Administration Of Monensin Research Articles

Gastrointestinal response to the early administration of antimicrobial agents in growing turkeys infected with Escherichia coli

This study investigated the effects of the early administration of enrofloxacin (E) or doxycycline (D) for the first 5 consecutive days of life, or the continuous administration of the coccidiostat monensin (M) throughout the rearing period on gastrointestinal function in turkeys infected with avian pathogenic Escherichia coli (APEC) in an early or later stage of rearing. Experiment 1 lasted 21 d, and turkeys in groups E, D, and M were infected with APEC on d 15. Experiment 2 lasted 56 d, and it had a factorial arrangement of treatments where birds in groups E, D, and M were infected with APEC on d 15 or d 50. In both experiments, control groups (C) consisted of infected and uninfected birds without antibiotic or coccidiostat administration. On d 21 (Experiment 1) and d 56 (Experiment 2), 8 birds from each subgroup were killed, and the ileal and cecal digesta were sampled to analyze the activity of bacterial enzymes and the concentrations of short-chain fatty acids (SCFA). The experimental treatments did not affect the final body weight or body weight gain of birds. Both experiments demonstrated that APEC contributed to an increase in ammonia levels of the cecal digesta (means from 2 experiments: 0.311 vs. 0.225 mg/g in uninfected birds) and ileal pH (6.79 vs. 6.00) and viscosity (2.43 vs. 1.83 mPa⋅s). Moreover, the E. coli challenge enhanced the extracellular activity of several cecal bacterial enzymes, especially in older turkeys infected with APEC in a later stage of life. The continuous administration of monensin throughout the rearing period resulted in a weaker gastrointestinal response in older birds, compared with the other 2 antibiotics administered for the first 5 d of life. The results of the study are inconclusive as both desirable and undesirable effects of preventive early short-term antibiotic therapy were observed in turkeys, including normalization of ileal viscosity and cecal ammonia concentration (positive effect), and disruption in cecal SCFA production (negative effect).

21 Intentionally Induced Barrier Dysfunction Causes Inflammation, Decreases Growth, and Alters Carcass Characteristics of Feedlot Cattle

Abstract There are a variety of acute and chronic psychological and physical stressors associated with management practices used in beef production systems. Primary challenges in feedlot cattle include heat stress, acute and subacute acidosis, weaning, transportation, feed deprivation/restriction, and social mixing/crowding. These stressors disturb the homeostatic state of the host and microbiome and cause acute or chronic inflammation resulting in damage to the gastrointestinal tract (GIT) epithelial barrier that leaves the animal vulnerable to enteric pathogens and toxins. A breach of the small intestinal barrier (leaky gut) allows unwanted pathogens and toxins to infiltrate into blood, causing infection, depressed feed intake, and diverts nutritional resources away from anabolic processes. We have demonstrated that intentionally inducing GIT inflammation in feedlot cattle with aspirin, which is known to cause mucosal injury and increase GIT barrier dysfunction, provides a model system to better understand the metabolic cost of leaky gut in grain-fed feedlot cattle. Indeed, aspirin increased leakage of chromium-EDTA into urine, raised serum concentrations of lipopolysaccharide binding protein (LBP), decreased growth by 4.5 to 8.5%, and re-partitioned carcass components from lean tissue (rib-eye area) into fat. Thus, the chronic inflammatory effects of leaky gut have the potential to create a significant economic loss. Our work also shows that in-feed administration of monensin and tylosin have offered a solution to the non-specific immune response observed in grain-fed cattle by increasing jejunal villus height to crypt depth ratio, diminishing leaky gut, and decreasing serum LBP. Finally, we have observed that molasses based liquid supplements increase ruminal butyrate concentration, resulting in improved gut barrier function, decreased serum inflammatory markers, and greater DMI and ADG in newly received feedlot cattle fed a 30% roughage diet.

