Effects Of Zilpaterol Hydrochloride Research Articles

Effects of Zilpaterol Hydrochloride with a Combination of Vitamin D3 on Feedlot Lambs: Growth Performance, Dietary Energetics, Carcass Traits, and Meat Quality.

This study evaluated the impact of supplementing ZH in combination with D3 on the growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper × Katahdin cross lambs (37.3 ± 5.72 kg) were utilized in a 29 d experiment in a completely randomized block design with a 2 × 2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg/kg PV-1) and two levels of D3 for 7 d (0 and 1.5 × 106 IU/d-1). ZH improved (p ≤ 0.05) the average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p ≤ 0.03). However, ZH increased (p < 0.01) muscle pH and Warner-Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (p ≤ 0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus thoracis muscle by 1.7% (p = 0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve the meat tenderness negatively affected by ZH supplementation.

Effect of Zilpaterol Hydrochloride and Zinc Methionine on Growth, Carcass Traits, Meat Quality, Fatty Acid Profile and Gene Expression in Longissimus dorsi Muscle of Sheep in Intensive Fattening

Zilpaterol hydrochloride (ZH) redistributes ingested energy and improves feed efficiency by increasing muscle mass and reducing fat in sheep and cattle carcasses in fattening; however, by increasing lipolysis and reducing intramuscular fat (IMF), it can affect meat quality in terms of the attributes of tenderness, juiciness, taste and color; in contrast, Zn methionine (ZM), due to its lipogenic effect, can improve meat marbling without affecting production efficiency. In the current study, 36 male Suffolk sheep were used (25 ± 0.58 kg live weight, LW) to evaluate the supply of ZH and ZM on growth, carcass traits, meat quality, fatty acid content and expression of genes which regulate the deposition of fatty acids (FA) in IMF. A completely randomized design was used, with factorial arrangement of 2 × 2 ZH (0 and 0.2 mg kg−1 LW) and ZM (0 and 80 mg Zn kg−1 dry matter, DM). The results showed that ZH increased (p &lt; 0.05) carcass yield, compactness index and chop eye area and decreased greasing (p &lt; 0.02). The content of ether extract in meat increased (p &lt; 0.05) in sheep with ZM plus ZH, and in sheep with ZM (p &lt; 0.01). ZH (p &lt; 0.05) reduced (p &lt; 0.02) the meat’s color index L*, a*, b*, C* and H*. The content in IMF of stearic (C18:0) and arachidic (C20:0) FA was reduced (p ≤ 0.05) by the effect of ZH, but the palmitoleic (C16:1), eicosatetraenoic (C20:4n6) and conjugated linoleic FA were increased (p ≤ 0.05) by the effect of ZH. ZM increased (p ≤ 0.05) palmitoleic (C16:1) and conjugated linoleic FA; the ZH interaction with ZM increased (p ≤ 0.05) linoleic (C18:2 c 9 c 12), linolenic (C18:3 c 9c12c15) and eicosatetraenoic (C20:4n6) FA. The ZH interaction with ZM influenced (p ≤ 0.05) the total saturated fatty acids (SFA), unsaturated fatty acids (UFA) and polyunsaturated fatty acids (PFA). ZH increased (p ≤ 0.05) the relative expression of mRNA from the enzymes lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), glycerol -3-phosphate acyltransferase (GPAT1) and diglyceride acyltransferase (DGAT1). ZM increased (p ≤ 0.05) the relative expression of mRNA from the enzyme gene acetyl-CoA carboxylase (ACC) and HSL, monoglyceride lipase (MGL). The ZM interaction with ZH increased (p ≤ 0.05) the relative expression of mRNA genes of the enzymes HSL and ACC. It was concluded that ZH improved feed conversion (FC), increased yield and reduced fat in carcasses; ZM increased IMF in Longissimus dorsi. ZH and ZM influenced the FA composition, reduced the SFA and increased the UFA and PFA; both additives also influenced the relative mRNA expression of genes involved in fatty acid metabolism.

