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Objective Our objective was to evaluate subsequent feedlot performance and carcass characteristics of steers that previously grazed endophyte-infected fescue and received either a mineral only (MIN) supplement or a cumulative management (CM) strategy. Materials and Methods Grazing occurred in autumn and winter of 2018 and 2019 with feedlot finishing after grazing. Within year, 60 fall-weaned steers (282 ± 7.7 kg) were randomly assigned to either MIN (n = 3) or CM (n = 3) pastures. The CM strategy include a steroidal growth implant, monensin, and 1% BW (as-fed basis) of 1:1 corn gluten feed:soybean hull mix. During feedlot finishing, steers were penned to maintain pasture groups. Results and Discussion Steers receiving CM were heavier (P = 0.002) entering the feedlot and finished 40 d earlier than MIN (161 vs. 201 ± 5.7 d, P Implications and Applications A CM strategy increases weight of steers grazing toxic fescue. This additional weight can reduce the days required for feedlot finishing without influencing carcass characteristics. Improved grazing performance and fewer days for feedlot finishing may reduce environmental impact.

Na ionophores increase intracellular Na+ ([Na+]i). Membrane potentials and currents were measured using microelectrode and whole-cell patch-clamp techniques. Monensin (10-6-3×10-5 M) reduced the slope of the pacemaker potentials and shortened the action potential duration (APD) in sino-atrial nodal and Purkinje cells. Monensin (10-5 M) shortened the APD and reduced the amplitude of the plateau phase in ventricular myocytes. Monensin decreased the hyperpolarization-activated inward current (If), and it increased the transient outward potassium current (Ito) in Purkinje cells. In addition, monensin decreased the sodium current (INa), shifting the inactivation curve to the hyperpolarized direction. Moreover, monensin decreased the L-type calcium current (ICa) in ventricular myocytes. The Na+-Ca2+ exchange current (INa-Ca) was augmented particularly in the reverse mode, and the Na+-K+ pump current (INa-K) was also activated by monensin in cardiomyocytes. The ATP-activated potassium current (IK,ATP) could be induced by monensin. Notably, the inward rectifying K+ current (IK1), and the slow delayed outward K+ current (IKs) were not affected evidently by monensin. Collectively, alteration of [Na+]i can influence the activities of various ion channels and transporters. Thus, the significance of altered [Na+]i should be taken into consideration in the action of drugs affecting [Na+]i such as digitalis, Na+ channel blockers, and Na+ channel activating agents.

Our objectives were to evaluate the effects of prepartum monensin supplementation and dry-period nutritional strategy on the postpartum productive performance of cows fed monensin during lactation. A total of 102 Holstein cows were enrolled in the experiment (32 primiparous and 70 multiparous). The study was a completely randomized design, with randomization restricted to balance for parity, body condition score, and expected calving date. A 2 × 2 factorial arrangement of prepartum treatments was used; the variables of interest were prepartum feeding strategy [controlled-energy diet throughout the dry period (CE) vs. controlled-energy diet from dry-off to 22 d before expected parturition, followed by a moderate-energy close-up diet from d 21 before expected parturition through parturition (CU)] and prepartum monensin supplementation [0 g/t (control, CON) or 24.2 g/t (MON); Rumensin; Elanco Animal Health, Greenfield, IN]. Lactation diets before and after the dry period contained monensin at 15.4 g/t. During the close-up period, cows fed CU had greater DM and NEL intakes than cows fed CE. Calf BW at birth tended to be greater for cows fed CU than for those fed CE but was not affected by MON supplementation. Diet did not affect calving difficulty score, but cows supplemented with MON had an increased calving difficulty score. We found a tendency for a MON × parity interaction for colostral IgG concentration, such that multiparous MON cows tended to have lower IgG concentration than CON cows, but colostral IgG concentration for primiparous MON and CON cows did not differ. Postpartum milk yield did not differ between diets but tended to be greater for cows supplemented with MON. Milk fat and lactose content were greater for cows fed CU than for those fed CE, and lactose content and yield were increased for cows supplemented with MON. Solids-corrected and fat-corrected milk yields were increased by MON supplementation, but were not affected by diet. Overall means for postpartum DMI did not differ by diet or MON supplementation. The CU diet decreased the concentration of nonesterified fatty acids during the close-up period but increased it postpartum. Neither diet nor monensin affected β-hydroxybutyrate or liver composition. Overall, postpartum productive performance differed little between prepartum dietary strategies, but cows fed MON had greater energy-corrected milk production. In herds fed monensin during lactation, monensin should also be fed during the dry period.

Although animal manure is applied to agricultural fields for its nutrient value, it may also contain potential contaminants. To determine the variability in such contaminants as well as in valuable nutrients, nine uncomposted manure samples from Idaho dairies collected during 2.5 years were analyzed for macro- and micro-nutrients, hormones, phytoestrogens, antibiotics, veterinary drugs, antibiotic resistance genes, and genetic elements involved in the spread of antibiotic resistance. Total N ranged from 6.8 to 30.7 (C:N of 10 to 21), P from 2.4 to 9.0, and K from 10.2 to 47.7 g/kg manure. Zn (103 – 348 mg/kg) was more abundant than Cu (56 – 127 mg/kg) in all samples. Phytoestrogens were the most prevalent contaminants detected, with concentrations fluctuating over time, reflecting animal diets. This is the first study to document the presence of flunixin, a non-steroidal anti-inflammatory drug, in solid stacked manure from regular dairy operations. Monensin was the most frequently detected antibiotic. Progesterones and sulfonamides were regularly detected. We also investigated the relative abundance of several types of plasmids involved in the spread of antibiotic resistance in clinical settings. Plasmids belonging to the IncI, IncP, and IncQ1 incompatibility groups were found in almost all manure samples. IncQ1 plasmids, class 1 integrons, and sulfonamide resistance genes were the most widespread and abundant genetic element surveyed, emphasizing their potential role in the spread of antibiotic resistance. The benefits associated with amending agricultural soils with dairy manure must be carefully weighed against the potential negative consequences of any manure contaminants.

Sixteen (16) West African dwarf goats weighing an average of 73 kg +1.2 were used in a completely randomized experimental design to determine the influence of feeding monensin on intake of some anti-nutritive components contained in the diet. Results showed that animals placed on monensin supplemented diets at levels of 15, 30 and 45 mg/kg DM had significantly (P0.05) occurred amongst the monensin-supplemented groups. Fecal concentrations of tannin, oxalate, saponin and nitrate were similarly observed to reduced (P0.05). Reductions in total dry matter intake were observed in response to monensin supplementation at 15, 30 and 45 mg/kg DM relative to the control but dry matter digestibility and weight gain in animals were not altered. The reductions in the intake of dry matter with monensin feeding were assumed to have consequently caused the reductions in the intake of anti-nutritive components from the diet. This reduction caused by monensin would be of benefit, in a bid to lessen some of the nutritional problems usually encountered when animals consume large quantities of these components in the diet. Monensin inclusion at levels between 15 and 45mg/kg DM could therefore be recommended to alleviate toxicity problems commonly associated with intake of anti-nutritive substances in feed.

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55°C that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

The glucagon receptor (GCGR) activated by the peptide hormone glucagon is a seven-transmembrane G protein-coupled receptor (GPCR) that regulates blood glucose levels. Ubiquitination influences trafficking and signaling of many GPCRs, but its characterization for the GCGR is lacking. Using endocytic colocalization and ubiquitination assays, we have identified a correlation between the ubiquitination profile and recycling of the GCGR. Our experiments revealed that GCGRs are constitutively ubiquitinated at the cell surface. Glucagon stimulation not only promoted GCGR endocytic trafficking through Rab5a early endosomes and Rab4a recycling endosomes, but also induced rapid deubiquitination of GCGRs. Inhibiting GCGR internalization or disrupting endocytic trafficking prevented agonist-induced deubiquitination of the GCGR. Furthermore, a Rab4a dominant negative (DN) that blocks trafficking at recycling endosomes enabled GCGR deubiquitination, whereas a Rab5a DN that blocks trafficking at early endosomes eliminated agonist-induced GCGR deubiquitination. By down-regulating candidate deubiquitinases that are either linked with GPCR trafficking or localized on endosomes, we identified signal-transducing adaptor molecule-binding protein (STAMBP) and ubiquitin-specific protease 33 (USP33) as cognate deubiquitinases for the GCGR. Our data suggest that USP33 constitutively deubiquitinates the GCGR, whereas both STAMBP and USP33 deubiquitinate agonist-activated GCGRs at early endosomes. A mutant GCGR with all five intracellular lysines altered to arginines remains deubiquitinated and shows augmented trafficking to Rab4a recycling endosomes compared with the WT, thus affirming the role of deubiquitination in GCGR recycling. We conclude that the GCGRs are rapidly deubiquitinated after agonist-activation to facilitate Rab4a-dependent recycling and that USP33 and STAMBP activities are critical for the endocytic recycling of the GCGR.