Effects of monensin supplementation on rumen fermentation, methane emissions, nitrogen balance, and metabolic responses of dairy cows: A systematic review and dose-response meta-analysis

To investigate the effects of supplemental monensin administration on the metabolic responses of dairy cows, a systematic review and dose-response meta-analysis were conducted. Initially, 604 studies were identified through comprehensive database searches, including Google Scholar, Scopus, Science Direct, and PubMed, using key words related to dairy cows, monensin, and metabolic outcomes. After a 2-stage screening process, 51 articles with a total of 60 experiments were selected for meta-analysis based on criteria such as study implementation date between 2001 and 2022, presence of a control group that did not receive monensin supplementation, reporting of at least 1 outcome variable, and presentation of means and corresponding errors. The meta-analysis used the 1-stage random-effects method, and sensitivity analyses were performed to assess the robustness of the results. The results showed that the administration of monensin at a dosage of 19 to 26 mg/kg was inversely related to methane emissions and that the administration of monensin at a dosage of 18 to 50 mg/kg resulted in a significant decrease in dry matter intake. Administration of monensin at doses of 13 to 28 and 15 to 24 mg/kg also resulted in a significant decrease in ruminal acetate proportion and an increase in propionate proportion, respectively, with no effects on ruminal butyrate, NH3, or pH levels. We found no effects on blood parameters or nitrogen retention, but a significant negative correlation was observed between monensin supplementation and fecal nitrogen excretion. Based on the analysis of all variables evaluated, the optimal dose range of monensin was estimated to be 19 to 24 mg/kg.

유박 비료 섭식 반려견 15 치료 증례

Castor gourd is produced by crushing castor seeds in an expeller to extract the oil. Castor gourd is one of the most versatile natural manures. It is a truly organic manure that improves soil fertility without causing damage or rot. Castor flour contains Ricinus communis, a substance that is toxic to humans, animals and insects. One of the major toxic proteins is “ricin”, which has been reported to cause abdominal pain, vomiting, diarrhea, dehydration, depression and death. In this case report, 15 dogs who received veterinary treatment after eating castor gourd in Gyeongsangnam-do were classified into a group that survived during the treatment period and a group that did not, and compared the differences in clinical features, CBC, chemical, and electrolyte tests. Be careful not to allow pets access to fertilizers containing ricin, and administration of monensin is recommended as a treatment.

The effect of early administration of antibiotics or feeding a diet containing a coccidiostat on inflammatory responses and the morphological structure of selected organs of the immune system in young meat-type turkeys

It was assumed that early administration of enrofloxacin or doxycycline may impair immune function and alter the morphology of organs of the immune system in turkeys, and that diets containing the coccidiostat monensin, an ionophore antibiotic, can exert similar effects. The aim of this study was to determine whether early antibiotic administration or feeding a diet containing a coccidiostat affect immune function in young turkeys. The experiment had a completely randomized design, with 8 groups (a total of 3,080 one-day-old turkeys), 7 replicate pens per group and 55 birds per pen. The experiment had a 2-factorial design, with 4 treatments (C-control, M-monensin, E-enrofloxacin, and D-doxycycline) and 2 groups of birds (vaccinated and unvaccinated) per treatment. Control group birds did not receive the coccidiostat or antibiotics. Group M was administered monensin at 90 mg/kg feed for the first 5 d of life, group E received enrofloxacin at 10 mg/kg BW, added to drinking water, for the first 5 d of life, and group D received doxycycline at 50 mg/kg BW, added to drinking water, for the first 5 d of life. One-day old turkeys from groups C+, M+, E+, and D+ were administered live-attenuated vaccines against turkey rhinotracheitis (TRT) (Poulvac TRT; Zoetis, Parsippany, NJ) and Newcastle disease (ND) (Nobilis ND clone 30; Merck, Rahway, NJ) by coarse spray; 28-day-old birds were administered a subcutaneously injected inactivated vaccine against Ornithobacterium rhinotracheale (ORT) (Ornitin, Phibro, Poland). Turkeys from groups C-, M-, E-, and D- were not vaccinated. It was found that early administration of enrofloxacin or doxycycline, or feeding a diet containing monensin, did not weaken the immune system of turkeys. The administration of monensin, in particular when combined with vaccination, was least effective in inhibiting inflammatory responses. Histological changes in immunocompetent organs (fatty degeneration) were also most severe in birds receiving monensin, followed by those administered doxycycline and enrofloxacin. The observed changes were exacerbated by vaccination.