Effects of duration of zilpaterol supplementation on growth-performance, dietary energetics, carcass characteristics, and meat quality of crossbred yearling heifers slaughtered at lighter, less-than-mature final body weight (460 kg)

Our objective was to examine the effects of duration of zilpaterol hydrochloride (ZH) supplementation on growth performance, estimated dietary energetics, carcass characteristics, and meat quality in crossbred yearling heifers when slaughtered at lighter, less-mature final weight. Treatments consisted of a finishing diet based on steam-flaked corn supplemented with (1) 0 ZH (negative control); (2) 0.15 mg of ZH/kg of live weight supplemented for 20 of the final 23 d of the finishing period; (3) 0.15 mg of ZH/kg of live weight supplemented for 25 of the final 28 d of the finishing period, or (4) 0.15 mg of ZH/kg of live weight supplemented for 30 of the final 33 d of the finishing period. Duration of ZH supplementation did not affect ( P ≥ 0.15) any of the variables measured. Compared with the control, ZH increased ( P ≤ 0.02) carcass-adjusted weight gain, G:F, and apparent dietary NE. Zilpaterol supplementation also increased ( P ≤ 0.05) hot carcass weight, carcass DP, and LM area without effects on USDA QG, fat thickness, or KPH fat. Zilpaterol supplementation increased ( P < 0.01) gross retail cuts by 3.6%, when adjusting to a constant carcass weight. There were no treatment effects ( P ≥ 0.11) on shear force or meat color. Zilpaterol hydrochloride supplementation in heifers slaughtered at a final weight that was less than was estimated to be mature (460 kg) improved growth performance, hot carcass weight, carcass DP, LM area, and retail cuts in a manner consistent with results of previous studies in which heifers were slaughtered at heavier (>550 kg) BW. Effects of ZH on meat quality was not significant. Reducing ZH feeding duration from 30 to 20 d may not adversely affect growth performance, carcass characteristics, and meat quality.

Growth performance and mammary gland development of Holstein calves fed milk with 15% solids and treated with growth promoters.

The objective of this study was to evaluate growth performance, and mammary gland parenchyma (PAR) development in Holstein female calves fed whole milk combined with milk replacer for 15% total solids (15TS) or only milk (11% TS; 11TS). The effects of zilpaterol hydrochloride (ZH) and an estrogenic implant (EI) on growth performance, serum metabolites, and PAR development in post-weaning calves (63-90days of age) fed 15TS or 11TS were also investigated. In the first phase, 78 calves were randomly divided into two groups (n = 39/group), 15TS, or 11TS (5 to 8 L/day; starter ad libitum). After weaning, calves were randomly assigned to four treatments, no EI, EI, ZH, and ZH-EI. In phase 1, 15TS calves had greater (P < 0.01) average body weight at weaning than 11TS calves (82.0 ± 5.8 vs. 74.1 ± 5.7kg). Pre-weaning average daily gain (718 ± 67 vs. 576 ± 64g/day)was higher (P < 0.01)for 15TS calves than 11TS calves. Feed/gain (1.5 ± 0.3 vs. 1.8 ± 0.3kg of DMI/kg of gain) was lower (P < 0.01) for 15TS calves than 11TS calves. PAR area (8.8 ± 3.3 vs. 5.0 ± 1.6 cm2) was greater (P < 0.01) for 15TS calves than 11TS calves. No differences (P > 0.10) in average daily gain (986 ± 79g/day across treatments) were observed in calves receiving ZH, EI, or ZH-EI fed 15TS or 11TS diets previously. However, the PAR area of 15TS calves administered ZH-EI was 2.2 times greater (P < 0.01) than 11TS calves with no ZH and CI. This study demonstrated the benefits of supplying milk with 15% TS for enhancing overall animal growth and PAR development. Further use of ZH and EI during the post-weaning period did improve mammary PAR growth.

Effect of Zilpaterol Hydrochloride on Performance and Meat Quality in Finishing Lambs

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 &lt; 0.05) for treatments where ZH was included. Values of luminosity decreased (p &lt; 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.

Welfare traits of Bos indicus cattle castrated immunologically and fed beta-adrenergic agonists.

