The effect of a direct-fed microbial (10-G) on live animal performance, carcass characteristics, and prevalence of fed beef heifers.

The objective of this study was to determine the efficacy of the direct-fed microbial 10-G upon cattle growth performance, liver and lung health, carcass quality, and yield outcomes, as well as prevalence and enumeration of in feces and lymph nodes. Fed beef heifers ( = 1,400; initial shrunk body weight [] 343.3 ± 36.

A randomized trial and multisite pooled trial analyses comparing effects of two hormonal implant programs and differing days-on-feed on carcass characteristics and feedlot performance of beef heifers.

Research objectives were to evaluate effects of two implant programs for beef heifers fed three different durations (days-on-feed; DOF) on carcass weight and composition (primary outcomes) and feedlot performance (secondary outcomes) at commercial feedlots. Data from a randomized trial in Kansas were analyzed separately and also pooled with data from two previously published trials conducted in Texas. Heifers were randomly allocated to pens within a block, and pens were randomized to treatments in a 2 × 3 factorial randomized complete block design.

Liver Abnormalities in Cattle: Effect of Liver Abscessation on Growth and Productivity of Cattle.

Liver abscess has been identified in multiple classes of cattle, but cattle consuming higher energy diets may have greater prevalence of abscessation. The presence and severity of liver abscess has been associated with reduced dry matter intake, daily gain, and gain efficiency of individually fed animals, and as the prevalence of abscesses within pens of animals increases, growth performance worsens. Because of the importance of the liver to metabolism, damage due to abscess could negatively affect energy utilization.

Evaluation of feeding ruminal-protected folate and cobalt pectinate on growth performance, carcass characteristics and plasma vitamin B and folate status in finishing beef steers.

A large pen feedlot study was conducted to evaluate the response of yearling steers fed novel sources of rumen-protected folate () and cobalt (cobalt pectinate; ) on plasma levels of vitamin B and folate, growth performance, and carcass characteristics. A total of 2,100 steers (initial BW = 381 ± 45.2 kg.

Effect of a direct-fed microbial (10-G Armor) on feedlot performance, carcass characteristics, and prevalence of in fed-beef heifers.

Crossbred beef heifers (= 1,394; initial shrunk body weight [BW] 291 ± 9.9 kg) were used to investigate the efficacy of 10-G Armor (Life Products, Inc., Norfolk, NE; 10-G) upon feedlot performance, carcass characteristics, and fecal and subiliac lymph nodes prevalence.

Erratum to: Effects of various doses of lubabegron on calculated ammonia gas emissions, growth performance, and carcass characteristics of beef cattle during the last 56 days of the feeding period.

[This corrects the article DOI: 10.1093/tas/txab137.].

Effects of various doses of lubabegron on calculated ammonia gas emissions, growth performance, and carcass characteristics of beef cattle during the last 56 days of the feeding period.

Lubabegron (LUB; Experior, Elanco, Greenfield, IN, USA) was approved by the U.S. Food and Drug Administration in 2018 and is indicated for the reduction of ammonia (NH) gas emissions·kg body weight (BW) and hot carcass weight (HCW) when fed to feedlot cattle during the final 14 to 91 d of the finishing period.

Effects of roughage type on particle separation, rumination, fiber mat characteristics, in situ degradation, and ruminal fermentation parameters in beef steers.

Six ruminally cannulated steers (average BW = 791 ± 71 kg) were used in a replicated 3 × 3 Latin square experiment to determine the effects of roughage type on rumination, fiber mat characteristics, and rumen fermentation variables. Three roughages were included at 7% (DM basis) in a steam flaked corn-based diet: cotton burrs (CB), wheat silage (WS), or corn stalks (CS). Steers were fitted with a sensory collar to record rumination behaviors in 2-h intervals at the beginning of the experiment.

A pooled analysis of six large-pen feedlot studies: effects of a noncoated initial and terminal implant compared with a single initial and delayed-release implant on arrival in feedlot heifers.

Randomized complete block design experiments ( = 6 experiments) evaluating steroidal implants (all from Merck Animal Health, Madison, NJ) were conducted in large-pen feedlot research facilities between 2015 and 2018 comparing an 80 mg trenbolone acetate (TBA) and 8 mg estradiol-17β (E) initial implant (Revalor-IH) and reimplanted with 200 mg TBA and 20 mg E (Revalor-200; REPEATED) to a single 80 mg TBA and 8 mg E uncoated; 120 mg TBA and 12 mg E coated implant (Revalor-XH) at arrival (SINGLE) on growth and carcass responses in finishing heifers. Experiments occurred in Nebraska, Oklahoma, Washington, and Texas. Similar arrival processing was used across experiments where 17,675 heifers [initial body weight = 333 kg SEM (4.

