Influence of ractopamine hydrochloride and days on feed on feedlot performance and red meat yield in thin cull beef cows targeted for a lean market

Abstract Thin, beef, cull cows [n = 144; initial body weight (BW) = 465.8 ± 56.9 kg, initial body condition score (BCS) = 2.13 ± 0.68] were serially slaughtered to evaluate the relationship between ractopamine hydrochloride (RH) administration and days on feed (DOF) on feedlot performance and carcass cutout value in a lean cow market. Cows were organized into a 3 × 2 factorial arrangement of treatments (48 pens, 8 pens per treatment, 3 cows per pen) and blocked by BW nested within pregnancy status. Treatment pens were top-dressed 400 mg per cow per day of RH (Actogain 45; Zoetis, Parsippany, NJ) for the final 28 d prior to slaughter to cows spending 28, 42, or 56 DOF. Pen served as the experimental unit, for all calculations. No RH × DOF interactions were detected (P ≥ 0.11), indicating that despite a majority of compensatory gain occurring during the first 28 d of the trial, the magnitude of the RH response was not affected by DOF. Compared to controls, RH incited improvements in feedlot performance, but had a greater extent on carcass weight gain and efficiency. Specifically, RH improved average daily gain (ADG) by 13.7% (P = 0.04) and carcass ADG by 16.9% (P = 0.02) Cattle fed RH displayed a 15.5% improved gain to feed ratio (P = 0.02) and a 20% improved carcass gain to feed ratio (P = 0.05). Inclusion of RH in the finishing diet increased hot carcass weight by 4.5% (P = 0.05; 12.9 kg). However, supplementation of RH did not alter red meat yield (P ≥ 0.16), but provoked a 11.1% improvement in lean maturity (P < 0.01). Evaluation of the main effect of DOF provided insight into the compensatory state of beef cull cows on a high-concentrate diet. Serial slaughter offal weights presented confounding results. With additional DOF, a numerical increase in liver weights (P = 0.20) suggested that organ tissue replenishment occurred throughout the trial, and cattle experienced compensatory gain during the entire feeding phase. In contrast, lung and heart weights were not altered, while kidney tended to decrease linearly (P = 0.08) despite additional DOF. Furthermore, extending DOF generated a linear increase in dry matter intake (P < 0.01) yet a tendency for a decline in ADG (P = 0.10), reinforcing the premise that most of compensatory gain occurred during the first 28 d of the trial. If thin (BCS ≤ 4), healthy candidates can be finished, feeders can reap the benefits of an additive relationship between compensatory gain and RH.

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Growth, performance, and carcass characteristics of feedlot Holstein steers fed ractopamine hydrochloride1

Translational Animal Science ◽

10.1093/tas/txz157 ◽

2019 ◽

Vol 4 (1) ◽

pp. 102-117

Author(s):

Cathy L Lockard ◽

Chris J Richards ◽

Caleb G Lockard ◽

Maggie Youngers ◽

Mariah A Woolsoncroft ◽

...

Keyword(s):

