adeno-associated viral (AAV) vector for treating MPS IIIB in young adult mice. This treatment resulted in a significantly prolonged lifespan of MPS IIIB mice (11.1-19.5 months), compared with that without treatment (7.9-11.3), and correlated with significantly improved behavioral performances, the restoration of functional NaGlu, and variable correction of lysosomal storage pathology in the CNS, as well as in different somatic tissues. This study demonstrated the great potential of combining i.v. and i.c. administration for improving rAAV CNS gene delivery and developing rAAV gene therapy for treating MPS IIIB in patients.

A new cause of 'non-responsiveness' in coeliac disease?

A 42 year old man presented with gluten-responsive coeliac disease and secondary pancreatic insufficiency. Subsequently his symptoms relapsed and repeat small intestinal biopsy showed villous atrophy and infiltration by leukaemic cells, despite continuation of a gluten-free diet. Serious causes of relapse and non-responsiveness in coeliac disease include enteropathy-associated T-cell lymphoma, ulcerative jejunitis and an end-stage hypoplastic mucosa. This is the first report of non-responsiveness due to infiltration by leukaemia.