Miscellaneous Growth Promotants

Public health officials and physicians are concerned about possible development of bacterial resistance and potential effects on human health that may be related to the use of antimicrobial agents in livestock feed. The focus of this research is aimed at determining the economic effects that subtherapeutic bans of antimicrobials would have on both swine producers and consumers. The results show that a ban on growth promotants for swine would be costly, totaling $242.5 million annually, with swine producers sharing the larger portion in the short run and consumers sharing the larger portion in the long run.

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Modification of beef quality through steer age at slaughter, breed cross and growth promotants

Canadian Journal of Animal Science ◽

10.4141/cjas2012-001 ◽

2012 ◽

Vol 92 (2) ◽

pp. 175-188 ◽

Cited By ~ 14

Author(s):

I. Girard ◽

J. L. Aalhus ◽

J. A. Basarab ◽

I. L. Larsen ◽

H. L. Bruce

Keyword(s):

Shear Force ◽

Sarcomere Length ◽

Gluteus Medius ◽

Beef Quality ◽

Water Losses ◽

Colour Measurements ◽

Hue Angle ◽

Red Angus ◽

Breed Crosses ◽

Growth Promotants

Girard, I., Aalhus, J. L., Basarab, J. A., Larsen, I. L. and Bruce, H. L. 2012. Modification of beef quality through steer age at slaughter, breed cross and growth promotants. Can. J. Anim. Sci. 92: 175–188. A 23 factorial experiment tested the interactions of slaughter age (12–13 or 18–20 mo), growth implants use (Component E-S, TE-S), ractopamine hydrochloride (RAC) feed supplementation use and breed cross [Hereford–Aberdeen Angus (HAA) or Charolais–Red Angus (CRA)] on pH, temperature, objective colour measurements, relative myoglobin states, sarcomere lengths, shear force, and water losses of m. semitendinosus (ST) and m. gluteus medius (GM) from 112 crossbred steers. In the ST, age affected objective colour measurements by increasing chroma and decreasing lightness (L*) and hue angle (P<0.05). Metmyoglobin (MMB) content of the ST also increased with steer age (P<0.05). In the GM, yearling-fed steers had greater MMB content than calf-fed steers, while hue angle varied the opposite way (P<0.05). Other variations in meat colour and myoglobin contents were more complex in the GM than the ST as they involved three-way interactions between the different treatments. Shear force and purge loss of the ST increased with implantation (P<0.05) with no change in sarcomere length (P>0.05). Shear force standard deviation was similar for breed crosses when yearling-fed but greatest for CRA breed cross when calf-fed (P<0.05). In both muscles, purge loss was increased by RAC supplementation (P<0.05). RAC supplementation did not affect sarcomere length and shear force in both muscles (P>0.10). In the GM, shear force increased with age and with CRA genetics (P<0.05). Results indicated that producers seeking to reduce beef toughness should consider using British crossbreds, exclude the use of hormonal implants and slaughter process steers at 12 to13 mo of age.

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Effects of hormonal growth promotants (HGP) on growth, carcass characteristics, the palatability of different muscles in the beef carcass and their interaction with aging

Australian Journal of Experimental Agriculture ◽

10.1071/ea07131 ◽

2008 ◽

Vol 48 (11) ◽

pp. 1405 ◽

Cited By ~ 29

Author(s):

J. M. Thompson ◽

B. M. McIntyre ◽

G. D. Tudor ◽

D. W. Pethick ◽

R. Polkinghorne ◽

...

Keyword(s):