Block Design ◽

Average Daily Gain ◽

Carcass Characteristics ◽

Carcass Weight ◽

Feed Ratio ◽

Negative Effects ◽

Feedlot Performance ◽

Randomized Complete Block Design ◽

Growth Promoting ◽

Daily Gain

Abstract Growth-promoting technologies such as implants, ionophores, and β-agonists improve feedlot performance, efficiency, and carcass characteristics of cattle. The objective of this experiment was to determine the effects of dose and duration of ractopamine hydrochloride (RH) on feedlot performance and carcass characteristics when fed to Holstein steers. A randomized complete block design was used with a 3 × 3 factorial arrangement of treatments with 3 RH doses (0, 300, or 400 mg∙steer−1∙d−1) fed for 3 durations (28, 35, or 42 d). Holstein steers (n = 855; initial body weight [BW] = 448 ± 37 kg) were blocked by BW and randomly allocated to 1 of 9 pens (15 blocks; 9 dose × duration treatment combinations) approximately 72 d before harvest. Weekly pen weights, chute temperament scores, and animal mobility were determined during the RH feeding period. At harvest, carcass data were collected on all steers, and tenderness was measured on steaks from 3 or 4 randomly selected steers from each pen and slice shear force (SSF) was determined on one steak selected from each side of the carcass after aging for 14 or 21 d. For feedlot performance, carcass characteristics, and SSF, no dose × duration interactions were observed (P ≥ 0.11). With increasing RH dose, average daily gain (ADG) and gain-to-feed ratio (G:F) increased linearly (P ≤ 0.01), whereas BW gain increased linearly with RH dose and duration (P ≤ 0.01). Hot carcass weight (P = 0.02) and longissimus muscle (LM) area (P ≤ 0.01) increased linearly with increasing RH dose. The percentage of carcasses in the USDA Yield Grade 2 category increased linearly (P ≤ 0.01) and percentage of carcasses in the USDA Yield Grade 4 category tended (P = 0.08) to decrease linearly as RH dose increased. In the 14-d aged steaks, the percentage of steaks with SSF ≤ 15.3 kg decreased linearly (P ≤ 0.01), whereas the percentage of steaks with ≥20.0 kg SSF increased linearly (P ≤ 0.01) with increasing RH dose. After 21-d aging, there was a tendency (P = 0.06) for a greater percentage of steaks from steers fed RH to have SSF ≥ 20.0 kg (2% of total steaks), but no difference (P ≥ 0.12) in the percentage of steaks with SSF ≤ 19.9 kg. Final chute temperament (P ≥ 0.45) and animal mobility (P ≥ 0.67) scores were not affected by feeding RH. Increasing the dose of RH (300 or 400 mg∙steer−1∙d−1) fed for 28 to 42 d before harvest increased ADG, G:F, hot carcass weight, and LM area when fed to Holstein steers with no negative effects on behavior or mobility. The percentage of steaks classified as not tender improved when steaks were aged for 21 d from steers treated with RH.

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Effect of a pine enhanced biochar on growth performance, carcass quality, and feeding behavior of feedlot steers1

Translational Animal Science ◽

10.1093/tas/txaa011 ◽

2020 ◽

Vol 4 (2) ◽

pp. 831-838

Author(s):

Stephanie A Terry ◽

Abby-Ann P Redman ◽

Gabriel O Ribeiro ◽

Alex V Chaves ◽

Karen A Beauchemin ◽

...

Keyword(s):

Feeding Behavior ◽

Growth Performance ◽

Dry Matter ◽

Transition Period ◽

Average Daily Gain ◽

Feed Ratio ◽

Experimental Unit ◽

Carcass Quality ◽

Period Effect ◽

Meat Yield

Abstract The objective of this study was to evaluate the effect of enhanced biochar (EB) on growth performance, carcass quality, and feeding behavior of feedlot steers fed high-forage and high-grain diets. A total of 160 crossbred steers (initial 286 ± 26 kg body weight [BW]) were blocked by BW and randomly assigned to 16 pens (10 steers per pen), 8 of which were equipped with the GrowSafe system for monitoring feeding behavior. Treatments were EB included in the diet at 0% (control), 0.5%, 1.0%, or 2.0% (dry matter [DM] basis) with four pens per treatment. The backgrounding phase (84 d) was divided into four 21-d periods, and the finishing phase (112 d) was divided into four 28-d periods, with a 28-d transition period for dietary adaptation. Pen was the experimental unit for all parameters except for feeding behavior, where steer was considered the experimental unit. Treatment was included as a fixed effect, and period was considered a repeated measure. Total weight gain and overall average daily gain (ADG) tended to decrease (P = 0.06) with 2.0% EB. There was no effect (P ≥ 0.13) of EB on dry matter intake (DMI), gain-to-feed ratio (G:F), net energy for gain, ADG, or final BW for the backgrounding or finishing phases. There was a treatment × period effect (P < 0.05) of EB on DMI, ADG, and G:F for both backgrounding and finishing phases. Hot carcass weight, dressing %, back fat, rib-eye area, and meat yield were not affected (P ≥ 0.26) by EB. Lean meat yield was increased (P = 0.03) by 2.0% EB compared to all other treatments. Compared to the control, 2.0% EB increased (P = 0.02) the number of carcasses that achieved Canada 1 grade. More (P = 0.05) carcasses from control steers were graded as Canada 3 as compared to those fed 0.5% or 2.0% EB. Quality grade and incidences of liver abscesses were not affected (P ≥ 0.44) by EB. Enhanced biochar had no effect (P ≥ 0.11) on feeding behavior during backgrounding or finishing phases. In conclusion, EB did not result in changes in growth rate, feed efficiency, or feeding behavior in feedlot cattle, but 2.0% EB increased lean carcass yield grade.

