PSVII-40 Late-Breaking Abstract: Ultrasonography and bacterial community of naturally occurring liver abscesses and non-abscessed livers in finishing Holstein steers

Abstract Liver abscesses persist in feedlot cattle representing a financial burden to both pre- and post-mortem sectors of the beef industry. Pre- and Post-mortem strategies are needed to understand onset, duration, and resolution of abscesses, etiology, and fully quantify their impact on performance. Holstein steers (n = 56; Initial BW=384±13.5 kg) consuming a finishing diet (90% concentrate) for 188 d (Final BW=660±42 kg) were used for live ultrasonography of the liver. Feed intake was recorded daily and BW and liver ultrasound images recorded every 28 d. At harvest, livers were graded and imaged to compare with ultrasound images. Tissue was sampled from both abscessed and non-abscessed livers and 16s rDNA sequencing performed. Steers ranked within feedlot performance variables for 188 days on feed (DOF) and the final 48 DOF were compared with post-mortem liver score using the FREQ procedure of SAS. A contingency table for abscess detection by ultrasound versus harvest was used to evaluate ultrasound accuracy. Abscess prevalence of Holstein steers was 60.7%. No relationship was detected between liver severity score and DMI, ADG and G:F calculated from the total days on feed (P ≥ 0.394). However, in the last 48 DOF, steers with non-abscessed or resolved liver abscesses tended to have greater ADG values (P = 0.099) and G:F (P = 0.049) than steers with mild and severely abscessed livers. Final ultrasound identified 14 of 23 abscessed livers. Abscesses not detected by ultrasound were inactive scars/adhesions, located on the visceral side or covered by lung or intestinal tissue. Non-abscessed and scarred livers had greater OTU richness and evenness while severely abscessed livers had greater dominance (P < 0.001). Beta-diversity indicated community separation of tissue from different severity scores. All 56 liver samples contained F. necrophorum and Bacteroides spp. DNA; abscessed or not. The true prevalence and duration of liver abscesses in finishing cattle requires greater pre-mortem surveillance.

Download Full-text

389 Interactions between zinc, copper, and growth promoting technologies in beef cattle

Journal of Animal Science ◽

10.1093/jas/skaa278.309 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 168-169

Author(s):

Olivia N Genther-Schroeder ◽

Remy N Carmichael ◽

Elizabeth M Messersmith ◽

Katherine Hochmuth ◽

Elisabeth Lonergan ◽

...

Keyword(s):

Phosphodiesterase Inhibitors ◽

Feedlot Cattle ◽

Beef Industry ◽

Finishing Cattle ◽

Biochemical Processes ◽

Feedlot Steers ◽

Current State ◽

Animal Growth ◽

Growth Promoting ◽

Anabolic Implants

Abstract Trace minerals (TM) are required for many biochemical processes and support optimal animal growth. However, as animal genetics and feed technologies in the beef industry have advanced, our understanding of the TM requirements of modern cattle has lagged. Recently, Zn and Cu have emerged as potential targets for better understanding the interaction between nutrition and growth-promoting technologies like anabolic implants and β-agonists (BA). Both Zn and Cu are phosphodiesterase inhibitors, potentially maintaining cAMP concentrations, potentiating the BA signal. Zinc supplementation well above national recommendations can improve ADG or HCW in finishing cattle during the BA feeding period, and N retention is increased by both Zn and BA supplementation, suggesting a major role for Zn is in protein accretion. Interestingly, Cu status of feedlot steers appears to affect ADG during the BA period, where steers with moderate liver Cu and 10 mg Cu/kg diet DM gaining more than steers with high or low Cu status. Anabolic implants likely improve growth through altering protein deposition, degradation and satellite cell proliferation, processes that can be linked to Cu and Zn metalloproteins. Implanting cattle decreases both plasma and liver Zn, and heifers receiving a long-lasting implant had greater HCW when supplemented with 100 mg Zn/kg DM when compared with 30 mg Zn/kg DM. It is apparent Cu status and supplementation also affect the response to hormone implants. Steers supplemented with 20 mg Cu/kg DM had greater liver Cu concentrations and a lesser response to an implant than steers supplemented with 10 mg Cu/kg DM. Current state of knowledge suggests TM status and diet concentrations can impact the response to growth promoting technologies. Much remains to be learned about cattle requirements for dietary TM, and the appropriate TM concentrations to optimize feedlot cattle performance.

