Objective: Our objective was to evaluate the effects of inclusion of condensed algae residue solubles (CARS) in corn-based cattle finishing diets on performance, carcass characteristics, and duodenal concentrations of fatty acids.Materials and Methods: In Exp. 1, 480 British (pre-dominately Angus) crossbred steers (initial BW = 432 kg; SD = 40 kg) were finished using a 2 x 3 factorial treat-ment arrangement. Treatments were CARS (0, 2.5, 5% of diet DM) displacing dry-rolled corn: high-moisture corn (DRC: HMC) or steam-flaked corn (SFC). In Exp. 2, feed-ing 0, 2.5, or 5% CARS in SFC diets was evaluated for digestibility and fatty acid flow using 6 ruminally can-nulated steers in a 3 x 3 replicated Latin Square design. Results and Discussion: The main effects of CARS included quadratic responses (P & LE; 0.01) for carcass-ad-justed final BW, ADG, G:F, hot carcass weight, 12th-rib fat, and YG. The main effects of diet indicated SFC di-ets had greater (P & LE; 0.02) G:F, hot carcass weight, and 12th-rib fat compared with DRC: HMC diets. In Exp. 2, inclusion of CARS in the diet did not affect total-tract DM, OM, or NDF digestibility (P & GE; 0.52). Total fatty acid flow at the duodenum was unaffected (P = 0.18) by treat-ment. However, there was a linear increase (P < 0.01) in C16:0, C18:0, C18:1 trans, C18:1 vaccenic acid, and C22:6 omega-3 docosahexaenoic fatty acid flow as CARS inclu-sion increased. Implications and Applications: Including 2.5% CARS in finishing diets improved G:F and increased n-3 fatty acids at the duodenum.

ABSTRACT Objective Two experiments evaluated the effects of delayed, long-lasting implant strategies for finishing heifers fed for constant or varying days on feed. Materials and Methods In Exp. 1, heifers (n = 500; initial BW = 280 ± 21 kg) were allotted randomly to 1 of 5 treatments, including no implant (CON), Revalor-XH on d 1 (XH), Revalor-200 on d 1 (E200), Revalor-XR on d 1 (XR), or Revalor-200 on d 70 (D200). All implants contained 200 mg of trenbolone acetate and 20 mg of estradiol. In Exp. 2, 720 heifers (initial BW = 281 ± 10 kg) were assigned randomly to treatments in a 3 × 4 factorial arrangement, with 3 implant treatments [no implant (NCON), Revalor-200 on d 1 and 100 (PCON), or Revalor-XH on d 1 (XH)] and 4 serial slaughter dates following 151, 165, 179, or 193 d on feed. Results and Discussion In Exp. 1, implanted heifers were heavier, gained more, and were more efficient (P ≤ 0.03) compared with CON heifers, but no differences were observed among implant treatments (P ≥ 0.21) over the 198-d finishing trial. Implanted heifers had greater hot carcass weight but lower marbling scores compared with CON heifers (P ≤ 0.04). In Exp. 2, there were no serial slaughter × implant treatment interactions for growth performance (P ≥ 0.23) or carcass characteristics (P ≥ 0.31). Final BW, fat thickness, and numerical YG increased linearly (P Implications and Applications Hot carcass weight was increased by implanting strategy and increasing days on feed, but aggressive initial implants did not improve performance.

A 3-yr study evaluated the effects of cow-calf production system and postweaning management on finishing performance and carcass characteristics of calves. Treatments were arranged as a 2 × 2 factorial (1 replication from each of 2 locations each year): (1) cow-calf production system: dry-lot feeding (DL) or grazing corn residue (GRZ) and (2) postweaning management: finishing (FIN) or grow-finishing (GRW). From November to mid-April, DL pairs were fed a distillers and crop residue–based diet in pens and GRZ pairs were supplemented with distillers-based cubes while grazing corn residue. All calves were weaned in mid-April and received into the feedlot for postweaning management. In the FIN treatment, calves were directly adapted to a finishing diet following weaning. Calves in the GRW treatment were placed on a growing diet (30% Sweet Bran, 35% distillers grains, and 35% wheat straw) for 76 d before being adapted to the common finishing diet. Calves from GRZ had lighter BW entering the finishing phase than calves from DL (P < 0.01). However, there were no effects of cow-calf production system on final BW or HCW (P ≥ 0.15). Calves in the FIN treatment had greater ADG (P < 0.01) and improved G:F (P < 0.01). The GRW calves produced 35-kg-greater final BW (P < 0.01) and 23-kg-greater HCW (P < 0.01). Economics indicate that directly finishing calves resulted in similar net return (P = 0.16) because increased HCW offset the cost of 49 additional days in the feedlot for the GRW treatment.

