Trace mineral source and chromium propionate supplementation affect performance and carcass characteristics in feedlot steers

Angus-crossbred steers (n = 400; 369.7 ± 7.6 kg) were used to determine the influence of trace mineral (TM) source and chromium propionate (Cr Prop) supplementation on performance, carcass characteristics, and ruminal and plasma variables in finishing steers. Steers were blocked by body weight (BW) and randomly assigned within block to treatments in a 2 × 2 factorial arrangement, with factors being: 1) TM source (STM or HTM) and 2) Cr supplementation (0 or 0.25 mg Cr/kg DM, -Cr or + Cr, respectively). Treatments consisted of the addition of: 1) sulfate TM (STM; 90, 40, and 18 mg/kg DM of Zn, Mn, and Cu, respectively), 2) STM and 0.25 mg Cr/kg DM from Cr Prop, 3) hydroxychloride TM (HTM; 90, 40, and 18 mg/kg DM of Zn, Mn, and Cu, respectively), and 4) HTM and 0.25 mg Cr/kg DM from Cr Prop. Each treatment consisted of 10 replicate pens with 10 steers per pen. Body weights were obtained on consecutive days at the initiation and termination of the 154-d study. Steers were fed a steam-flaked corn-based finishing diet. Ractopamine hydrochloride was fed for the last 31 d of the study. Ruminal fluid and blood samples were obtained from one steer per pen on days 28 and 84 for ruminal volatile fatty acids (VFA) and plasma TM and glucose analysis. Steers were slaughtered at the end of the study and individual carcass data were collected. No Cr × TM source interactions (P = 0.48) were detected. Steers supplemented with HTM had greater (P = 0.04) hot carcass weight (HCW), dressing percentage (DP), longissimus muscle (LM) area, and USDA yield grade (YG), and tended (P = 0.12) to have greater average daily gain (ADG) than those receiving STM. Average daily gain, gain:feed, dressing percentage, and longissimus muscle area were greater (P = 0.04) for + Cr steers compared to-Cr steers. Hot carcass weight tended (P = 0.06) to be greater for + Cr steers. Ruminal acetate concentrations at 28 d were lesser (P = 0.01) for HTM vs. STM steers, and greater (P = 0.04) for + Cr steers compared to-Cr steers. Plasma concentrations of Zn, Cu, and Mn were not affected by TM source or Cr supplementation. Steers supplemented with Cr had greater (P = 0.05) plasma glucose concentrations than-Cr steers at 28 but not at 84 d. Results of this study indicate replacing STM with HTM improved carcass characteristics in finishing steers, and Cr Prop supplementation improved steer performance and carcass characteristics.

Evaluation of Trace Mineral Sources

Several trace mineral sources, including inorganic, numerous organic, and hydroxychloride sources, are available for dietary supplementation or inclusion in a free-choice supplement. Inorganic forms of copper and manganese differ in their bioavailability. Although research results have been variable, organic and hydroxychloride trace minerals are generally considered more bioavailable than inorganic sources. Research indicates that fiber digestibility is lower in ruminants fed sulfate trace minerals compared with hydroxychloride and some organic sources. Compared with free-choice supplements, individual dosing with rumen boluses or injectable forms ensures that each animal receives the same quantity of a trace mineral.

The effects of chromium propionate supplementation to yearling steers in a commercial feedyard on growth performance, carcass characteristics, and health