ObjectiveThis work was carried out to evaluate the effects of zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RH) combined with immunocastration on the welfare traits of feedlot Nellore cattle.MethodsNinety-six Nellore males (average body weight [BW] = 409±50 kg; average 20 mo of age) were divided into two groups according to BW; half of the animals in each group received two doses of an immunocastration (ImC) vaccine in a 30 day interval, and the other half did not receive the vaccine (NoC). Afterward, the animals were housed and fed a common diet for 70 days. Then, they were split into three groups and fed one of the following diets for 30 additional days: control (CO) diet, with no β-AA; ZH diet, containing 80 mg/d ZH; and RH diet, containing 300 mg/d RH. Welfare traits were assessed by monitoring body surface temperature using infrared thermography (IRT) and plasma cortisol and temperament measurements.ResultsThere was no interaction between sexual condition and diet for any trait. The ImC and NoC groups did not differ in rectal and ocular temperatures. The ImC animals had higher flight speeds (p = 0.022) and tended to have higher cortisol levels (p = 0.059) than the NoC animals. Animals fed ZH and RH did not differ in cortisol levels, respiratory rate, rectal temperature, temperature measured by IRT, or temperament behaviour.ConclusionThe ImC animals showed a less stable temperament during handling practices than NoC, whereas ZH and RH supplementation had no adverse effects on animal welfare.

The effect of zilpaterol hydrochloride on beef producer and processor revenue of calf-fed Holstein steers.

A serial harvest was conducted every 28 d from 254 to 534 days on feed (DOF) to quantify changes in growth and composition of calf-fed Holstein steers (n = 110, initial BW = 449.2 ± 19.9 kg). One-half were supplemented the β-2 adrenergic agonist zilpaterol hydrochloride (ZH; 8.33 mg/kg 100% DM basis), and the remainder fed a control (CON) ration during the final 20 d followed by a 3 d withdrawal prior to harvest. Cattle were randomly allocated to dietary treatment and harvest endpoint (254, 282, 310, 338, 366, 394, 422, 450, 478, 506, and 534 DOF) using a 2 × 11 factorial treatment structure and a completely randomized experimental design structure. The objective of this ad-hoc investigation was to quantify changes in value across multiple harvest endpoints and marketing strategies for cattle supplemented with ZH. Cattle-fed ZH had increased (P < 0.01) value when sold on a dressed basis (+$82.64) or on a value-based formula (+$75.59) compared with CON cattle. No differences (P ≥ 0.14) were detected between ZH and CON carcasses for premiums and discounts related to HCW, yield grade, or quality grade. Moreover, no differences (P = 0.98) were detected for overall adjusted carcass value between ZH and CON carcasses. Fabrication values revealed that ZH carcasses had greater (P < 0.01) revenue than CON carcasses for primal round (+$36.23), loin (+$38.16), flank (+$8.95), rib (+$16.33), and chuck (+$27.49) regardless of DOF. Increased primal values ultimately led to greater (P < 0.01) processor revenue (+$138.94) and carcass value per 45.4 kg (+$6.45) for cattle-fed ZH compared with CON cattle. Overall, increased carcass weight and improved fabrication yield led to greater revenue at all harvest endpoints for cattle-fed ZH. Linear increases in live and dressed values indicated the daily change in live value was $3.48, which is less than an increase of $3.77 daily for dressed carcass value. Greater beef processor margin and profitability are expected when this growth technology is used.

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.

Effects of zilpaterol hydrochloride on methane production, total body oxygen consumption, and blood metabolites in finishing beef steers.

An indirect calorimetry experiment was conducted to determine the effects of feeding zilpaterol hydrochloride (ZH) for 20 d on total body oxygen consumption, respiratory quotient, methane production, and blood metabolites in finishing beef steers. Sixteen Angus steers (initial BW = 555 ± 12.7 kg) were individually fed at ad libitum intake and used in a completely randomized design. The model included the fixed effects of dietary treatment, day, and treatment × day. Dry matter intake did not differ between the treatments ( = 0.89), but was greater on d 0 than any other day ( < 0.01). Oxygen consumption was not different between treatments ( = 0.79), but was different across day ( < 0.01) on d 7, 14, 21, and 28. Respiratory quotient was less for cattle fed ZH than control ( < 0.01), and also different across day ( < 0.01), being greater on d 7, 21, and 28 than d 3 or 21. Methane production (L/kg of DMI) was greater for steers fed the control vs. the ZH diet ( < 0.01), and it also differed by day ( < 0.01), being greater on d 21 and 28 than d 0, 3, 7, and 14. Nonesterified fatty acids were not different across treatments ( = 0.82), and there was no effect of treatment on β-hydroxybutyrate concentration ( = 0.45). Whole blood glucose concentrations were not affected by feeding ZH in this experiment ( = 0.76); however, lactate concentrations were reduced by feeding ZH ( = 0.03). Additionally, there was no treatment effect on ɑ-amino-N, blood glutamate, or glutamine ( ≥ 0.16). Plasma NH was not affected by ZH ( = 0.07), but plasma urea nitrogen was reduced by ZH ( < 0.01). Urinary creatinine was increased by steers receiving ZH ( = 0.01), and urine 3-methylhistidine (3-MH) concentrations were normalized to creatinine, the 3-MH:creatinine ratio decreased from d 0 to d 3 in steers fed ZH, and remained less than control steers until d 28. These data provide insight into how β-agonists alter nutrient partitioning and improve the efficiency of tissue accretion, mainly through decreased muscle protein turnover and altering the catabolic fuel for peripheral tissues.