Two experiments were conducted to evaluate high-protein distillers grains (HIPRO) and corn bran plus solubles (BRAN+SOL) in finishing diets on performance, carcass characteristics and nutrient digestibility. In Exp. 1, 300 crossbred calf-fed steers (initial BW = 282 kg; SD = 10 kg) were used in a generalized randomized block design with treatments being a corn-based control (CON), traditional dry distillers grains plus solubles (DDGS), traditional wet distillers grains plus solubles (WDGS), HIPRO, and BRAN+SOL. Byproducts were included at 40% of diet (DM) and replaced a 50:50 blend of high-moisture and dry-rolled corn. All diets contained 15% corn silage and supplement. In Exp 2, six ruminally fistulated steers were utilized in a 6 × 6 Latin square design with six periods and six treatments. Diets were similar to those in Exp. 1 with the addition of a 20% HIPRO treatment (HIPRO20). Treatments included a corn control, high protein distillers grains plus solubles included at 40% of diet DM (HIPRO40), BRAN+SOL, WDGS, DDGS. In Exp. 1, feeding HIPRO and BRAN+SOL increased ADG and G:F (P < 0.05) compared to CON and WDGS while steers fed DDGS were intermediate. Feeding BRAN+SOL and HIPRO increased G:F by 10.3% and 8.6%, respectively. Final BW and HCW followed the same trend as ADG and G:F. In Exp. 2, feeding HIPRO40 or BRAN+SOL decreased DM and OM digestibility compared to CON (P ≤ 0.08), but were similar to WDGS and DDGS (P ≥ 0.16). Neutral detergent fiber digestibility and acid ADF digestibility were greatest for BRAN+SOL, but were not statistically different (P > 0.14) from all other treatments except DDGS (P < 0.01), which

A 190-d finishing study was conducted using 300 crossbred steers (282 kg; SD=10) to evaluate the feeding value of the distillers grains that have undergone a fiber separation process on steer performance and carcass characteristics. Cattle were blocked by BW and assigned randomly within block to pen with 10 steers/pen. Pens were assigned randomly to 1 of 5 treatments with 6 replications/treatment. The treatments included a corn control (CON), traditional wet distillers grains plus solubles (WDGS; CP=32.2%, NDF=34.0%), traditional dry distillers grains plus solubles (DDGS; CP=29.3%, NDF=31.5%), high protein DDGS (HIPRO; CP=41.3%, NDF=35.1%), and a mixture of corn fiber and solubles (BRAN+SOL; CP=29.4%, NDF=38.2%). All byproducts were fed at 40% of diet (DM) and replaced a 50:50 blend of high-moisture and dry-rolled corn. All diets included 15% corn silage and supplement. Data were analyzed using the MIXED procedure of SAS as a randomized block design with pen as experimental unit and block as fixed effect. Intakes were not different between treatments (P = 0.62) averaging 9.68 kg/d. Treatment impacted final BW, HCW, ADG, and G:F (P < 0.03). Steers fed BRAN+SOL and HIPRO did not differ in ADG (P = 0.50) but were greater (P < 0.04) than steers fed CON and WDGS. Steers fed CON and WDGS had similar ADG (P = 0.96) but were the lowest (P < 0.05) of all treatments. Steers fed DDGS had ADG intermediate to cattle fed BRAN+SOL and HIPRO or cattle fed CON and WDGS, and not different (P > 0.14) from all treatments. Steers fed BRAN+SOL (0.193) and HIPRO (0.190) did not differ in G:F (P = 0.65) but were greater (P < 0.05) than steers fed CON (0.175) and WDGS (0.179; SEM = 0.004). Steers fed CON and WDGS did not differ in G:F (P = 0.60) but were the lowest (P < 0.05) of all treatments. Steers fed DDGS (0.183) had intermediate efficiency to steers fed BRAN+SOL and HIPRO or steers fed CON and WDGS, and was not different (P > 0.20) from HIPRO, CON, and WDGS. Feeding BRAN+SOL tended to increase (P = 0.09) G:F compared to DDGS. Carcass characteristics other than HCW were not affected by treatment (P ≥ 0.69). The fiber removal process concentrates CP and NDF in the two byproduct feeds. Based on G:F, feeding value of high protein distillers grains is 121% of corn and the isolated bran plus solubles is 126% of corn.