Carcass Characteristics ◽

Gluteus Medius ◽

Biceps Femoris ◽

Sensory Testing ◽

Fat Percentage ◽

Triceps Brachii ◽

Trenbolone Acetate ◽

Aging Rates ◽

Growth Promotants ◽

Feed Samples

Effects of hormonal growth promotant (HGP) implantation on liveweight, carcass and meat quality measurements were examined using 80 Angus yearling cattle. After entry to the feedlot, 40 steers and 40 heifers were implanted with Revalor-S (28 mg oestradiol and 140 mg trenbolone acetate) and Revalor-H (20 mg oestradiol, 200 mg trenbolone acetate), respectively. Cattle were slaughtered after 55 and 65 days on feed. Samples from the Mm. longissimus dorsi, biceps femoris (the cap and body portions), gluteus medius (the eye and D portions), infraspinatus and triceps brachii were prepared for sensory testing after aging for 5 and 21 days after slaughter. A total of 854 muscle samples were cooked by grill (601) or roast (253) methods and served to consumers using the Meat Standards Australia taste panel protocols. When adjusted to the same initial liveweight, implantation with Revalor-H and Revalor-S resulted in a 4 and 7% increase in slaughter weight, respectively. Implantation resulted in an increased ossification score in steers (P < 0.05), but not in heifers. There was a significant interaction (P < 0.05) between HGP implantation and days aged for shear force. There was a small effect of HGP implants on compression (P < 0.05), but not on cook loss and intramuscular fat percentage. Muscles differed in their response to HGP implantation (P < 0.05) for tenderness, overall liking and palatability scores. Muscles also differed in their aging rates after slaughter (P < 0.05). The greatest response in sensory scores to HGP implantation was found in those muscles that had the highest aging rates. Possible mechanisms by which muscles differed in their response to HGP implantation are discussed.

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Susceptibility of Meat Starter Cultures to Antimicrobials Used in Food Animals in Canada

Journal of Food Protection ◽

10.4315/0362-028x-73.5.916 ◽

2010 ◽

Vol 73 (5) ◽

pp. 916-922 ◽

Cited By ~ 3

Author(s):

R. P. CORDEIRO ◽

T. DU ◽

M. R. MULVEY ◽

D. O. KRAUSE ◽

R. A. HOLLEY

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Antimicrobial Agents ◽

Antibiotic Resistance Genes ◽

Starter Cultures ◽

Phenotypic Resistance ◽

Negative Results ◽

Susceptibility Tests ◽

Growth Promotants ◽

Or Genes

Lactic acid bacteria (LAB) are extensively used in the food industry for fermentation processes. However, it is possible that these bacteria may serve as a reservoir for antibiotic resistance genes that can be transferred to pathogens, giving rise to public health concerns. Animal operations that use antimicrobials as growth promotants have been linked to the origin of resistance due to the selective effect of low levels of antimicrobial used in this management strategy. The objective of this study was to determine the antimicrobial susceptibilities and mechanisms of resistance for 30 isolates of meat starter cultures commonly used in dry sausage fermentations to 20 antimicrobial agents. Susceptibility tests were performed by broth microdilution using Iso-Sensitest broth (90%, vol/vol) and de Man Rogosa Sharpe (MRS) broth (10%, vol/vol). The results showed that all 30 isolates exhibited resistance to at least three antimicrobials regardless of antimicrobial class while 17 or 30% of strains were resistant to antibiotics in three or six different classes, respectively. The incidence of antimicrobial resistance was higher among Pediococcus pentosaceus and lower for Staphylococcus carnosus strains. Genetic determinants for the lincosamide, macrolide, and tetracycline antimicrobials were not found using PCR. Phenotypic resistance in the absence of known resistance genes found here suggests that other mechanisms or genes might have contributed to the negative results. Further studies are needed to explore the genetic mechanisms underlying the prevalence of antibiotic resistance in Pediococcus species.

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Effects of hormonal growth promotants on beef quality: a meta-analysis

Journal of Animal Science ◽

10.1093/jas/sky123 ◽

2018 ◽

Vol 96 (7) ◽

pp. 2675-2697 ◽

Cited By ~ 2

Author(s):

Ian J Lean ◽

Helen M Golder ◽

Natasha M Lees ◽

Peter McGilchrist ◽

José E P Santos

Keyword(s):

Meta Analysis ◽

Beef Quality ◽

Growth Promotants

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Effects of calf- and yearling-fed beef production systems and growth promotants on production and profitability

Canadian Journal of Animal Science ◽

10.4141/cjas2012-035 ◽

2013 ◽

Vol 93 (1) ◽

pp. 171-184 ◽

Cited By ~ 16

Author(s):

Óscar López-Campos ◽

Jennifer L. Aalhus ◽

Erasmus K. Okine ◽

Vern S. Baron ◽

John A. Basarab

Keyword(s):

