Feedlot performance, carcass characteristics and meat quality of Zebu heifers supplemented with two β-adrenergic agonists

2017 ◽  
Vol 57 (10) ◽  
pp. 2125 ◽  
Author(s):  
F. J. Meraz-Murillo ◽  
L. Avendaño-Reyes ◽  
C. Pérez-Linares ◽  
F. Figueroa-Saavedra ◽  
V. Torres-Rodríguez ◽  
...  

The aim was to evaluate effects of administration of two β-adrenergic agonists (β-AA) on growth performance, carcass characteristics and meat-quality traits of Zebu heifers finished in a feedlot. Fifty-four Zebu heifers weighing 397 ± 29.1 kg were used in a randomised complete block design with three treatments and six blocks (i.e. 18 pens with 3 heifers per pen). Treatments were as follows: (1) control (C; no supplement); (2) zilpaterol hydrochloride (ZH; 60 mg per heifer per day); and (3) ractopamine hydrochloride (RH; 300 mg per heifer per day). The β-AA were added to the diets during the final 33 days of the finishing period, after which the heifers were immediately slaughtered. Relative to C, average daily gain and gain : feed ratio were improved (P < 0.05) in heifers supplemented with ZH, but not in those supplemented with RH. Feed intake in C heifers was lower (P < 0.05) than in ZH heifers, but similar (P > 0.05) to RH heifers. The hot carcass weight showed a trend to be heavier (P = 0.096) in ZH than in C heifers. However, Longissimus dorsi (LM) area was increased (P < 0.05) by ZH (73.94 cm2), but RH (70.45 cm2) and C (66.3 cm2) groups had a similar (P > 0.05) LM area. The meat from the ZH- and RH-supplemented heifers had higher Warner–Bratzler shear-force values (P < 0.01) than that from C heifers (ZH = 5.11; RH = 5.50; C = 4.89 kg/cm2), and the meat from RH-supplemented heifers was classified as ‘tough’. Variables associated with meat colour indicated that ZH led to a lower b* average, which was related to a lighter LM area than in C. In general, feedlot performance was enhanced only by the β-AA ZH, with meat tenderness from RH heifers classified as ‘tough’. Meat colour was not altered by β-AA supplementation. These data suggested that while ZH supplementation to Bos indicus heifers offered advantages in feedlot performance and some carcass traits, RH supplementation did not positively affect these biological responses.

2019 ◽  
Vol 4 (1) ◽  
pp. 102-117
Author(s):  
Cathy L Lockard ◽  
Chris J Richards ◽  
Caleb G Lockard ◽  
Maggie Youngers ◽  
Mariah A Woolsoncroft ◽  
...  

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.


2019 ◽  
Vol 4 (1) ◽  
pp. 67-74
Author(s):  
Tony C Bryant ◽  
Josh I Szasz ◽  
Lois F G Pringle ◽  
Eddie Crispe ◽  
K Shawn Blood ◽  
...  

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 &lt; 0.001) compared to CON cattle. Furthermore, carcass-adjusted ADG and feed efficiency did not differ (P &gt; 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 &lt; 0.001) for RAC treatments vs. CON, and no differences were detected (P &gt; 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.


2019 ◽  
Vol 4 (1) ◽  
pp. 206-213 ◽  
Author(s):  
Pedro Henrique Vilela Carvalho ◽  
George A Perry ◽  
Tara L Felix

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 &lt; 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 &lt; 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 &lt; 0.01) in serum E2 concentrations. Serum E2 concentrations were not altered in nonimplanted Holstein steers, whereas E2 concentration increased (P &lt; 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.


Author(s):  
Erin L Deters ◽  
Emma K Niedermayer ◽  
Olivia N Genther-Schroeder ◽  
Christopher P Blank ◽  
Remy N Carmichael ◽  
...  

