We evaluated the effects of dietary NDF concentration from alfalfa hay and bulk density of steam- flaked corn (SFC) on growth performance, carcass characteristics, and liver abscesses in finishing ...beef steers.
Crossbred beef steers (n = 214; 60 pens; initial BW = 417 ± 11.9 kg) were blocked by BW and assigned randomly to treatments and fed an average of 112 d. The treatments were arranged as a 2 × 3 factorial with 10 pens per treatment and consisted of 3 NDF concentrations from alfalfa hay (3%, 4.5%, or 6%) and 309 g/L (24 lb/bu) or 412 g/L (32 lb/bu) SFC (69% or 33% starch availability, respectively). Growth performance and carcass data were analyzed with PROC MIXED of SAS with pen as the experimental unit. Quality grades and liver scores were analyzed as binomial proportions using PROC GLIMMIX. Contrast statements were used to separate linear and quadratic effects of increasing roughage NDF.
Dry matter intake responded quadratically from d 0 to 35 as roughage NDF increased from 3% to 6%, and DMI increased linearly as roughage NDF increased on d 70 to 105 and d 0 to final. Otherwise, no differences in growth performance were noted. Marbling score responded quadratically to roughage level and was greater for steers fed 3% than for those fed 4.5% or 6% roughage NDF. Steers fed 309 g/L SFC tended to have a larger LM area than those fed 412 g/L SFC. The total percentage of abscessed livers at slaughter decreased linearly as roughage NDF was increased from 3% to 6% of DM as did the presence of A+ abscesses. In addition, total liver abscesses were 13.9 percentage points less in steers fed 412 versus 309 g/L SFC.
Results suggest that increasing roughage NDF and bulk density of SFC are dietary strategies that can decrease the presence of liver abscesses at slaughter without negatively affecting growth performance.
Abstract
The objective was to evaluate the effects of dietary forage inclusion during finishing on growth performance, feeding behavior, and ruminal fermentation in steers at risk for acidosis. Angus ...× Simmental steers (n = 240; body weight = 350 ± 58 kg) were blocked by body weight and allotted into 18 pens. Feeding behavior was collected and analyzed from the initial 45 d steers were fed a high-moisture corn-based finishing ration in GrowSafe bunks to determine steers (20%) at greatest risk for developing acidosis. The at-risk steers (n = 48) were utilized in a randomized complete block design. Steers were stratified by initial body weight within block and assigned to 8 pens of 6 steers. Pens were randomly assigned to 1 of 2 dietary treatments: (1) 15% (15CS) or (2) 30% corn silage (30CS) on a dry matter basis where corn silage replaced high moisture corn in the finishing diet. Overall body weight, average daily gain, dry matter intake, and gain:feed were not affected (P ≥ 0.19) by treatment. Carcass characteristics were not affected by treatment (P ≥ 0.39). Steers consuming 30CS had greater (P ≤ 0.05) meal frequency and eating rate, as well as decreased meal length, from d 0 to 112. Fluctuations in dry matter intake during the final 56 d of finishing were not affected by treatment (P ≥ 0.20). Ruminal pH was collected prior to feeding and tended to exhibit a treatment × day effect (P = 0.05) with 30CS steers having increased ruminal pH on d 56 and 112. No treatment × day effect was observed for molar proportions of acetate, propionate, and butyrate (P ≥ 0.11) in ruminal fluid. Overall, increasing dietary forage during finishing altered feeding behaviors and ruminal fermentation in steers at risk for acidosis, but did not affect growth performance.