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Evaluation of a novel threonine source for nursery pig diets

Translational Animal Science ◽

10.1093/tas/txaa182 ◽

2020 ◽

Vol 4 (4) ◽

Author(s):

Dalton Humphrey ◽

Spenser Becker ◽

Jason Lee ◽

Keith Haydon ◽

Laura Greiner

Keyword(s):

Repeated Measures ◽

Fixed Effects ◽

Average Daily Gain ◽

Covariance Structure ◽

Treatment Phase ◽

Positive Control ◽

Negative Control ◽

Feed Ratio ◽

Experimental Unit ◽

Nursery Pigs

Abstract Four hundred and eighty (PIC 337 X 1050, PIC Genus, Hendersonville, TN) pigs were used to evaluate a novel threonine source (ThrPro, CJ America Bio, Fort Dodge, IA) for nursery pigs from approximately 7 to 20 kg body weight (BW). After weaning, pigs were sorted by sex and fed a common diet for 1 wk. Upon completion of the first week, pigs were sorted into randomized complete blocks, equalized by weight, within 16 replications. Pigs were allocated to one of three dietary treatments: positive control (POS)—standard ileal digestible threonine-to-lysine ratio (SID; Thr:Lys) 0.60, negative control (NEG)—SID Thr:Lys ≤0.46, and alternative Thr source (TEST)—SID Thr:Lys 0.60. The alternative Thr source included fermentative biomass and was assumed to contain 75% Thr and a digestibility coefficient of 100% based on the manufacturer’s specifications. All other nutrients met or exceeded the NRC recommendations. Growth and intake data were analyzed as repeated measures with a compound symmetry covariance structure using the MIXED procedure in SAS 9.4 (SAS Institute Inc., Cary, NC) with pen as the experimental unit. Treatment, phase, the interaction between treatment and phase, and block were included as fixed effects in the model. Differences in total removals were tested using Fisher’s Exact Test of PROC FREQ. Results were considered significant at P ≤ 0.05 and considered a trend at P > 0.05 and P ≤ 0.10. During the first 14 d, pigs fed TEST had decreased gain-to-feed ratio (G:F; 0.77 vs. 0.80, P = 0.022) compared to POS and increased G:F (0.77 vs. 0.73, P < 0.001) compared to NEG. Over days 14–28, pigs fed TEST had similar G:F (0.71 vs. 0.70, P = 0.112) compared to POS and increased G:F (0.71 vs. 0.63, P < 0.001) compared to NEG. Overall (days 0–28), pigs fed TEST had similar average daily gain (ADG; 0.47 vs. 0.47 kg/d, P = 0.982) and G:F (0.76 vs. 0.74, P = 0.395) compared to POS and increased ADG (0.47 vs. 0.43 kg/d, P < 0.001) and G:F (0.76 vs. 0.67, P < 0.001) compared to NEG. The average daily feed intake was not significantly different across treatments for the entirety of the study. In conclusion, the replacement of crystalline L-Thr with a novel Thr source resulted in similar growth performance in nursery pigs from approximately 7 to 20 kg.

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Effects of various ractopamine hydrochloride withdrawal periods on performance, health, and carcass characteristics in yearling steers

Translational Animal Science ◽

10.1093/tas/txz148 ◽

2019 ◽

Vol 4 (1) ◽

pp. 67-74

Author(s):

Tony C Bryant ◽

Josh I Szasz ◽

Lois F G Pringle ◽

Eddie Crispe ◽

K Shawn Blood ◽

...