Our objective was to evaluate the interaction of supplemental essential oils (EO) and monensin (MON) on performance and digestion. Two levels of EO (0 vs 0.011% Xtract®) and two levels of MON (0 vs 33 mg/kg) were evaluated in a 2 × 2 factorial arrangement. Treatment effects on 216-d growth performance were evaluated in 96 Holstein steers. Supplemental MON enhanced (P ≤ 0.05) ADG, DMI and gain efficiency. Without EO, MON improved (P

Coccidiosis is a high-prevalence disease that annually entails huge costs for the poultry industry. Control of coccidiosis in poultry production is based on the use of coccidiostats and vaccines. However, along with the problem of drug resistance, there is a concern about food safety and drug residues in poultry products. The objective of this study was to evaluate the effect of sodium bisulfate (SBS) in comparison with monensin (M) and their combination (SBSM) effects on controlling coccidiosis in broilers. In a randomized design, 300 chickens (Ross 308) were divided into 5 treatments and 4 replications (15 birds per replicate). All birds, except the negative control (NC), were orally inoculated with 4 Eimeria species on 14 D of age. Treatments included were as follows: NC, an unsupplemented basal diet, nonchallenged; positive control, a basal diet unsupplemented, challenged with Eimeria spp; a basal diet supplemented with 5 g/kg of SBS; a basal diet supplemented with 1 g/kg of M; and a basal diet supplemented with 5 g/kg SBS and 1 g/kg M (SBSM). Oocyst shedding per gram (OPG) of the faecal sample from each experimental unit was counted on 5 to 14 D after inoculation. Two chicks from each experimental unit were euthanized to investigate intestinal lesions on day 5 after inoculation. The NC birds showed the highest BW gain and the lowest feed conversion ratio. The birds in the SBSM group had improved feed consumption compared with the M group in the prechallenge period (P < 0.05). All supplemented treatments resulted in a significant decrease in OPG. The M and SBSM treatments showed more efficacy than the SBS group (P < 0.05) in reducing OPG. There was a significant reduction in cecal lesions owing to supplementation with SBS, but the effect of SBS in the upper part of the intestine was lower than the M and SBSM groups (P < 0.05). Based on the results of this study, SBS has protective effects against coccidiosis in ceca, and the combination of M and SBS (SBSM) did not show any further improvement effect compared with M alone on the control of coccidiosis.

The amount of milk Canadian dairy farmers produce is limited to a production quota expressed in milk fat. Because milk economic value is primarily based on fat and protein, it can be advantageous to decrease the milk fat to protein ratio. Monensin sodium has been suggested to reduce milk fat proportion and outputs, but not milk protein. Publications using lactating dairy cows were utilized to assess predictability of production responses to monensin feeding based upon their base production characteristics and diet composition. Predicted animal output changes due to monensin had poor fits with low r2 (0.31–0.44) and unevenly distributed residuals. Further assessment revealed that cow characteristics, and diets, were not independent of monensin feeding level. Thus, the 43 comparisons were clustered into levels of 10–12, 14–18, or 20–24 mg kg−1 of diet dry matter (DM). Milk fat yield reductions due to monensin differed (P −1 DM), or tended to differ (P = 0.057; 20–24 mg kg−1 DM), from zero (i.e., no change). Monensin addition to total mixed rations of lactating dairy cows negatively impacted milk fat yield to a greater extent than milk protein.

Summary: This study assesses the efficacy of 2 different potentiated ionophores (monensin and narasin) and a chemical (nicarbazin, a shuttle) in program with narasin to control coccidiosis in challenged male broilers through the evaluation of performance and macroscopic lesions of internal organs. A total of 4,400 broiler chicks were housed in 44 floor pens of 100 birds each; birds of the first group were fed a narasin/nicarbazin (NN)–containing diet from 0 to 27 D of age followed by narasin diet until market age, and those of group 2 were fed a monensin/nicarbazin diet followed by narasin ration for the same trial periods. The coccidia challenge was performed at day 1 by the inclusion of a proven Eimeria-infected litter in the bedding of all floor pens followed by an oral challenge using a commercial cocci vaccine at 7 D of age with a concentration of 11 times the vaccine dose. Although results showed that NN and monensin/nicarbazin treatments both demonstrated efficacy at reducing coccidian lesions, NN significantly increased BW and reduced feed conversion ratio (P < 0.05) at 27 (1,405 vs. 1284 g and 1.458 vs. 1.566, respectively) and at 33 D of age (2,178 vs. 2,026 g and 1.549 vs. 1.642, respectively). Weight and weight percentages of the ready-to-cook carcass and carcass cutup parts were significantly improved by NN. Narasin/nicarbazin inclusion in diet for 0 to 27 D followed by narasin until market weight was a successful strategy because, in addition to preventing and controlling coccidiosis, it improved performance of broiler chickens.

Our previous work indicated that feeding oregano essential oil (OEO) in combination with monensin (MON) may not be mutually beneficial to dairy calf growth performance. To evaluate this observation further, a 240-d long-term growth experiment was conducted using 12 young growing Holstein bulls using a 2 × 2 factorial treatment arrangement. Main factors were OEO and MON arranged in 4 individual treatments: (1) ration fed without OEO or MON (control), (2) OEO fed at 26 mg/kg of dry matter (DM), (3) MON fed at 25 mg/kg of DM, and (4) OEO and MON fed in combination (OEO+MON). Holstein bulls were 70 d of age and similar in body weight (BW; 93.3 ± 4.54 kg) and individually fed for 240 d. The targeted feeding rates of OEO and MON were blended into 200 g of concentrate and top dressed each morning to a corn stalklage-based ration. Body weights, frame measurements, and blood samples were collected monthly. Interactions of OEO by MON were detected for BW, BW gain, average daily gain, and a trend for feed conversion. Bulls fed OEO or MON demonstrated greater final BW (368, 385, 381, and 358 kg for control, OEO, MON, and OEO+MON, respectively), and BW gains (278, 292, 285, and 265 kg) and average daily gain (1.16, 1.22, 1.19, 1.11 kg/d) were greatest for bulls fed OEO or MON compared with bulls fed OEO+MON; bulls fed the control were intermediate and similar to bulls fed MON. Intake of DM was greater for bulls fed OEO (6.55, 6.99, 6.60, and 6.42 kg/d) compared with bulls fed remaining treatments. Frame growth gain measurements for heart girth, abdominal girth, withers height, body length, and cannon bone circumference were similar for bulls fed all treatments. Serum triglyceride (0.23, 0.25, 0.28, and 0.24 mmol/L) concentrations were greater for bulls fed MON compared with bulls fed the control and OEO+MON, and bulls fed OEO were intermediate and similar. Cholesterol (2.06, 2.29, 2.20, and 2.07 mmol/L) concentrations were greater for bulls fed OEO compared with bulls fed the control and OEO+MON, and bulls fed MON were intermediate and similar. Serum antioxidant measurements were similar for bulls fed all treatments. Serum IgA, IgG, and IgM concentrations were similar for bulls fed all treatments. Feeding OEO or MON separately can improve growth performance of growing Holstein bulls. We do not know why the combination of OEO and MON is antagonistic to growth performance of Holstein bulls. However, these technologies should not be fed in combination to growing dairy cattle.

Objective The objective of this research was to determine the effect of differential monensin (Rumensin, Elanco Animal Health, Greenfield, IN) intake in a free-choice loose mineral on performance of grazing beef steers. Material and Methods Treatments consisted of offering ad libitum access to minerals (AMPT-A, ADM Animal Nutrition, Quincy, IL) supplying 0 (0M), 882 (800M), or 1,764 (1600M) g of monensin/t with targeted daily monensin intakes of 0, 100, or 200 mg of monensin per steer. Steer calves (n = 605, BW = 278 ± 27 kg) were fed hay with a hand-fed supplement (block 1); grazed wheat (Triticum aestivum) pasture (blocks 2, 3, and 6); or bermudagrass (Cynodon dactylon) pasture (blocks 4 and 5). There were no treatment × diet interactions (P ≥ 0.97); therefore, data were pooled across blocks for statistical analysis. Results and Discussion Steers offered 800M and 1600M had greater (P ≤ 0.02) final BW, ADG, and total BW gain compared with 0M steers fed mineral without monensin. Mineral intake decreased linearly (P Implications and Applications Monensin supplementation improved growth performance compared with an unmedicated control within the doses observed in this experiment and regardless of basal forage quality. Intake of a self-fed monensin-containing mineral can be decreased by at least 50% without affecting performance response to monensin of steers on forage-based diets.