Abstract
The objectives were to (1) assess acidosis risk during the end of the finishing phase and (2) build a predictive model utilizing initial feed intake behavior to identify steers at risk for ...acidosis. For objective 1, dry matter intake (DMI) data from beef steers (n = 733) fed a corn-based diet were collected from the last 56 d of the finishing phase using a GrowSafe system. Acidosis risk was determined as the percentage of days DMI fluctuated more than 30% from the previous day. Steers (n = 80) were selected for divergent acidosis risk. High-risk steers with greater DMI fluctuation had decreased (P ≤ 0.02) ruminal pH and average daily gain (ADG; 1.72 kg) compared with low-risk steers (1.94 kg). These findings suggest steers with greater DMI fluctuation have an increased risk for acidosis. For objective 2, DMI and feed intake behavior data from beef steers (n = 623) fed a corn-based diet were collected over the finishing phase using a GrowSafe system. A stepwise regression model was constructed using the GLMSELECT procedure of SAS 9.4 to predict acidosis risk during the last 56 d of the finishing phase. Acidosis risk was best predicted (r2 = 42.6; RMSE = 0.159) by 21 feed intake behavior traits. Those accounting for the greatest variation included head-down duration, sum of meal duration, and bunk visit frequency. The model predicted 72% of steers at greatest risk for acidosis. Overall, greater DMI fluctuation was indicative of acidosis risk based on decreased ruminal pH and ADG. A stepwise regression model was able to predict acidosis risk based on initial DMI and feed intake behaviors. Early identification of steers at risk for acidosis may facilitate mitigation strategies during the finishing phase to improve cattle health and growth performance.
Abstract
The objective was to determine the effects of injectable vitamin E (VE) before or after transit on feedlot cattle receiving performance, health, and blood parameters. Angus × Simmental ...steers (n = 196; body weight BW = 163 ± 29 kg) were utilized in a randomized complete block design. Steers were blocked by BW and randomly assigned to 1 of 3 treatments: intramuscular injections of saline pre- and post-transit (CON), intramuscular injections of VE (2,000 mg d-α-tocopherol) pre-transit and saline post-transit (PRE), or intramuscular injections of saline pre-transit and VE (2,000 mg d-α-tocopherol) post-transit (POST). Pre-transit injections were administered on day 0, and steers were transported on day 7 for approximately 4 h (348 km). After arrival, steers were fed a common corn silage-based diet in GrowSafe bunks. Final BW tended to be greater (P = 0.08) for CON steers compared with POST steers while PRE steers were intermediate. From days 7 to 63, treatment affected average daily gain (ADG) with PRE and CON steers exhibiting (P = 0.04) greater ADG compared with POST steers. Dry matter intake (DMI), water intake, and gain to feed from days 7 to 63 were not affected (P ≥ 0.17) by treatment. Day 0 serum α-tocopherol concentrations were considered marginal (2.3 ± 0.2 mg/l). A treatment × day interaction (P < 0.01) was observed for serum α-tocopherol concentrations. Serum α-tocopherol concentrations were greatest for PRE steers on day 7 (prior to and post-transit), but greater for POST steers on dys 10 and 14. Plasma ferric-reducing antioxidant potential concentrations increased (P = 0.04) for POST steers compared with CON steers and PRE steers being intermediate. Plasma non-esterified fatty acids (NEFA) concentrations exhibited a treatment × day interaction (P = 0.04) with CON and POST steers being 16% and 14% greater than PRE steers on day 14, respectively. On day 21, NEFA concentrations were greatest for POST steers compared with PRE steers and CON steers being intermediate. There was no main effect (P ≥ 0.14) of treatment on the number of bovine respiratory disease morbidity treatments. Hair cortisol concentrations were decreased (P < 0.01) 14 days after transit for PRE and POST steers compared with CON steers. Overall, injectable VE administered before or after transit increased serum tocopherol concentrations while reducing stress, but did not improve the growth performance of beef steers during the receiving phase.
Transportation stressors can negatively impact lightweight calf performance and health. An injection of VE before or after the transit may reduce stress through improved antioxidant status during the receiving phase.
Lay Summary
Cattle are transported multiple times throughout their lifespan due to the geographic distribution of the United States beef industry. However, transportation can elicit a variety of stressors that jeopardize cattle growth performance and health. Lightweight feeder calves are at the greatest risk for stress-related morbidity and mortality during the feedlot receiving phase. This study evaluated the effects of injectable vitamin E (VE) before or after transit on feedlot receiving phase growth performance, health, and blood parameters of lightweight beef steers. Steers receiving an injection of VE before or after transit had increased serum α-tocopherol concentrations. However, treatment with VE did not improve growth performance and feed intake. Steers injected with VE before or after transit experienced a decrease in hair cortisol concentrations 14 d after transit while steers injected with VE after transit had improved antioxidant status 14 d after transit compared with control steers and those receiving VE before transit. These results indicate that an injection of VE around the time of transit had no effect on growth performance and intake but can improve antioxidant status during the receiving phase.