British crossbred steers (n = 3,072; initial body weight [BW] = 358 ± 37 kg) were used to evaluate the effects of chromium propionate supplementation to yearling steers in a commercial feedyard on growth performance, carcass characteristics, and health. Steers were blocked by initial BW; pens were assigned randomly to one of two dietary treatments within block. Treatments, replicated in 15 pens per treatment with 75 to 135 heads per pen, included 1) control, 0 mg supplemental Cr/kg dietary dry matter (DM) (CTL); 2) 0.50 mg supplemental Cr/kg diet DM (chromium propionate; KemTRACE Chromium 0.4%, Kemin Industries, Des Moines, IA) (chromium propionate, CR). Final BW (638 vs. 641 kg), average daily gain (1.81 vs. 1.82 kg), DM intake (11.02 vs. 11.02 kg), and gain efficiency (0.164 vs. 0.165) did not differ between CTL and CR, respectively (P ≥ 0.75). No differences among treatments for hot carcass weight (407 vs. 408 kg, CTL and CR, respectively), dressing percentage, longissimus muscle area, or yield grade were observed (P ≥ 0.15). Twelfth-rib fat thickness tended (P = 0.10) to be greater for CR vs. CTL (1.55 vs. 1.29 cm, respectively). A trend (P = 0.10) for marbling score to be higher for CR vs. CTL was detected (452 vs. 440, respectively). Distribution of quality grade was similar between CR and CTL; 1.52% of carcasses graded prime (P = 0.68), and 87.2% of carcasses graded choice (P = 0.68). Respiratory morbidity was low (1.93%) and not different among treatments (P = 0.20); likewise, there was no difference in respiratory treatment rates between treatments (P ≥ 0.18). Supplementing Cr to high-performing yearling steers did not alter growth performance, carcass characteristics, or health outcomes.

Post-slaughter indicators of meat productivity and chemical composition of the muscular tissues of bulls receiving corrective diet with protein-vitamin premix

The problem of increasing the production of beef to provide the population with domestically-produced meat is mainly being solved by selective breeding of dairy and combined breeds. Therefore, there is a need for the development and introduction of complex measures to increase meat productivity of young cattle, especially regarding the completeness of diet and optimal content of mineral elements in it. The study was conducted on bulls of the Ukrainian Black-Spotted Dairy breed starting from the age of 6 up to the age of 15 months. At the end of the experiment, the animals were slaughtered, 5 from each group. The study was aimed at determining the effect of the protein-vitamin premix Intermix Fattening on the slaughter parameters, morphological composition of carcass and flesh composition by quality grades, chemical composition of the muscle tissue. Statistical analysis of the results revealed that feeding bulls with the supplement increased pre-slaughter live weight by 7.1% and slaughter weight by 9.8%. After meat separation, more edible parts of carcass were obtained in the absolute value. The weight of paired carcass was 9.5% higher. Intake of the diet with protein-vitamin premix influenced the bulls’ characteristics of growth and development of musculature and bones, intensity of fat deposition, leading to 10.8% increase in flesh and no statistical decrease in the yield of bones compared with the carcass weight. Muscle-bone ratio equaled 4.27 in the control, and 4.56 in the experimental animals. Meatiness index of the young animals that had received the supplement with the diet was higher by 11.1%. Flesh of carcasses of bulls belonging to the experimental group had higher content of valuable grades of beef. We obtained 27.3% more flesh of the highest quality and 11.5% of the first-grade quality. In the muscle tissue and the longissimus of the bulls that had been consuming the premix, the concentration of dry matter was higher by 0.78%, and protein by 0.85%. Use of the Intermix protein-vitamin premix would lead to an increase in live weight of animals, and therefore significantly increase the yield of meat and improve the morphological composition of the bulls’ carcasses.

Chromium propionate supplementation alters animal growth performance, carcass characteristics, and skeletal muscle properties in feedlot steers