The effect of kernel processing and corn silage hybrid were evaluated for digestion by beef cattle fed dry rolled corn-based diets with 40% silage inclusion. Six ruminally fistulated steers (518 ± 40 kg) were used in a 126-d metabolism study in a 6 × 6 Latin Square design. Three corn silage hybrids were evaluated (CON; hybrid TMF2H708), a brown midrib hybrid (bm3; hybrid F1557952), and Unified™ corn silage with SilaSoft™ kernel technology, which was a brown midrib with a floury endosperm (bm3-EXP; hybrid F15578XT). The treatment design was a 2 × 3 factorial with the three hybrids and kernel processed or not. Silage was included in the diet at 40% on a DM basis. Each period was 21 d, which included a 14-day adaptation period followed by a 7-day collection period. Titanium dioxide was intraruminally dosed from days 10-21 as digestibility marker. Fecal samples were collected days 16-20, four times daily. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC.), with individual steer within period serving as the experimental unit. No interaction between corn silage hybrid and kernel processing were observed (P > 0.14). Corn silage treatment affected OM digestibility, with cattle fed bm3-EXP having greater OM digestibility than CON (P = 0.03), and both did not differ from bm3 (P > 0.17). Feeding bm3 and bm3-EXP corn silage did not have different (P = 0.17) NDF digestibility (54.4 and 58.2%, respectively), but both were greater (P < 0.01) than CON (45.5%). Digestibility of ADF did not differ from NDF with greater digestion for both brown midrib corn silages over the CON (P < 0.05). Total GE intake (Mcal/day) was greatest for bm3 corn silage (P < 0.07) as compared to CON and bm3-EXP, which did not differ (P = 0.94). Digestible energy (Mcal/day) was greater for bm3 over CON (P = 0.02) and bm3-EXP was intermediate between the two (P > 0.20). Digestible energy per unit of intake (Mcal/kg) was lowest (P < 0.03) for CON (3.09 Mcal/kg), with no difference (P = 0.24) between bm3 (3.25 Mcal/kg) and bm3-EXP (3.33 Mcal/kg). The use of kernel processing did not affect any digestibility parameters (P > 0.11) or measured DE. The use of brown midrib corn silage hybrids improved fiber digestibility and energy content of finishing diets at 40% inclusion.

Receiving and finishing experiments were conducted utilizing 600 crossbred steers (initial BW = 261 kg; SD = 7.72 kg) to evaluate a non-antibiotic alternative for control of liver abscesses. Three treatments consisted of a negative control diet (-CON) without tylosin, a positive control diet (+CON) with tylosin (Tylan-40®; Elanco Animal Health) included at 90 mg/steer daily, and a diet containing Ramaekers Immune Primer (RAM; Ramaekers Nutrition) that contains a proprietary blend of vitamins, minerals, prebiotics, and probiotics. A total of 30 pens were used in the study with 20 steers per pen and 10 pens per treatment. During the receiving phase (d 1 – d 19), RAM steers received two boluses of RAM at arrival and two boluses on d 19. Steers also received 14 g/steer RAM daily through the supplement. All steers received the same receiving diet with 31.67% alfalfa hay, 31.66% dry-rolled corn (DRC), and 31.67% Sweet Bran along with 5% supplement (DM basis). During the finishing phase, RAM was fed once weekly, to target 14 g/steer daily. All steers were fed the same finishing diet of a 40:60 blend of DRC and high-moisture corn with 25% wet distillers grains plus solubles, 5% wheat straw, and 4% supplement. Monensin was included at 33.2 mg/kg DM in all diets during receiving and finishing. Carcass and performance data were analyzed using the MIXED procedure of SAS where pen was the experimental unit. Liver abscess incidence, morbidity, and mortality were analyzed as binomial using PROC GLIMMIX of SAS. During the receiving period, no differences were observed in ending BW, ADG, or G:F (P ≥ 0.48). However, DMI was significant (P ≥ 0.02) where +CON and RAM treatments had lesser DMI than the -CON. No differences (P ≥ 0.19) were observed for final BW, DMI, ADG, G:F, HCW, marbling, LM area, 12th rib fat or calculated yield grade (P ≥ 0.25) over the entire feeding period (224 d). Morbidity and mortality percentages were not impacted by treatment (P ≥ 0.19). Liver abscess incidence was impacted by treatment (P < 0.01), with lesser percentage (P < 0.01) of total liver abscesses in the +CON (7.7 %) treatment compared to both RAM (20.3 %) and -CON (21.3 %), which were not different (P = 0.38). These data suggest there was no impact from treatment on overall performance. Compared to tylosin, RAM was not efficacious in reducing total liver abscesses.