Download Full-text

299 Combination of Essential Oils, α-amylase and 25-hydroxy-vitamin-d3 Increases Carcass Production by feedlot Cattle

Journal of Animal Science ◽

10.1093/jas/skab235.301 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 164-164

Author(s):

Maria B Niehues ◽

Hugo L Correa ◽

Victor Valério de Carvalho ◽

Alexandre Perdigão ◽

Tiago S Acedo ◽

...

Keyword(s):

Essential Oils ◽

Vitamin D3 ◽

Block Design ◽

Animal Health ◽

Feedlot Cattle ◽

Feed Additives ◽

Biological Efficiency ◽

Feedlot Performance ◽

Finishing Cattle ◽

Randomized Block Design

Abstract Our objective was to evaluate the effects of associating feed additives on feedlot performance of Nellore bulls. One hundred and sixtieth Nellore bulls (iBW, 380± 5.8 kg; age, 18 mo) were allocated in 20 pens (n = 8/pen), in a completely randomized block design, according to the treatments: 1) MON+VM - Sodium Monensin (MON, 25 mg/kg DM, Elanco Animal Health, Indianapolis, IN), + Virginiamycin (VM, 30 mg/kg DM, Phibro Animal Health Corporation, Guarulhos, São Paulo), and 2) CRD - Crina® RumistarTM + HyD® - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25-hydroxy-vitamin-D3 at 1 mg/animal/d (DSM Nutritional Products, Basel, Switzerland). The initial BW was utilized as a criterion for block formation. Pens were considered experimental units (10 pens per treatment). Animals were adapted to the diets during 14 days with gradually increasing concentrate level from 70% to 86% of diet DM, and fed for 90 days. Weight assessments were performed at day 0 and 90 after 14h fasting. Data were analyzed using PROC MIXED of SAS and means were separated using the PDIFF statement, adopting P < 0.05. Feeding CRD increased the DMI (12.13 kg vs. 10.52 kg, P < 0.01), ADG (1.86 vs. 1.63 kg/d, P < 0.01) and final BW (542 vs. 521 kg, P < 0.01) compared to animals fed MON+VM. In addition, feeding CRD increased final HCW in 15 kg (311 vs. 296 kg; P < 0.01), carcass ADG in 0,16 kg/d (1.31 vs. 1.15 kg/d; P < 0.01) and dressing percentage in 0.48 percent points (57.34 vs. 56.86%; P < 0.01) compared to MON+VM. The G:F (0.155, P = 0.53) and biological efficiency (137.9 kg DM/15 kg carcass, P = 0.87) were similar among treatments. Therefore, the inclusion of Crina® RumistarTM +HyD® can be used as a tool to increase carcass gain of feedlot finishing cattle.

Download Full-text

83 Evaluation of feeding immunoglobulin-Y to Holstein feeder cattle for the control of liver abscesses & reduction of macrolide-resistant bacteria dissemination

Journal of Animal Science ◽

10.1093/jas/skz397.022 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 10-10

Author(s):

Miranda K Stotz ◽

Diego Casas Murillo ◽

Darren D Henry ◽

Whitney L Crossland

Keyword(s):