Monensin inhibits mast cell mediated airway contractions in human and guinea pig asthma models

Asthma is a common respiratory disease associated with airway hyperresponsiveness (AHR), airway inflammation and mast cell (MC) accumulation in the lung. Monensin, an ionophoric antibiotic, has been shown to induce apoptosis of human MCs. The aim of this study was to define the effect of monensin on MC responses, e.g., antigen induced bronchoconstriction, and on asthmatic features in models of allergic asthma. Tracheal segments from house dust mite (HDM) extract sensitized guinea pigs were isolated and exposed to monensin, followed by histological staining to quantify MCs. Both guinea pig tracheal and human bronchi were used for pharmacological studies in tissue bath systems to investigate the monensin effect on tissue viability and antigen induced bronchoconstriction. Further, an HDM-induced guinea pig asthma model was utilized to investigate the effect of monensin on AHR and airway inflammation. Monensin decreased MC number, caused MC death, and blocked the HDM or anti-IgE induced bronchoconstriction in guinea pig and human airways. In the guinea pig asthma model, HDM-induced AHR, airway inflammation and MC hyperplasia could be inhibited by repeated administration of monensin. This study indicates that monensin is an effective tool to reduce MC number and MCs are crucial for the development of asthma-like features.

Changes in Soil and Plant Microbial Community Populations Following Administration of Manure Containing Oxytetracycline or Monensin

Changes in Soil and Plant Microbial Community Populations Following Administration of Manure Containing Oxytetracycline or Monensin

EFFECTS OF DIETARY SODIUM MONENSIN ON THE METABOLIC AND HORMONAL PROFILES OF DAIRY GOATS DURING THE PERIPARTUM PERIOD

Abstract This study aimed to investigate the energetic and hormonal profiles of dairy goats fed diets supplemented with monensin during the peripartum period. Eleven pregnant Saanen goats were subdivided into two random groups, a control group (GC) and the monensin group (MG). The MG group received 40 mg sodium monensin per animal per day for 15 days before partum and throughout the subsequent experimental period. Clinical observations and sample collection were performed at 30, 15, and 7 days before birth; on the day of partum; and at 5, 15, and 30 days after birth. The following biochemical and hormonal profile variables analyzed were: cholesterol, triglycerides, glucose, fructosamine, non-esterified fatty acids (NEFAs) and β-hydroxybutyrate (BHB), cortisol, and insulin. The ruminal fluid pH, chloride content, and volatile fatty acids were also measured. Statistical analysis of the data was performed using repeated measures ANOVA (p < 0.05) and Pearson's correlation. At partum, the MG group had lower values of NEFAs and lower acetate/propionate ratio. MG had higher triglycerides during the entire experiment period. The administration of monensin generated benefits in terms of energy parameters, improving the metabolic status of the dairy goats during peripartum.

Comparative effects of meso-2,3- dimercaptosuccinic acid, monensin, and salinomycin on cadmium-induced brain dysfunction in cadmium-intoxicated mice.

Cadmium (Cd) is a risk factor for neurodegenerative diseases. The purpose of this study was to compare the effects of meso-2,3-dimercaptosuccinic acid (DMSA) and the polyether ionophorous antibiotics monensin and salinomycin on Cd-induced neurodegenerative alterations in mice. The results show that subacute intoxication of mice with Cd (II) acetate (20 mg/kg body weight (BW) for 14 days) caused a significant accumulation of cadmium (Cd) in the brain. Treatment of Cd-exposed mice with DMSA (20 mg/kg BW for 14 days) significantly increased the Cd concentration in the brains compared to those of the Cd-treated group. However, administration of monensin (20 mg/kg BW for 14 days) or salinomycin (20 mg/kg BW for 14 days) significantly reduced the Cd concentration in the brains of Cd-treated mice compared to the toxic control group. Histopathological analysis of brain tissues from the Cd-treated mice revealed that Cd induced neuronal necrosis, characterized by many shrunken, darkly stained pyknotic neurons with prominent perineuronal spaces. Whereas monensin and salinomycin significantly reduced the adverse effects of Cd on brain morphology of Cd-treated mice, DMSA did not. Monensin slightly increased the copper and iron endogenous levels in the brains of Cd-exposed mice compared to those of the untreated mice. Salinomycin did not affect the concentrations of biometal ions in the brain of Cd-exposed mice compared to untreated controls. The results demonstrated salinomycin to be a better potential chelating agent for treatment of Cd-induced brain injury compared to DMSA and monensin.