The effect of corn silage hybrid and varying inclusion of silage in corn-based finishing diets were evaluated for impact on finishing performance and carcass characteristics. Steers (n = 288, 318 ± 3.0 kg) were blocked into two BW groups and assigned randomly to one of 36 pens (8 steers/pen). Two hybrids of corn silage were fed and included a traditional control corn silage (CON; hybrid TMF2H708) and a brown midrib hybrid (bm3; hybrid F27F627). Corn silage was included in the diet at three inclusions of 15%, 45%, and 75/15%. The 75/15% treatment was designed where silage was reduced to 15% after d70 to mimic the same silage usage as feeding 45% silage continuously. The treatment design was a 2 × 3 factorial with hybrid and inclusion as factors. Steers were ultrasounded on d70 and d126/127 to determine backfat deposition rate for a target endpoint of 1.4 cm. Data were analyzed using the MIXED procedure of SAS (SAS Inc., Cary, NC), with pen as experimental unit. Cattle on the 15% inclusion were slaughtered on d153 of the trial, and cattle fed the 45% inclusion and the treatment where 75/15% was fed followed by 15% inclusion of each corn silage hybrid were slaughtered on d181. Cattle were adapted to the 15% inclusion of silage over 24 d and four diets, and those fed 45% silage were adapted over a period of ten days and three diets. No interactions were observed between silage inclusion and hybrid (P > 0.10). Animals fed 45 and 75/15% silage inclusion had greater final BW due to greater days, but lower G:F (0.162) than cattle fed 15% silage (0.170; P < 0.01). Steers fed 45% and 75/15% inclusion had a lower ADG than 15% inclusion (P < 0.01). Carcass characteristics were affected by silage inclusion; those fed 45 and 75/15% had greater final HCW and LM area, and lower dressing percentage (P < 0.01) than 15%. Backfat thickness was greater for steers fed 45% (1.5 cm) over 15% (1.3 cm; P < 0.01), and 75/15% (1.4 cm) was intermediate between the two (P > 0.12). Dry matter intake was greater for cattle fed bm3 silage (P = 0.02), but did not translate to improved ADG or G:F (P > 0.18). Feeding corn silage at a consistent 45% inclusion throughout the feeding period resulted in similar performance to cattle fed 45% corn silage on average by feeding 75% then 15% inclusion.

Research has indicated that cornstalk grazing can be integrated into a semi-confined cow-calf production system. Furthermore, post-weaning management can affect finishing performance and carcass characteristics of beef cattle. The objective of this study was to evaluate cow-calf production system and post-weaning management on finishing performance and carcass characteristics of calves produced from a confined cow-calf production system. The study was conducted over 2 years. Cows with summer-born calves at side were assigned to 1 of 2 treatments: dry-lot feeding or cornstalk grazing with supplementation. Cow-calf pairs assigned to the dry-lot treatment were fed a distillers and corn residue-based diet, and pairs assigned to cornstalk grazing were supplemented with distillers-based cubes. Following the cornstalk grazing period from November to mid-April, all calves were weaned and received into the feedlot. Summer-born steer (n=78) and heifer (n = 60) calves (BW = 265 42 kg; 270 d of age) were allocated by previous cow-calf production system, stratified by initial BW, and assigned randomly to 1 of 2 post-weaning treatments with 2 replications per treatment. The treatment design was a 2 x 2 factorial arrangement. Treatment factors included: 1) cow-calf production system: dry-lot feeding (DLOT) or cornstalk grazing (STALK) and 2) post-weaning management: finishing (FINISH) or pre-finishing growing (GROW). In the FINISH treatment, weaned calves were directly adapted to a finishing diet. Calves in the GROW treatment were placed on a growing diet for 76 days before being adapted to the common finishing diet. No significant interactions were observed between treatments (P ≥ 0.98) so main effects will be presented. Cattle were fed to a common compositional endpoint, and 12th rib fat thickness did not differ among treatments (P ≥ 0.30). Calves from STALK had lighter initial BW entering the finishing phase than calves from DLOT (P = 0.02). However, there were no effects of cow-calf production system on final BW or carcass weight (P = 0.39). Calves in the FINISH treatment had greater ADG (P < 0.01) and improved G:F (P < 0.01); however, GROW calves had 32 kg greater final BW (P < 0.01) and 20 kg greater carcass weight (P < 0.01). An economic analysis would suggest that directly finishing calves results in greater net profit compared to growing calves prior to the finishing phase (P < 0.01) as the extra carcass weight did not offset the cost of the 76 d growing period.