Net protein contribution of beef feedlots from 2006 to 2017.

Feedlot efficiency increases as technologies are adopted and new feed ingredients, especially byproducts, become available and incorporated into diets. Byproduct availability increased in response to the renewable fuels standard of 2005, creating substantial amounts of feedstuffs best used by ruminants. Cereal grains have been partially replaced with human-inedible byproducts, as they provide comparable levels of energy in cattle diets.

Effects of a single initial and delayed release implant on arrival compared with a non-coated initial implant and a non-coated terminal implant in heifers fed across various days on feed.

Two experiments evaluated the effect of implant number, type, and total steroidal dose on live animal performance and carcass traits in heifers fed for three different days on feed (DOF). In experiment 1, heifers ( = 3,780; 70 heifers/pen and 9 pens/treatment; initial body weight [BW] = 309 kg) were used in a 2 × 3 factorial arrangement of treatments. Factors were as follows: 1) implant (all from Merck Animal Health, De Soto, KS): 200 mg trenbolone acetate (TBA) and 20 mg estradiol-17β (E) administered on arrival (SINGLE), or 80 mg TBA and 8 mg E administered on arrival followed by 200 mg TBA and 20 mg E after approximately 90 d (REPEATED) and 2) duration of DOF: harvested after approximately 172, 193, and 214.

Acute immunologic and metabolic responses of beef heifers following topical administration of flunixin meglumine at various times relative to bovine herpesvirus 1 and challenges.

Objective: To quantify acute immunologic and metabolic responses of beef heifers following topical administration of transdermal flunixin meglumine (TDFM) at various times relative to bovine herpesvirus 1 (BHV1) and challenges.

Animals: 32 beef heifers (mean body weight, 170 kg).

Procedures: Heifers were assigned to 1 of 4 groups.

Immune and metabolic responses of beef heifers supplemented with to a combined viral-bacterial respiratory disease challenge.

Two treatments were evaluated in heifers to determine the effects of a yeast supplement on immune and metabolic responses to a combined (tandem viral-bacterial) respiratory disease challenge. Thirty-two beef heifers (325 ± 20.1 kg BW) were selected from a larger population previously assigned to one of two treatments: Control (CON), receiving no yeast supplement in the diet, or yeast (YST), CON diet plus a combination live yeast (2.

Effectiveness of sorting calves with high risk of developing bovine respiratory disease on the basis of serum haptoglobin concentration at the time of arrival at a feedlot.

Objective: To evaluate serum haptoglobin concentration at feedlot arrival and subsequent performance and morbidity and mortality rates of calves that developed bovine respiratory disease.

Animals: 360 heifer calves and 416 steer and bull calves.

Procedures: Serum samples were obtained from cattle at the time of arrival to a feedlot (day -1) and analyzed for haptoglobin concentration.

Fetal protection in heifers vaccinated with a modified-live virus vaccine containing bovine viral diarrhea virus subtypes 1a and 2a and exposed during gestation to cattle persistently infected with bovine viral diarrhea virus subtype 1b.

Objective: To determine efficacy of a modified-live virus (MLV) vaccine containing bovine viral diarrhea virus (BVDV) 1a and 2a against fetal infection in heifers exposed to cattle persistently infected (PI) with BVDV subtype 1 b.

Animals: 50 heifers and their fetuses.

Procedures: Susceptible heifers received a placebo vaccine administered IM or a vaccine containing MLV strains of BVDV1a and BVDV2a administered IM or SC.

Evaluation of breath biomarkers and serum haptoglobin concentration for diagnosis of bovine respiratory disease in heifers newly arrived at a feedlot.

Objective: To evaluate exhaled N(2)O (eN(2)O), exhaled CO (eCO), and serum haptoglobin concentrations as diagnostic criteria for bovine respiratory disease (BRD) and determine whether a combination of biomarkers would be useful for predicting health outcomes of heifer calves.

Animals: 337 heifer calves newly arrived at a feedlot.

Procedures: Body weights, serum haptoglobin concentrations, and rumen temperatures were determined.

Comparison of single vaccination versus revaccination with a modified-live virus vaccine containing bovine herpesvirus-1, bovine viral diarrhea virus (types 1a and 2a), parainfluenza type 3 virus, and bovine respiratory syncytial virus in the prevention of bovine respiratory disease in cattle.

Objective-To compare effects of administration of a modified-live respiratory virus vaccine once with administration of the same vaccine twice on the health and performance of cattle. Design-Randomized, controlled trial. Animals-612 mixed-breed male cattle with unknown health histories.