Analysis of modern technologies commonly used in beef cattle production: Conventional beef production versus nonconventional production using meta-analysis

Abstract

Conventional feeding systems use pharmaceutical products not allowed in natural or organic systems for finishing cattle. This review of data compares the performance effects (ADG, G:F, DMI) of technologies used in conventional feeding programs that are prohibited in organic programs, natural programs, or both. The technologies evaluated were steroid implants, monensin, tylosin, endectocides, and metaphylaxis with any antimicrobial. For inclusion in this analysis, studies were conducted in North America, reported randomization to treatment group, used beef cattle, contained an untreated control group, and were sourced from peer-reviewed journals. Forest plots were used to examine the data visually for trends toward a uniform effect of the technology on the outcomes of interest (ADG, DMI, G:F). Technologies that displayed a uniform response on the forest plot compared with negative controls were then analyzed using mixed models. Examination of forest plots for endectocides, steroid implants, monensin, and metaphylaxis technologies appeared to show performance advantages for treated cattle relative to cattle in negative control groups. An insufficient number of studies met the inclusion criteria to conduct meta-analyses comparing endectocides, monensin, or tylosin with negative controls. Average daily gain in feeder cattle given metaphylaxis on arrival was 0.11 kg/d (P < 0.01) greater relative to cattle that did not receive metaphylaxis on arrival. Implanting heifers increased ADG by 0.08 kg/d compared with nonimplanted controls (P = 0.09). Implants had no effect on G:F (P = 0.14) in heifers or on DMI (P = 0.44) relative to nonimplanted control heifers. Implanting steers was associated with greater ADG, by 0.25 kg/d (P < 0.01), and DMI, by 0.53 kg/d (P < 0.01), relative to nonimplanted control steers. Implants also improved G:F in steers relative to nonimplanted steers, by 0.02 (0.17 vs. 0.15; implanted vs. controls, P < 0.01; n = 21 studies). When average estimated differences in ADG and G:F for implanted and nonimplanted steers were incorporated into a breakeven model, implanted steers had a $77/animal lower cost of production than nonimplanted steers and a $349/animal lower cost of production than organically raised steers. These data illustrate the importance of capturing premiums when operating natural and organic production systems to maintain economic viability.

Feeding subtherapeutic antimicrobials to low-risk cattle does not confer consistent performance benefits

“…In year 2, TYL also improved gain:feed compared with Control cattle in the backgrounding period in accordance with previous research by Brown et al (1975) and Meyer et al (2009), although Wileman et al (2009) found that feeding TYL did not show a consistent advantage relative to Control cattle with respect to ADG, gain:feed or DMI. However, the observed reduction in DMI in year 2 during the finishing period and overall with TYL relative to all other treatments is inconsistent with other studies (Meyer et al 2009).…”

“…Although feeding subtherapeutic antimicrobials did not confer consistent performance advantages under the experimental conditions of the present study, the option of directly purchasing calves from a single source would not be available to most commercial feedlots, and housing cattle in small pens of 10 steers would undoubtedly raise costs. Similarly, Wileman et al (2009) estimated that a $78 per animal premium would be necessary for commercial beef production without the use antimicrobial metaphylaxis on arrival at the feedlot or tylosin in diets, due to predicted reductions in ADG and increases in liver abscesses, morbidity and mortality. The results of the present study demonstrate that low-risk cattle raised in small pens may have similar growth performance, health status and carcass characteristics to cattle fed subtherapeutic antimicrobials.…”

“…Tylosin or tetracycline to control liver abscesses and ionophores to improve ruminal energetic efficiency are the primary antimicrobials used in the feedlot industry (Wileman et al 2009). In-feed antimicrobials used to reduce liver abscesses target specific bacterial populations, such as Fusobacterium necrophorum and Actinomyces pyogenes that enter the portal circulatory system through lesions in the ruminal epithelium.…”

Liver abscesses in cattle: A review of incidence in Holsteins and of bacteriology and vaccine approaches to control in feedlot cattle12

“…The mode of action of tylosin is believed to be its inhibitory effect on F. necrophorum in the rumen, in the liver, or both (Nagaraja and Lechtenberg, 2007). A meta-analysis on liver abscess risks of cattle receiving tylosin vs. cattle not receiving tylosin in conventional feeding systems showed that the feeding of tylosin reduced the risk of liver abscesses from 30% to 8% (Wileman et al, 2009). The incidence of liver abscesses in tylosin-fed cattle may be because of the development of resistance in F. necrophorum or abscesses caused by bacteria other than F. necrophorum.…”

Effects of delayed steroid implanting on health, performance, and carcass quality in high health risk, auction market-sourced feedlot steers1,2

“…It is imperative to improve cattle growth efficiency and decrease the time to get animals to market. One particular technology, hormone implants, have been FDA approved for use in beef cattle production since 1957 (Raun, 2002) and are considered the single best management tool to improve feed efficiency and average daily gain in beef cattle (Wileman, 2009;Hermesmeyer, 2000;Johnson, 1998;Lawrence, 2007). The use of hormonal implants in cattle improve ADG, DMI, HCW and lower feed-to-gain ratios when compared to non-implanted cattle (Reinhardt, 2014).…”