Keyword(s):

Feed Efficiency ◽

Dry Matter ◽

Block Design ◽

Average Daily Gain ◽

Carcass Characteristics ◽

Average Dose ◽

Withdrawal Period ◽

Feedlot Performance ◽

Dressing Percentage ◽

Ractopamine Hydrochloride

Abstract Ractopamine hydrochloride (RAC) is a β-adrenergic agonist approved for feeding during the last 28 to 42 d prior to cattle slaughter to improve feedlot performance and carcass characteristics. Three thousand crossbred yearling steers (527 ± 2.4 kg; AVG ± SD) were used in two periods to evaluate the effects of various RAC withdrawal times on feedlot performance, health, and carcass characteristics. In Period 1, 6 blocks of 30 pens totaling 1,500 steers were utilized, which was repeated for Period 2. In a randomized complete block design, cattle were assigned to 1 of 5 treatments consisting of 1) No RAC fed (CON), 2) 12-h RAC withdrawal (12-hRAC), 3) 2-d RAC withdrawal (2-dRAC), 4) 4-d RAC withdrawal (4-dRAC), and 5) 7-d RAC withdrawal (7-dRAC). Cattle were fed for a total of 62 d, and applicable treatments were supplemented with 30.0 ppm (dry matter basis) of RAC (average dose = 322 mg per steer per day) for 33 d at the end of the feeding period, corresponding to their respective withdrawal times. Initial body weight (BW) displayed a quadratic curve, with 2-dRAC and 4-dRAC withdrawal periods having the greatest BW. Accordingly, dry matter intake (DMI) responded quadratically (P = 0.034), with 2-dRAC and 4-dRAC treatments demonstrating the greatest DMI. No significant treatment differences (P ≥ 0.641) were observed in final live BW, average daily gain (ADG), or feed efficiency. Alternatively, when using a common dressing percentage to calculate live BW, cattle on RAC treatments exhibited 7.6 kg additional live BW (P < 0.001) compared to CON cattle. Furthermore, carcass-adjusted ADG and feed efficiency did not differ (P > 0.10) between RAC treatments but were improved compared to the CON treatment (P ≤ 0.002). Hot carcass weight (HCW) was on average 4.9 kg greater (P < 0.001) for RAC treatments vs. CON, and no differences were detected (P > 0.10) among RAC treatments. Within RAC treatments, carcass cutability responded quadratically (P ≤ 0.005) to withdrawal period, with the 2-dRAC and 4-dRAC treatments containing more Yield Grade 4 and 5 and fewer Yield Grade 1 and 2 carcasses than the other RAC treatments. On the basis of the results of this experiment, feeding RAC improves dressing percentage, HCW, and carcass-adjusted BW, ADG, and feed efficiency. Furthermore, extending the RAC withdrawal period to 7 d does not have a significant impact on cattle performance or health and has minimal effects on carcass characteristics.

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Evaluation of hybrid rye on growth performance, carcass traits, and efficiency of net energy utilization in finishing steers

Translational Animal Science ◽

10.1093/tas/txaa173 ◽

2020 ◽

Vol 4 (3) ◽

Author(s):

Warren C Rusche ◽

Julie Ann Walker ◽

Peter Sexton ◽

Rebecca S Brattain ◽

Zachary K Smith

Keyword(s):