Abstract Angus-crossbred steers (n = 180; 292 ± 18 kg) from a single ranch were used to investigate the effects of a novel rumen-protected folic acid (RPFA) supplement on feedlot performance and carcass characteristics. On d 0, steers were blocked by body weight to pens (5 steers/pen), and pens within a block were randomly assigned to dietary treatments (n = 6 pens/treatment): target intake of 0 (CON), 30 (RPFA-30), 60 (RPFA-60), 90 (RPFA-90), 120 (RPFA-120), or 150 (RPFA-150) mg RPFA·steer -1·d -1. Steers were weighed before feeding on d -1, 0, 55, 56, 86, 87, 181, and 182. Pen average daily gain (ADG), dry matter intake (DMI), and gain:feed (G:F) were calculated for growing (d 0 to 56), dietary transition (d 56 to 87), finishing (d 87 to 182), and overall (d 0 to 182). Liver and blood samples were collected from two steers/pen before trial initiation and at the end of growing and finishing. Steers were slaughtered on d 183, and carcass data were collected after a 48-h chill. Data were analyzed as a randomized complete block design using ProcMixed of SAS 9.4 (fixed effects of treatment and block; experimental unit of pen). Liver abscess scores were analyzed using the Genmod Procedure of SAS 9.4. Contrast statements assessed the polynomial effects of RPFA. Supplemental RPFA linearly increased plasma folate at the end of growing and finishing (P &lt; 0.01), and linearly decreased plasma glucose at the end of growing (P = 0.01). There was a cubic effect of RPFA on liver folate at the end of growing (P = 0.01), driven by lesser concentrations for RPFA-30, RPFA-60, and RPFA-150. Growing period ADG and G:F were greatest for CON and RPFA-120 (cubic P ≤ 0.03). Transition period DMI was linearly increased due to RPFA (P = 0.05). There was a tendency for a cubic effect of RPFA on the percentage of livers with no abscesses (P = 0.06), driven by a greater percentage of non-abscessed livers in RPFA-30 and RPFA-60. Despite supplementing 1 mg Co/kg DM, and regardless of treatment, plasma vitamin B12 concentrations were low (&lt; 200 pg/mL), which may have influenced the response to RPFA as vitamin B12 is essential for recycling of folate.


2015 ◽  
Vol 13 (4) ◽  
pp. e0610 ◽  
Author(s):  
Sergio P. Iraira ◽  
Ana Madruga ◽  
María Pérez-Juan ◽  
José L. Ruíz-de-la-Torre ◽  
María Rodríguez-Prado ◽  
...  

<p>Eighteen Simmental heifers were fed concentrate and barley straw offered as a total mixed ration (TMR) or separately as a free choice (FCH) to compare performance, behaviour, and meat quality. The heifers were assigned to treatments in a randomized complete block design. Animals were allotted to roofed pens with 3 animals per pen, and 3 pens per treatment. Intake of concentrate, average daily gain, and gain to feed ratio were not different between diets, being on average 7.6 kg/day, 1.38 kg/day and 0.18 kg/kg, respectively. Straw intake was greater in TMR than in FCH treatment (0.7 <em>vs</em> 0.3 kg/day, respectively; <em>p</em>&lt;0.001). Crude protein intake, neutral detergent fibre intake and water consumption did not differ between treatments. Time spent eating was longer in FCH than in TMR (<em>p=</em>0.001), whereas time spent ruminating and total chewing time were longer (<em>p</em>&lt;0.01) in TMR than in FCH. The number of displacements resulting from competition for feed in the main feeder in TMR treatment tended to be greater than in FCH treatment. There were no differences in the carcass characteristics and quality of meat of animals assigned to the different feeding methods, but the percentage of 18:2 n-6 was higher in FCH treatment. In summary, these results suggest that the use of TMR as a feeding method in beef cattle fed high concentrate diets did not affect performance and increased time spent ruminating with a potential decrease of ruminal acidosis incidence.</p>


2019 ◽  
Vol 3 (2) ◽  
pp. 731-736 ◽  
Author(s):  
Henrique S Cemin ◽  
Jason C Woodworth ◽  
Mike D Tokach ◽  
Steve S Dritz ◽  
Joel M DeRouchey ◽  
...  