Made available in DSpace on 2020-12-11T21:11:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Oligo Basics USA, LLC (Cary, NC) North Carolina Agricultural Foundation, Inc. (Raleigh, NC) USDA-NIFA Project Two experiments were conducted to evaluate the effects of functional oils containing cashew nutshell and castor oil on turkey performance and intestinal morphology. In experiment 1, 585 hatchlings were randomly placed in 15 replicate floor pens, (13 poults/pen) with recycled litter and provided feed and water ad libitum. Birds were randomly assigned to 3 dietary treatments from 1 to 12 wk: nonmedicated control, 0.15% functional oils, and 66-ppm monensin. From wk 13 to 20, each initial treatment group was further divided into 3 treatments-control (no additive), 0.15% of functional oils, or 20 ppm of virginiamycin to produce 9 different treatments, 5 replicate pens per treatment. Data on feed weights were collected weekly, and body weight bi-weekly. At termination (20 wk), birds were euthanized, and their meat was processed to determine mass of carcass sections and meat quality, while intestinal samples were collected for histology. In experiment 1, toms fed monensin or functional oils were 10.5 and 4.5% heavier (P < 0.05), respectively, than the controls at 12 wk. Birds fed monensin had a 4% improvement (P < 0.05) in feed conversion as compared to the other treatments. Neither virginiamycin nor the functional oils affected bird performance when fed from 13 to 20 wk. The jejunum villi surface area at 3 wk was most enhanced (P < 0.05) for the poults fed monensin. Supplementation with functional oils significantly reduced leg yield and thiobarbituric-acid reactive substances of white meat after 7 D of storage (P < 0.05). There were no effects on performance or carcass characteristics in experiment 2. While additional confirmatory studies are needed, functional oils in the diet of turkey toms may be a viable alternative to antibiotic growth promotants. NCSU, Prestage Dept Poultry Sci, Raleigh, NC 27695 USA Sao Paulo State Univ, Sao Paulo, SP, Brazil ARS, USDA, Market Qual & Handling Res Unit, Raleigh, NC 27695 USA Oligo Basics USA LLC, Cary, NC 27519 USA Sao Paulo State Univ, Sao Paulo, SP, Brazil USDA-NIFA Project: NC06343

Objective The objectives of this research were to determine the effects of medicated feed additives on performance, health, and coccidia infection in newly received calves classified as high risk for bovine respiratory disease infection. Materials and Methods Growing steers and bulls were received to evaluate the effects of supplying 20 mg/calf bambermycin or 0.77 mg/kg of BW monensin in receiving supplements (20% CP and 78% TDN) compared with a nonmedicated supplement. Fecal samples were collected from 6 steers/pen on d 0, 14, and 28 to evaluate coccidia infection. Water in the bambermycin pens was treated from d 14 to 19 with 10 mg/kg of BW amprolium. Steers remained on treatment for 56 to 84 d for block 1, 49 d for block 2, and 42 d for block 3, depending on availability of wheat forage for subsequent grazing. Results and Discussion There were no differences (P ≤ 0.36) in morbidity, mortality, or animals identified as chronically morbid. Monensin decreased coccidia (P ≤ 0.03) compared with control and bambermycin, which did not differ (P = 0.85). At the end of receiving, BW and ADG for control calves was less than (P ≤ 0.04) for calves receiving bambermycin and monensin. Implications and Applications Monensin or bambermycin can effectively improve BW gain of calves at high risk for bovine respiratory disease. Monensin provides superior control of natural infection of coccidia based on fecal oocyst counts compared with bambermycin. Neither medicated feed additive altered morbidity or mortality due to bovine respiratory disease or treatment response to bovine respiratory disease.

A clinical study was made into the abilities of nicarbazin and monensin and a nicarbazin + monensin combination to control Eimeria acervulina, E. maxima, and E. tenella in chickens. When included i...

BACKGROUND: Monensin is widely used in livestock and poultry production to promote animal growth and control coccidiosis. Most monensin is excreted as unchanged parent compounds via feces. However，monensin is very stable and difficult to degrade in the environment, and is potentially risky for the health of wildlife and humans. To date, the biodegradation process of monensin by bacteria and its mechanism is unclear. In this study, we found that a Stenotrophomonas maltophilia DM‐2 strain isolated from chicken manure could effectively degrade monensin. RESULT: The optimum temperature and pH for DM‐2 to degrade monensin were 40 °C and pH 7.0. A potential degradation pathway of monensin was proposed based on the identification and characterization of two new monensin metabolic intermediates by liquid chromatography quadrupole time‐of‐flight mass spectroscopy. In addition, an inducible monensin‐degrading activity was present in DM‐2. A soluble epoxide hydrolysis (sEH) gene highly expressed in the DM‐2 on day 3 and 6 under monensin stress, which was not observed in the DM‐2 without monensin stress. When a specific inhibitor TPPU (1‐(1‐propanoylpiperidin‐4‐yl)‐3‐[4‐(trifluoromethoxy)phenyl]urea) of sEH was added into the cell‐free extract, the degradation of monensin was inhibited. CONCLUSION: Strain DM‐2 can biodegrade monensin by soluble epoxy hydrolase and produce two new intermediates. To our knowledge, this is the first report of the degradation of monensin by Stenotrophomonas strains. The novel metabolic pathways of monensin which we found may provide new insight into the environmental fate of monensin. © 2020 Society of Chemical Industry

Objective The objective was to assess activity of steers grazing tall fescue pastures varying in toxicity with and without a combination management practice including supplemental feed, ionophore, and a steroidal implant. Materials and Methods Activity of steers was monitored using IceQube (IceRobotics Ltd., Edinburgh, UK) accelerometers. Steers grazed 1 of 15 pastures differing in ergovaline (EV) in spring 2016. For 7 pastures, steers were offered mineral-only (MIN) management (MGMT). In the remaining pastures, steers received a cumulative (CM) MGMT strategy including 1% BW, 1:1 corn gluten feed:soybean hulls, 150 mg/head per day monensin, and a steroidal implant containing 40 mg of trenbolone acetate, 8 mg of estradiol, and 29 mg of tylosin tartrate. Physical activities—lying bouts, steps, and standing time—were reported in 2 periods: period 1 (27 d) and period 2 (26 d). Results and Discussion Period 1 lying bouts were not different for MGMT (P = 0.11) or EV (P = 0.26). Period 2 lying bouts exhibited a MGMT × EV interaction (P = 0.02). Time steers spent standing was not different between CM and MIN during period 1 (P = 0.79) but differed during period 2 (P Implications and Applications Behavioral changes due to EV and MGMT appeared more prevalent during period 2 when warmer weather and changing forage quality would be expected to worsen the effects of fescue toxins. The CM may elicit greater satiety or reduce heat stress. Strategies that improve productivity of cattle on toxic fescue may also improve welfare as expressed through physical activity changes.

By being at the interface of the exocytic and endocytic pathways, the plant trans-Golgi network (TGN) is a multitasking and highly diversified organelle. Despite governing vital cellular processes, the TGN remains one of the most uncharacterized organelle of plant cells. In this review, we highlight recent studies that have contributed new insights and to the generation of markers needed to answer several important questions on the plant TGN. Several drugs specifically affecting proteins critical for the TGN functions have been extremely useful for the identification of mutants of the TGN in the pursuit to understand how the morphology and the function of this organelle are controlled. In addition to these chemical tools, we review emerging microscopy techniques that help visualize the TGN at an unpreceded resolution and appreciate the heterogeneity and dynamics of this organelle in plant cells.

Objective Two experiments evaluated the effects of supplemental monensin on growth and physiology of early-weaned beef calves grazing ryegrass (Exp. 1) or bahiagrass (Exp. 2). Materials and Methods Brangus calves were weaned at 3 mo of age, stratified by sex and BW, and randomly assigned into 1 of 8 pastures (2 steers and 2 heifers per pasture per year) of ryegrass (Exp. 1; n = 2 yr) or bahiagrass (Exp. 2; n = 1 yr) from d 0 to 84. Treatments were assigned to pastures (4 pastures per treatment per year) and consisted of concentrate supplementation at 1 or 2% of BW (DM basis) in Exp. 1 and 2, respectively, with or without 20 mg of monensin/kg of DMI. Results and Discussion Herbage nutritive value and allowance did not differ (P ≥ 0.23) between treatments in Exp. 1 and 2, but herbage mass tended (P = 0.10) to increase by 5% for monensin versus control calves in Exp. 1. Calf overall ADG increased (P ≤ 0.005), whereas fecal coccidia egg count on d 84 decreased (P ≤ 0.0004), for monensin versus control calves in Exp. 1 and 2. Monensin supplementation tended (P ≤ 0.08) to increase plasma insulin concentrations in Exp. 1 and 2 and increased (P ≤ 0.03) plasma IGF-1 concentrations on d 56 in Exp. 1 and plasma urea nitrogen concentrations on d 84 in Exp. 2. Implications and Applications Supplemental monensin led to subtle changes to physiological parameters associated with energy metabolism, reduced coccidiosis infestation, and promoted the growth performance of early-weaned calves grazing ryegrass and bahiagrass pastures.

