Effects of ractopamine supplementation on growth performance and carcass characteristics of feedlot steers differing in biological type

2007 ◽  
Vol 85 (7) ◽  
pp. 1809-1815 ◽  
Author(s):  
S. L. Gruber ◽  
J. D. Tatum ◽  
T. E. Engle ◽  
M. A. Mitchell ◽  
S. B. Laudert ◽  
...  
2009 ◽  
Vol 89 (2) ◽  
pp. 263-271 ◽  
Author(s):  
J. Baah ◽  
Y. Wang ◽  
T A McAllister

The effect of a direct-fed microbial (DFM) poduct containing a mixed culture of Lactobacillus casei and L. lactis on in vitro ruminal fermentation of barley-grain/barley-silage-based backgrounding and finishing diets and on growth performance and carcass characteristics of feedlot cattle was evaluated during backgrounding (84 d) and finishing (140 d) of 100 Hereford × Angus steers (initial body weight = 280 ± 15.5 kg). The inclusion rates of DFM in the in vitro study were 4, 8, 12 and 16 million colony forming units (CFU) of lactic acid bacteria (LAB) kg-1 DM of substrate. Total in vitro volatile fatty acids (VFA) production increased at 6 and 12 h of incubation (P < 0.01; linear response) when the backgrounding diet was supplemented with DFM. Dry matter digestibility and VFA production also increased (P < 0.05) during a 12-h fermentation of the finishing diet. Steers were randomly allocated to one of four dietary treatments that comprised feeding DFM tp provide 0 (control), 4 × 107, 8 × 107, or 12 × 107 CFU kg-1 diet DM. Average daily gain (ADG, kg) and feed efficiency (G:F; kg gain kg-1 DM consumed) of steers improved (P = 0.002 and 0.001, respectively) as a result of feeding DFM during the backgrounding period, but not during the finishing period. Saleable meat and rib eye area decreased (P = 0.038, linear; and P = 0.041, quadratic) with DFM supplementation. The results indicated that supplementing barley-grain/barley-silage-based feedlot cattle diets with 12 × 107 CFU of the mixed culture of lactobacilli used in these studies could improve ruminal fermentation, ADG and G:F in backgrounding feedlot steers. However, supplementation during the finishing period may not be warranted in terms of growth performance and carcass characteristics. Differences in the microbial ecology of the intestinal tract as a result of differences in diet composition may account for the varied response between the backgrounding and finishing periods.Key words: Beef cattle, direct-fed microbial, growth performance, Lactobacillus casei, Lactobacillus lactis, ruminal fermentation


2018 ◽  
Vol 2 (2) ◽  
pp. 216-222
Author(s):  
Tara L Felix ◽  
Chloe J Long ◽  
Madeline R Stierwalt ◽  
Pedro H V Carvalho ◽  
Howard M Blalock

Abstract Feeding cattle liquid supplements has become increasingly popular in the feedlot industry; however, optimal inclusion of liquid supplements in feedlot cattle diets is not known. The objectives of this study were to determine the optimal inclusion of liquid supplementation to maximize growth performance and improve carcass characteristics, as well as estimate the energy value of liquid supplementation when used as a direct corn replacement, for feedlot steers fed a concentrate-based diet. Two hundred and eighty steer calves were stratified by BW into light (BW = 208 ± 9 kg; n = 24) and heavy (BW = 275 ± 8 kg; n = 16) pens. Pens within BW block were randomly assigned to 1 of 4 supplements: 1) dry at 4.5% inclusion (0LIQ), 2) liquid (a proprietary blend from Quality Liquid Feeds; Dodgeville, WI) at 4.5% inclusion (4.5LIQ), 3) liquid at 9% inclusion (9LIQ), or 4) liquid at 13.5% inclusion (13.5LIQ). The remainder of the diet was 47.5% to 55.5% dry rolled corn, 20% corn silage, and 20% modified wet distillers grains with solubles (DM basis). Data were analyzed as a randomized complete block design and linear and quadratic were examined to determine effects of increasing dietary concentrations of liquid. Steers fed 4.5LIQ and 9LIQ had greater (quadratic; P ≤ 0.05) final BW, HCW, and NEm and NEg, and less DMI as a percent of BW compared to steers fed 13.5LIQ. Steers fed 0LIQ were intermediate and not different from other treatments. However, ADG and total BW gain did not differ (P ≥ 0.15) among treatments. Despite the lack of treatment effect on live measures of gain, feeding steers 4.5LIQ and 9LIQ resulted in greater carcass ADG (quadratic; P = 0.03), total carcass gain (quadratic; P = 0.04), and more efficient carcass gain (quadratic; P ≤ 0.01) compared to carcasses from steers fed 13.5LIQ. Feeding steers a liquid supplement at 9% of the diet, DM allowed for the greatest final BW and ADG in this study; however, there was no benefit of increasing liquid to 13.5%.