Zilpaterol hydrochloride improves growth performance and carcass traits without affecting wholesale cut yields of hair sheep finished in feedlot

ABSTRACTFourteen Dorper × Pelibuey ram lambs (initial body weight [BW] = 37.4 ± 1.0 kg and age = 4.5 mo) were housed in individual pens during a 30-d feeding period, and then slaughtered to determine the effects of zilpaterol hydrochloride (ZH) supplementation on productive performance, carcass characteristics and wholesale cut yields. Lambs were assigned under a randomized complete block design (initial BW as blocking factor) to one of two dietary treatments: basal diet without (control) or with 10 mg daily of ZH/lamb. Lambs fed ZH had greater (P ≤ .04) final BW, average daily gain and dry matter intake, but similar (P = .24) feed efficiency compared with control lambs. Hot and cold carcass weight, dressing percentage, longissimus muscle area and leg perimeter were greater (P ≤ .05) for ZH-fed lambs than for control lambs. With exception of blood percentage which decreased (P < .01) with ZH, wholesale cut yields and non-carcass components were unaffected (P ≥ .12) by ZH supplementation. In conclusion, ZH can be used to improve growth rate and dressing percentage, but not to increase wholesale cut yields in feedlot finishing ram lambs.

Effects of zilpaterol hydrochloride on methane production, total body oxygen consumption, and blood metabolites in finishing beef steers

Effects of zilpaterol hydrochloride on methane production, total body oxygen consumption, and blood metabolites in finishing beef steers

Effect of vitamin D, zilpaterol hydrochloride supplementation, and postmortem aging on shear force measurements of three muscles in finishing beef steers.

Vitamin D (D3) supplementation may be used to increase tenderness in beef from cattle fed zilpaterol hydrochloride (ZH). The study was arranged as a 2 × 2 factorial with fixed effects of ZH (no ZH or ZH fed at 8.3 mg/kg DM for 20 d with a 3-d withdrawal) and D3 (no D3 or 500,000 IU D3·steer·d for 10 d prior to harvest). Cattle ( = 466) were harvested in 2 blocks on the basis of BW with subsequent collection of carcass data. Full loins and inside rounds ( = 144 of each subprimal) were collected for fabrication of 5 steaks from the longissimus lumborum (LL), gluteus medius (GM), and semimembranosus (SM), which were aged for 7, 14, 21, 28, or 35 d. Warner-Bratzler shear force (WBSF) was used to evaluate mechanical tenderness of LL, GM, and SM steaks at all aging periods. Slice shear force (SSF) analysis was conducted on only 14- and 21-d LL steaks. No interactions ( > 0.05) between ZH and D3 occurred throughout the entire study. Supplementing ZH resulted in increased HCW ( < 0.01), larger LM area ( < 0.01), and improved calculated yield grades ( < 0.01) with decreases in fat thickness ( = 0.02) and marbling scores ( = 0.05). Supplementation with D3 increased calculated yield grade ( < 0.01) and decreased ( = 0.01) rib eye area. Feeding ZH increased ( ≤ 0.05) WBSF of LL steaks at each postmortem age interval, whereas D3 had no effect ( > 0.05) on WBSF or SSF of LL steaks. Like for WBSF, ZH supplementation increased SSF values at 14 and 21 d postmortem ( < 0.01) compared with those for non-ZH steaks. There was an interaction between ZH and postmortem age ( < 0.01) for WBSF of LL steaks. At 7 d LL steaks from ZH steers sheared over 0.6 kg greater than non-ZH steaks; however, by 21 d this difference was reduced to an average of 0.2 kg. Differences in distribution between LL steaks below 3.0 kg from non-ZH and ZH-fed cattle were also notable ( ≤ 0.05) through 21 d of aging. At 35 d postmortem a high proportion of LL steaks (68.5%) from ZH-fed steers required less than 3.0 kg to shear. Supplementation with ZH and D3 had no impact ( > 0.05) on WBSF values of GM steaks. Feeding ZH did not alter WBSF of SM steaks, but at 28 d D3 increased ( = 0.04) WBSF values. Shear force in ZH steaks was not effectively reduced by feeding D3 for 10 d to steers prior to harvest. Aging, however, was an effective method of reducing initially greater shear force values in LL steaks and, to a lesser degree, GM steaks from ZH-fed cattle.

Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls

Rodríguez-Gaxiola, M. A., Domínguez-Vara, I. A., Barajas-Cruz, R., Mariezcurrema-Berasain, M. A., Bórquez-Gastelum, J. L. and Cervantes-Pacheco, B. J. 2015. Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls. Can. J. Anim. Sci. 95: 609–615. Sixty beef bulls with a body weight (BW) of 314.7±16.2 kg were used to evaluate the effects of zilpaterol hydrochloride (ZH) and zinc methionine (ZM) on growth performance and carcass characteristics. The experimental design was a randomized complete block, with a factorial 2×2 arrangement of treatments (ZH: 0 and 0.15 mg kg−1BW; ZM: 0 and 80 mg kg−1dry matter). The ZH increased (P&lt;0.05) the final BW, average daily gain, feed conversion, carcass yield and longissimus dorsi area. Bulls fed ZH plus ZM had less (P&lt;0.01) backfat thickness and intramuscular fat (IMF) compared with those fed ZH or ZM alone. The ZH increased (P&lt;0.02) the meat crude protein content and cooking loss. It is therefore concluded that ZH increases growth performance, carcass yield, longissimus dorsi area, and meat crude protein. The interaction of ZM and ZH did not present additional advantages. The reason for the reduction in backfat thickness and IMF by ZH plus ZM is unclear, and implies that our knowledge of β-agonistic adrenergic substances and their interactions with minerals is incomplete.

Meat Quality in Katahdin Lamb Terminal Crosses Treated with Zilpaterol Hydrochloride

&lt;p&gt;The effect of Zilpaterol hydrochloride (ZH) supplementation (0 &lt;em&gt;vs.&lt;/em&gt; 0.15 mg/kg live weight) on the meat quality was evaluated in Katahdin x Charollais (32 KCh) and Katahdin x Dorper (28 KD) crosses. Lambs were fed a totally mixed ration with 14% crude protein (CP) and 2.9 Mcal EM/kg DM. Data were analyzed using a completely randomized 2 x 2 factorial design: 2 genotypes (KCh and KD) and 2 ZH levels (0 and 0.15 mg/kg live weight). No interaction was found between ZH and the genotypes. The breed of the sire (BS) did not affect most of the meat traits, only KCh crosses had higher color values (L* = 34.0±0.6 &lt;em&gt;vs.&lt;/em&gt; 35.6±0.6; a* = 13.4±0.3 &lt;em&gt;vs.&lt;/em&gt; 14.9±0.4; b* = 5.6±0.3 &lt;em&gt;vs.&lt;/em&gt; 6.6±0.4; h* = 20.8±0.9 &lt;em&gt;vs.&lt;/em&gt; 23.0±0.09; C* = 14.7±0.4 &lt;em&gt;vs.&lt;/em&gt; 16.4±0.5), more fat (11.2±0.5 &lt;em&gt;vs.&lt;/em&gt; 11.9±0.5) and less protein (21.3±0.1 &lt;em&gt;vs. &lt;/em&gt;21.8±0.0) than KD. ZH meat had lower values (P &amp;lt; 0.001) than meat from the control animals: L* (31.9±0.6 &lt;em&gt;vs.&lt;/em&gt; 37.7±0.6), a* (12.9±0.4 &lt;em&gt;vs.&lt;/em&gt; 15.5±0.4), h* (15.1±0.9 &lt;em&gt;vs.&lt;/em&gt; 28.6±0.9) and C* (13.5±0.5 &lt;em&gt;vs.&lt;/em&gt; 17.7±0.8). ZH increased shear force on meat (5.4±0.2 &lt;em&gt;vs.&lt;/em&gt; 3.7±0.2 kgf), and produced less fat (9.7±0.5 &lt;em&gt;vs.&lt;/em&gt; 12.5±0.5%) and bone (23.2±0.3 &lt;em&gt;vs.&lt;/em&gt; 24.6±0.2%), but more muscle (65.8±0.5 &lt;em&gt;vs.&lt;/em&gt; 61.2±0.4%). Zilpaterol hydrochloride use in lamb production caused leaner yield and more protein retention, at the expense of reducing meat sensory qualities.&lt;/p&gt;