The effects of a blend of encapsulated organic acids with essential oils (EOA) as an alternative to antimicrobial growth promoter (AGP) on growth performance and gut health of Eimeria spp./Clostridium perfringens (C. perfringens) in chickens infected with necrotic enteritis (NE) broilers was investigated. A total of 432 male Arbor Acres broilers (1-day-old) were randomly distributed into 6 treatment groups, namely noninfected negative control (A); NE-infected positive control (D); NE-infected broiler chickens fed a basal diet supplemented with 250 mg/kg bacitracin methylene disalicylate (BMD) plus 90 mg/kg monensin; and NE-infected broiler chicken fed 200; 500; and 800 mg/kg EOA (E, F, G, and H group). Feeding EOA at 200 and 500 mg/kg considerably improved the feed conversion ratio, reduced gut lesions, serum fluorescein isothiocyanate dextran level, and C. perfringens load in the caecum and liver of the NE-infected broiler chickens. This feed was similar to AGP. Furthermore, the increased villous height-to-crypt depth ratio and goblet cells counts, upregulated claudin-1, glucagon-like peptide-2 (GLP-2), insulin-like growth factor-2 (IGF-2) mRNA gene expression, downregulated occludin, zonula occludens-1 (ZO-1), toll-like receptor (TLR-4), interleukin (IL-1β), interferon γ (IFN-γ), TNF receptor-associated factor 6 (TRAF-6), tumor necrosis factor superfamily member 15 (TNFSF15), and Toll-interacting protein (Tollip) genes expression in the jejunum were observed in the NE-infected broiler chickens that received EOA at 200 and 500 mg/kg compared with those of the single NE-challenged groups without EOA supplementations (P < 0.05). The 16S analysis revealed that EOA supplemented with 200 or 500 mg/kg enriched relative abundance of Lactobacillus, unclassified_Lachnospiraceae, and Enterococcus, and carbohydrate metabolic pathways but suppressed unclassified_Erysipelotrichacease and organismal systems involved in the immune system (P < 0.05). Feeding EOA could alleviate NE-induced gut impairment and growth depression and modulate cecal microbiota composition, which has potential as antimicrobial alternatives.

Exosomes are small extracellular vesicles released by cells and play important roles in intercellular communication and pathogen transfer. Exosomes have been implicated in several neurodegenerative diseases, including prion disease and Alzheimer disease. Prion disease arises upon misfolding of the normal cellular prion protein, PrP(C), into the disease-associated isoform, PrP(Sc). The disease has a unique transmissible etiology, and exosomes represent a novel and efficient method for prion transmission. The precise mechanism by which prions are transmitted from cell to cell remains to be fully elucidated, although three hypotheses have been proposed: direct cell-cell contact, tunneling nanotubes, and exosomes. Given the reported presence of exosomes in biological fluids and in the lipid and nucleic acid contents of exosomes, these vesicles represent an ideal mechanism for encapsulating prions and potential cofactors to facilitate prion transmission. This study investigates the relationship between exosome release and intercellular prion dissemination. Stimulation of exosome release through treatment with an ionophore, monensin, revealed a corresponding increase in intercellular transfer of prion infectivity. Conversely, inhibition of exosome release using GW4869 to target the neutral sphingomyelinase pathway induced a decrease in intercellular prion transmission. Further examination of the effect of monensin on PrP conversion revealed that monensin also alters the conformational stability of PrP(C), leading to increased generation of proteinase K-resistant prion protein. The findings presented here provide support for a positive relationship between exosome release and intercellular transfer of prion infectivity, highlighting an integral role for exosomes in facilitating the unique transmissible nature of prions.

The targeted manipulation of polyketide synthases has in recent years led to numerous new-to-nature polyketides. For type I polyketide synthases the response of post-polyketide synthases (PKS) processing enzymes onto the most frequently polyketide backbone manipulations is so far insufficiently studied. In particular, complex processes such as the polyether cyclisation in the biosynthesis of ionophores such as monensin pose interesting objects of research. We present here a study of the substrate promiscuity of the polyether cyclisation cascade enzymes in monensin biosynthesis in the conversion of redox derivatives of the nascent polyketide chain. LC-HRMS/MS2 -based studies revealed a remarkable flexibility of the post-PKS enzymes. They acted on derivatized polyketide backbones based on the three possible polyketide redox states within two different modules and gave rise to an altered polyether structure. One of these monensin derivatives was isolated and characterized by 2D-NMR spectroscopy, crystallography, and bioactivity studies.

Methane and ammonia are byproducts of rumen fermentation that do not promote animal growth, and methane is a key contributor to anthropogenic climate disruption. Cows eructate every few breaths and typically emit 250–500 L of methane gas daily. Significant research is focused on finding diets and additives that lower the production of methane and ammonia. Emerging research has shown that humulones and lupulones, molecules that are found in the cones of hops (Humulus lupulus), have potential in this regard. These molecules, which are also key flavor components in beer, are biologically active: they are known inhibitors of Gram-positive bacteria. Ruminants' sophisticated digestive systems host billions of microorganisms, and these systems' outputs will likely be affected in the presence of brewer's yeast (Saccharomyces cerevisiae). So-called spent yeast is produced during the beer-brewing process and contains humulones and lupulones in concentrations that vary by beer style, but it is generally discarded as waste. Our research suggests that adding spent craft brewer's yeast to rumen microbes by single time-point 24-h in vitro incubations suppresses production of methane and ammonia. This project examines the correlation between the quantities of hop acids in spent yeast and the production of methane and ammonia by bovine rumen microbes in vitro. We determined, by HPLC, the hop acid concentrations in spent yeast obtained from six beer styles produced at a local brewery. We performed anaerobic incubation studies on bovine rumen microbes, comparing the effects of these materials to a baker's yeast control and to the industry-standard antibiotic monensin. Results include promising decreases in both methane (measured by GC–FID) and ammonia (measured by colorimetric assay) in the presence of craft brewer's yeast, and a strong correlation between the quantities of hop acids in the spent yeast and the reduction of methane and ammonia. Notably, two of the yeast samples inhibited methane production to a greater degree than the industry-standard antibiotic monensin. Our results suggest that spent brewer's yeast has potential to improve ruminant growth while reducing anthropogenic methane emission.

The objective of this study was to evaluate diets containing monensin (MON) associated or not with virginiamycin (VM) or functional oil based on cashew nut shell and castor beans (FOcc) for beef cattle in feedlots on nutritional (intake and digestibility) and productive parameters. A total of 1410 non-castrated Nellore cattle were selected, with an average age of 18 months and with an initial mean body weight (BW) of 305 ± 41.52 kg. The diet showed a roughage to concentrate ratio of 23:77, with the supply of corn silage as a source of roughage. The following additive inclusions in the diet were evaluated: (1) MON: 27 mg MON/kg dry matter (DM); (2) MON + VM: 22 mg MON/kg DM + 19 mg VM/kg DM; and (3) MON + FOcc: 22 mg MON/kg DM + 500 mg FOcc/kg DM. Statistical analyses were obtained through a linear model using initial BW and days of feedlot as covariables and comparisons between treatments using mutually orthogonal linear contrasts with a 5% significance level. The association or not of MON with VM or FOcc does not affect any of the nutritional and productive parameters evaluated. Animals that receive diets with MON + VM have higher average daily gain and feed efficiency (FE) than those that receive MON + FOcc without showing differences in nutritional parameters. The supply of MON associated with VM or FOcc does not increase intake and productive performance and, consequently, efficiency of feedlot beef cattle. However, in the case of use associated with MON, the VM provides greater performance than FOcc without changing food intake.