Abstract
This study investigated the effects of injectable vitamin C (VC) at weaning and prior to transit on growth performance and immune function in early-weaned beef steers. On day 0, 91 Angus × ...Simmental steers (92 ± 4 kg) were weaned (65 ± 11 d of age), given vaccination boosters, blocked by age, and randomly assigned to weaning (WEAN) treatments: intramuscular injections (20 mL per steer) of VC (250-mg sodium ascorbate per mL; 5 g per steer) or saline (SAL). From days 0 to 48, steers were housed at the Dixon Springs Agricultural Center (Simpson, IL) in pens (six pens; N = 14 to 16 steers per pen) equipped with two to three Vytelle bunks to measure individual daily feed disappearance. On day 49, half of the steers in each WEAN treatment were randomly assigned to an additional injection treatment (20 mL per steer) of VC or SAL prior to transport (TRANS). After administering pretransit injections, all steers were loaded onto a commercial livestock trailer with equal representation of treatments across compartments. Steers were transported for 6 h (approximately 480 km) to the Illinois Beef and Sheep Field Laboratory (Urbana, IL). Upon arrival, steers were sorted into pens (six pens; N = 13 to 17 steers per pen) with 2 Vytelle bunks per pen. Steers were weighed on days 0, 1, 14, 48, 49, 64, 78, 106, and 107. Blood was collected (WEAN = 24 steers per treatment; TRANS = 12 steers per treatment) on days 0, 1, 2, 14, 49 (pre- and posttransit), 50, and 51. Data were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of age block, WEAN, TRANS, and WEAN × TRANS. Plasma ascorbate concentrations were greater (WEAN × time P < 0.01) on days 1 and 2 for steers that received VC at weaning. Similarly, for steers that received VC on day 49 pretransit, ascorbate concentrations were greater (TRANS × time P = 0.04) on days 49 posttransit, 50, and 51. Treatments did not affect (P ≥ 0.13) body weight, average daily gain, or gain to feed throughout the trial. Serum Bovine Viral Diarrhea Virus type 1 and 2 antibody titers on days 14 and 51 were not affected (P ≥ 0.32) by treatment. Injectable VC administered to early-weaned beef steers at the time of weaning or pretransit increased plasma ascorbate concentrations but did not improve growth performance or antibody response to vaccination booster.
Beef calves weaned at a younger age may encounter greater physiological or oxidative stress during weaning and transit. This research examined the ability of an injectable vitamin C to affect growth performance and immune function in early-weaned beef calves.
Lay Summary
Weaning and transit represent the primary stressors for beef calves in the United States and are responsible for increasing inflammation, suppressing the immune system, and decreasing antioxidant status. These adverse physiological responses to stressors may decrease growth and increase morbidity in beef calves. Vitamin C is the primary water-soluble antioxidant in plasma and when provided intramuscularly prior to the stress event, may be able to attenuate aspects of a stress response on growth and immune function. This study evaluated the effects of injectable vitamin C given to early-weaned beef calves prior to weaning on day 0 and a 6-h transit on day 49 after weaning. Basal levels of plasma ascorbate were lower than prior studies in older and larger animals. As expected, injectable vitamin C rapidly increased plasma ascorbate concentrations at 24 h, but concentrations also increased in control calves receiving a saline injection. Treatments did not affect overall growth performance or dry matter intake. Treatments also did not impact the immune response to a booster vaccination provided at weaning. While other research has indicated a positive effect of injectable vitamin C prior to transit, additional research is needed to refine the dosage and physiological need for exogenous antioxidants like vitamin C based on the severity and duration of a stress event in lightweight beef calves.