EFEITO DA MONENSINA SÓDICA SOBRE O PERFIL METABÓLICO DE OVELHAS ANTES E APÓS O PARTO

Resumo O estudo foi realizado com o intuito de avaliar o efeito da monensina, suplementada a partir de 60 dias antes do parto (dap) e por 30 dias pós-parto, sobre o perfil metabólico e hormonal de ovelhas. As ovelhas prenhas (n=13), foram divididas, de forma aleatória, em dois grupos, um que recebeu a monensina (n=7) (30 mg/dia) e o controle (n=6). Amostras de sangue e fluido ruminal foram colhidas aos 60, 50, 40, 30, 20 e 10 dias antes do parto, no momento do parto e nos 10, 20 e 30 dias pós-parto. As variáveis mensuradas foram: glicose, frutosamina, ácidos graxos não esterificados (AGNEs), β-hidroxibutirato, colesterol, triglicérides, proteína total, albumina, ureia e pesquisa de corpos cetônicos na urina. As determinações hormonais foram cortisol e a insulina. No fluido ruminal foi determinado o pH e a concentração dos ácidos graxos voláteis. Na análise estatística foi empregada a ANOVA e estudo de correlação (P<0,05). A monensina elevou (P<0,05) a concentração do propionato no rúmen e frutosamina e insulina no sangue. A administração da monensina promoveu melhora em alguns indicadores do balanço energético.

Effects of monensin on production and energy metabolism in early lactation cows

The aim of the research was to investigate effects of monensin controlled-release capsules on production and metabolism in early lactation cows, with relation to the time of administration of monensin. The study was performed in 2014 (from 01/05/2014 to 01/10/2014) at a Lithuanian cattle farm having 500 dairy cows. Four experimental groups were applied as follows: 1) Group 1 (G1) control (no supplementation, n = 20); 2) Group 2 (G2) with supplementation of monensin (32.4 g monensin controlled-release capsule (MCRC), n = 20). Both groups were on 30th day before expected calving; 3) Group 3 (G3) control (no supplementation, n = 10); 4) Group 4 (G4) with supplementation of monensin (32.4 g monensin controlled-release capsule (MCRC), n = 10). Both groups were on day 1 post partum. Group 2 (G2) received MCRC 30 days before calving, Group 4 (G4) 1 day after calving. Experimental and control cows received the same diet and were exposed to the same environment and management conditions during the entire experimental protocol. Blood samples were collected from the coccygeal vessels: G1 and G2 cows from day –30 (before expected calving, prior to supplementation), each day, up to 30 days post partum; G3 and G4 from day 1 post partum, each day, up to 30 days post partum. Blood serum was tested for beta-hydroxybutyrates (BHB) and glucose concentration. The daily milk yield was measured electronically (DairyPlan C21, Westfalia Surge Inc., GEA). Milk was sampled once monthly. Samples were analyzed for contents of fat, protein, lactose, urea, and somatic cells count. The BHB concentration decreased more efficiently after the supplementation of MCRC after calving. After supplementation with monensin on the first day after calving, it has been identified that the BHB concentration in serum of experimental group (G4) cows statistically significantly decreased after 3 days (p < 0.05). During this period, the average BHB concentration of control group (G3) cows was 0.414 (±0.05) mmol/l, while the BHB concentration of experimental group (G4) cows was 0.27 (±0.03) mmol/l. Statistically significant differences between the experimental and the control groups were observed during the entire study (p < 0.05). After calving, cows supplemented with monensin showed statistically significant higher production of milk (p < 0.05) than the control group. Statistically significant differences in the blood glucose and BHB concentration, quantity of milk and production average between two experimental groups (G2 and G4) were not identified.