The objective of this study was to evaluate the effects of increasing concentrations of Cr propionate (CrP) on feedlot performance, blood parameters, carcass characteristics, and skeletal muscle fiber properties in feedlot steers. Crossbred steers (n = 32; 367 ± 2.5 kg; 16 pens; 2 hd/pen) were blocked by body weight (BW), and treatment was randomly assigned to pen: (1) 0 mg added Cr/kg diet dry matter (DM) (control), (2) 0.15 mg added Cr/kg diet DM (CrP; KemTRACE Chromium 0.04%, Kemin Industries, Des Moines, IA), (3) 0.30 mg added Cr/kg diet DM, and (4) 0.45 mg added Cr/kg diet DM. Steers were fed ad libitum, and the treatment was top-dressed at the time of feeding. Body weights, blood samples, and longissimus biopsies were collected before feeding on days 0, 28, 56, 91, 119, and 147. Blood sera were harvested for analysis of glucose, insulin, sera urea nitrogen, and non-esterified fatty acid concentrations. Longissimus biopsies were collected for gene expression, protein expression, and immunohistochemical (IHC) analysis. Pen was the experimental unit for live and carcass data, and steer was the experimental unit with day as a repeated measure for sera and IHC analyses. For the entire duration of the trial, a linear increase in average daily gain (ADG) (P = 0.01) and improvement in G:F was observed (P = 0.01) with no change in DMI (P = 0.11) with increasing CrP. A linear increase in hot carcass weight (HCW) (P ≤ 0.01) with no other changes in carcass composition were noted (P ≥ 0.38) as the level of dietary CrP increased. There was no effect of treatment on any sera parameters measured (P ≥ 0.10). No difference was detected for gene or protein expression of glucose transporter type 4 (GLUT4) due to CrP supplementation (P ≥ 0.10). For skeletal muscle fiber distribution and cross-sectional area, there was no effect of treatment (P ≥ 0.10). Density of total GLUT4 did not change due to CrP (P ≥ 0.10). Internalization of GLUT4 was increased in the 0.30 and 0.45 mg/kg treatments (P < 0.01). For total nuclei density and myonuclei density, there were treatment × day interaction tendencies (P ≤ 0.08). Supplementation of CrP did not alter density of satellite cells (P ≥ 0.10). The number of transporters located in the sarcolemma of skeletal muscle fibers did decrease, implying fewer proteins were needed to transport extracellular glucose into the muscle fiber. Therefore, CrP may augment cellular function and growth via increased efficiency of GLUT4 function. These results indicated CrP increases BW, ADG, and HCW, without changes in circulating sera parameters or total GLUT4 expression.

Effect of zinc source and concentration and chromium supplementation on performance and carcass characteristics in feedlot steers1,2,3

Four hundred crossbred steers were used in a randomized complete block design to investigate the effects of supplemental Zn source and concentration, and dietary Cr on performance and carcass characteristics of feedlot steers fed a steam-flaked corn-based finishing diet. Steers were blocked by initial BW within cattle source (3 sources) and randomly assigned within block to 1 of 5 treatments. Before the initiation of the experiment, trace mineral supplement sources were analyzed for Zn and Cr. Zinc and Cr concentrations of the Zn sources were used to balance all dietary treatments to obtain correct Zn and Cr experimental doses. Treatments were the addition of: 1) 90 mg Zn/kg DM from ZnSO4 and 0.25 mg Cr/kg DM from Cr propionate (90ZS+Cr); 2) 30 mg Zn/kg DM from Zn hydroxychloride and 0.25 mg Cr/kg DM from Cr propionate (30ZH+Cr); 3) 90 mg Zn/kg DM from Zn hydroxychloride and 0.25 mg Cr/kg DM from Cr propionate (90ZH+Cr); 4) 60 mg Zn/kg DM from ZnSO4 and 30 mg Zn/kg DM from Zn methionine (90ZSM); and 5) 90 mg Zn/kg DM from Zn hydroxychloride (90ZH). Steers were individually weighed on d-2 and on 2 consecutive days at the end of the experiment. Initial liver biopsies were obtained from all steers at processing. Equal numbers of pen replicates per treatment were slaughtered at a commercial abattoir on day 162, 176, and 211; individual carcass data and final liver samples were collected. Total finishing dietary Zn and Cr concentrations were 118.4, 58.2, 114.2, 123.0, and 108.2 mg Zn/kg DM and 0.740, 0.668, 0.763, 0.767, and 0.461 mg Cr/kg DM, for treatments 1 to 5, respectively. Data were analyzed statistically using preplanned single degree of freedom contrasts. Steers receiving 90ZH+Cr had greater final BW (P < 0.04) and ADG (P < 0.03) when compared with steers receiving 90ZH. Additionally, hot carcass weight was 8.5 kg greater (P < 0.03) for 90ZH+Cr compared with 90ZH supplemented steers. Steers receiving 90ZH+Cr had greater longissimus muscle area when compared with steers receiving 90ZSM. Dry matter intake, G:F, morbidity and mortality, and all other carcass measurements were similar across treatments. These data indicate that under the conditions of this experiment, Zn source and concentration had no impact on live performance, liver Zn and Cu concentrations, and carcass characteristics. Supplemental Cr in diets containing 90 mg of supplemental Zn/kg DM from ZH improved final BW, ADG, and hot carcass weights.