Financial Burden ◽

Feedlot Cattle ◽

Feed Additives ◽

Experimental Unit ◽

Resistant Bacteria ◽

Continuous Variables ◽

Immunoglobulin Y ◽

Muscle Area ◽

Feeder Cattle ◽

Liver Abscesses

Abstract Despite the regular use of macrolide-antibiotics in the diets of feedlot cattle, liver abscesses persist representing a financial burden to both pre- and post-mortem sectors of the beef industry. Alternative strategies, which simultaneously address liver infections and reduce the dissemination of antibiotic-resistant bacteria, are needed. An immunoglobulin-Y (IGY) product, developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses and its effect on macrolide-resistant Enterococcus growth from feces. Sixty-four Holstein steers (Initial BW= 384± 13.5kg) consuming a finishing diet (90% concentrate) for 188 days (Final BW= 660± 42 kg) were used in a completely randomized design where steer was experimental unit and treatments included: TYL (Tylosin phosphate fed at 90mg/hd/day; n = 32) or IGY (fed at 2.5g/hd/day; n= 32). Feed intake was recorded daily and BW was recorded every 28 days until slaughter. After 150 d on treatment fecal samples were randomly obtained from each treatment group four times (n = 40) and cultured on bile-esculine agar enriched with 8 μg/mL of erythromycin. Continuous variables of feedlot growth performance, carcass data and bacterial growth were analyzed using the MIXED procedure of SAS with the fixed effect of treatment and random effects of steer or sampling day, respectively. Ordinal carcass data were analyzed using the FREQ procedure of SAS observing the Cochran-Mantel-Haenszel value. Treatment did not affect DMI (P= 0.21), ADG (P = 0.50) or G:F (P = 0.36). Treatment neither affected hot carcass weight (P = 0.37) nor longissimus muscle area (P = 0.25). However, TYL resulted in greater back fat thickness than IGY (0.32 vs. 0.23 in.; P < 0.02) and consequently greater numerical yield grade (P < 0.02). Quality grade was not affected by treatment (P = 0.65). No treatment difference was observed for liver abscesses prevalence (TYL=63% vs. IGY=52%; P = 0.40) or severity (P = 0.23). There was a greater proportion of erythromycin-resistant Enterococcus growth for TYL than IGY (42.6 vs. 21.9%; P < 0.04). Specifically formulated IGY feed additives may be viable alternatives to antibiotics in feedlot cattle diets.

Download Full-text

224 Epimural microbiota and rumen epithelial gene expression in healthy and liver-abscessed animals

Journal of Animal Science ◽

10.1093/jas/skaa054.234 ◽

2020 ◽

Vol 98 (Supplement_3) ◽

pp. 135-135

Author(s):

Waseem Abbas ◽

Amanda K Lindholm-Perry ◽

Brittney N Keel ◽

James E Wells ◽

Kristin Hales ◽

...

Keyword(s):

Gene Expression ◽

Bacterial Community ◽

Differentially Expressed Genes ◽

Feedlot Cattle ◽

Differentially Expressed ◽

Feed Additive ◽

Rumen Content ◽

Liver Abscesses ◽

Rdna Sequencing ◽

Wide Range

Abstract Different dietary and feed additive strategies have been developed to reduce the liver abscess in feedlot cattle, but liver abscesses are still a major problem in beef production. We have limited knowledge about how rumen microbial communities interact with host epithelial gene expression in healthy and liver-abscessed animals. The objective of this study was to investigate the associations between the rumen content associated and rumen epimural microbiome and epithelial gene expression in liver-abscessed and healthy animals. To this end, we collected the ruminal contents and tissue samples from healthy (N=30; score=0, steers n=19 and heifers n=11) and liver-abscessed (N=30; score=A+, steers n=21 and heifers n=9) feedlot cattle at harvest. The bacterial community compositions in the ruminal contents and papillae were evaluated via 16S rDNA sequencing of the V4 region using the Illumina MiSeq platform. Additionally, total RNA was extracted from rumen epithelial tissues and sequenced using the Illumina NextSeq platform. The permutational analysis (PERMANOVA) on Bray Curtis distances matrices showed the microbial community in the ruminal contents was significantly different (P< 0.001) from the bacterial community observed in rumen papillae. The ruminal contents contained a higher abundance of Bacteroidetes and Proteobacteria while papillae contained higher abundance of Firmicutes. The epimural microbiota was different (P< 0.01) between healthy and liver abscessed animals while ruminal contents microbiome was not different between the two groups. The DeSeq2 algorithm identified differentially expressed genes (221) related to MAPK, NF-kappa B signaling pathway, immune and inflammatory response in liver-abscessed animals. Additionally, a wide range of epimural bacterial taxa were correlated (-0.52 to 0.67) with differentially expressed genes. These data demonstrate the interaction between epimural microbiota and the host and its effect on liver abscesses, and indicate the need to study the epimural microbiome for its impact on liver abscesses in feedlot cattle. USDA is an equal opportunity provider and employer.

