Effects of dietary protein concentration and ractopamine hydrochloride on performance and carcass characteristics of finishing beef steers1

2016 ◽  
Vol 94 (5) ◽  
pp. 2097-2102 ◽  
Author(s):  
K. E. Hales ◽  
S. D. Shackelford ◽  
J. E. Wells ◽  
D. A. King ◽  
N. A. Pyatt ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Protein Concentration ◽  
Carcass Characteristics ◽  
Ractopamine Hydrochloride

scholarly journals 401 Effect of zinc source and ractopamine hydrochloride on the growth performance and carcass characteristics of steers fed in confinement to harvest

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 160-160
Author(s):  
John Wagner ◽  
William T Nelson ◽  
Terry Engle ◽  
Jerry Spears ◽  
Jeff Heldt ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
Feedlot Cattle ◽  
Beef Steers ◽  
Live Animal ◽  
Zinc Source ◽  
Dressing Percentage ◽  
Ractopamine Hydrochloride ◽  
Daily Gain

Abstract Four hundred and thirty-two beef steers (346.3 ± 63.7 kg BW) were used to determine the effects of Zn source on feedlot cattle fed ractopamine hydrochloride. Cattle were blocked in groups of 54 by BW and housed in 48 pens containing 9 steers per pen. Pens within a weight block were randomly assigned to treatments in a 2 x 3 factorial arrangement, with factors being: 1) 0 or 30.1 mg of ractopamine HCl/kg DM fed during the final 29 days on feed; and 2) Zn source: 90 mg of supplemental Zn/kg DM from ZnSO4; Zn sulfate (67%) + Zn methionine (33%); and Zn from Zn hydroxychloride, fed through the entire feeding period. Cattle were fed a high concentrate finishing diet for 154 d and slaughtered at a commercial abattoir. Average daily gain, DMI, feed efficiency and carcass characteristics were determined after slaughter. Zinc source had no impact on live animal performance. Cattle fed ractopamine HCl had greater (P < 0.01) final BW, greater (P < 0.001) ADG, improved (P < 0.001) G:F, heavier (P < 0.01) HCW, and larger (P < 0.05) longissimus muscle compared to non-ractopamine supplemented steers. There was a Zn source by ractopamine interaction (P < 0.01) for dressing percentage. Cattle receiving ractopamine HCl with Zn hydroxychloride had a greater dressing percentage (P < 0.05) when compared to ractopamine HCl cattle fed other Zn sources. Cattle receiving ractopamine HCl with Zn sulfate had a lesser dressing percentage (P < 0.05) when compared to ractopamine HCl cattle fed other Zn sources. Additional Zn source by ractopamine HCl interactions were not significant. These data indicate that Zn source has minimal impacts on feedlot steer performance and carcass characteristics when supplemented to cattle receiving 0.0 or 30.1 mg of ractopamine HCl/kg DM.

scholarly journals Effects of voluntary removal of ractopamine hydrochloride (Optaflexx) on live performance and carcass characteristics of beef steers

2021 ◽  
Author(s):  
P J Rincker ◽  
J B Allen ◽  
M Edmonds ◽  
M S Brown ◽  
J C Kube
Keyword(s):  
Dry Matter ◽  
Carcass Characteristics ◽  
Carcass Weight ◽  
Dry Matter Intake ◽  
Beef Steers ◽  
Live Performance ◽  
Meet Residue ◽  
Ractopamine Hydrochloride ◽  
The Impact ◽  
Linear Manner

Abstract There is a lack of consistency across the globe in how countries establish tissue ractopamine residue limits and which residue limits are applied to various tissues, particularly for edible noncarcass tissues. Therefore, some US beef slaughter organizations have recommended a 48-h voluntary removal of ractopamine before slaughter in order to meet residue requirements of specific export countries and maintain international trade. Our objective was to assess the impact of voluntary removal of ractopamine hydrochloride (Optaflexx®; Elanco, Greenfield, IN) up to 8 d before slaughter on growth performance and carcass characteristics. Crossbred beef steers (60 pens of 10 animals/pen) with an initial shrunk body weight (BW) of 611.8 ± 10 kg SEM were fed one of six treatments over 42 d. Treatments included a control that did not receive ractopamine, on-label use of ractopamine (0-d withdrawal), and 2, 4, 6, or 8 d of voluntary removal of ractopamine from feed before slaughter. The start of ractopamine feeding (30.1 mg/kg of diet dry matter for 32 d) was staggered so that blocks could be slaughtered on the same day. Dry matter intake was decreased by 0.5 kg/d when ractopamine was fed with a 0-d withdrawal (P = 0.04) compared to the control, but was not altered (P = 0.56) as the duration of ractopamine removal increased from 0 to 8 d. Final BW, total BW gain, and average daily BW gain were increased by feeding ractopamine with a 0-d withdrawal (P = 0.09) compared to the control, but these variables decreased in a linear manner (P = 0.10) as the duration of removal increased from 0 to 8 d. Gain efficiency was improved by 15% (P < 0.01) by feeding ractopamine with a 0-d withdrawal compared to the control, and gain efficiency decreased linearly (P = 0.06) as the duration of ractopamine removal increased. Approximately 2/3 of the increase in gain efficiency remained after 8 d of removal. Hot carcass weight was increased by 6 kg (P = 0.02) by feeding ractopamine with a 0-d withdrawal compared to the control. Measured carcass characteristics were not altered by ractopamine feeding or by removal before slaughter (P ≥ 0.24). The consequences of voluntary removal of ractopamine up to 8 d before slaughter were a linear decrease in live BW gain (0.64 kg/d), poorer gain efficiency, and numerically lighter carcass weight.