Monensina sódica sobre vacas em fase inicial de lactação: produção de leite e peso vivo

Avaliou-se o efeito do fornecimento de monensina sódica no desempenho de vacas leiteiras em fase inicial de lactação, cuja alimentação, em sua dieta total no cocho, compôs-se em 81,4% de silagem de milho e 18,6% de concentrado, em que se fez uso de maior proporção de silagem de milho de que concentrado. Foram utilizadas 14 vacas multíparas 7/8 Holandês, aos 20±10 dias pós-parto aproximadamente, com média de 22±0,5kg vaca-1 dia-1 de leite, em delineamento de blocos casualizados, adotando-se o esquema de parcelas subdivididas no tempo, em modelo de medidas repetidas. Os tratamentos nas parcelas foram diferenciados pela presença (200mg animal-1dia-1) ou ausência da monensina na ração e, nas subparcelas, pelos diferentes períodos de avaliação. Não se observaram diferenças no consumo em matéria seca da dieta, conversão alimentar, produção de leite in natura e corrigida e peso vivo nas médias diárias de cada período. No entanto, a produção de sólidos totais foi superior para os tratamentos com o ionóforo, sinalizando que a administração da monensina sódica para vacas no início de lactação modifica o rendimento em produção de leite.

Changes in blood profile in sheep receiving raw garlic, garlic oil or monensin

This study aimed to evaluate the effects of supplementing a basal diet (CTR) with raw garlic (GAR) or garlic oil (GAO) on blood profile in sheep. Monensin (MON, 33 mg/kg DM) was used as positive control. Four ruminally fistulated rams were used in three experiments each arranged in a 4 × 4 Latin square design with 28-day periods. Experiments 1 and 2 differed in the dose of GAR (75 vs. 100 g/kg DM) and GAO (500 vs. 750 mg/kg DM), while experiment 3 was designed to compare the two doses of each additive (GAR and GAO). The animals were fed a basal diet as TMR consisting of 77.83% forage (alfalfa hay and corn silage) and 22.17% concentrate, providing 10.50 MJ/kg DM (metabolizable energy) and 16.5% crude protein to cover maintenance energy and protein requirements. Supplementation of monensin decreased (P < 0.05) β-hydroxybutyrate (BHB) and non-esterified fatty acid (NEFA) concentrations in the blood compared with other treatments. There was no significant effect of additives on serum concentration of glucose, total triglycerides, cholesterol, total protein, albumin and blood urea nitrogen (BUN). Although the serum insulin concentration was elevated in sheep receiving MON and GAO (P < 0.01), no change was observed in blood glucose concentration. No significant effect of GAO and GAR was observed in key energy and protein-related blood metabolites. However, administration of monensin had a positive influence on energy indices. In conclusion, whereas parameters characterizing the energy balance did not show a significant effect of GAR supplementation, a higher insulin concentration in GAO-treated animals was observed.

Monensin Inhibits Canonical Wnt Signaling in Human Colorectal Cancer Cells and Suppresses Tumor Growth in Multiple Intestinal Neoplasia Mice

The Wnt signaling pathway is required during embryonic development and for the maintenance of homeostasis in adult tissues. However, aberrant activation of the pathway is implicated in a number of human disorders, including cancer of the gastrointestinal tract, breast, liver, melanoma, and hematologic malignancies. In this study, we identified monensin, a polyether ionophore antibiotic, as a potent inhibitor of Wnt signaling. The inhibitory effect of monensin on the Wnt/β-catenin signaling cascade was observed in mammalian cells stimulated with Wnt ligands, glycogen synthase kinase-3 inhibitors, and in cells transfected with β-catenin expression constructs. Furthermore, monensin suppressed the Wnt-dependent tail fin regeneration in zebrafish and Wnt- or β-catenin-induced formation of secondary body axis in Xenopus embryos. In Wnt3a-activated HEK293 cells, monensin blocked the phoshorylation of Wnt coreceptor low-density lipoprotein receptor related protein 6 and promoted its degradation. In human colorectal carcinoma cells displaying deregulated Wnt signaling, monensin reduced the intracellular levels of β-catenin. The reduction attenuated the expression of Wnt signaling target genes such as cyclin D1 and SP5 and decreased the cell proliferation rate. In multiple intestinal neoplasia (Min) mice, daily administration of monensin suppressed progression of the intestinal tumors without any sign of toxicity on normal mucosa. Our data suggest monensin as a prospective anticancer drug for therapy of neoplasia with deregulated Wnt signaling.

