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

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.

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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.

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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.

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213 Feeding essential oils and α-amylase or its association with 25-hydroxy-vitamin-D3 improves productive performance by feedlot cattle

Journal of Animal Science ◽

10.1093/jas/skaa278.294 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 160-161

Author(s):

Maria Betania Niehues ◽

Alexandre Perdigão ◽

Victor V Valério de Carvalho ◽

Tiago S Acedo ◽

Guilherme S F M Vasconcellos ◽

...

Keyword(s):

Essential Oils ◽

Vitamin D3 ◽

Electronic System ◽

Feedlot Cattle ◽

Feed Additives ◽

Biological Efficiency ◽

Experimental Unit ◽

Productive Performance ◽

Finishing Cattle ◽

Tukey Test

Abstract Our objective was to evaluate the effects of associating feed additives on performance of finishing cattle when fed a high-concentrate diet for 105 days. Twenty-four Angus-Nellore crossbred bulls (iBW, 456 ± 10.04 kg; age, 18 mo) were randomly allocated to three treatments with eight replicates per treatment (animal as experimental unit). The treatments were: 1) Control (MON) - Sodium Monensin, 26 mg/kg DM; 2) Crina® RumistarTM (CR) - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM) and 3) CR + HyD® (25-hydroxy-vitamin-D3 at 1 mg/animal/d). The DM intake and animalsˈ weight variables were assessed individually, by using the Intergado® electronic system and the Bosch® Precision Livestock platform placed in the feedlot pen, respectively. Data were analyzed using the Mixed procedure of SAS and means comparison evaluated by Tukey test at P < 0.05. The initial BW was used as a covariate when significant. Feeding CR and CR+HyD increased DMI (13.18 and 12.82 kg vs. 10.77 kg P < 0.01) and tended to increase ADG (1.94, 1.92 vs. 1.68kg/d, P = 0.07) and final BW (654, 652 vs. 628 kg, P = 0.08) compared with MON. Likewise, animals fed CR and CR+HyD had greater carcass ADG (1.38, 1.41 vs. 1.14 kg/d, P < 0.01), and HCW (368.53 and 371.87 vs. 344.13 kg; P < 0.01) compared to MON. In addition, feeding CR+HyD increased the dressing percentage in 2.1 percent points compared with MON (57.4 vs. 55.3%; P < 0.03). The G:F and the biological efficiency were similar among treatments (P = 0.50). We conclude that including Crina® RumistarTM +HyD® can be used as a tool to increase carcass production by feedlot cattle.

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PSXIV-18 Feeding behavior of feedlot steers fed combinations of feed additives

Journal of Animal Science ◽

10.1093/jas/skz258.865 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 437-437

Author(s):

Evandro Dias ◽

Jhones O Sarturi ◽

Tosha opheim ◽

Darren D Henry ◽

Carly A Hoffmann ◽

...

Keyword(s):

Feeding Behavior ◽

Block Design ◽

Random Effect ◽

Feedlot Cattle ◽

Feed Additives ◽

Feed Additive ◽

Experimental Unit ◽

Beef Steers ◽

Single Animal ◽

The Difference

Abstract The effects of dietary feed additives (single or combination) on feeding behavior of feedlot cattle, and the representativeness of one individual animal within the experimental unit were evaluated. Crossbred-Angus beef steers (n = 240; initial BW = 319 ± 29 kg) were used in an randomized complete block design (block = BW), 4 steers/pen (experimental unit; n = 12/treatment), and randomly assigned to the following treatments: 1) no feed additive; 2) monensin (300 mg/animal-daily) + tylosin (90 mg/animal-daily); 3) monensin + L. salivarius L28 (106 CFU/animal-daily); 4) tylosin; and 5) L. salivarius. Animals were fed (steam-flaked corn-based finishing diet) once-daily (clean-bunk management). Feeding behavior (24 h; 5 min intervals) was measured as time spent in activities. In addition, one steer/pen was individually assessed. The Glimmix procedures of SAS were used for statistical analyses (fixed effect = treatment; random effect = block). Feed additives did not affect time spent eating (163 min/d; P = 0.42); ruminating (71 min/d; P = 0.82); chewing (234 min/d; P = 0.21); drinking (18 min/d; P = 0.59); ruminating/kg of DM (9 min/d; P = 0.75); chewing/kg of DM (30 min/d; P = 0.40); resting (1085 min/d; P = 0.25); or other activities (102 min/d; P = 0.32). The difference between feeding behavior pen average and the value from the single animal marked within the same pen was different from zero for rumination (P ≤ 0.04), eating (P = 0.03), and other activities (P = 0.04), while not different from zero for chewing (P ≥ 0.21), drinking (P ≥ 0.13; except for one treatment P < 0.01), and resting (P ≥ 0.12; tendency exhibited by one treatment P < 0.09). Feed additives seem to not affect feeding behavior half-way-through the finishing phase. One animal within a 4-animal/pen unit did not represent the pen average feeding behavior.

