Effect of essential oils, tylosin, and monensin on finishing steer performance, carcass characteristics, liver abscesses, ruminal fermentation, and digestibility1

Abstract

A feedlot (Exp. 1) experiment was conducted to evaluate the effects of an essential oil mixture (EOM), experimental essential oil mixture (EXP), tylosin, and monensin (MON) on performance, carcass characteristics, and liver abscesses. A metabolism experiment (Exp. 2) was conducted to evaluate the effects of EOM, EXP, and MON on ruminal fermentation and digestibility in finishing steers. In Exp. 1, 468 yearling steers (398 ± 34 kg initial BW) were used in 50 pens (10 pens/treatment) and received their respective dietary treatments for 115 d. Five dietary treatments were compared in Exp. 1: 1) control, no additives (CON); 2) EOM, 1.0 g/steer daily; 3) EXP, 1.0 g/steer daily; 4) EOM, 1.0 g/steer daily plus tylosin, 90 mg/ steer daily (EOM+T); and 5) monensin, 300 mg/steer daily plus tylosin, 90 mg/steer daily (MON+T). Compared with CON, steers fed MON+T had decreased DMI (P < 0.01), and steers fed EOM+T and MON+T had improved G:F (P ≤ 0.02). Average daily gain was not different among treatments (P > 0.58). There was a trend (P = 0.09) for a treatment effect on 12th-rib fat thickness, which resulted in a significant increase in calculated yield grade for the EOM+T treatment. No other carcass characteristics were affected by treatment (P ≥ 0.10). Prevalence of total liver abscesses was reduced for steers fed tylosin compared with no tylosin (P < 0.05). In Exp. 2, 8 ruminally fistulated steers (399 ± 49 kg initial BW) were assigned randomly to 1 of 4 treatments in a replicated 4 × 4 Latin square designed experiment. Treatments were 1) CON, 2) EOM, 3) EXP, and 4) MON with feeding rates similar to Exp. 1. There were no differences in DMI, OM intake, and apparent total tract DM or OM digestibilities among treatments (P > 0.30). Feed intake patterns were similar among feed additive treatments (P > 0.13). Total VFA (P = 0.10) and acetate (P = 0.06) concentrations tended to be affected by treatment with EOM numerically greater than CON. Average ruminal pH ranged from 5.59 to 5.72 and did not differ among treatments. Addition of a EOM or monensin to a diet containing tylosin improves G:F, but little difference was observed in metabolism or digestibility.

Addition of increasing doses of ricinoleic acid from castor oil (<i>Ricinus communis</i> L.) in diets of Nellore steers in feedlots

“…The results for ADG and BW in this trial disagree with a large number of studies with essential oils, since Beauchemin et al (2006) and Meyer et al (2009) when supplementing beef cattle with essential oils, observed no difference in ADG compared with the control diets. Both authors emphasize that the lack of effect on performance is due to the similarity in dry matter intake of animals in different treatments.…”

“…With regard to the feed and conversion ratios in a similar experiment, Meyer et al (2009) observed no effect on feed efficiency in cattle supplemented with essential oils compared with the control diet. Moreover, Benchaar and McGinn (2008) when evaluating beef cattle fed 0.2 or 4 g/day of essential oils found a quadratic effect on feed efficiency, with it being better in the animals fed with 2 g of essential oil.…”

“…With regard to dry matter intake, some data from the literature show that essential oils have attractive and palatable properties that influence intake by animals (Wallace, 2004) (Table 3). Other authors, however, observed no effect on the dry matter intake of beef cattle supplemented with essential oils (Meyer et al, 2009). Hence, reports on the effect of essential oils on dry matter intake are contradictory.…”

Essential Oils in the Diet of Crossbred (½ Angus vs. ½ Nellore) Bulls Finished in Feedlot on Animal Performance, Feed Efficiency and Carcass Characteristics

“…Benchaar et al (2006) fed crossbred steers and heifers (Angus vs. Hereford) with distinct levels (~250 or 500 mg/kg of DM) of a mix of essential oils (clove, vanillin, lemon and thymus), and no differences in FBW and ADG were observed. Likewise, no differences on FBW and ADG were observed when young steers received 80 mg/kg of DM of a mix of thymol, eugenol, vanillin, guaiacol and limonene (Meyer et al, 2009 (Benchaar & Greathead, 2011). Thus, essential oils can modulate the rumen microbiota, consequently affecting the production volatile organic compounds and protein degradation (Calsamiglia et al, 2007).…”

Effect of Orange Oil on the Oral Absorption of Enrofloxacin in Rats

“…Some essential oils have demonstrated strong antimicrobial, antifungal, anti-inflammatory and insecticidal activities [1,7,9,16,20]. Recently, there was extensive research on the biomedical applications in industrial animals served as antibiotic alternatives and natural insecticides [2,14,17,28].…”