Effects of increasing supplemental dietary Zn concentration on growth performance and carcass characteristics in finishing steers fed ractopamine hydrochloride

Angus-cross steers (n = 288; 427 ± 0.4 kg) were utilized in a finishing study to evaluate the influence of increasing dietary Zn concentration on growth performance and carcass characteristics of steers fed ractopamine hydrochloride (RAC). In a randomized complete block design, steers were blocked by weight (6 steers/pen) and fed a dry-rolled corn-based diet for 79 d containing no supplemental Zn (CON; n = 8), 60 mg Zn/kg from ZnSO4 and no supplemental Zn-amino acid complex (ZnAA; ZnAA0; n = 8) or ZnAA0 diet supplemented with 60 (ZnAA60; n = 8), 90 (ZnAA90; n = 7), 120 (ZnAA120; n = 8), or 150 (ZnAA150; n = 8) mg Zn/kg DM from ZnAA. Thirty-one days prior to harvest (day 48 of study) all steers began receiving RAC at 300 mg⋅steer-1⋅d-1. This study was organized as 2 groups (GRP) of steers and groups were stagger started so that GRP1 started and ended 2 wk before GRP2. Pen was the experimental unit, and the statistical model included the fixed effects of treatment and block nested within GRP. Three a priori single degree of freedom contrasts were developed: linear and quadratic effects of ZnAA supplementation (ZnAA0, ZnAA60, ZnAA90, ZnAA120, and ZnAA150), and CON vs. Zn (CON vs. ZnAA0, ZnAA60, ZnAA90, ZnAA120, and ZnAA150). Dietary Zn concentration did not affect growth performance prior to RAC supplementation (P ≥ 0.17). During the RAC-period ADG and DMI were not affected by dietary Zn (P ≥ 0.16), while there was a linear effect of dietary Zn supplementation to decrease G:F (P = 0.04). Marbling scores were greatest in CON steers (P = 0.03). Liver Cu (day 45 and 80) and meat Cu (harvest) concentrations were greater in CON steers relative to Zn-supplemented steers (P ≤ 0.05), and plasma Zn linearly increased as dietary Zn increased (P = 0.007). Warner-Bratzler shear force was not different among treatments (P ≥ 0.25), and meat total collagen was quadratically affected by dietary Zn supplementation (P ≤ 0.002) where ZnAA0 was greatest. Overall, there was no effect of dietary Zn concentration on growth performance of RAC-supplemented steers in this study.

Interaction between supplemental zinc oxide and zilpaterol hydrochloride on growth performance, carcass traits, and blood metabolites in feedlot steers