Growth Performance ◽

Average Daily Gain ◽

Carcass Traits ◽

Energy Utilization ◽

Carcass Weight ◽

Experimental Unit ◽

Net Energy ◽

Complete Replacement ◽

Finishing Steers ◽

Hybrid Rye

Abstract Crossbred beef steers with a high percentage of Angus ancestry [n = 240, initial shrunk body weight (BW), 404 ± 18.5 kg] were used in a 117-d feedlot experiment to evaluate the effect of hybrid rye (Rye; KWS Cereals USA, LLC, Champaign, IL) as a replacement for dry-rolled corn (DRC) on growth performance, carcass traits, and comparative net energy (NE) value in diets fed to finishing steers. Rye from a single hybrid (KWS Bono) with an ergot alkaloid concentration of 392 ppb was processed with a roller mill to a processing index (PI) of 78.8 ± 2.29. Four treatments were used in a completely randomized design (n = 6 pens/treatment; 10 steers/pen), where DRC (PI = 86.9 ± 4.19) was replaced by varying proportions of Rye [DRC:Rye, dry matter (DM) basis (60:0), (40:20), (20:40), and (0:60)]. Liver abscess scores and carcass characteristics were collected at the abattoir. Carcass-adjusted performance was calculated from hot carcass weight (HCW)/0.625. Performance-adjusted NE was calculated using carcass-adjusted average daily gain (ADG), DM intake (DMI), and mean equivalent shrunk BW with the comparative NE values for rye calculated using the replacement technique. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with pen as the experimental unit. Treatment effects were tested using linear and quadratic contrasts, as well as between diets with and without Rye. Replacing DRC with Rye linearly decreased (P ≤ 0.01) carcass-adjusted final BW, ADG, DMI, and gain:feed (G:F). Feeding rye linearly decreased HCW and longissimus muscle area (P ≤ 0.04). Distributions of liver scores and USDA grades for quality and yield were unaffected by treatment (P ≥ 0.09). Estimated replacement NE for maintenance (NEm) and gain (NEg) values for rye, when included at 60% of diet DM, were 1.90 and 1.25 Mcal/kg, respectively. Rye can be a suitable feed ingredient in finishing diets for feedlot steers. Estimated replacement values of Rye when fed at 60% of diet DM closely agreed with current tabular standards but, when included at 20% of diet DM, estimated NEm and NEg values of Rye were increased 9.5% and 12.8%, respectively. Net energy value of Rye for gain is approximately 84% compared to DRC; thus, the complete replacement of DRC with Rye depressed DMI, ADG, G:F, and carcass weight.

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Effects of steroidal implants on feedlot performance, carcass characteristics, and serum and meat estradiol-17β concentrations of Holstein steers

Translational Animal Science ◽

10.1093/tas/txz186 ◽

2019 ◽

Vol 4 (1) ◽

pp. 206-213 ◽

Cited By ~ 1

Author(s):

Pedro Henrique Vilela Carvalho ◽

George A Perry ◽

Tara L Felix

Keyword(s):

Feed Efficiency ◽

Animal Health ◽

Average Daily Gain ◽

Carcass Characteristics ◽

Feed Ratio ◽

Longissimus Muscle ◽

Feedlot Performance ◽

Trenbolone Acetate ◽

Daily Gain ◽

Estradiol 17Β

Abstract The objectives of the study were to determine the effect of steroidal implants on growth performance, carcass characteristics, and estradiol-17β (E2) concentrations in the blood and longissimus muscle of Holstein steers fed a grain-based diet. Seventy Holstein steers (average initial BW = 275 ± 6.4 kg, 10 to 12 mo of age) were assigned to treatments: (i) implanted with 80 mg of trenbolone acetate (TBA) and 16 mg of E2 (Component TE-IS with Tylan; Elanco Animal Health, Greenfield, IN) at the start of the trial (day 0), and reimplanted with 120 mg of TBA and 24 mg of E2 (Component TE-S with Tylan; Elanco Animal Health) on day 84 of the experiment; or (ii) no implant. Implanted Holstein steers were heavier (P ≤ 0.01) than nonimplanted Holstein steers in the middle (day 84) and at the end of the experiment (day 186). Implanting Holstein steers increased (P < 0.01) average daily gain (ADG) and dry matter intake (DMI) without affecting gain-to-feed ratio compared with nonimplanted animals. Carcasses from implanted Holstein steers had greater (P < 0.01) hot carcass weight (HCW) and longissimus muscle (LM) area than carcasses from nonimplanted steers. Implanting did not affect (P ≥ 0.21) other carcass characteristics. There was an increase (P = 0.03) of 1.3 pg of E2/g of muscle in implanted Holstein steers compared with that from nonimplanted Holstein steers. There was an implant × day interaction (P < 0.01) in serum E2 concentrations. Serum E2 concentrations were not altered in nonimplanted Holstein steers, whereas E2 concentration increased (P < 0.01) after steers were implanted, regardless of implant characteristics. Serum E2 peaked at 28 days after the first implant and then rapidly declined after day 56. In summary, steroidal implants administered on days 0 and 84 increased DMI, ADG, HCW, and LM area in Holstein steers compared with nonimplanted steers due to increased serum E2 concentrations. However, these changes did not improve feed efficiency or other carcass characteristics.