Various antimicrobial agents are used in the poultry industry to treat microbial infections and prevent disease or as growth promoters. As a result, poultry litter (PL) can contain antibiotic residues (AR), antibiotic-resistant bacteria (ARB), and antibiotic resistance genes. Still, PL is used in many countries as a fertilizer and feed supplement for cattle. To evaluate whether usage of PL in agriculture leads to the accumulation of AR and ARB accumulate in the soil, we (i) measured the concentration of monensin, tylosin, ciprofloxacin, oxytetracycline, and chlortetracycline and the abundance of culturable monensin-, tylosin-, and ciprofloxacin-resistant bacteria in 15 commercial PL samples and (ii) exposed soil microcosms to two PL regimes and followed the persistence of PL-associated ARB for 128 days through cultivation on media containing antibiotics. The PL samples analyzed contained high concentrations of monensin (27–95 mg kg−1), tylosin (152–450 mg kg−1), ciprofloxacin (29–101 mg kg−1), and (oxy/chlor)tetracycline (13–87 mg kg−1). Congruently, they included large absolute and relative numbers of bacteria capable of growing on agar plates supplemented with 5 to 50 μg mL−1 monensin (medians, 107–109 CFU g−1, 0.6–45%) or 25 to 50 μg mL−1 tylosin (median, 108 CFU g−1, 14–26%). By contrast, the abundance of bacteria resistant to 25–250 μg mL−1 CP in the PL samples was much lower (median values ranging from 106 to less than 102 CFU g−1, relative abundances

Monensin is an ionophore for monovalent cations, which is frequently used to prevent ketosis and to enhance performance in dairy cows. Studies have shown the rumen bacteria Prevotella bryantii B14 being less affected by monensin. The present study aimed to reveal more information about the respective molecular mechanisms in P.&nbsp, bryantii, as there is still a lack of knowledge about defense mechanisms against monensin. Cell growth experiments applying increasing concentrations of monensin and incubations up to 72 h were done. Harvested cells were used for label-free quantitative proteomics, enzyme activity measurements, quantification of intracellular sodium and extracellular glucose concentrations and fluorescence microscopy. Our findings confirmed an active cell growth and fermentation activity of P.&nbsp, bryantii B14 despite monensin concentrations up to 60 µM. An elevated abundance and activity of the Na+-translocating NADH:quinone oxidoreductase counteracted sodium influx caused by monensin. Cell membranes and extracellular polysaccharides were highly influenced by monensin indicated by a reduced number of outer membrane proteins, an increased number of certain glucoside hydrolases and an elevated concentration of extracellular glucose. Thus, a reconstruction of extracellular polysaccharides in P.&nbsp, bryantii in response to monensin is proposed, which is expected to have a negative impact on the substrate binding capacities of this rumen bacterium.

Simple Summary The transition period is a challenging time, which combines a massive increase in nutrient requirements and leads to a negative energy balance. Therefore, disorders related to negative energy balance, such as ketosis, are more frequent. In addition, in this period, oxidative stress increases, favoring immune suppression functions and inflammation, which may lead to increased susceptibility to other diseases such as metritis and mastitis. Therefore, the combination of ionophores, such as monensin, that mitigate the accentuated negative energy balance; vitamin A, which plays an important role in supporting the immune system; and a high level of crude protein might improve immune parameters in dairy cows in the transition period. This study demonstrated that monensin and vitamin A supplementation and high crude protein levels enhanced some vitamin status and inflammatory markers when used during the late prepartum period. Abstract The objective of this study was to determine the effect of feeding different combinations of dietary vitamin A supplementation (0 or 110 IU/kg body weight), protein (10.3% or 12.2%), and an ionophore (monensin at 0 or 400 mg/day) on retinoid metabolism and immune function of dairy cows. Eighty multiparous Holstein dairy cows were studied from d −35 to +21 relative to expected parturition in a complete randomized block design with a 2 × 2 × 2 factorial arrangement of treatments. The significance of treatments was declared at p ≤ 0.05. Dairy cows receiving high crude protein (CP) diets with monensin had a greater retinol-binding protein serum concentration than cows receiving high CP diets without monensin (p = 0.04). Animals supplemented with vitamin A showed lower SCC (p = 0.04) and a higher thiobarbituric acid reactive substances concentration (p = 0.06) than cows non-supplemented. Moreover, cows receiving low crude protein diets had a greater haptoglobin concentration (p = 0.01). In addition, cows fed a high crude protein diet had a greater TNF-α expression in peripheral blood mononuclear cells (p = 0.04). Animals fed diets without monensin had a greater serum haptoglobin on day 3 postpartum than those fed monensin (p = 0.01). Moreover, dietary vitamin A increased serum 13-cis retinoic acid postpartum. We conclude that vitamin A, crude protein levels, and monensin fed during the close-up period affect milk somatic cell count, some vitamin statuses, and inflammatory markers during early lactation.

Made available in DSpace on 2022-04-29T08:32:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-02 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Feedlot cattle are usually adapted to high-concentrate diets containing sodium monensin (MON) in more than 14 days. However, for finishing diets with lower energy content, the use of MON during adaptation may hold dry matter intake (DMI), and virginiamycin (VM) may be an alternative. This study was designed to determine the potential of shortening the adaptation of Nellore cattle to high-concentrate diets using only VM as a sole feed additive relative to feedlot performance, feeding behavior, and ruminal and cecum morphometrics. The experiment was designed as a completely randomized block replicated six times (four animals/pen) in which 120 Nellore bulls (390.4 ± 19.0 kg) were fed in 30 pens for 111 days according to the following treatments: (1) MON and adaptation for 14 days (MON14), (2) MON + VM and adaptation for 14 days (MONVM14), (3) VM and adaptation for 14 days (VM14), (4) VM and adaptation for 9 days (VM9), and (5) VM and adaptation for 6 days (VM6). At the end of the adaptation, 30 animals (n = 1 per pen) were randomly slaughtered for rumen and cecum evaluations. The remaining 90 bulls were harvested at the end of the study. No effects of treatments were observed (P < 0.10) for final body weight, average daily gain (ADG), and hot carcass weight (HCW). Cattle fed VM14 presented a greater (P ≤ 0.03) DMI, expressed as percent of body weight (BW), than animals fed either MON14 or MONVM14; however, cattle fed either MON14 or MONVM14 improved (P ≤ 0.02) the gain-to-feed ratio (G/F) by 10.4 or 8.1%, respectively, when compared to bulls fed VM14. Bulls fed VM14 had smaller (P < 0.05) papillae area (0.34 vs. 0.42 cm2) and rumen absorptive surface area (28.9 vs. 33.8 cm2) than those fed MON14. The shortening of the adaptation period linearly decreased the 12th rib fat (P = 0.02) and biceps femoris fat daily gain (P = 0.02) of Nellore bulls fed only VM, which linearly decreased the final biceps femoris fat thickness (P < 0.01). Feedlot cattle fed VM as a sole feed additive should not be adapted to high-concentrate diets in less than 14 days. Regardless of either adaptation length or feed additive, feedlot cattle need at least 14 days to adapt to finishing diets. Department of Breeding and Animal Nutrition School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Animal Production College of Agricultural and Technological Sciences São Paulo State University (UNESP) Department of Breeding and Animal Nutrition School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Animal Production College of Agricultural and Technological Sciences São Paulo State University (UNESP)

Nisin is a low molecular weight bacteriocin which is produced by Lactococcus lactis. Literature about the effects of nisin on pure cultures of rumen bacteria is scarce. The objective of the present study was to investigate the comparative effects of nisin and monensin on pure cultures of some Gram-positive and Gram-negative rumen bacteria. The antibacterial activity assays of nisin and monensin were carried out using broth microdilution method in anaerobic conditions. Antibacterial effect of monensin on Gram-positive rumen bacteria was higher than nisin. Ruminococcus albus and Eubacterium ruminantium were the most sensitive bacteria to monensin. Growth of these bacteria was inhibited completely by monensin, at 6 and 12 µg/mL concentrations respectively. Nisin exhibited stimulatory effects on R. albus, E. ruminantium and, Streptecoccus bovis (p

The aim of this study was to determine the susceptibility of Lactobacillus bacteria to selected coccidiostats. Seventy-five Lactobacillus isolates obtained from chickens were classified by MALDI-TOF mass spectrometry and 16S rDNA restriction analysis into seven species, among which L. salivarius (33%) and L. johnsonii (24%) were dominant. Susceptibility of lactobacilli to coccidiostats was determined by broth microdilution method. The ranges of minimum inhibitory concentrations (MICs) were 0.5-≥128 µg/ml for monensin, 0.125-8 µg/ml for salinomycin, ≤0.03-2 µg/ml for lasalocid A, and 4-16 µg/ml for robenidine. Coccidiostats in low concentrations inhibited in vitro growth of most lactobacilli and therefore there is a high probability that administration of this drugs to chickens would reduce the number of lactobacilli in the gut.