Interactive effects of supplemental Zn and zilpaterol hydrochloride (ZH) were evaluated in feedlot steers ( = 40; 652 kg ± 14 initial BW) to determine their impact on feedlot performance, blood constituents, and carcass traits. The study was conducted as a randomized complete block design with a 2 × 2 factorial treatment arrangement. Steers were blocked by BW and randomly assigned to treatments. Factors consisted of supplemental Zn (60 or 300 mg/kg diet DM) and ZH (0 or 8.33 mg/kg) in the diets. For diets supplemented with 300 mg Zn/kg DM, 60 mg Zn/kg was supplemented as zinc sulfate and 240 mg Zn/kg was supplemented as zinc oxide, and the diet was fed for 24 d. Zilpaterol hydrochloride was fed for 21 d followed by a 3-d withdrawal. Cattle were housed in partially covered individual feeding pens equipped with automatic waterers and fence-line feed bunks and were fed once daily for ad libitum intake. Plasma samples were collected on d 0 and 21 to assess changes in Zn, plasma urea nitrogen (PUN), glucose, and lactate concentrations, and serum samples were collected on d 21 to assess IGF-1 concentration. On d 25, cattle were weighed and transported 450 km to a commercial abattoir for harvest; HCW and incidence of liver abscesses were recorded. Carcass data were collected after 36 h of refrigeration. Data were analyzed as a mixed model with Zn, ZH, and Zn × ZH as fixed effects; block as a random effect; and steer as the experimental unit. No interaction or effects of Zn or ZH were observed for IGF-1 concentration, plasma glucose, or lactate concentrations ( ≥ 0.25). No interaction between Zn and ZH was observed for PUN concentration, but PUN decreased with ZH ( < 0.01). There were no effects of ZH or Zn on ADG, DMI, final BW, feed efficiency, HCW, back fat, KPH, quality grade, or incidence of liver abscesses ( > 0.05). Zinc supplementation tended ( = 0.08) to improve the proportion of carcasses grading USDA Choice. Feeding ZH decreased yield grade ( = 0.05) and tended to increase LM area ( = 0.07). In conclusion, increasing dietary concentrations of Zn does not impact response to ZH, but feeding ZH altered circulating concentrations of PUN.

Interactive effects of supplemental Zn sulfate and ractopamine hydrochloride on growth performance, carcass traits, and plasma urea nitrogen in feedlot heifers

Interactive effects of supplemental Zn and ractopamine hydrochloride (RH) were evaluated using 156 crossbred heifers (initial BW = 527 kg ± 6.61; gross BW × 0.96) to determine the impact on feedlot performance, plasma urea nitrogen (PUN), and carcass characteristics. The study was conducted as a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Factors consisted of 1) 30 or 100 mg supplemental Zn/kg diet DM (30Zn or 100Zn) as Zn sulfate and 2) 0 or 200 mg RH/heifer daily. Heifers were blocked by BW and assigned randomly within block to treatments for a 43-d trial. Heifers were housed in partially covered feeding pens (3 heifers/pen; 13 pens/treatment) and provided ad libitum access to feed. Ractopamine hydrochloride was fed for 42 d and removed from the diet until cattle were harvested on d 43. Zinc treatments were fed until harvest. Plasma samples were collected on d 0 and 36 to assess changes in plasma Zn and PUN. On d 43, heifers were weighed, then transported to a commercial abattoir where HCW and incidence of liver abscesses were recorded. Carcass data were collected after 32 h of refrigeration. No Zn × RH interactions were observed for plasma Zn or PUN ( ≥ 0.58); however, there was a tendency for a RH × day interaction for PUN ( = 0.08). Supplementing 100Zn resulted in increased plasma Zn ( = 0.02) compared to 30Zn. No RH × Zn interactions were observed for feedlot performance ( ≥ 0.24). Final BW and ADG increased with RH supplementation ( ≤ 0.02), but DMI was not affected ( = 0.63); thus, feed efficiency improved ( < 0.01) when heifers were fed RH. Supplementing 100Zn tended to reduce ADG ( = 0.07) but did not affect other measures of feedlot performance ( ≥ 0.12). Zinc × RH interactions were observed for LM area and yield grade ( ≤ 0.01); LM area decreased and yield grade increased when heifers were supplemented 100Zn with no RH compared to other treatments. A tendency for a Zn × RH interaction was observed for dressed yield ( = 0.08), but no other interactions or effects of Zn were detected for carcass traits ( ≥ 0.11). Supplementing RH increased HCW ( = 0.03) but did not affect other carcass traits ( ≥ 0.13). In conclusion, supplemental Zn had little impact on feedlot performance or PUN concentration but may alter muscle and fat deposition when fed in conjunction with RH.