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Evaluation of an active live yeast (Levucell Saccharomyces cerevisiae, CNCM l-1077) on receiving and backgrounding period growth performance and efficiency of dietary net energy utilization in low health risk beef steers1

Translational Animal Science ◽

10.1093/tas/txaa127 ◽

2020 ◽

Vol 4 (3) ◽

Author(s):

Zachary K Smith ◽

Kip Karges ◽

Angel Aguilar

Keyword(s):

Health Risk ◽

Growth Performance ◽

Block Design ◽

Average Daily Gain ◽

Energy Utilization ◽

Feed Ratio ◽

Experimental Unit ◽

Net Energy ◽

Respiratory Pathogens ◽

Live Yeast

Abstract The objective of this experiment was to evaluate the influence of an active live yeast direct-fed microbial (DFM) product on receiving and backgrounding period growth performance and efficiency of dietary net energy (NE) utilization in low health risk beef steers. Maine-Anjou × Angus steers (n = 199; body weight [BW] = 252 ± 32.1 kg) were received from two sources at the Ruminant Nutrition Center in Brookings, SD, in November 2019 and used in a 77-d feedlot receiving and backgrounding experiment. Steers were provided access to long-stem hay and ad libitum water upon arrival. Steers were weighed, vaccinated for respiratory pathogens (source 2 only): infectious bovine rhinotracheitis, bovine viral diarrhea types 1 and 2, parainfluenza-3 virus, and bovine respiratory syncytial virus (Bovi-Shield Gold 5, Zoetis, Parsippany, NJ) vaccinated for clostridial species (Ultrabac 7/Somubac, Zoetis) and pour-on moxidectin (Cydectin, Bayer, Shawnee Mission, KS). Steers (n = 176 steers; initial unshrunk BW = 235 ± 27.6 kg) were allotted to pens (n = 20 pens; 10 pens per treatment; eight or nine steers per pen). Diets were based upon corn silage, dry-rolled corn, and dried distillers grains; dietary treatments were 1) no DFM (CON) and 2) DFM (Levucell SC, Advantage Titan, CNCM l-1077), fed at 10 g/steer/d providing 8 × 109 CFU of active live yeast to each steer daily (DFM). Initial BW was the average of day −1 and day 1 BW (n = 176 steers; initial BW = 253 ± 27.6 kg). On day 21, steers received a 200-mg progesterone and 20-mg estradiol benzoate implant. Data were analyzed from day 1 to 47 (receiving period), day 48 to 77, and from day 1 to 77 as a randomized complete block design; pen served as the experimental unit for all analyses. On day 47 of the experiment, DFM had greater BW (P = 0.01) by 0.9% and average daily gain (ADG; P = 0.01) by 4.2% and gain-to-feed ratio (G:F) tended (P = 0.13) to be 2.8% greater. Day 77 BW did not differ (P = 0.60), cumulative (days 1–77): ADG (P = 0.47), dry matter intake (P = 0.66), and G:F (P = 0.56) were similar. Yeast inclusion had no appreciable influence on performance-based dietary NE utilization or the ratio of observed/expected dietary NE (P ≥ 0.59). In low health risk steers, DFM improved performance during the feedlot receiving period. However, no improvements for DFM were detected for cumulative performance from day 1 to 77. The confirmation of yeast counts indicated the CFU to be above the expected level at the start of the trial but was found below expected level at the end of the trial. This may explain differences during the initial 47 d compared to cumulative growth performance results.