Effect of prepartum administration of monensin on metabolism of pregnant ewes

A prospective study involving 18 pregnant ewes of Baloochi breed were conducted to measure the effect of monensin administered 40 days pre-lambing on metabolic function pre-parturition and post-parturition. The pregnant ewes were randomly assigned to one of the 4 treatments: 1) were received monensin and fed an ordinary ration, 2) received monensin and fed restricted ration, 3) fed restricted ration without monensin and 4) control group which fed an ordinary ration without monensin administration. Blood was sampled from each sheep at days 60, 45, 30, 20, 15, 10, 5, 1 prior to parturition, and hour 12 and days 1, 2, 3, 4, 7, 13, 19 and 21 postpartum. The BHB concentrations significantly decreased in animals which received monensin and fed a restricted or an ordinary ration in comparison to the group which not received monensin and fed a restricted ration at prepartum period. The sheep which received monensin showed lower concentrations of NEFA in comparison to animals which were not received monensin. There was no significant effect of monensin on energy, protein indicators and electrolytes in postpartum period. However, feed restriction significantly decreased the concentrations of cholesterol, urea, albumin and Mg at post-parturition period. The results of this study indicate that administration of monensin to pregnant ewes during prepartum period had a markedly positive influence on energy indicators in late pregnancy.

A Pilot Study for Inducing Chronic Heart Failure in Calves by Means of Oral Monensin

Introduction: Heart failure remains a major cause of mortality in the United States, despite advancing technologies, newer methods of treatment, and novel devices. To evaluate such novel devices, a large-animal model of chronic heart failure is critical in carrying out preclinical animal studies. Methods: We evaluated the efficacy of oral monensin in inducing stable heart failure in five Jersey calves. Various doses of monensin were administered. Hemodynamics, pressure–volume loops, echocardiographic measurements, extent of tissue perfusion, and histopathologic data were recorded before and after induction of heart failure. Results: Responses were variable in the animals. One experiment showed a significant decrease in cardiac output within one week, associated with simultaneous increases in left atrial pressure, central venous pressure, and mean pulmonary artery pressure. Left ventricular pressure-volume loops showed that the slope of the end-systolic pressure-volume relation decreased markedly between the baseline and terminal study, suggesting a decrease in contractility. Echocardiographic studies indicated a decrease in ejection fraction. Histopathologic analysis in cardiac tissue showed extensive fibrosis and necrosis. Conclusion: We demonstrated the feasibility of inducing and maintaining severe yet stable heart failure for up to 3 weeks in a calf model by administration of oral monensin.

Clinical Findings and Serum Cardiac Troponin I Concentrations in Horses after Intragastric Administration of Sodium Monensin

Six adult horses were administered sodium monensin, 1.0-1.5 mg/kg, via gastric gavage. Anorexia and/or diarrhea occurred within 24 hr after monensin administration in all 6 horses. Cardiac disease and dysfunction were evaluated by both elevations in heart rate, echocardiography, and an increase in serum concentrations of cardiac troponin I (cTnI), occurred in 4 horses. The development and severity of cardiac disease was likely affected by the monensin dose, vehicle (water or corn oil) mixed with monensin, and/or whether the monensin was administered to fed or fasted horses. Initial increases in cTnI concentrations occurred between 24 and 72 hr after monensin administration. The 2 horses with the highest cTnI concentrations died or were euthanized within 5 days after monensin administration and had severe cardiac disease. One horse had increased cTnI concentrations from day 2 to day 16, but no apparent change in ventricular contractile function was evident on echocardiography. The fourth diseased horse did not return to cTnI reference intervals until day 27 after monensin administration, and the ventricular function was still abnormal just before euthanasia 9 months later. Cardiac troponin I measurements could be useful in managing farm outbreaks of accidental monensin feeding by the early identification of horses with cardiac disease.