Download Full-text

82 Evaluation of feeding immunoglobulin-Y to Holstein feeder cattle for the control of liver abscesses & reduction of macrolide-resistant bacteria dissemination

Journal of Animal Science ◽

10.1093/jas/skz397.116 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 50-51

Author(s):

Miranda K Stotz

Keyword(s):

Financial Burden ◽

Fusobacterium Necrophorum ◽

Feedlot Cattle ◽

Feed Additives ◽

Resistant Bacteria ◽

Continuous Variables ◽

Immunoglobulin Y ◽

Muscle Area ◽

Feeder Cattle ◽

Liver Abscesses

Abstract Despite the regular use of macrolide-antibiotics in the diets of feedlot cattle, liver abscesses persist representing a financial burden to both pre- and post-mortem sectors of the beef industry. Alternative strategies, which simultaneously address liver infections and reduce the dissemination of antibiotic-resistant bacteria, are needed. An immunoglobulin-Y (IGY) product, developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses and its effect on macrolide-resistant Enterococcus growth from feces. Sixty-four Holstein steers (Initial BW= 384±13.5kg) consuming a finishing diet (90% concentrate) for 188 days (Final BW= 660±42 kg) were used in a completely randomized design where treatments included: TYL (Tylosin phosphate fed at 90 mg/hd/day; n = 32) or IGY (fed at 2.5g/hd/day; n = 32).Feed intake was recorded daily and BW was recorded every 28 days until slaughter. After 150 d on treatment fecal samples were randomly obtained from each treatment group four times (n = 40) and cultured on bile-esculine agar enriched with 8 μg/mL of erythromycin. Continuous variables of feedlot growth performance, carcass data and bacterial growth were analyzed using the MIXED procedure of SAS with the fixed effect of treatment and random effects of steer or sampling day, respectively. Ordinal carcass data was analyzed using the FREQ procedure of SAS observing the Cochran-Mantel-Haenszel value. Treatment did not affect DMI (P = 0.21), ADG (P = 0.50) or G:F (P = 0.36). Treatment neither affected hot carcass weight (P = 0.37) nor longissimus muscle area (P = 0.25). However, TYL resulted in greater back fat thickness than IGY (0.32 vs. 0.23 in.; P < 0.02) and consequently greater numerical yield grade (P < 0.02). Quality grade was not affected by treatment (P = 0.65). No treatment difference was observed for liver abscesses prevalence (TYL= 63% vs. IGY= 52%; P = 0.40) or severity (P = 0.23). There was a greater proportion of erythromycin-resistant Enterococcus growth for TYL than IGY (42.6 vs. 21.9%; P < 0.04). Specifically formulated IGY feed additives may be viable alternatives to antibiotics in the diets of feedlot cattle.

Download Full-text

81 Evaluation of feeding immunoglobulin-Y to Holstein feeder cattle for the control of liver abscesses & reduction of macrolide-resistant bacteria dissemination

Journal of Animal Science ◽

10.1093/jas/skz397.053 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 23-24

Author(s):

Miranda K Stotz

Keyword(s):

Financial Burden ◽

Fusobacterium Necrophorum ◽

Feedlot Cattle ◽

Feed Additives ◽

Resistant Bacteria ◽

Continuous Variables ◽

Immunoglobulin Y ◽

Muscle Area ◽

Feeder Cattle ◽

Liver Abscesses

Abstract Despite the regular use of macrolide-antibiotics in the diets of feedlot cattle, liver abscesses persist representing a financial burden to both pre- and post-mortem sectors of the beef industry. Alternative strategies, which simultaneously address liver infections and reduce the dissemination of antibiotic-resistant bacteria, are needed. An immunoglobulin-Y (IGY) product, developed to target Fusobacterium necrophorum andTrueperella pyogenes, was evaluated for the control of liver abscesses and its effect on macrolide-resistant Enterococcus growth from feces. Sixty-four Holstein steers (Initial BW= 384±13.5kg) consuming a finishing diet (90% concentrate) for 188 d (Final BW= 660±42 kg) were used in a completely randomized design where treatments included: TYL (Tylosin phosphate fed at 90 mg/hd/day; n = 32) or IGY (fed at 2.5g/hd/day; n = 32). Feed intake was recorded daily and BW was recorded every 28 d until slaughter. After 150 d on treatment fecal samples were randomly obtained from each treatment group four times (n = 40) and cultured on bile-esculine agar enriched with 8 μg/mL of erythromycin. Continuous variables of feedlot growth performance, carcass data and bacterial growth were analyzed using the MIXED procedure of SAS with the fixed effect of treatment and random effects of steer or sampling day, respectively. Ordinal carcass data was analyzed using the FREQ procedure of SAS observing the Cochran-Mantel-Haenszel value. Treatment did not affect DMI (P = 0.21), ADG (P = 0.50) or G:F (P = 0.36). Treatment neither affected hot carcass weight (P = 0.37) nor longissimus muscle area (P = 0.25). However, TYL resulted in greater back fat thickness than IGY (0.32 vs. 0.23 in.; P < 0.02) and consequently greater numerical yield grade (P < 0.02). Quality grade was not affected by treatment (P = 0.65). No treatment difference was observed for liver abscesses prevalence (TYL= 63% vs. IGY= 52%; P = 0.40) or severity (P = 0.23). There was a greater proportion of erythromycin-resistant Enterococcus growth for TYL than IGY (42.6 vs. 21.9%; P < 0.04). Specifically formulated IGY feed additives may be viable alternatives to antibiotics in the diets of feedlot cattle.