© The Board Regents of the University of Nebraska. All rights reserved. the morning prior to feeding. These same three animals were used for both blood collections. The first blood collection was on d 28 of the finishing period after all cattle had been fully adapted onto their respective finishing diet. The second blood collection was on d 92 of the finishing period. Cattle were implanted with a TEIS (Elanco Animal Health) on d 28 and reimplanted with a TES (Elanco Animal Health) on d 90 of the finishing period. The Heavy block was on feed for 153 days and the light and mid blocks were on feed for 167 days. Cattle were slaughtered at a commercial abattoir (Cargill Meat Solutions, Fort Morgan, CO) and carcass data collected. Data were analyzed using the mixed procedure of SAS for performance, carcass and blood variables with block and treatment as fixed effects. Blood data were analyzed as a repeated measure over time. Due to missing carcass data on the heavy block, data from that block were omitted from the carcass and carcass adjusted analysis of performance leaving 36 pens with 4 replications per treatment for these observations.

Crossbred steers (n=80; initial BW = 274 kg, SD = 21) were used to evaluate the effect of DMI on CH4 production in growing steers. Two treatments with 4 pens per treatment (10 steers/pen) were used in a generalized randomized block designed experiment using 4 blocks based on BW. The treatments included feeding the same diet either ad-libitum or limit-fed. Diets consisted of 45% alfalfa, 30% sorghum silage, 22% modified distillers grains plus solubles and supplement at 3% on a DM basis. The limit-fed cattle were fed 75% of the ad-lib cattle intake from the previous week from their corresponding paired pen. Methane measurements were performed on cattle using pen-scale methane chambers within each block so that both treatments (ab-libitum and limit-fed) could be measured at the same time. The steers were limit fed for 5 d at the beginning and end of the trial and weighed on two consecutive days to equalize gut fill for accurate initial and ending BW measurements. Steers were fed treatments for 105 d and emissions data were collected for 3, 5 consecutive d periods. The results presented are only from one rotation (3rd collection) through the barn due to sensor errors for methane data collection in the first 2 periods. Steers fed ad-libitum had greater ending BW, DMI, and ADG (P < 0.01) compared to limit-fed cattle; however, G:F was not different between treatments (P = 0.33) because DMI was 26.2% greater and ADG was 23.3% greater for ad-libitum cattle compared to limit-fed cattle. Cattle fed ad-libitum eructated 156 g/d which was greater (P < 0.01) than limit-fed cattle (126 g/steer daily). When adjusted to an equivalent DMI basis, limit-fed steers tended to produce more CH4 (P = 0.06) than ad-libitum fed steers. No difference was observed when expressing CH4 per unit of ADG (P = 0.46) between ad-libitum and limit-fed treatments. Cattle fed ad-libitum produced more CO2 (P = 0.04) per day compared to limit-fed cattle, but produced more (P = 0.02) CO2 per unit of DMI. These data are consistent with previous work, illustrating that level of intake affects daily amounts of methane production but lower intakes result in slightly greater amounts of methane per unit of intake.

The objective of this study was to evaluate new implant strategies on performance and carcass characteristics of feedlot heifers compared to non-implanted heifers. Crossbred heifers (n=500; initial BW= 280 kg, SD= 21 kg) were utilized in generalized randomized block design with 2 initiation times and BW blocks within start, and assigned randomly to pens within block. Pens were assigned randomly to one of 5 treatments. Treatments included heifers not implanted or given a Revalor (Merck Animal Health, De Soto, KS) implant. Implant treatments consisted of Revalor-XR on day 1, Revalor-XH on day 1, Revalor-200 on day 1, or Revalor-200 on day 70. All implants provided 200 mg of trenbolone acetate (TBA) and 20 mg estradiol (E2) but timing of release varies across implant treatments. Heifers were fed for 198 days. There were no differences in DMI (P = 0.22) between all treatments. Implanted cattle had heavier carcass-adjusted final BW (P < 0.01), but there was no difference in BW between implanted treatments (P > 0.87). All implanted cattle had greater ADG compared to control cattle (P = 0.03), which resulted in an improvement in carcass-adjusted G:F (P < 0.01). Implanted heifers had greater HCW (P < 0.01) and lower marbling scores (P < 0.01) compared to non-implanted heifers, but there were no differences in HCW, dressing percentage, fat thickness, or marbling score among implant treatments (P > 0.38). Non-implanted cattle had lower dressing percentage and greater marbling scores compared to implanted heifers (P ≤ 0.04). Revalor-XH, Revalor-XR, and Revalor-200 day 70 treatments increased LM area (P < 0.01) compared to Revalor-200 on day 1 or non-implanted heifers, which translated into a lower calculated yield grade (P = 0.04). Distribution of quality grade (P = 0.07) and yield grade (P = 0.10) between implanted and non-implanted heifers varied. During the first 70 days of the feeding period, Revalor-XH and Revalor-200 on day 1 treatments had greater ADG and G:F (P < 0.01) compared to the other implant treatments and control heifers. From days 70 to 140, heifers implanted with Revalor-XR or Revalor-200 on day 70 had greater ADG and G:F (P < 0.01) compared to the other treatments. Until day 175, all implanted cattle were heavier than the control (P < 0.01). Implanting heifers improved ADG, G:F, and HCW compared to non-implanted heifers. While interim performance varied, the timing of release did not affect heifer performance over the entire 198 days.