Abstract A total of 2,430 pigs (PIC 337 × 1050; Hendersonville, TN; initially 30.1 kg) were used in a 113-d growth trial to determine the effects of increasing dietary Zn on growth performance and carcass characteristics of finishing pigs raised under commercial conditions. Pens of pigs were assigned to be fed one of five dietary treatments in a randomized complete block design. Treatments consisted of 50, 87.5, 125, 162.5, or 200 mg/kg added Zn from Zn hydroxychloride (IntelliBond Z, Micronutrients, Indianapolis, IN). Two identical barns were used for a total of 18 pens per treatment with 27 pigs per pen. Experimental diets were fed in five phases and contained a vitamin-trace mineral premix without added Zn. Pens of pigs were weighed approximately every 2 wk to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). At the end of the experimental period, pigs were tattooed with a pen identification number and transported to a packing plant to measure hot carcass weight (HCW), backfat, loin depth, and calculated lean percentage. Data were analyzed block nested within barn as a random effect and pen as the experimental unit. From days 0 to 42, pigs fed diets with increasing added Zn had lower (linear, P = 0.043) ADFI and a tendency (P = 0.092) for lower ADG. From days 42 to 113, increasing added Zn resulted in a quadratic response (P = 0.042) for ADFI and a tendency (linear, P = 0.056) for improved G:F. Overall (days 0 to 113), there were tendencies for quadratic responses for ADFI (P = 0.073) and G:F (P = 0.059), with the greatest G:F observed when 125 mg/kg of Zn was fed. Increasing added Zn resulted in a linear increase (P &lt; 0.001) in daily Zn intake. There were no differences (P &gt; 0.10) in overall ADG, final body weight, HCW, backfat, loin depth, lean percentage, mortality, and removal rate. In conclusion, there were no improvements in ADG when feeding beyond 50 mg/kg added Zn; however, providing 125 mg/kg added Zn resulted in the greatest G:F.


Agriculture ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 241
Author(s):  
Jorge Adalberto Cayetano-De-Jesus ◽  
Rolando Rojo-Rubio ◽  
Alicia Grajales-Lagunes ◽  
Leonel Avendaño-Reyes ◽  
Ulises Macias-Cruz ◽  
...  

Twenty-four Dorper x Pelibuey lambs were housed in individual pens during a 31-d feeding period and assigned to four treatments (n = 6) under a randomized complete block design with different daily doses of zilpaterol hydrochloride (ZH): 0 (control), 0.1, 0.2, and 0.3 mg/kg BW to determine the effects of ZH supplementation on productive performance, meat quality, and wholesale cut yields. Final BW (p = 0.02) and average daily gain (ADG, p = 0.04) were greater in lambs supplemented with 0.2 mg/kg BW. Supplemental ZH tended to improve dry matter intake (DMI, p = 0.008) and ADG:DMI ratio (p = 0.078). Wholesale cut yields were not affected by ZH supplementation. Percentage of head was greater (p = 0.04) in lambs treated with ZH. The ZH supplementation did not affect carcass characteristics. However, longissimus thoracis et lumborum (LTL) presented a linear trend (p = 0.08) of increasing with ZH supplementation. Percentage of blood presented a trend (p = 0.051) of decreasing with ZH supplementation. Also, liver decreased in size (p < 0.05) for treatments where ZH was included. Values of luminosity decreased (p < 0.02) when ZH dosage increased. The value of protein Lowry was greater, with 0.3 mg kg−1 (p = 0.04). Cathepsin B + L was greater in the lambs from the control treatment (p = 0.05). In conclusion, using a daily ZH dosage of 0.2 mg per kg of BW produced the best productive performance, carcass characteristics, and some changes in the meat of hair-breed lambs.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 126-126
Author(s):  
Warren C Rusche ◽  
Julie Walker ◽  
Zachary K Smith

Abstract One hundred ninety-two Continental × British steers (initial BW 420 kg [SD 24.7]) were used in a randomized complete block design finishing study to evaluate the effects of feeding two types of silage germplasm at two inclusion rates. A 2 × 2 factorial arrangement of treatments was used with either a conventional (CON) or increased expression of alpha-amylase (Enogen, Syngenta Seeds, LLC, ENO) hybrid fed at either 12% (12SIL) or 24% (24SIL) of diet DM. Steers were blocked (n = 5) and assigned randomly within block to treatments, resulting in five pens and 48 steers per treatment. Steers were harvested after 126 (12SIL) or 140 (24SIL) days on feed. There were no silage source by inclusion rate interactions detected for live growth performance. Silage source did not affect live based average daily gain (ADG), gain to feed ratio (G:F), or final BW (FBW; P ≥ 0.35). Feeding 24% silage reduced ADG (P = 0.04) and G:F (P = 0.01) but increased FBW (P = 0.02) compared to 12SIL. A source by inclusion rate interaction was detected (P = 0.04) for calculated yield grade (YG) with steers fed 24% silage having increased YG within CON but not ENO. Hot carcass weight and ribfat were unaffected by silage source (P ≥ 0.81), but were increased by feeding 24% silage (P = 0.03 and P = 0.02, respectively). Feeding increased amounts of silage increased beef produced per hectare (P = 0.05). Conventional silage produced more beef per hectare (P &lt; 0.01) due to differences in silage yield, but source of silage did not affect feedlot performance independent of silage yield. Feeding increased amounts of silage reduced DM efficiency on a live animal basis but increased beef produced per hectare which is of major value to cattle feeders who produce the majority of their own feedstuffs.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 55-56
Author(s):  
Ning Lu ◽  
Carine Vier ◽  
Wayne Cast ◽  
Uislei Orlando ◽  
Márcio Gonçalves ◽  
...  