Bu çalışmada, Urtica dioica, Matricaria chamomilla ve Vitex agnus-castus’un yüksek fenolik içerikli kuru ekstraktlarının normal koşullar ve asidoz koşulları altında rumen mikrobiyal fermentasyonu üzerine monensin ile karşılaştırmalı etkilerinin Rumen Similasyon Tekniği (RUSITEC) kullanılarak araştırılması amaçlanmıştır. Deneme grupları, negatif kontrol (katkı maddesi yok), pozitif kontrol (5 mg/gün monensin) ve U. dioica (500 mg/gün), M. chamomilla (500 mg/gün) ve V. agnus-castus (500 mg/gün) ekstraktlarından oluşmuştur. Bitki ekstraktları ve monensin ruminal pH’yi normal koşullar ve asidoz koşulları altında değiştirmemiştir. Deneme gruplarının toplam uçucu yağ asidi (UYA) ve propiyonat üretimi ile kuru madde sindirilebilirliği (KMS) üzerine etkilerinin koşuldan bağımsız olarak gerçekleştiği gözlenmiştir. Üç ekstrakt da monensin’e benzer şekilde toplam UYA üretimini arttırmıştır (P, The aim of this study wasto investigate the effects of dry extracts ofUrtica dioica, Matricaria chamomilla, and Vitex agnus-castuswith high phenolic contents on rumen microbial fermentation as compared with thoseof monensin, a common ionophoreantibiotic, using Rumen Simulation Technique (RUSITEC) under normal andacidosis conditions. The treatments were as follows: negative control (noadditive), positive control (5 mg/d monensin), and extracts of U. dioica (500mg/d), M. chamomilla (500 mg/d), and V. agnus-castus (500 mg/d). Neitherthe plant extracts nor monensin altered the ruminal pH under normal or acidosisconditions. All the treatments affected total volatile fatty acid (VFA) production,propionate production, and dry matter digestibility (DMD), regardless of the fermentation conditions.All threeextracts increased (P

The objective of this study to evaluate the effect of secondary plant compounds present in essential oils in replacement of monensin on in vitro ruminal fermentation parameters. It was adopted a completely randomized design with nine treatments and four replicates. The treatments were: control (CON), monensin (MON), garlic oil (ALH), cinnamon oil (CAN), clove oil (CRA), mint oil (HOR), juniper oil (JUN), bitter orange oil (LAR), and melaleuca oil (MEL). The in vitro gas technique was used to record total gas production at 4, 8, 12 and 24 h after incubation. MON, CAN and CRA increased gas production Only the garlic and cinnamon treatments reduced the digestibility of organic matter in 20 and 26% in relation to the control treatment. Methane production reduced (P

The objective of this study was to evaluate the effect of four essential oils (EOs) from guava (Psidium guajava), citronella (Cymbopogon nardus), lemongrass (Cymbopogon citratus), and geranium (Pelargonium graveolens) on gas production and rumen fermentation in vitro as a natural substitute for the ionophore antibiotic monensin. These EOs are chemically characterized by Gas Chromatography-Mass and evaluated in vitro at four different concentrations (0, 15, 30, and 45 µl per 45 ml buffered rumen fluid) regarding their effects on gas production and rumen fermentation characteristics and were compared to those of monensin. Compared to the negative control, monensin significantly depressed gas production and truly degraded dry matter (TDDM) but enhanced propionate production. All EOs except P. graveolens significantly decreased gas production with increasing concentrations. TDDM was significantly reduced with C. citratus (at 45 µl) and P. graveolens (at 30 and 45 µl). No significant change was detected in the ammonia nitrogen concentration with all assayed EOs except C. nardus and C. Citrus. Compared to monensin and the negative control, C. nardus and C. Citrus reduced the ammonia concentration at high levels. High levels of all tested EOs significantly reduced protozoa counts. The EOs of C. citratus (at 45 µl) and P. graveolens (at 30 and 45 µl) also significantly increased the acetate proportion. Moreover, the acetate to propionate ratio was significantly increasedby30 µl P. graveolens. The results of the current study concluded that the tested EOs, except P. graveolens, efficiently diminished gas production with a similar potency to monensin. Furthermore, they exceed the monensin in their ability to reduce the ammonia nitrogen concentration and protozoa count without adversely affecting volatile fatty acid levels. But, they were less effective than monensin in modifying ruminal volatile fatty acid profile especially propionate and acetate to propionate ratio. Hence, P. guajava, C. nardus, and C. citratus EOs could be a safe and promising rumen manipulator.

Nitrogen fertilization is a major input cost of forage production, and alternatives that maintain yield and nutritive value would be advantageous. A 3-yr study was conducted to evaluate forage nutritive value and clover proportion when N fertilizer was replaced partially with interseeded clovers (Trifolium spp.) or protein supplements for stocker cattle grazing annual ryegrass (Lolium multiflorum Lam.). Nitrogen delivery methods with or without monensin included annual ryegrass fertilized with 112 kg N ha⁻¹ in split application (NFERT), and other methods that received 56 kg N ha⁻¹, including annual ryegrass interseeded with crimson clover (CC, Trifolium incarnatum L.) or arrowleaf clover (AC, Trifolium vesiculosum Savi), or grazing cattle supplemented with distillers dried grains plus solubles at a rate of 0.65% body weight daily (DDGS) or whole cottonseed (Gossypium hirsutum L.) at the rate of 0.65% body weight daily (WCS). Clover proportion was greater (P = 0.003) for CC than AC across all 3 yr of the study, and CC was more (P = 0.003) abundant when monensin was fed. Year affected forage in vitro true digestibility (IVTD, P < 0.001) and crude protein (CP, P < 0.001) concentration such that IVTD and CP were greatest in Year 3, intermediate in Year 2, and least in Year 1. Forage degradable intake protein (DIP) concentration was affected by N delivery method (P < 0.001) and year (P < 0.001) such that CC was less than NFERT, DDGS, WCS, and AC, and Year 1 was greatest, Year 2 was intermediate, and Year 3 was the least. Results are interpreted to mean that year affected forage nutritive value more than did N delivery method.

Background When present in animal feedstuff, mycotoxins contaminants and antibiotic residues can have negative implications for animal production and Public Health, including the transmission of carcinogenic compounds and the selection of antibiotic resistant bacteria, respectively. So far there are no available methods in which both mycotoxins and antibiotic residues are analyzed using a parallel extraction approach. To address this issue, we developed a LC/MS methodology with high sensitivity (0.005 to 6.42 and 24.55 to 132.73 μg kg− 1 for mycotoxins and antimicrobials) and specificity (unique target ion mass/charge) that allows the detection of 26 mycotoxins and 23 antibiotic residues in animal feedstuff and validated it through the determination of these analytes in 294 animal feed and feed ingredient samples in the framework of a country-wide surveillance program. Two hundred and five of these samples were analyzed for mycotoxins and 89 for antibiotics. Findings Fumonisin was the most frequently toxin found, with FB1 and FB2 presenting prevalences of 50 and 52% and maximum concentrations of 14,927.61 and 8646.67 μg kg− 1, respectively. Other toxins, including diacetoxyscirpenol n = 4/101 (3.96%), fusarenon-X n = 2/101 (1.98%), citrinin n = 2 (1.98%), and patulin n = 1 (0.99%) were rarely found. Toxicologically relevant concentrations of toxin metabolites, such as HT-2 (6.38–485.49 μg kg− 1) and 3−/15-acetoxydeoxynivalenol (877.89–3236.56/5.44–1685.3 μg kg− 1), were also found. Few samples exceeded threshold mycotoxin concentrations defined in current EU guidelines. Dairy cattle and swine feeds included the higher number of samples exceeding guideline values (n = 6 and n = 5, respectively). From the total of samples analysed for antibiotics, 7.7% (n = 7/89) were classified as medicated for poultry and pigs. Unexpectedly, 57% of these medicated samples contained no detectable antibiotics (n = 4/7). The remaining 43% of the samples (n = 3/7) presented inconsistencies regarding the concentration of analytes declared on the labels or the antibiotics found. Likewise 74.6% (n = 50/67) of the non-medicated feed samples analyzed had antibiotic residues. Additionally, we analyzed commercial monensin standards for purity and evaluate batch-to-batch flushing feed industry practices. Conclusions Herein we report the results for a year-wide analysis for mycotoxins and antibiotics in feed samples. Mycotoxins, several metabolites, and the occurrence of these emerging contaminants were evaluated and antibiotic residues in non-medicated feed samples were found using a targeted MS-based LC approach. This validated multi-analyte method is expected to facilitate the monitoring and surveillance of contaminants, from natural and anthropogenic origin, in animal feed.