The effect of kernel processing and corn silage hybrid was evaluated for growth performance of beef cattle fed dry rolled corn-based diets. Crossbred steers (n = 360, 400 ± 5.35 kg) were blocked into 2 BW groups and assigned randomly to one of 36 pens (10 steers/pen). The three corn silage hybrids utilized were a standard corn hybrid (CON; hybrid TMF2H708), a brown midrib hybrid (bm3; hybrid F1557952) and Unified™ brown midrib corn silage with SilaSoft™ kernel technology with a floury endosperm (bm3-EXP; hybrid F15578XT). The treatment design was a 2 × 3 factorial with the three hybrids and kernel processed or not. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC), with pen serving as the experimental unit. Silage was included in the finishing diet at 40% on a DM basis. Cattle were slaughtered on d 104 of the trial. Cattle were adapted to their finishing treatment diets over a period of 21 days and 4 diets. There were no interactions observed between kernel processing and corn silage hybrid (P > 0.45). Feeding both bm3 hybrids increased DMI and ADG over the CON silage hybrids (P < 0.01). Steers fed CON had the lowest G:F (0.132; P < 0.03), whereas cattle fed bm3 and bm3-EXP silage hybrids had similar G:F (0.138 and 0.139, respectively; P = 0.88). Cattle fed bm3-EXP had a greater HCW than CON steers (P = 0.04), with bm3 fed steers similar to bm3-EXP (P = 0.75). Kernel processing silage decreased DMI (P = 0.04) with a similar ADG (P = 0.93), but tended to increase G:F (P = 0.10) by 2.6% with 40% inclusion of silage in the diet. The improvement due to the kernel processing at harvest improved the silage by 6.5% (2.6/0.40), as compared to not kernel processing the corn silage hybrids. Kernel processing and using brown midrib silage both improve G:F of finishing cattle when fed at 40% in grain-based diets.

Crossbred yearling steers (n=80; initial BW = 369 kg; SD = 25) were used to evaluate the effects of corn oil on methane (CH4) and carbon dioxide (CO2) production in finishing diets. Two treatments with four pens per treatment (10 steers/pen) were used in a RCBD-design experiment with four BW blocks. The treatments consisted of a control diet (CON) containing 33 % dry-rolled corn, 33% high moisture corn, 15% wet distillers grains plus solubles, 15% corn silage, and 4% supplement. The corn oil treatment (OIL) displaced corn with 3% corn oil added to the diet. Steers were limit fed for 5 d at the beginning of the trial and weighed on d 0 and 1 to equalize gut fill and were implanted on d 1 with Synovex Choice (100 mg TBA, Zoetis). Steers were harvested on d 127 and carcass data were collected. Continuous measurement of methane and carbon dioxide emissions were collected in an enclosed methane barn over 5d periods, with 3 collection periods per pen. CH4 and CO2 were collected by rotating between pens every 6 minutes with an ambient sample taken in between pen measurements. Initial BW, final BW, ADG, HCW, REA, fat thickness, and marbling were not impacted by treatment (P > 0.14) while G:F (P =0.03) increased and DMI (P = 0.03) decreased by feeding OIL. There was a treatment by collection period interaction (P = 0.01) due to a differing magnitude of differences between OIL and CON across time. Feeding OIL decreased (P < 0.01) methane by 32, 9, and 16 g/steer daily during the three collection periods respectively. Methane production (g/steer daily) was lower (P < 0.01) for the OIL fed cattle compared to the CON fed cattle while CO2 production was not different between treatments. CH4 g/kg of DMI was decreased (P < 0.01) by 0.09 g for the OIL treatment versus the CON treatment and was lower (P < 0.01) by .07, .02, and .07g across collection periods. CO2 g/kg of DMI was not different between treatments but was lower (P < 0.02) for cattle on OIL treatment across time. CH4/ADG kg was decreased (P < 0.01) by 1.3g for the OIL treatment compared to the CON treatment while CO2/ADG kg was not different between treatments. Feeding corn oil at 3% of diet DM reduced enteric methane production by 14.6% which was partially due to a 4.4% decrease in DMI.