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Evaluation of feedlot performance, carcass characteristics, carcass retail cut distribution, Warner-Bratzler shear force, and fatty acid composition of purebred Jersey and crossbred Jersey steers

Translational Animal Science ◽

10.1093/tas/txz110 ◽

2019 ◽

Vol 3 (4) ◽

pp. 1475-1491 ◽

Cited By ~ 2

Author(s):

Jerad R Jaborek ◽

Henry N Zerby ◽

Steven J Moeller ◽

Francis L Fluharty ◽

Alejandro E Relling

Keyword(s):

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Shear Force ◽

Dry Matter ◽

Red Meat ◽

Dry Matter Intake ◽

Feedlot Performance ◽

Meat Yield ◽

Carcass Yield

AbstractFeedlot performance, carcass yield, fatty acid composition, and tenderness of crossbred Jersey steers compared with purebred Jersey steers was investigated. Purebred Jersey (n = 21) and crossbred Jersey steers sired by Angus (n = 9), SimAngus (n = 10), and Red Wagyu (n = 15) bulls were assessed. Adjusted to a common initial body weight (BW), crossbred Jersey steers had a greater rate of BW gain (P ≤ 0.01) compared with purebred Jersey steers. Angus sired steers had a greater daily dry matter intake (P ≤ 0.01) compared with Wagyu and Jersey sired steers, whereas SimAngus sired steers had a greater daily dry matter intake compared with Jersey sired steers. Wagyu sired steers were more feed efficient (P ≤ 0.03) compared with Jersey sired steers. Even with a greater (P ≤ 0.01) number of days on feed, off-test BW of purebred Jersey steers was less (P ≤ 0.01) compared with crossbred Jersey steers. Adjusted to a common hot carcass weight, Angus sired steers had a greater backfat thickness (P ≤ 0.01) compared with steers from the other sire breeds. Kidney fat percentage (P ≤ 0.01) was greatest for Jersey sired steers, with SimAngus and Wagyu sired steers being intermediate, and the lowest for Angus sired steers. Carcasses from Angus and Wagyu sired steers had a greater marbling score (P ≤ 0.03) compared with carcasses from Jersey sired steers. Carcasses from Wagyu sired steers had a greater (P ≤ 0.01) total red meat yield compared with Angus and Jersey sired steers, whereas SimAngus sired steers had a greater total red meat yield compared with Jersey sired steers. Carcasses from Angus sired steers tended (P = 0.07) to have a greater percentage of fat trim compared with Wagyu sired steer carcasses. There were no sire breed differences (P = 0.38) for the percentage of total bone from the carcasses. Tenderness, measured by Warner-Bratzler shear force (WBSF), was improved (P ≤ 0.01) with 14 d of postmortem aging compared with 7 d. Wagyu and SimAngus sired steers produced steaks with a lesser (P ≤ 0.01) WBSF compared with steaks from Angus and Jersey sired steers. Steaks from Angus sired steers tended (P = 0.10) to have a greater percentage of total lipid and had a greater (P ≤ 0.05) percentage of 16:0 compared with steaks from Jersey sired steers. Overall, crossbred Jersey steers improved economically relevant production parameters of feedlot performance, carcass quality, carcass yield, and instrumental predictors of eating quality compared with purebred Jersey steers.

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Digestible tryptophan to lysine ratios for weaned piglets at 26 days of age

Animal Production Science ◽

10.1071/an15504 ◽

2017 ◽

Vol 57 (10) ◽

pp. 2027 ◽

Cited By ~ 1

Author(s):

G. M. Oliveira ◽

A. S. Ferreira ◽

P. F. Campos ◽

V. V. Rodrigues ◽

F. C. O. Silva ◽

...