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Nutritionally related disorders affecting feedlot cattle

Canadian Journal of Animal Science ◽

10.4141/a02-061 ◽

2003 ◽

Vol 83 (1) ◽

pp. 13-20 ◽

Cited By ~ 32

Author(s):

M. L. Galyean ◽

J. D. Rivera

Keyword(s):

Environmental Factors ◽

Feed Intake ◽

Metabolic Disorders ◽

Microbial Population ◽

Feedlot Cattle ◽

Feed Additives ◽

Nutritional Management ◽

Direct Effects ◽

Liver Abscesses ◽

Digestive Disorders

Digestive disorders account for approximately 25 to 33% of deaths in feedlot cattle and likely contribute to decreased performance and efficiency of production. A variety of nutritional, management, genetic, behavioural, and environmental factors seem to be involved in the development of metabolic disorders in feedlot cattle. Excessive production of acid in the rumen is often either the cause of or a significant contributing factor to metabolic and nutritional disorders, including acute or sub-acute (chronic) acidosis, liver abscesses, and feedlot bloat. Decreasing the percentage of highly fermentable concentrates in feedlot diets by increasing roughage level or limiting feed intake should decrease the incidence of these disorders, but this approach is usually not economically feasible. Careful feed bunk management is often thought to be important for decreasing the incidence of nutritionally related disorders, but research to support its importance is limited and conflicting. Certain feed additives like ionophores seem to be effective for decreasing the incidence of acidosis and feedlot bloat, presumably through decreased total feed intake, smaller and more frequent meals, and direct effects on the ruminal microbial population. The incidence of liver abscesses can be decreased by the feeding of various antibiotics. Polioencephalomalacia (PEM) can result from several causes, including thiamine deficiency; however, recent data suggests that overproduction of H2S in the rumen is an important cause of PEM when intakes (feed and water) of sulfur are high in feedlot cattle. Key words: Beef cattle, acidosis, bloat, liver abscesses, polioencephalomalacia

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

Journal of Animal Science ◽

10.1093/jas/skaa278.603 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 339-340

Author(s):

Miranda K Stotz ◽

Whitney L Crossland

Keyword(s):

Financial Burden ◽

Feedlot Cattle ◽

Ultrasound Images ◽

Post Mortem ◽

Beef Industry ◽

Feedlot Performance ◽

Finishing Cattle ◽

Liver Abscesses ◽

Rdna Sequencing ◽

Severity Scores

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.

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Evaluation of Immunoglobulin-Y in Place of Tylosin Phosphate in the Diets Fed to Holstein Steers and Preliminary Analysis of Liver Abscess Duration on Animal Growth Performance

Translational Animal Science ◽

10.1093/tas/txaa225 ◽

2020 ◽

Author(s):

Miranda K Stotz ◽

Darren D Henry ◽

Whitney L Crossland

Keyword(s):

Growth Performance ◽

Liver Abscess ◽

Financial Burden ◽

Average Daily Gain ◽

Carcass Characteristics ◽

Immunoglobulin Y ◽

Liver Abscesses ◽

Performance Reduction ◽

Animal Growth ◽

The Impact

Abstract Despite the regular use of feed-grade macrolide-antibiotics, bovine liver abscesses persist, representing a financial burden to pre- and post-mortem sectors of the beef industry. An immunoglobulin-Y (IGY) additive developed to target Fusobacterium necrophorum and Trueperella pyogenes, was evaluated for the control of liver abscesses. Research is needed for the impact of liver abscess severity as well as abscess duration on steer performance and carcass characteristics. Holstein steers (n=64; initial body weight (BW)=372.5±2.41 kg) consuming a finishing diet for 188 d were used in a completely randomized design where treatments included: TYL (tylosin phosphate 90 mg/day; n=32) or IGY (2.5 g/day; n=32) and steer was the experimental unit. Feed intake was recorded daily while BW and liver ultrasound outcome (normal or abnormal) was recorded every 28 d until slaughter to estimate duration of abscess presence (DUR). Continuous variables of animal growth performance and carcass characteristics were analyzed using the MIXED procedure of SAS. Categorical quality grade and liver data were analyzed using the GLIMMIX procedure of SAS. Treatment did not affect live or carcass-adjusted growth performance (P≥0.131). However, steers fed TYL had greater (P=0.042) empty body fat (EBF) % and a greater proportion of carcasses grading premium choice than steers fed IGY (P=0.030). Treatment did not affect prevalence of abscessed livers, abscess severity or estimated abscess duration (P≥0.213) but datasets with greater experimental units are needed to substantiate this outcome. Increasing abscess severity tended (P≤0.10) to linearly reduce carcass-adjusted gain to feed (G:F), fat thickness, and EBF. Carcass dressing % was only affected by severe (A+ and A+AD) abscess scores (P=0.010). Carcass-adjusted final BW, average daily gain, G:F, and hot carcass weight was decreased only when the estimated DUR was ≥140 d (P≤0.05). Carcass dressing %, however, was linearly affected by estimated liver abscess DUR (P≤ 0.005), regardless of abscess severity. Preliminary evidence suggests that measuring the duration of liver abscess affliction during the feeding period may also give insight to the degree of performance reduction.