The effects of feeding zilpaterol hydrochloride (ZH) and shade were evaluated on blood metabolites in finishing beef steers ( = 480). Cattle were fed 0 or 8.33 mg/kg of diet DM ZH for 21 d with a 3- or 4-d withdrawal before harvest and were housed in open or shaded pens. Blood samples were collected the day before ZH was fed and on the day the cattle were shipped to the commercial abattoir. Lactate concentration was not different between cattle fed ZH in open or shaded pens ( = 0.12). Nonetheless, a tendency for a diet × time interaction was detected for lactate concentration ( = 0.09), in which it was greater in cattle fed the control diet in open pens before being fed ZH. Cortisol concentration was less before and after ZH was fed ( = 0.01). Glucose was greater for cattle fed the control diet than cattle fed ZH for 21 d ( = 0.03). Cattle fed in open vs. shaded pens did not differ in glucose concentration ( = 0.12), whereas glucose concentrations were greater before ZH was fed than after ( = 0.02). In contrast, plasma urea nitrogen (PUN) concentration was not different in response to diet ( = 0.24), housing type ( = 0.65), or before vs. after being fed ZH ( = 0.60). Lactate concentrations were not different across diet or shade treatments before ZH was fed, whereas after ZH, lactate concentrations were greater in control cattle than cattle fed ZH. Additionally, cortisol was less after feeding ZH. Glucose was greater before than after feeding ZH.

Crossbred beef steers (n = 96) were utilized in a study conducted at the University of Nebraska-Lincoln Agricultural Research and Development Center research feedlot near Mead, NE to determine the effect of feeding Agrimos (Lallemand Animal Nutrition; Montreal, Canada) and 2.5-cm ground wheat straw to finishing steers during the summer on body temperature and panting score in addition to performance, carcass characteristics and blood metabolites. Three treatments with 4 replications per treatment were set up in a completely randomized design. Treatments consisted of a basal control diet (CON); consisting of 68.5% corn, 20% modified distillers grains plus solubles, 7.5% sorghum silage, and 4% supplement, the inclusion of Agrimos (MOS; 30 g/steer daily), and 2.5-cm ground wheat straw replacing 5% corn (WHT). Cattle were stratified by initial BW between pens and pen was assigned randomly to treatment. Rumen boluses to collect body temperature were inserted on d 21 of the trial after cattle were adapted to finishing diets. Blood was collected in July and August (7 collection wk) of the trial via jugular venous puncture. There were no differences (P > 0.19) observed for final BW, ADG, and DMI among treatments. Additionally, no difference (P > 0.24) was observed for carcass-adjusted final BW or ADG. Feed efficiency was decreased (P < 0.02) on both a live- and carcass-adjusted basis for cattle fed WHT when compared to CON and MOS. Hot carcass weight, dressing %, LM area, and marbling score were not different (P > 0.36) among treatments. Cattle fed the CON had greater 12th rib fat depth and USDA yield grade (P < 0.02) than cattle fed WHT and MOS. Both average and maximum body temperatures were greater (P < 0.01) for cattle fed MOS than for cattle fed CON or WHT. There was no difference (P = 0.18) for area under the curve body temperature between treatments. Panting scores were least (P < 0.01) for cattle fed the WHT when compared to CON and MOS. Time and treatment interactions (P < 0.05) were observed for bilirubin, blood urea nitrogen, calcium, chloride, carbon dioxide, creatinine, potassium, lactate dehydrogenase, phosphorus, total protein, triglyceride, uric acid, red blood cell count, hemoglobin, and hematocrit levels. No effect on animal performance was realized from the addition of Agrimos to the diet, however, body temperature was increased slightly. Adding 5% finely ground wheat straw decreased G:F and reduced panting score but did not affect body temperature.