The objective of this work was to evaluate the efficiency of nutrient absorption with the use of additives such as monensin and flavomycin in steers performance. Performance parameters were studied in 111 (one hundred and eleven) uncastrated steers with aged 20 to 22 months and mean live weight of 469.8 kg, divided into two experimental groups: 54 steers Nellore flavomycin (NF) and 57 steers Nellore with flavomycin and monensin (NFM). NFM animals had total weight gain, mean daily gain and percentage gain (p

Plant extracts may be highly effective as natural dietary supplementation options to alternate the dietary antibiotics as growth promotors in ruminant diets. The current study was conducted to evaluate the dose response effects of the moringa (Moringa oleifera) leaf extract (MLE) as a natural alternative to monensin in sheep diets, on ruminal methane production (CH4), gas production (GP), nutrient degradability and fermentation parameters. The in vitro semi-automatic system of GP was used. The treatments were MLE added to a basal diet (consisted of 50 concentrate: 50 forage) at 0 (control), 50 (MLE low) and 500 (MLE high) mg/ kg dry matter, and the ionophore antibiotic monensin was added at 40 mg/kg dry matter. Abundant quantities of essential amino acids, monosaccharides, glycosides and benzene derivatives phytochemicals components were detected by the GC–MS analysis of MLE. The most effective treatments to decrease (P < 0.05) CH4 were monensin and MLE high, while only MLE high enhanced (P < 0.05) the overall mean of total volatile fatty acids (VFAs) concentrations compared to the other treatments and the molar proportion of acetate compared to monensin. A decline (P < 0.05) in protozoal count was observed by monensin, while such effect did not appear at other treatments. No significant differences were observed among the experimental treatments in the ruminal degradability, ammonia concentrations or GP. This study demonstrated efficiency of MLE as an effective natural intervention to monensin in sheep diets.

To monitor monensin (MON) residues in chicken tissues, a monoclonal antibody (mAb)–based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed in this study. The haptenMON was obtained by adding hydrochloric acid to a MON salt, and then was coupled with carrier protein. After the inoculation of female Balb/c mice and cell fusions, one cell line, MON/4C9, was obtained. The MON/4C9 antibody exhibited the ability to specifically recognize MON with IC50 1.28 μg L−1.Based on this mAb, an optimized ic-ELISA protocol was performed using only methanol-water (8:2, v/v) in chicken tissue samples. The limits of detection and the limits of quantification of MON in various sample matrices varied from 0.38 to 1.01 μg kg−1. The recoveries ranged from 71.9 to 116.9% in chicken tissues, and the intra- and inter-assay CVs were all less than 18%. Moreover, the developed method also exhibited a positive correlation with the results of HPLC-MS conducted on the samples. These results suggest that the prepared mAb and the developed ic-ELISA method will be a useful tool for detecting MON in chicken tissues.

The incorporation of new-to-nature extender units into polyketide synthesis is an important source for diversity yet is restricted by limited availability of suitably activated building blocks in vivo. We here describe a straightforward workflow for the biogenic activation of commercially available new-to-nature extender units. Firstly, the substrate scope of a highly flexible malonyl co-enzyme A synthetase from Streptomyces cinnamonensis was characterized. The results were matched by in vivo experiments in which the said extender units were accepted by both the polyketide synthase and the accessory enzymes of the monensin biosynthetic pathway. The experiments gave rise to a series of predictable monensin derivatives by the exploitation of the innate substrate promiscuity of an acyltransferase and downstream enzyme functions.

Stocker operators generally graze cattle on California annual rangelands from November to May. The profit margins of these operators is low as cattle sell for less per unit at the end of the season when compared with the beginning. This creates a need for methods to economically increase weight gain, which can help to mitigate market volatility. The use of monensin is common in much of the United States but has not been researched in the unique winter annual rangelands of California. Likewise, research that formally documents weight gain from the correction of selenium deficiency on these rangelands is also lacking. Trials were conducted over 2 years to determine weight gain differences with treatments of salt only (control), salt with monensin, mineral supplement, and mineral supplement with monensin. All three treatments increased weight gain by 12%, 9%, and 15% over feeding straight salt, respectively. It appears that selenium deficiency correction and supplemental monensin should be considered economical weight gain improvement tools for yearling cattle grazing California annual rangeland.

Ruminants contribute significantly to global methane (CH4) emissions. This study aimed to evaluate the in vitro effects of monensin sodium salt (MSS) and disodium fumarate (DF) on CH4 production, rumen fermentation, and microbial community, with different substrates. The addition of MSS and DF, alone and in combination, significantly reduced the concentration and production of CH4 (p &lt, 0.05), and while with vinasse as substrate, the CH4 production was higher for forage. The highest propionate production and lowest acetate and propionic ratio (A:P) values were all observed in cultures added to the combination of 14 mmol/L DF and 80 mg/kg MSS in both substrates, suggesting that these additives improved the rumen fermentation efficiency. The diversity indexes of prokaryotic microbiota with forage as the substrate were significantly higher than vinasse, and there were different effects on diversity indexes with the addition of MSS and DF depending on the incubated substrate. Supplementation with MSS and DF increased the number of starch degradation and fumarate reducing bacteria, decreased the number of methanogens, but had no significant effect on the number of fibrolytic bacteria. pH, NH3-N, and rumen volatile fatty acids (VFA) were the main factors influencing prokaryotic community structure. In conclusion, basal substrates (forage and vinasse) and CH4 mitigation additives (MSS and DF) have interactions on the in vitro rumen fermentation and microbial composition.

Two experiments were conducted to evaluate the effects of feed additives [monensin (MON); 30 mg/kg of dry matter (DM), and virginiamycin (VM); 25 mg/kg DM] and grain adaptation programs [adding roughage (ROU; sugarcane bagasse) or not (NO-ROU) during the 20-d adaptation period] on performance, carcass characteristics, and nutrient digestibility of Bos indicus cattle fed finishing diets containing 85% whole shelled corn and 15% of a pelleted protein-mineral-vitamin supplement. In Exp.1, 105 Nellore bulls [initial body weight (BW) = 368 ± 25 kg] were used in a complete randomized block design with a 2 × 2 factorial arrangement of treatments, consisting of two feed additives (MON and VM) associated with two adaptation programs (ROU or NO-ROU during the 20-d adaptation period). Effects of feed additives × adaptation programs were not detected (P ≥ 0.13). Feed additives did not affect dry matter intake (DMI), average daily gain (ADG), and feed efficiency (G:F) during the 20-d adaptation period (P ≥ 0.35). During the total feeding period (105 d), feeding MON decreased DMI (P ≤ 0.03) compared to VM. Adding sugarcane bagasse to finishing diets during the 20-d adaptation period (ROU) increased ADG (P = 0.05) and G:F (P = 0.03), and tended to increase BW (P = 0.09) compared to NO-ROU. In Exp. 2, 10 ruminally cannulated Nellore steers (BW = 268 ± 38 kg) were used in a completely randomized design to evaluate the effects of the two feed additives used in the Exp. 1 (MON and VM; 5 steers/treatment) on DMI, total apparent digestibility of nutrients, and ruminal fermentation characteristics. No differences in DMI, total tract apparent digestibility of nutrients, and ruminal fermentation characteristics were observed between MON and VM (P ≥ 0.32). An effect of sampling day (P < 0.001) was observed for ruminal pH, which was greater on day 0 compared to day 7, 14, and 21 of the experimental period (P ≤ 0.05). In summary, supplementing monensin and virginiamycin for finishing Nellore bulls fed whole shelled corn diets, resulted in similar growth performance and carcass characteristics. Including sugarcane bagasse to adapt finishing bulls to no-roughage diets containing whole shelled corn is an alternative to increase growth performance.

Lubabegron (LUB; Experior, Elanco, Greenfield, IN, USA) was approved by the U.S. Food and Drug Administration in 2018 and is indicated for the reduction of ammonia (NH3) gas emissions·kg−1 body weight (BW) and hot carcass weight (HCW) when fed to feedlot cattle during the final 14 to 91 d of the finishing period. LUB demonstrates antagonistic behavior at the β 1 and β 2 receptor subtypes and agonistic behavior at the β 3 receptor subtype in cattle and is classified by the Center for Veterinary Medicine as a “beta-adrenergic agonist/antagonist.” This report describes a randomized complete block study that evaluated LUB dose (0, 1.5, 3.5, and 5.5 mg·kg−1 dry matter) during the last 56 d of the feeding period on calculated NH3 gas emissions, live weight, carcass weight, and associated ratios in beef feedlot cattle. Carcass characteristics, mobility, and health were also evaluated. All cattle received monensin and tylosin throughout the study. Ammonia gas emissions were calculated using the equation developed by Brown et al. (Brown, M. S., N. A. Cole, S. Gruber, J. Kube, and J. S. Teeter. 2019. Modeling and prediction accuracy of ammonia gas emissions from feedlot cattle. App. Anim. Sci. 35:347–356). The reduction in calculated cumulative NH3 gas emissions with LUB ranged from 1.3% to 11.0% (85 to 708 g/hd). When NH3 gas emissions were expressed on a live weight (unshrunk) and carcass weight basis, calculated NH3 gas emissions decreased by 3.0% to 12.8% and 3.8% to 14.6%, respectively. Daily dry matter intake was 2.3% greater (Ptrt < 0.05) for steers that received LUB. Average daily gain was 13.7% greater (Ptrt < 0.05; 1.68 vs. 1.91 kg), while gain efficiency was 10.8% greater (Ptrt < 0.05; 0.167 vs. 0.185) for steers fed LUB. Animal mobility was scored in the pen approximately 1 wk prior to harvest, when cattle were loaded on trucks scheduled for harvest, and at antemortem inspection during lairage. No treatment differences (Ptrt ≥ 0.170) were observed at any time for the percent of cattle receiving mobility scores of 1 or 2 (normal or minor stiffness but moving with the normal cattle, respectively). Cattle mobility scored as a 1 or 2 equaled or exceeded 92% at all times. Final BW and HCW increased (Ptrt < 0.05) 11.6 to 15.7 kg and 11.3 to 17.1 kg, respectively, in cattle receiving LUB compared to cattle receiving monensin plus tylosin alone.