Effect of zilpaterol hydrochloride on the carcass characteristics of Katahdin lamb terminal crosses

Veterinaria México OA ISSN: 2448-6760Cite this as:Partida-de-la-Peña JA, Casaya-Rodríguez TA, Rubio-Lozano MS, Méndez-Medina RD. Effect of zilpaterol hydrochloride on the carcass characteristics of Katahdin lamb terminal crosses. Veterinaria México OA. 2015;2(2). doi: 10.21753/vmoa.2.2.346.Zilpaterol hydrochloride (ZH) supplementation (0 vs. 0.15 mg/kg live weight) was evaluated based on the carcass characteristics of Katahdin x Charollais (32 KCh) and Katahdin x Dorper (28 KD) crosses. Lambs were fed a mixed ration with 14% crude protein (CP) and 2.9 Mcal EM/kg DM. Data were analyzed using a completely randomized 2 x 2 factorial design: 2 genotypes (KCh and KD) and 2 ZH levels (0 and 0.15 mg/kg live weight). No interaction was found between ZH and the genotypes. Zilpaterol hydrochloride increased dressing percentage from 52.1 ± 0.3 to 53.7 ± 0.4% (P &lt; 0.001). Animals that received ZH supplementation increased (P &lt; 0.001) the area of their Longissimus dorsi (Ld) by 18.5% and had 7.5% more muscle, 6.0% less bone and 22.4% less fat compared with control lambs (P &lt; 0.05). The breed of the sire had no effect on any of the variables studied. Final pH, fat thickness, conformation and linear carcass measurements did not change with ZH supplementation.Figure 1. Separation of the left shoulder [normalized method defined by Boccard and Dumont (1955) and modified by Colomer-Rocher et al., (1988)].

Effect of zilpaterol hydrochloride on the carcass characteristics of Katahdin lamb terminal crosses

Zilpaterol hydrochloride (ZH) supplementation (0 vs. 0.15 mg/kg live weight) was evaluated based on the carcass characteristics of Katahdin x Charollais (32 KCh) and Katahdin x Dorper (28 KD) crosses. Lambs were fed a mixed ration with 14% crude protein (CP) and 2.9 Mcal EM/kg DM. Data were analyzed using a completely randomized 2 x 2 factorial design: 2 genotypes (KCh and KD) and 2 ZH levels (0 and 0.15 mg/kg live weight). No interaction was found between ZH and the genotypes. Zilpaterol hydrochloride increased dressing percentage from 52.1 ± 0.3 to 53.7 ± 0.4% (P &lt; 0.001). Animals that received ZH supplementation increased (P &lt; 0.001) the area of their Longissimus dorsi (Ld) by 18.5% and had 7.5% more muscle, 6.0% less bone and 22.4% less fat compared with control lambs (P &lt; 0.05). The breed of the sire had no effect on any of the variables studied. Final pH, fat thickness, conformation and linear carcass measurements did not change with ZH supplementation.

Effects of zilpaterol hydrochloride on growth performance, blood metabolites, and fatty acid profiles of plasma and adipose tissue in finishing steers1