Download Full-text

Bacterial community analysis of purulent material from liver abscesses of crossbred cattle and Holstein steers fed finishing diets with or without tylosin

Journal of Animal Science ◽

10.1093/jas/skab076 ◽

2021 ◽

Vol 99 (4) ◽

Author(s):

Raghavendra G Amachawadi ◽

Wesley A Tom ◽

Michael P Hays ◽

Samodha C Fernando ◽

Philip R Hardwidge ◽

...

Keyword(s):

Bacterial Community ◽

Community Composition ◽

Bacterial Community Composition ◽

Feedlot Cattle ◽

Crossbred Cattle ◽

Sequence Analyses ◽

Gram Negative ◽

Treatment Groups ◽

Finishing Diets ◽

Liver Abscesses

Abstract Liver abscesses in feedlot cattle are polymicrobial infections. Culture-based studies have identified Fusobacterium necrophorum as the primary causative agent, but a number of other bacterial species are frequently isolated. The incidence of liver abscesses is highly variable and is affected by a number of factors, including cattle type. Holstein steers raised for beef production have a higher incidence than crossbred feedlot cattle. Tylosin is the commonly used antimicrobial feed additive to reduce the incidence of liver abscesses. The objective of this study was to utilize 16S ribosomal RNA amplicon sequence analyses to analyze the bacterial community composition of purulent material of liver abscesses of crossbred cattle (n = 24) and Holstein steers (n = 24), each fed finishing diet with or without tylosin. DNA was extracted and the V3 and V4 regions of the 16S rRNA gene were amplified, sequenced, and analyzed. The minimum, mean, and maximum sequence reads per sample were 996, 177,070, and 877,770, respectively, across all the liver abscess samples. Sequence analyses identified 5 phyla, 14 families, 98 genera, and 102 amplicon sequence variants (ASV) in the 4 treatment groups. The dominant phyla identified were Fusobacteria (52% of total reads) and Proteobacteria (33%). Of the top 25 genera identified, 17 genera were Gram negative and 8 were Gram positive. The top 3 genera, which accounted for 75% of the total reads, in the order of abundance, were Fusobacterium, Pseudomonas, and Bacteroides. The relative abundance, expressed as percent of total reads, of phyla, family, and genera did not differ (P > 0.05) between the 4 treatment groups. Generic richness and evenness, determined by Shannon–Weiner and Simpson’s diversity indices, respectively, did not differ between the groups. The UniFrac distance matrices data revealed no clustering of the ASV indicating variance between the samples within each treatment group. Co-occurrence network analysis at the genus level indicated a strong association of Fusobacterium with 15 other genera, and not all of them have been previously isolated from liver abscesses. In conclusion, the culture-independent method identified the bacterial composition of liver abscesses as predominantly Gram negative and Fusobacterium as the dominant genus, followed by Pseudomonas. The bacterial community composition did not differ between crossbred and Holstein steers fed finishing diets with or without tylosin.

Download Full-text

Effects of Syngenta Enogen Feed Corn containing an α-amylase trait on finishing cattle performance and carcass characteristics1

Translational Animal Science ◽

10.1093/tas/txy121 ◽

2018 ◽

Vol 3 (1) ◽

pp. 504-512 ◽

Cited By ~ 1

Author(s):

M L Jolly-Breithaupt ◽

M E Harris ◽

B L Nuttelman ◽

D B Burken ◽

J C MacDonald ◽

...