Two finishing trials were conducted utilizing 80 crossbred beef steers (in each) across 2 seasons (summer and winter; initial BW = 489 ± 20.4, 387 ± 15.9 kg, respectively) at the University of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Neb. Continuous rumen temperature was collected throughout the duration of both trials. Blood samples were taken via jugular venous puncture every 2 wk until 4 wk before harvest for a total of 6 collections during the summer and 8 collections during the winter. Cattle in both trials were fed the same diet consisting of 51% HMC, 40% Sweet Bran, 5% wheat straw, and 4% supplement. Individual steer rumen temperature was used in the statistical model as a covariate. Only blood measures where rumen temperature was significant as a covariate were chosen to be reported. These selected blood measures were correlated to the 3-d prior average environmental temperature and the 3-d comprehensive climate index (CCI) relative to that blood collection day. Correlations between the change in blood measures and the respective change in rumen temperature, across collection points, were also analyzed. Additionally, environmental conditions were correlated to DMI and rumen temperature. Direct bilirubin, red blood cell count, hematocrit, and hemoglobin levels were all correlated (R > 0.22), during at least one season, to both the 3 d average environmental conditions and 3-d rumen temperature. Lactate dehydrogenase was negatively correlated (R < −0.62) to both 3-d averaged environmental conditions during the winter trial and also during the summer trial (R > −0.28). Red blood cell count was negatively correlated (R < −0.23) to 3-d environmental conditions during the winter trial however, was not correlated (R > −0.10) to environmental conditions during the summer trial. Rumen temperature was positively correlated to CCI and environmental temperature (R = 0.65, R = 0.63; respectively) during the summer. During the winter, rumen temperature was negatively correlated to CCI and environmental temperature (R = −0.27 and R = −0.19). Intake was negatively correlated to both CCI and environmental temperature (R = −0.32; R = −0.30) in the summer trial, however, during the winter trial DMI was positively correlated to CCI and environmental temperature (R = 0.22 and R = 0.24). Some blood metabolites change in accordance to environmental conditions and may be important during times of environmental stress. Additionally, environmental conditions affect both DMI and rumen temperature.

Enteric methane production from cattle and its effect on climate change has been a topic of debate. Multiple studies have explored methods to reduce cattle enteric methane production while simultaneously improving performance. However, most strategies developed have not been widely implemented by cattle producers. Knowledge of producer concerns and perceptions on methane production from cattle and its effect on the environment may be limited. Therefore, the objectives of this survey were to determine what Nebraska producers know about methane production by cattle and how it affects performance and to determine whether different age groups, regions of Nebraska, and production size and type affects producer opinions on enteric methane production and climate change. The survey had a response rate of 22%. Regarding climate change, approximately 39% of producers disagreed, 33% were neutral, and 28% agreed they were concerned. However, producers in central and eastern Nebraska were closer to neutral than producers in western Nebraska (P < 0.05). Younger producers perceived cattle to have a more positive effect on the environment and reported that they were more likely to adopt new management techniques that have been shown to improve animal performance than older producers (P < 0.05). Most producers reported receiving production-related information from veterinarians (47.6%), followed by the “other” category (34.9%), the University of Nebraska (15.6%), and state and federal governments, which were the lowest (1.4 and 0.6%, respectively). In the last 3 yr, approximately 57% of producers attended one or fewer extension meetings, but 37% had not attended any extension meetings.

Steers ( = 480; 22% with black hides and 78% with red hides) were used to study the effects of shade and feeding zilpaterol hydrochloride (ZH) on performance, carcass quality, heat stress, mobility, and body temperature (BT). A randomized block design with a 2 × 2 factorial treatment arrangement was used with 4 replicates per treatment. Factors included housing type (open or shaded pens) and the feeding of ZH (0 or 8.33 mg/kg DM) the last 21 d on feed with a 3-d withdrawal. Cattle were blocked by BW into a heavy or light block and randomly assigned to pen within each block. Rumen boluses to record BT were inserted before ZH feeding. Respiration rate and panting scores were recorded daily during the ZH feeding period. Mobility scores were collected at various time points from before ZH feeding through harvest. Interactions between ZH and housing type were not significant ( > 0.26) for animal performance, carcass characteristics, and respiration or panting score. No differences ( > 0.44) were observed for DMI, ADG, or G:F on a live basis due to ZH; however, cattle fed in open pens tended ( = 0.08) to have a greater ADG than cattle in shaded pens. Cattle fed ZH had 14 kg heavier carcasses with larger LM area ( < 0.01) than control cattle. Respiration rates for cattle fed ZH were greater ( = 0.05) with no differences ( = 0.88) due to housing. Time affected ( < 0.01) mobility scores, with observations on the morning of harvest at the abattoir being the worst for all groups of cattle. An interaction ( < 0.01) was observed between ZH and housing type for BT. Cattle fed ZH, in both shaded and open pens, had lower ( < 0.05) average, maximum, and area under the curve BT than control cattle fed in the same housing type. However, the observed reduction in BT due to ZH was greater for cattle fed ZH in open pens than for cattle fed ZH in shaded pens. From these results, we conclude that ZH improved HCW with little impact on heat stress or mobility, suggesting that animal welfare was not affected by feeding ZH for 21 d at the end of the feeding period.