The effects of zilpaterol hydrochloride (ZH) on blood metabolites and fatty acid profiles of plasma and adipose tissue were evaluated in crossbred finishing steers (n = 18, BW 639 ± 12.69 kg) that were stratified by BW and randomly assigned, within strata (block), to receive 0 (control) or 8.33 mg/kg diet DM ZH. Cattle were fed once daily ad libitum in individual feeding pens (9 pens/treatment). Zilpaterol hydrochloride was fed for 23 d and withdrawn 3 d before harvest. Blood samples and measures of BW were taken on d 0, 7, 14, and 21. Concentrations of β-hydroxybutyrate (BHB), glucose, and lactate were determined from whole blood. Nonesterified fatty acids, urea nitrogen (PUN), glucose, lactate, and long-chain fatty acid (LCFA) concentrations were analyzed from plasma. Postharvest, adipose tissue samples (approximately 20 g) from subcutaneous fat covering the lumbar vertebrae were collected after 48 h of refrigeration and analyzed for LCFA profiles. Feeding ZH decreased DMI by 8% (P = 0.03) but did not affect BW gain or efficiency (P = 0.83 and P = 0.56, respectively). Addition of ZH resulted in greater HCW, dressing percentage, and LM area ( P = 0.02, P = 0.08, and P = 0.07, respectively) but did not influence other carcass traits (P > 0.10). A ZH × d interaction was observed for PUN and whole-blood glucose concentrations (P = 0.06), in which concentrations decreased in cattle receiving ZH. Nonesterified fatty acids, BHB, plasma glucose, whole-blood, and plasma lactate concentrations were unaffected by ZH (P > 0.10). Zilpaterol hydrochloride increased plasma concentrations of elaidic (P = 0.03), vaccenic (P = 0.006), and docosapentaenoic acids ( P= 0.08), but LCFA concentrations of adipose tissue were unaffected ( P> 0.10), suggesting no preferential oxidation of specific fatty acids. In conclusion, ZH supplementation decreased PUN concentration possibly due to decreased muscle catabolism, but components of blood related to lipid oxidation were unaffected.

Effect of zilpaterol hydrochloride on animal performance and carcass characteristics in sheep: a meta-analysis

The present study constitutes a meta-analysis of the use of zilpaterol hydrochloride (ZH) in sheep production (18 studies, n = 724 animals were evaluated), focused in its effects on productive performance and carcass characteristics in sheep who were given ZH in different doses (control 0, ≤0.50 and ≥0.54 mg/kg raised to the power 0.75 body weight (BW)). The analysis of the data assembled in the database was conducted by a statistical meta-analysis based on mixed model methodology. Results on weight gain were higher (P < 0.03) for the group supplemented with ≥0.54 mg vs. control treatment, feed conversion improved (P < 0.01) with the inclusion of ZH compared with the control group. Carcass yield and Longissimus dorsi area showed no differences (P > 0.05) between treatments, fat content in the carcass diminished in a linear effect (P = 0.02) with the inclusion of ZH. The results show a positive effect on improving animal performance, mainly in the characteristics on the fat deposition. The optimal dose varies depending on the variable to improve, ranged in 0.24 up to 1.21 mg ZH/kg BW0.75 to reduce fat and carcass get leaner or increase average daily gain, respectively.

A meta-analysis of zilpaterol and ractopamine effects on feedlot performance, carcass traits and shear strength of meat in cattle.

This study is a meta-analysis of the effects of the beta-agonists zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RAC) on feedlot performance, carcase characteristics of cattle and Warner Bratzler shear force (WBSF) of muscles. It was conducted to evaluate the effect of the use of these agents on beef production and meat quality and to provide data that would be useful in considerations on the effect of these agents on meat quality in Meat Standards Australia evaluations. We conducted a comprehensive literature search and study assessment using PubMed, Google Scholar, ScienceDirect, Scirus, and CAB and identification of other studies from reference lists in papers and searches. Searches were based on the key words: zilpaterol, zilmax, ractopamine, optaflexx, cattle and beef. Studies from theses obtained were included. Data were extracted from more than 50 comparisons for both agents and analysed using meta-analysis and meta-regression. Both agents markedly increased weight gain, hot carcase weight and longissimus muscle area and increased the efficiency of gain:feed. These effects were particularly large for ZH, however, fat thickness was decreased by ZH, but not RAC. Zilpaterol also markedly increased WBSF by 1.2 standard deviations and more than 0.8 kg, while RAC increased WBSF by 0.43 standard deviations and 0.2 kg. There is evidence in the ZH studies, in particular, of profound re-partitioning of nutrients from fat to protein depots. This work has provided critically needed information on the effects of ZH and RAC on production, efficiency and meat quality.

Effect of Zilpaterol Hydrochloride on Feedlot Performance and Carcass Characteristics in Weaner Steers

Effect of Zilpaterol Hydrochloride on Feedlot Performance and Carcass Characteristics in Weaner Steers