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PSIV-11 Effects of Phytogenic Feed Additives on Growth Performance Traits of Finishing Swine

Journal of Animal Science ◽

10.1093/jas/skab054.312 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 187-188

Author(s):

Pengcheng Xue ◽

Don W Giesting ◽

Mark D Newcomb ◽

Chad M Pilcher ◽

Matthew J Ritter

Keyword(s):

Growth Performance ◽

Random Effect ◽

Live Weight ◽

Feed Additives ◽

Experimental Unit ◽

Finishing Pigs ◽

Performance Traits ◽

And Gender ◽

Dietary Treatments ◽

Commercial Research

Abstract This study was conducted at a commercial research facility and utilized 1,092 finishing pigs (PIC® 337 × Camborough®) in a RCBD with 3 dietary treatments to determine the effects of commercially available phytogenic feed additives on growth performance traits in finishing swine for the last 35 d prior to marketing. The dietary treatments were as follows: 1) Control; 2) Aromex Pro® (AP; Delacon) fed at 0.01%; and 3) Ambitine® (AM; PMI) fed at 0.1%. Pens with 13 pigs/pen and 0.66 m2/pig were randomly allotted to treatments on the basis of live weight and gender. Pigs had ad libitum access to corn-soy diets that met or exceeded the pig’s requirements (NRC, 2012). Aromex Pro® and Ambitine® were added to the diets at the expense of corn. Dietary treatments started on day 0 (BW = 97.7 kg; SEM = 1.04) and were fed throughout the 35 d trial period. On d 21, the two heaviest pigs per pen were marketed, while the remaining pigs in each pen were marketed on d 35. Pigs and feeders were weighed on d 0, 21, and 35. Data were analyzed by using PROC MIXED of SAS® version 9.4, and pen was the experimental unit. The model included the fixed effect of treatment and random effect of replicate. Pre-planned orthogonal contrasts were used to compare AP vs. Control and AM vs. Control. Feeding AP or AM for the last 35 d in finishing both improved (P < 0.05) ADG by 4%, ADFI by 3% and final BW by 1.6 kg over Control, but did not change feed to gain or mortality. These data demonstrate that phytogenic feed additives can improve growth performance traits in finishing swine.

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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.

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Impact of a phytogenic feed additive on growth performance, feed intake, and carcass traits of finishing steers

Translational Animal Science ◽

10.1093/tas/txz109 ◽

2019 ◽

Vol 3 (4) ◽

pp. 1162-1172

Author(s):

Tassilo Brand ◽

Martin Hünerberg ◽

Tim A McAllister ◽

Maolong He ◽

Atef M Saleem ◽

...

Keyword(s):

Growth Performance ◽

Feed Intake ◽

Dry Matter ◽

Average Daily Gain ◽

Carcass Traits ◽

Feed Additive ◽

Muscle Area ◽

Mineral Supplement ◽

Liver Abscesses ◽

Finishing Steers

Abstact: The purpose of this study was to evaluate the effect of a phytogenic feed additive (Digestarom [DA]; Biomin, Getzersdorf, Austria) on growth performance, feed intake, carcass traits, fatty acid composition, and liver abscesses of finishing steers. One hundred twenty Angus × Charolais crossbred steers (488 ± 26.5 kg) were used in a 110-d feeding experiment. Steers were blocked by weight and randomly assigned to 12 pens with 10 steers per pen. Each pen was allocated to one of three diets. Each diet contained 86.5% barley, 10.0% barley silage, and 3.5% vitamin and mineral supplement on a dry matter (DM) basis. The diets contained 0, 0.05, and 0.1 g DA/kg complete diet (DM basis), to achieve average daily DA intakes of 0 (control), 0.5 (LowDA), and 1.0 g (HighDA) per steer. Diets were prepared once daily and provided ad libitum. Two pens per treatment were equipped to record individual feed intake behavior. Steers were weighed every 28 d and carcass traits and liver scores were recorded at slaughter. Dry matter intake (average: 9.34 kg/d) did not differ (P > 0.05) among diets. Average daily gain tended to increase linearly as DA increased (control: 1.82; LowDA: 1.87; and HighDA: 1.95 kg/d; P < 0.09), but gain:feed ratio was not affected. Supplementation of DA affected longissimus muscle area quadratically (P = 0.05) with the largest area observed for LowDA. However, dressing percentage decreased linearly in response to increasing level of DA (P < 0.01). Total abscessed livers were not affected, whereas proportion of severe liver abscesses was numerically lower with DA (30.8% and 42.5% for LowDA and HighDA) compared to the control (50%).

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