Dry Matter ◽

Production Systems ◽

Beef Production ◽

Feed Conversion ◽

Adrenergic Agonist ◽

Growth Implants ◽

Quality Grade ◽

Reduce Risk ◽

Growth Promotants ◽

Growth Implant

López-Campos, Ó., Aalhus, J. L., Okine, E. K., Baron, V. S. and Basarab, J. A. 2013. Effects of calf- and yearling-fed beef production systems and growth promotants on production and profitability. Can. J. Anim. Sci. 93: 171–184. In each of 2 yr, 112 spring-born steers were used to evaluate the effect of calf-fed vs. yearling-fed with and without growth implant and β-adrenergic agonist on production parameters and economic potential. Steers were grouped into: (1) non-implanted feeders harvested at 11–14 mo of age, (2) growth implanted feeders harvested at 11–14 mo of age, (3) non-implanted feeders harvested at 19–23 mo of age, and (4) growth implanted feeders harvested at 19–23 mo of age. Production data were collected and economic evaluation was performed. Calf-fed steers grew slower (1.21 vs. 1.99±0.07 kg d−1) and had a poorer feed conversion ratio [5.32 vs. 4.99±0.34 kg dry matter intake (DMI) kg−1 gain] during the feedlot dietary adjustment period than yearling-fed. Calf-fed steers were more efficient than yearling-fed during the first 76–83 d (5.16 vs. 7.33±0.11 kg DMI kg−1 gain) and latter 48–79 d (5.69 vs. 14.28±1.50 kg DMI kg−1 gain) of the finishing period. Implanted steers were more efficient than non-implanted during the dietary feedlot adjustment period (4.80 vs. 5.52±0.15 kg DMI kg−1 gain), and during the first 76–83 d (6.05 vs. 6.44±0.11 kg DMI kg−1 gain) and latter 48–79 d of the finishing period (9.29 vs. 10.69±1.50 kg DMI kg−1 gain). Implanted steers grew 11.4–19.6% faster than non-implanted throughout the finishing period, while yearling-fed grew 11.1–12.9% faster during the first 76–83 d, but 49.1–64.4% slower during the last 48–79 d of the finishing period compared with calf-fed. Quality grade was improved for non-implanted steers, with 43.6% of yearling-fed and 35.7% calf-fed steers grading AAA. Adjusted net return was best for calf-fed implanted ($17.52 head−1), followed by calf-fed non-implanted ($−41.92 head−1), yearling-fed implanted ($−73.77 head−1), and yearling-fed non-implanted ($−99.65 head−1) production strategies. The results of the present study suggest that reducing age at slaughter combined with growth implant can increase profit and reduce risk, but growth implants can negatively affect the carcass quality.

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A systems evaluation of high-input management using fortified molasses for beef production in Australia's dry tropics

Animal Production Science ◽

10.1071/ea07225 ◽

2009 ◽

Vol 49 (3) ◽

pp. 177 ◽

Cited By ~ 3

Author(s):

Geoffry Fordyce ◽

Ruth Coates ◽

Megan Debney ◽

Stan Haselton ◽

Robert Rebgetz ◽

...

Keyword(s):