Keyword(s):

Phase I ◽

Phase Ii ◽

Feed Intake ◽

Average Daily Gain ◽

Control Treatment ◽

Feed Ratio ◽

Experimental Unit ◽

Limiting Factor ◽

Initial Growth ◽

Linear Effect

With the objective of determining the optimal digestible tryptophan to lysine ratios (Trp : Lys) in feed, 192 crossbred piglets were weaned at 26.3 ± 2.0 days, with initial weights of 8 ± 0.360 kg. The piglets were blocked by bodyweight and randomly allotted into six treatments, eight repetitions and four piglets per experimental unit. The treatments included five ratios of digestible Trp : Lys of 0.15, 0.17, 0.19, 0.21 and 0.23 with 1.26% digestible lysine and one positive control treatment (C+) with a Trp : Lys ratio of 0.19 and digestible lysine of 1.33%. The piglet’s performance and other characteristics were evaluated in phases: Phase I lasted from weaning up to Day 14 of the experiment, and Phase II lasted from weaning up to Day 21 of the experiment. The feed intake during Phase I, including the protein and fat deposition rates, the kidney relative weights and carcass yield were not influenced by the Trp : Lys ratios (P > 0.05). The Trp : Lys ratios had a linear effect on the liver and kidney absolute weights (P < 0.05). The ratio also had a linear effect (P < 0.01) on the bodyweight, the average daily gain, the gain : feed ratio of the piglets during Phases I and II and on the feed intake during Phase II (P < 0.05). The effect of the Trp : Lys ratios on the digestible lysine level (P = 0.04) demonstrated that digestible lysine was a limiting factor. The Linear Response Plateau model indicated that the best Trp : Lys ratio (P = 0.04) was 0.20 during Phase I and 0.22 (P < 0.01) during Phase II. Thus, the optimal digestible Trp : Lys ratio for piglets during the initial growth phase (from 26 to 47 days of age) is 0.22.

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160 Injectable Vitamin C Prior to Transit and Transit Duration Effects on Feedlot Performance, Inflammation, and Muscle Fatigue of Beef Steers

Journal of Animal Science ◽

10.1093/jas/skab054.200 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 121-121

Author(s):

Aubree M Beenken ◽

Erin L Deters ◽

Stephanie L Hansen

Keyword(s):

Vitamin C ◽

Muscle Fatigue ◽

Repeated Measures ◽

Fixed Effects ◽

Average Daily Gain ◽

Blood Parameters ◽

Serum Lactate ◽

Sodium Ascorbate ◽

Experimental Unit ◽

Feedlot Performance

Abstract This study examined the effects of injectable vitamin C (VC) before transport and duration of transit on feedlot performance, inflammation, and muscle fatigue in cattle. One hundred thirty-one, Angus-cross steers (409 ± 4 kg) were stratified by bodyweight (BW) to a 2 × 2 factorial of intramuscular injection (INJ; 20 mL/steer): VC (250 mg sodium ascorbate/mL) or saline (SAL) and road transit duration (DUR): 18 (18; 1,770 km) or 8 h (8; 727 km). On d 0, steers were weighed and received INJ of SAL or VC immediately before transport. Upon return (d 1), BW and blood were collected before steers returned to pens with GrowSafe bunks. Steers were weighed on d 0, 1, 7, 15, 30, 31, 54, and 55. Data were analyzed via ProcMixed of SAS (experimental unit = steer; 32–34 steers/treatment) with fixed effects of INJ, DUR, and the interaction. Blood was collected on d -5, 1, 2, and 3 (9 steers/treatment); blood parameters were analyzed as repeated measures. Average daily gain (ADG) and BW were greater on d 7 and 15 for SAL-18 compared to all other treatments (INJ × DUR, P < 0.01). Final BW, overall ADG, and gain:feed were greater for 18 than 8 (P < 0.01). Injection did not affect BW (P > 0.13) but VC decreased overall dry matter intake compared to SAL (P = 0.03). Steers transported for 18 h had greater serum lactate, haptoglobin, and non-esterified fatty acid concentrations on d 1 compared to steers transported for 8 h (DUR × DAY, P < 0.01). Day 1 plasma ascorbate concentrations were greater for VC and returned to baseline concentrations by d 2 (INJ × DAY, P < 0.01). In contrast to previous work, VC did not improve post-transit performance; however, longer transit duration increased indicators of muscle fatigue and inflammation.

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