Effects of ractopamine hydrochloride on growth performance, carcass characteristics, and physiological response to different handling techniques1,2

2017 ◽  
Vol 95 (5) ◽  
pp. 1977-1992 ◽  
Author(s):  
J. A. Hagenmaier ◽  
C. D. Reinhardt ◽  
M. J. Ritter ◽  
M. S. Calvo-Lorenzo ◽  
G. J. Vogel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Physiological Response ◽  
Carcass Characteristics ◽  
Ractopamine Hydrochloride

Dietary Protein Requirements of Fishes — A Reassessment

1987 ◽  
Vol 44 (11) ◽  
pp. 1995-2001 ◽  
Author(s):  
Stephen H. Bowen
Keyword(s):  
Growth Rate ◽  
Dietary Protein ◽  
Protein Concentration ◽  
Trophic Ecology ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Intake Rate ◽  
Protein Requirement ◽  
Fish Physiology ◽  
Protein Retention

It is widely believed that fishes require more dietary protein than other vertebrates. Many aspects of fish physiology, nutrition, and trophic ecology have been interpreted within the context of this high protein requirement. Here, fishes are compared with terrestrial homeotherms in terms of (1) protein requirement for maintenance, (2) relative protein concentration in the diet required for maximum growth rate, (3) protein intake rate required for maximum growth rate, (4) efficiency of protein retention in growth, and (5) weight of growth achieved per weight of protein ingested. The two animal groups compared differ only in relative protein concentration in the diet required for maximum growth rate. This difference is explained in terms of homeotherms' greater requirement for energy and does not reflect absolute differences in protein requirement. The remaining measures of protein requirement suggest that fishes and terrestrial homeotherms are remarkably similar in their use of protein as a nutritional resource. Reinterpretation of the role of protein in fish physiology, nutrition, and trophic ecology is perhaps in order.

scholarly journals Effects of restricted feeding and re-alimentation of dietary protein or energy on compensatory growth of sheep

1970 ◽  
Vol 47 (3) ◽  
pp. 389-396
Author(s):  
W. Addah ◽  
A. Ayantunde ◽  
E.K. Okine
Keyword(s):  
Growth Performance ◽  
Dietary Protein ◽  
Feed Efficiency ◽  
Average Daily Gain ◽  
Carcass Characteristics ◽  
High Energy ◽  
Utilization Efficiency ◽  
Eating Quality ◽  
Nutrient Utilization Efficiency ◽  
Daily Gain

The study investigated the effects of re-alimenting dietary protein or energy on growth, carcass characteristics and meat eating quality parameters of sheep. Twenty-seven intact rams (~9 months; 11.3 ± 0.5 kg) were randomly divided into three groups. Each group was fed a maintenance diet (MT) containing, on dry matter (DM) basis, 105 g/kg crude protein (CP) and 8.4 MJ/kg DM metabolizable energy (ME) for 30 days. Thereafter, they were continually fed the same MT or re-alimented with a high protein diet (HP) containing 169 g/kg DM CP and 9.3 MJ/kg ME or a high energy diet (HE) containing 123 g/kg DM CP and 10.6 MJ/kg ME for an additional 30 days to determine the effects of re-alimentation of protein or energy on their growth performance and carcass characteristics. During the initial 30-day period, DM intake (DMI) and growth performance were similar among the three groups. However, upon re-alimentation, average daily gain (ADG) and feed efficiency of sheep re-alimented with HP were greater than those maintained continually on MT or re-alimented with HE. Sheep on HP had higher feed efficiency, ADG and heavier carcasses than those fed MT or re-alimented with HE during the whole 60-day period. Growth of most viscera was less responsive to the restriction-re-alimentation feeding regimen except for the weights of the lungs, heart and intestines. Meat from sheep re-alimented with HE had a more intense ‘sheepy’ flavour than those fed MT or re-alimented with HP, but juiciness and tenderness were not affected. The higher ADG of sheep re-alimented with protein may be related more to enhanced efficiency of feed utilization than to higher DMI.Keywords: average daily gain, feed restriction, nutrient utilization efficiency, visceral organs

The effect of variation in dietary protein concentration and energy intake on mineral accretion in early-weaned lambs

1981 ◽  
Vol 96 (3) ◽  
pp. 557-560 ◽  
Author(s):  
J. Davidson ◽  
I. McDonald
Keyword(s):  
Energy Intake ◽  
Dietary Protein ◽  
Protein Concentration ◽  
Calcium Concentration ◽  
Mineral Content ◽  
Calcium And Phosphorus ◽  
Rates Of Growth ◽  
Mineral Analyses

SUMMARYMineral analyses for calcium and phosphorus were carried out on lambs which had been fed diets contrasting in protein or energy or calcium concentration and had been slaughtered at defined live weights. Despite considerable variation in rates of growth arising from the widely different nutritional programmes, the mineral content of these lambs at a given weight remained remarkably stable on practical diets.

The Effects of Dietary Protein and Lysine Levels on Broiler Performance, Carcass Characteristics and N Excretion

2004 ◽  
Vol 3 (2) ◽  
pp. 148-152 ◽  
Author(s):  
M. Rezaei . ◽  
H. Nassiri Moghaddam . ◽  
J. Pour Reza . ◽  
H. Kermanshahi .
Keyword(s):  
Dietary Protein ◽  
Carcass Characteristics ◽  
Broiler Performance
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