Best Practice ◽

Pregnancy Rates ◽

Reproductive Efficiency ◽

Price Rise ◽

High Input ◽

Net Worth ◽

Dry Tropics ◽

Age Cohort ◽

Beef Producers ◽

Growth Promotants

The potential of beef producers to profitably produce 500-kg steers at 2.5 years of age in northern Australia’s dry tropics to meet specifications of high-value markets, using a high-input management (HIM) system was examined. HIM included targeted high levels of fortified molasses supplementation, short seasonal mating and the use of growth promotants. Using herds of 300–400 females plus steer progeny at three sites, HIM was compared at a business level to prevailing best-practice, strategic low-input management (SLIM) in which there is a relatively low usage of energy concentrates to supplement pasture intake. The data presented for each breeding-age cohort within management system at each site includes: annual pregnancy rates (range: 14–99%), time of conception, mortalities (range: 0–10%), progeny losses between confirmed pregnancy and weaning (range: 0–29%), and weaning rates (range: 14–92%) over the 2-year observation. Annual changes in weight and relative net worth were calculated for all breeding and non-breeding cohorts. Reasons for outcomes are discussed. Compared with SLIM herds, both weaning weights and annual growth were ≥30 kg higher, enabling 86–100% of HIM steers to exceed 500 kg at 2.5 years of age. Very few contemporary SLIM steers reached this target. HIM was most profitably applied to steers. Where HIM was able to achieve high pregnancy rates in yearlings, its application was recommended in females. Well managed, appropriate HIM systems increased profits by around $15/adult equivalent at prevailing beef and supplement prices. However, a 20% supplement price rise without a commensurate increase in values for young slaughter steers would generally eliminate this advantage. This study demonstrated the complexity of profitable application of research outcomes to commercial business, even when component research suggests that specific strategies may increase growth and reproductive efficiency and/or be more profitable. Because of the higher level of management required, higher costs and returns, and higher susceptibility to market changes and disease, HIM systems should only be applied after SLIM systems are well developed. To increase profitability, any strategy must ultimately either increase steer growth and sale values and/or enable a shift to high pregnancy rates in yearling heifers.

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Greenhouse Gas Emissions from Calf- and Yearling-Fed Beef Production Systems, With and Without the Use of Growth Promotants

Animals ◽

10.3390/ani2020195 ◽

2012 ◽

Vol 2 (2) ◽

pp. 195-220 ◽

Cited By ~ 28

Author(s):

John Basarab ◽

Vern Baron ◽

Óscar López-Campos ◽

Jennifer Aalhus ◽

Karen Haugen-Kozyra ◽

...

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Production Systems ◽

Beef Production ◽

Gas Emissions ◽

Growth Promotants

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Behavioural effects of yearling grain-finished heifers exposed to differing environmental conditions and growth-promoting agents

Australian Journal of Experimental Agriculture ◽

10.1071/ea07385 ◽

2008 ◽

Vol 48 (9) ◽

pp. 1155 ◽

Cited By ~ 4

Author(s):

T. L. Mader ◽

J. B. Gaughan ◽

W. M. Kreikemeier ◽

A. M. Parkhurst

Keyword(s):

Heat Stress ◽

Cold Stress ◽

Feed Intake ◽

Environmental Conditions ◽

Time Of Day ◽

Feedlot Cattle ◽

Trenbolone Acetate ◽

Growth Promoting ◽

Adverse Environmental Conditions ◽

Growth Promotants

Two groups of 108 Angus cross yearling heifers were utilised to determine the effects of growth-promoting agents on behaviour, when utilised under thermoneutral, hot and cold environmental conditions. Pens of heifers were observed throughout the day for feed intake pattern via bunk score, panting (hot), degree of bunching and shivering (cold). For cattle that were exposed to cold stress, feed intake was greater earlier in the day, with the majority of the feed consumed by 1500 hours and little or no feed consumed at night, while the opposite trend occurred under heat stress. Nearly 46% of the pens containing heat-stressed heifers had greater than 50% of their feed remaining in the bunk at 1900 hours. Pens of heifers exposed to thermoneutral conditions had a tendency to show elevated panting scores at 0700 hours, while heifers exposed to hot conditions did not, indicating some acclimation to heat stress had already taken place for the heifers exposed to hot conditions. Panting score did not appear to be affected by growth-promoting treatment. Under cold stress, 100% of the cattle displayed bunching behaviour throughout the day, while under hot and thermoneutral conditions, maximum bunching (25 to 30%) occurred at 1500 hours. Within an environmental condition, trenbolone acetate cattle tended to bunch more under thermoneutral and hot conditions, particularly in the morning, when compared with other treatment groups; control and oestrogen-treated cattle tended to bunch less under the same conditions, regardless of the time of day. Although data were inconclusive as to overall effects of growth promotants on mitigating cold stress, shivering scores were increased with a more aggressive growth-promoting treatment (P < 0.05). These findings suggest that if growth promotants, which are used in feedlot cattle, impact cattle exposed to adverse environmental conditions, then they tend to be more effective at mitigating heat stress than cold stress.

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