Abstract
The objective was to evaluate the effects of injectable vitamin C (VC) at transit before slaughter on meat color. The prevalence of dark-cutting beef can be exacerbated by transit and ...environmental conditions resulting in a less desirable product to consumers. Angus × Simmental steers (n = 48; BW = 670 ± 47 kg) were utilized in a completely randomized design. Steers were stratified by BW within pen and randomly assigned to 1 of 2 treatments: an intramuscular injection of saline immediately prior to transit (CON), or an intramuscular injection of VC (15 g sodium ascorbate) immediately prior to transit (VITC). Blood was collected prior to treatment injection to assess plasma ascorbate status. Following pre-transit treatment injections, steers were transported for approximately 6 h (639 km) and slaughtered at a commercial abattoir. At 24 h postmortem, surface color readings were measured using a HunterLab Miniscan EZ spectrophotometer and marbling scores were evaluated on the left and right longissimus muscle. Data were analyzed using the MIXED and GLIMMIX procedures of SAS 9.4 with fixed effects of treatment, truck, and sire, and random effect of carcass side. Pre-transit plasma ascorbate, body weight, and marbling score were used as covariates. No treatment differences were observed for L* (lightness), a* (redness), and b* (yellowness) values (P > 0.16). Hue angle, saturation index, and prevalence of dark cutters (6% of total carcasses) were not affected by treatment (P > 0.78). Initial plasma ascorbate concentrations did not differ between treatments (P = 0.85) but increased with BW (r = 0.39; P ≤ 0.01). Body weight was correlated (r=0.24 to 0.28; P < 0.02) with HunterLab L*, a*, b*, and saturation index values. Overall, injectable VC administered prior to transit to a harvest facility did not impact meat color of beef steers 24 h postmortem.
Written exposure therapy (WET) is a brief, manualized trauma-focused treatment typically delivered in five individual weekly sessions. Given the brevity and effectiveness of WET, researchers have ...begun to focus on its delivery in a massed format. However, only one case study examining massed delivery has been published to date. As such, the objective of the current study was to examine the acceptability, feasibility, and preliminary effectiveness of massed WET among veterans with a trauma- and stressor-related disorder receiving care on an acute inpatient mental health unit. Veterans (N = 26) were assessed prior to, immediately after, and 1 month following massed WET. Most veterans found massed WET to be useful and acceptable. Recruitment and retention rates suggested that the treatment was feasible. Notably, the results revealed statistically significant reductions in overall posttraumatic stress symptoms, η
= .81, p < .001; depressive symptoms, η
= .71, p < .001; and functional impairment, η
= .42, p = .002. These findings add to a growing body of literature highlighting the preliminary effectiveness of WET across various settings, populations, and delivery formats. Limitations include the small sample size and uncontrolled design.
The objective was to investigate the influence of cattle origin and region of finishing on the prevalence of
,
O157:H7, and select antimicrobial resistance in
populations. Yearling heifers (
= 190) ...were utilized in a 2 × 2 factorial arrangement. After determining fecal
prevalence, heifers were sorted into one of four treatments: heifers originating from South Dakota (SD) and finished in SD (SD-SD); heifers originating from SD and finished in Texas (SD-TX); heifers originating from TX and finished in SD (TX-SD); and heifers originating from TX and finished in TX (TX-TX). Fecal, pen, and water scum line samples were collected longitudinally throughout the study; hide swab and subiliac lymph node (SLN) samples were collected at study end. A treatment × time interaction was observed (
≤ 0.01) for fecal
prevalence, with prevalence being greatest for TX-TX and TX-SD heifers before transport. From day (d) 14 through study end, prevalence was greatest for TX-TX and SD-TX heifers compared with SD-SD and TX-SD heifers.
prevalence on hides were greater (
≤ 0.01) for heifers finished in TX compared with SD.
prevalence in SLN tended (
= 0.06) to be greater in TX-TX and SD-TX heifers compared with TX-SD and SD-SD. Fecal
O157:H7 prevalence had a treatment × time interaction (
= 0.04), with SD-TX prevalence being greater than TX-SD on d 56 and SD-SD and TX-TX being intermediate. A treatment × time interaction was observed for fecal trimethoprim-sulfamethoxazole-resistant and cefotaxime-resistant
O157:H7 prevalence (
≤ 0.01). Overall, these data suggest that the region of finishing influences pathogenic bacterial shedding patterns, with the initial 14 d after feedlot arrival being critical for pathogen carriage.