Author(s):  
A M Pittaluga ◽  
S Yu ◽  
W Li ◽  
J C McCann

Abstract The objective was to evaluate the effect of adding an exogenous glucoamylase (GA) enzyme from the fungus Trichoderma reesei on in vitro fermentation, growth performance, and carcass characteristics of feedlot steers fed a dry-rolled corn-based diet. Experiment 1 evaluated 3 levels of added enzyme (0, 0.24, and 0.72 GA enzyme units) and 2 corn particle sizes (CPS; 2 and 4 mm) in a factorial arrangement using a 7 h in vitro batch culture fermentation. Addition of GA increased (P &lt; 0.01) in vitro dry matter disappearance by 13% and decreased final pH (P &lt; 0.01). Molar proportion of propionate increased with GA inclusion (P &lt; 0.01). A smaller CPS increased (P &lt; 0.01) in vitro dry matter disappearance and total volatile fatty acid and decreased final pH (P &lt; 0.01). A smaller CPS also decreased (P &lt; 0.01) the molar proportion of acetate and increased (P &lt; 0.01) the molar proportion of butyrate. In Experiment 2, Angus × Simmental steers (n = 105; initial BW = 329 ± 38 kg) were used to evaluate the inclusion of an exogenous GA on growth performance and carcass characteristics. Steers were fed a basal diet consisting of 60% dry-rolled corn, 17.5% modified distillers grains with solubles, 12.5% corn silage and 10% dry supplement on a dry matter basis for 136 d. Steers were blocked by weight and allotted to pens. Pens were randomly assigned to one of 3 treatments (5 pens/treatment): diet with no GA (CON), low inclusion of GA (122 enzyme units/kg DM; LGA), or high inclusion of GA (183 enzyme units/kg DM; HGA). Inclusion of GA did not affect (P ≥ 0.23) final BW, DMI, or ADG for the 136-d feeding period. Feed conversion was affected (P = 0.02) by treatment with steers fed HGA having ~8% greater G:F compared with LGA and CON. Treatment did not affect (P = 0.32) fecal starch. Inclusion of GA did not affect (P ≥ 0.19) carcass traits including HCW, 12 th rib fat thickness, yield grade, longissimus muscle area, or marbling score. Overall, results suggest inclusion of exogenous GA enzyme increased in vitro dry matter disappearance in batch culture and improved feed conversion in steers fed 183 enzyme units/kg DM during the finishing phase.


2021 ◽  
Author(s):  
Anchalee Khongpradit ◽  
Phoompong Boonsaen ◽  
Nitipong Homwong ◽  
Keiji Matsuba ◽  
Yasuo Kobayashi ◽  
...  

Abstract The effects of PS were determined as a concentrate added to feed and of the days it was short-term and long-term fed to fattening dairy steers on their growth performance, carcass characteristics, meat quality, and economic return. The experimental units comprised 36 feedlot dairy steers arranged as a 2 ⋅ 3 factorial in a completely randomized design. The first term (diet factors) consisted of ground corn (GC), ground cassava (CA), or pineapple stem starch (PS) at 37% dry matter (DM) in the concentrate. The second term (feeding factors) consisted of feeding the concentrate from 1 to 206 days (short-term feeding) or from 1 to 344 days (long-term feeding). At the end of the feeding term periods, the animals were slaughtered and the growth performance, carcass characteristics, and meat quality were evaluated. The average daily gain (ADG), feed:gain ratio, dry matter intake (DMI), hot carcass and cool carcass percentages, and backfat thickness were greater for steers on short-term than on long-term feeding. Feeding the different starch sources had no negative influence on the growth performance, carcass characteristics, and meat quality. However, the ADG of steers fed PS tended (P = 0.07) to be higher than for those fed GC or CA. In addition, the concentration of the fatty acid C14:1 in the longissimus dorsi muscle was the highest in steers fed CA. Different starch sources had similar values for saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA.) Long-term feeding increased MUFA. Pineapple stem starch could be a useful feed ingredient for feedlot steers as an alternative starch source for energy.


2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Katie J Heiderscheit ◽  
Stephanie L Hansen

Abstract The objective of this study was to evaluate growth performance, carcass characteristics, and plasma amino acid profiles of feedlot steers fed rumen-protected Lys. Forty-two Angus-cross steers (304 ± 25 kg) were blocked by weight and fed treatment diets for 180 d (growing days 0 to 55; finishing days 56 to 180): 1) Lys-deficient diet (CON; n = 12 steers), 2) Lys-adequate diet containing soybean meal (POS; n = 12 steers), or 3) Lys-deficient diet plus supplemental rumen-protected Lys (RPL; AjiPro-L; Ajinomoto Animal Nutrition North America, Eddyville, IA; n = 18 steers). Consecutive day bodyweights (BWs) were recorded to begin and end growing and finishing. Individual steer dry matter intake (DMI) was recorded. Blood was collected on days 0, 56, and 179 for analysis of physiological free amino acids. Steers were harvested on day 180 and carcass characteristics were recorded. Data were analyzed using Proc Mixed of SAS 9.4. Steer was the experimental unit and treatment was the fixed effect for all parameters. Block was a fixed effect for growth performance, feed intake, and carcass data. The day 0 value for each parameter of physiological free amino acids was used as a covariate during analysis. The CON steers had greater BW, average daily gain (ADG), and gain to feed (G:F) at the end of growing (day 56; P ≤ 0.05) vs. POS and RPL. The CON steers also had greater final BW (P = 0.04) and overall ADG (P = 0.04) than RPL, while POS was intermediate. Carcass characteristics were not different across treatments [hot carcass weight, dressing percent, ribeye area, back fat, kidney/pelvic/heart (KPH) percent, marbling, or calculated yield grade; P ≥ 0.13]. Plasma urea N was greater in POS steers on days 56 and 179 (P ≤ 0.04). Plasma Lys and Arg concentrations were greater in POS at day 56 (P ≤ 0.02); however, there was no difference among treatments for these two variables at day 179 (P ≥ 0.44). Steers in all treatments had greater DMI than predicted, causing a negative metabolizable Lys balance for all treatments during growing. Though the metabolizable Lys balance was positive for POS and RPL-fed steers during finishing, the increased metabolizable Lys in these treatments may have decreased performance if other amino acids were imbalanced due to increased intakes.


2017 ◽  
Vol 95 (9) ◽  
pp. 4052 ◽  
Author(s):  
K. F. Coble ◽  
J. M. DeRouchey ◽  
M. D. Tokach ◽  
S. S. Dritz ◽  
R. D. Goodband ◽  
...  

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