Abstract Our objective was to determine the effects of feeding different net energy (NE) and neutral detergent fiber (NDF) on performance of growing-finishing pigs from 30- to 135-kg. A total of 2,058 barrows and gilts (PIC 380×Camborough, initial BW 33.4±0.60 kg) were used in a 97-d growth trial with 21 pigs per pen and 14 pens per treatment in a randomized complete block design. Treatments were formulated to contain 2.11, 2.21, 2.32, 2.42, 2.53, 2.63, and 2.73 Mcal NE/kg; and 24.2, 19.7, 15.1, 10.6, 10.2, 9.8, and 9.5% NDF throughout the experiment. Wheat, wheat byproducts, barley, rye, peas, fababeans, and canola oil were used with NRC (2012) loading values to achieve the treatments. Dietary lysine levels were set to meet PIC2016 lysine requirements for finishing gilts. Experimental data were analyzed using generalized linear mixed models and linear and quadratic polynomial contrasts were built with pen as the experimental unit. Increasing NE or decreasing NDF improved (linear and quadratic, P&lt; 0.05) average daily gain (ADG), gain-to-feed ratio (G:F), carcass ADG, and carcass G:F (Table 1); but reduced (linear and quadratic, P&lt; 0.05) average daily feed intake (ADFI). Comparing to pigs fed 2.42 Mcal/kg diet (energy equivalent to a corn-soybean meal diet), even though those fed 2.11 Mcal/kg diet had 8.7% increment on ADFI, daily NE intake was still 5.4% less. Hot carcass weight, backfat depth, and carcass yield increased (linear and quadratic, P&lt; 0.05) and lean yield decreased (linear and quadratic, P&lt; 0.05) with increasing dietary NE and decreasing NDF. No evidence for differences (P &gt;0.10) were observed for loin depth. Removal and mortality rate was reduced (quadratic, P&lt; 0.05) with increasing dietary NE and decreasing dietary NDF. In summary, increasing dietary NE while reducing dietary NDF resulted in improvements on growth performance, carcass characteristics, and removal and mortality rate.


1997 ◽  
Vol 77 (4) ◽  
pp. 655-662 ◽  
Author(s):  
P. S. Mir ◽  
D. R. C. Bailey ◽  
Z. Mir ◽  
S. D. M. Jones ◽  
T. Entz ◽  
...  

Growth performance, carcass characteristics and meat quality of European and British crossbred (EBC; no Wagyu genetics; 28 heifers and 30 steers) cattle were compared with crossbred cattle with 75% Wagyu genetics (WC; seven heifers and 14 steers) to determine the influence of Wagyu genetics on marbling grade of beef cattle fed barley-based diets in a factorial design experiment. Weaned calves (250 d average age) were fed, one of two diets (diet 1, 35% barley grain; diet 2, 40% hay cubes on DM basis, with barley silage, protein and vitamin/mineral premix) for 84 d and then fed diet 1 until they weighed 394 to 432 kg. All cattle were finished on an 80% (DM basis) rolled barley diet and slaughtered. Carcasses were graded and samples procured for meat quality and Warner–Bratzler shear force determination. Number of days on backgrounding diets to arrive at target weight (380 kg) was greater (P < 0.05) for the WC cattle, owing to relatively lower ADG, but days on the finishing diet were fewer for these cattle, compared with EBC cattle. Warm carcass yield (dressing percent) was greater (P < 0.05), but backfat depth was lower (P < 0.05) for WC cattle relative to that of EBC cattle, yet proportion of lean meat yield was similar. Eighty three percent of WC cattle carcasses had Canada AAA (small or more) marbling grade compared with 13% for EBC cattle carcasses. Mean shear force of meat samples from EBC and WC cattle was 4.2 and 3.8 kg, respectively. Results indicated that the extent of carcass marbling can be increased by incorporating Wagyu genetics but age at slaughter of WC cattle was 19 d greater than that of EBC cattle and carcass size was reduced. Key words: Average daily gain, carcass characteristics, European and British crossbred, feed to gain ratio, meat quality, Wagyu crossbred cattle


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