Keyword(s):

Feed Efficiency ◽

Carcass Characteristics ◽

Feedlot Performance ◽

Finishing Cattle ◽

Main Effect ◽

University Of Nebraska Lincoln ◽

The University ◽

Extension Center ◽

Enzyme Supplement ◽

Corn Hybrid

Abstract Two experiments evaluated the effects of feeding a new corn hybrid, containing an α-amylase enzyme trait, Syngenta Enogen Feed Corn (SYT-EFC), on feedlot performance and carcass characteristics at two locations. Experiment 1 utilized 300 calffed steers (298.5 ± 16.3 kg of BW) at the University of Nebraska–Lincoln Eastern Nebraska Research and Extension Center Mead, NE. Treatments were designed as a 2 × 2 + 1–factorial arrangement with factors consisting of 1) corn type (SYT-EFC or conventional [CON]) and 2) byproduct type (with or without Sweet Bran [SB]), or a BLEND of STY-EFC and CON without SB. In Exp. 2, 240 crossbred, calf-fed steers (287.6 ± 15.4 kg of BW) were utilized at the University of Nebraska–Lincoln Panhandle Research and Extension Center near Scottsbluff, NE. Steers were fed SYT-EFC, CON, BLEND, or CON with a commercial α-amylase enzyme supplement (CON-E). In Exp. 1, there was an interaction for ADG (P = 0.05) and G:F (P = 0.02). Steers fed SYT-EFC with SB had greater ADG and G:F than CON; however, in diets without SB, SYT-EFC and CON were not different resulting in a 10.1% change in G:F when steers were fed SYT-EFC in SB compared with CON and only 1.6% change between SYT-EFC and CON without SB. Energy values, based on performance data, resulted in a 6.5% and 8.3% change in NEm and NEg, respectively, for steers fed SYT-EFC and CON with SB and 1.6% change for both NEm and NEg for steers fed SYT-EFC and CON without SB. For the main effect of corn trait, steers fed SYT-EFC had greater marbling scores, fat depth, and calculated yield grade compared with CON (P ≤ 0.03). In diets without SB, there was no difference between SYT-EFC, CON, or BLEND for DMI, final BW, ADG, G:F, NEm, or NEg (P ≥ 0.35). In Exp. 2, cattle fed SYT-EFC, BLEND, or CON-E had greater final BW, ADG, and G:F than cattle fed CON (P ≤ 0.03). On average, NEm and NEg were 4.9% and 7.0% greater, respectively, for steers fed amylase enzyme treatments compared with CON (P ≤ 0.01). Hot carcass weights were greater in steers fed α-amylase treatments compared with CON (P < 0.01). Feeding Syngenta Enogen Feed Corn, which contains an α-amylase enzyme trait, at both locations improved feed efficiency in finishing cattle diets containing WDGS or SB.

Download Full-text

Effects of Replacing Antibiotics in Finishing Cattle Diets with Plant-Based Additives on Meat Quality and Sensory Attributes

Meat and Muscle Biology ◽

10.22175/mmb.10840 ◽

2019 ◽

Vol 3 (2) ◽

Author(s):

L. M. Wang ◽

B. M. Bohrer

Keyword(s):