This study evaluated the growth, physiology, and coccidiosis infestation of suckling beef calves provided monensin and grazing limpograss (Exp. 1) or bahiagrass (Exp. 2) pastures. Treatments were randomly assigned to pastures (4 pastures/treatment; 3 cow-calf pairs/pasture in Exp. 1; 4 pastures/treatment; 10 cow-calf pairs/pair of pastures in Exp. 2) and comprised of supplementation of 0.40 kg/d of soybean meal added or not with monensin (20 mg/kg of total DM intake) for 112 and 78 days before weaning in Exp. 1 and 2, respectively. In Exp. 1, supplement DM disappearance tended (P = 0.10) to be less for calves supplemented with vs. without monensin, but treatment × day and treatment effects were not observed (P ≥ 0.18) for herbage mass (HM), herbage allowance (HA), cow body condition score (BCS), calf average daily gain (ADG), calf plasma data, and fecal coccidia egg count. In Exp. 2, forage nutritive value, HM and HA, and cow BCS did not differ (P ≥ 0.43) between treatments. Supplemental monensin did not impact (P ≥ 0.78) plasma concentrations of insulin-like growth factor 1 but increased (P ≤ 0.05) calf overall ADG and plasma concentrations on day 78 and reduced plasma concentrations of urea nitrogen (PUN) on day 78 and fecal coccidia egg count on day 78 compared to calves provided no monensin supplementation. Hence, monensin supplementation successfully improved growth performance of creep-fed suckling beef calves, when herbage mass was not a limiting factor and coccidiosis infestation occurred.

Made available in DSpace on 2021-06-25T10:26:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Additives used to improve feed efficiency of beef cattle on high-grain diets requires products that not only increase animal performance but also provide food safety for consumers. Since phytogenic additives such as essential oils (EO) are the main substitutes for monensin in the diet of cattle fed high-grain diets, this study aimed to evaluate, through meta-analysis, the effects of EO as an alternative to monensin in diets for beef cattle on feed intake, performance, carcass characteristics and ruminal fermentative parameters. Ten peer-reviewed publications with 27 treatment means were included in the data set. These effects were evaluated using random-effect models to examine the weighted mean differences (WMD) between EO treatment and control treatment (diets with monensin). Heterogeneity was explored by meta-regression and subgroup analysis. The substitution of EO for monensin did not affect methane production, ruminal pH values, average daily gain, feed efficiency or carcass weight. However, carcass dressing percentage (WMD = 0.38%; P = 0.03), ribeye area (WMD = 0.82 cm2; P < 0.0001) and subcutaneous fat thickness (WMD = 0.56 mm; P < 0.0001) values increased. Although the use of EO instead of monensin had no influence on the performance of beef cattle fed high-grain diets, the prevalence of hepatic abscesses increased 84.9% and the replacement of monensin by EO increased the risk ratio of hepatic abscess prevalence by 107%. Therefore, the use of EO in high-grain beef cattle diets was ineffective in protecting the liver against abscesses. Animal Unit of Digestive and Metabolic Studies Department of Animal Science School of Agricultural and Veterinary Sciences São Paulo State University (UNESP) Federal University of Piauí Department of Biological Safety German Federal Institute for Risk Assessment Federal University of Espírito Santo Department of Animal Science Animal Unit of Digestive and Metabolic Studies Department of Animal Science School of Agricultural and Veterinary Sciences São Paulo State University (UNESP)

A 2-yr grazing experiment was conducted to evaluate efficacy of nitrogen (N) fertilization, interseeded legumes, and protein supplementation for N delivery to stocker cattle grazing annual ryegrass (Lolium multiflorum). Each year, 90 steers (initial BW, 241 ± 13 kg) were assigned to the following N-delivery methods, with or without monensin fed in a free-choice mineral supplement as a 5 × 2 factorial arrangement of treatments: ryegrass fertilized with 112 kg N/ha (NFERT); ryegrass interseeded with crimson clover (CC, Trifolium incarnatum); ryegrass interseeded with arrowleaf clover (AC, Trifolium vesiculosum); ryegrass plus distillers dried grains with solubles (DDGS) supplemented at 0.65% BW daily; and ryegrass plus whole cottonseed (WCS) supplemented at 0.65% BW daily. Pastures within the interseeded-clover and protein-supplementation treatments were fertilized with 56 kg N/ha at time of establishment. Steers were weighed every 28 d, and forage mass (FM, kg DM/ha) was measured concurrently using the destructive harvest/disk meter double-sampling method. Each of 30 0.81-ha paddocks was stocked initially with 3 “tester” steers, and stocking density (steers/ha) was adjusted using “put-and-take steers” based on changes in FM and steer BW in order to maintain a uniform forage allowance (FA) of 1 kg DM/kg steer BW. Grazing was discontinued on May 11, 2016 in Yr 1 and May 10, 2017 in Yr 2 following 140 and 84 d of grazing, respectively. Data were analyzed as a completely randomized design with repeated measures for which pasture (n = 3) was the experimental unit. Ionophore inclusion did not affect (P > 0.10) any variable measured. Mean FM differed (P < 0.0001) between years and among N-delivery methods (P < 0.10), and mean FA differed (P = 0.005) among N-delivery methods. Steer ADG differed among N-delivery methods (P = 0.02) and between years (P < 0.001), whereas total gain/ha differed (P < 0.0008) among N-delivery methods, but not between years (P = 0.78). Stocking density differed among N-delivery methods (P = 0.02) and between years (P < 0.0001), and grazing-days/ha differed between years (P < 0.0001) and among N-delivery methods (P = 0.001). Results indicate that supplementation with a high-protein by-product feed for cattle grazing annual ryegrass maintained ADG, total gain/ha and grazing-days/ha compared with N-fertilized annual ryegrass, and increased ADG, total gain/ha, and grazing-days over interseeded legumes.

Performance benefits of monensin have been extensively studied in finishing and stocker cattle, but considerably less published work is available evaluating response to monensin supplementation in cow-calf production systems. Feed additives are more difficult to study in cow-calf production systems due to unstable diet characteristics and cow physiological state throughout the production cycle. This meta-analysis investigated the impacts of monensin on performance of extensively raised beef cow-calf and developing replacement heifers. The replacement heifer analysis was conducted with a maximum of 48 treatment means in 18 experiments. The mature cow analysis included 21 publications and 26 mean comparisons. The metaphor package (version 2.4-0; Viechtbauer, 2010) for R (version 4.0.3; www.r-project.org) was used to determine the overall effect size of monensin compared to a negative control. Each study’s n, means, and SEM or P-value was used to calculate the mean difference and estimate of within study variance for responses of interest. For replacement heifers, average daily gain (+0.03 ± 0.008 kg/d), feed efficiency (+0.013 ± 0.008 gain:feed), and percentage cycling before the breeding season (+15.9 ± 5.13%) were increased (P < 0.01), while dry matter intake (-4.3%) and age at puberty (-8.9 ± 1.48 d) were decreased (P < 0.01). Six studies reporting ad libitum forage intake for mature cows showed that monensin decreased (P = 0.008) DMI by 0.85 ± 0.322 kg/day. Six studies showed monesin increased (P = 0.01) milk yield 0.39 ± 0.15 kg/day by mature cows in early lactation. There were no differences in artificial insemination pregnancy nor total pregnancy for either the heifer or mature cow data sets. This analysis also indicates potential for use of monensin in beef cow production systems, but further research is needed to elucidate the effects on DMI and milk production in beef cows.