Benzoic Acid ◽

Essential Oils ◽

Meat Quality ◽

Fixed Effects ◽

Cooking Loss ◽

Post Mortem ◽

Finishing Cattle ◽

Flavor Intensity ◽

Beef Flavor ◽

Off Flavors

ObjectivesLimited research has investigated the effects of plant-based additives fed to feedlot cattle beyond cattle growth performance and carcass characteristics. Thus, the objective of this study was to investigate the effects of feeding antibiotic supplements versus essential oils and/or benzoic acid to finishing cattle on meat quality and sensory attributes of the longissimus thoracis (LT) muscle.Materials and MethodsCrossbred steers (N = 63) were placed into 3 blocks based on initial weight. Within each block, 1 of 5 treatments were randomly applied using an Insentec feeding system for 98 d: (1) control (CON) diet (no supplement); (2) monensin/tylosin (M/T) diet (monensin supplemented at 33 mg/kg on dry matter (DM) basis; tylosin supplemented at 11 mg/kg on DM basis); (3) essential oils (EO) diet (supplemented at 1.0 g/steer/day); (4) benzoic acid (BA) diet (supplemented at 0.5% on DM basis); and (5) combination (COMBO) diet (essential oils supplemented at 1.0 g/steer/day and benzoic acid supplemented at 0.5% on DM basis). Beef rib (IMPS#107) sections from the right side of carcasses were collected from a commercial processing facility and transported to the U of Guelph meat science laboratory and processed into 2.54 cm LT steaks. pH and objective color were collected for the LT steaks at 6 d post-mortem. Samples for cooking loss and shear force were aged for 7 d and 14 d post-mortem. Samples for sensory were aged for 7 d post-mortem. Duplicate 5 to 6 g homogeneously blended LT samples were analyzed for moisture content by forced-air convection oven drying at 100°C for 24 h (Method 950.46, AOAC. Lipid content of the dried samples were determined by Soxhlet extraction with petroleum ether, followed by 24 h of oven drying at 100°C. Cooking loss was measured after cooking samples to an internal temperature of 72°C. Warner-Bratzler shear force (WBSF) was measured on 1.3 cm diameter cores that were cut parallel to muscle fibers. Meat quality results were analyzed as a randomized complete block design (RCBD) with fixed effects of treatment, block and their interaction using PROC GLIMMIX of SAS. For sensory analysis, 8 highly trained panelists evaluated the tenderness, juiciness, chewiness, beef flavor intensity, and off-flavor intensity of steaks using a 15-cm line scale. Each steak was cooked to 68°C and served to each panelist as two 1-cm cubes. Results were analyzed as a RCBD with the fixed effects of treatment, panelist, and their interaction and the random effect of session.ResultsThere were no significant differences (P > 0.07) among treatments in this study for pH, objective color, % moisture, WBSF, or cooking loss of LT samples. Ribeye from the CON diet had significantly less % crude fat (P = 0.05) compared to other treatments. There was an effect of diet on the tenderness, chewiness, juiciness and beef flavor intensity of steaks as determined by the panelist. Specifically, CON and COMBO steaks were tougher, chewier and less juicy. All steaks had strong beef flavor, especially the BA steaks. Off-flavors were barely detectable.ConclusionResults showed that EO and BA when fed to finishing cattle do not affect meat quality. Trained panelists reported steaks in the M/T, EO, and BA diet were tender, juicier, and had stronger beef flavors. Potential off-flavors and off-aromas in finishing feed did not translate to beef products.

Download Full-text

66 Overview of Different Cattle Finishing Facilities: Economic Summary and Future Innovations

Journal of Animal Science ◽

10.1093/jas/skaa054.019 ◽

2020 ◽

Vol 98 (Supplement_3) ◽

pp. 12-12

Author(s):

Tom Peters

Keyword(s):

Feedlot Cattle ◽

Finishing Cattle ◽

Excessive Heat ◽

Housing Systems ◽

Future Improvement ◽

Building Ventilation ◽

Moisture Conditions ◽

Economic Considerations ◽

Management Issues ◽

Cattle Performance

Abstract Environment and weather may have a significant impact on feedlot cattle growth. Most U.S. feedlot cattle are finished/fed in open-mound, dirt lots. Historic closeout data conclude that cattle performance has been optimal when finishing cattle in well groomed, dry, dirt mound lots. However, weather challenges including excessive heat, cold, or moisture conditions negatively impact cattle performance. Past attempts to provide shelter for finishing feedlot cattle with buildings/sheds have often yielded subpar finishing cattle growth expectations when compared to well-groomed dirt mounds. Improved cattle housing designs including building ventilation and flooring types are being utilized in many Northern Plains and Midwest cattle operations during the last decade. This symposium will address current designs, management issues, economic considerations and future improvement challenges for finishing cattle housing systems. Performance and economics comparing various cattle breeds and varied in-weights throughout finishing period in differing cattle facilities will be evaluated. Comparison of expected and realized performance of finishing cattle when housed in bedded barns, conventional scrape yards with sheds and cattle comfort finishing shelters will be reviewed.

Download Full-text