Real-Time Quantitative PCR Measurement of Ileal Lactobacillus salivarius Populations from Broiler Chickens To Determine the Influence of Farming Practices

A real-time quantitative PCR assay targeting a 16S-23S intergenic spacer region sequence was devised to measure the sizes of populations of Lactobacillus salivarius present in ileal digesta collected from broiler chickens. This species has been associated with deconjugation of bile salts in the small bowel and reduced broiler productivity. The assay was tested as a means of monitoring the sizes of L. salivarius populations from broilers fed diets with different compositions, maintained at different stocking densities, or given the antimicrobial drugs bacitracin and monensin in the feed. Stocking densities did not influence the numbers of L. salivarius cells in the ileum. A diet containing meat and bone meal reduced the size of the L. salivarius population relative to that of chickens given the control diet, as did administration of bacitracin and monensin in the feed. These changes in the target bacterial population were associated with improved broiler weight gain.

Effect of administration of a controlled-release monensin capsule on incidence of calving-related disorders, fertility, and milk yield in dairy cows

To determine the effect of a controlled-release monensin capsule administered at cessation of lactation on incidence of calving-related disorders, fertility, and milk yield in dairy cows. 290 dairy cows treated with monensin and 290 untreated control cows. Treated cows received a capsule that released monensin at 335 mg/d for 95 days. Incidence of calving-related disorders; daily milk yield up to 20 days postpartum; test-day milk yield, fat, protein, and mature-equivalent 305-day milk production; and body condition score at calving were determined. Reproductive variables were conception rate at first service, pregnancy rate, and calving-to-conception interval. Cows treated with monensin were 2.1 times as likely to develop dystocia and 0.8 times as likely to develop metritis as control cows. For milk yield, there was an interaction of treatment X time X parity. In multiparous cows, monensin significantly improved milk yield at test days 4 and 7. In addition, monensin increased body condition score at calving. Despite increasing the likelihood of developing dystocia and metritis, administration of monensin improved the lactational performance of multiparous cows and may be a promising additive for use at the time of cessation of lactation.

Effectiveness of oral Elancoban™ and Avimix-ST™ against Nematopsis (Apicomplexa: Porosporidae) gametocyts infecting the shrimp Litopenaeus vannamei

Gregarines from Nematopsis genus are a common intestinal parasite infection in the white shrimp, Litopenaeus vannamei, that is cultured on the Pacific coast of Mexico. Slow growth and mortalities of white shrimp have been associated with gregarine infections. Control of gregarine infections in Mexican shrimp farms with antibiotics by empirical methods is becoming increasingly important. However, no effective chemotherapeutic control has been demonstrated. The objective of the present study was to evaluate the effectiveness of oral administration of sodium monensin, Elancoban™ and sulfachloropyrazine, Avimix-ST™ in removing Nematopsis gametocysts from the intestine of naturally infested cultured white shrimp ( L. vannamei). Four experiments were carried out where different concentrations of antibiotics were administered to naturally infested shrimp through medicated feed for 5 consecutive days. The experimental system consisted of glass aquaria containing 8–10 shrimp. Concentrations of antibiotic varied from 2 to 8 g kg −1 for Elancoban™ and from 1.5 to 7 g kg −1 for Avimix-ST™. After 5 days of treatment, both products significantly reduced the mean intensity of Nematopsis gametocysts when compared to the control. Elancoban™ treatment reduced Nematopsis gametocysts by 92% and 94% at 5.5 and 6 g kg −1, respectively, and Avimix-ST™ reduced the numbers of gametocysts by 85% and 83% at 2.5 and 3.5 g kg −1, respectively. No mortalities were recorded for these treatments. The study demonstrates the effectiveness of Elancoban™ and Avimix-ST™ used in medicated feed as a gregarinostats in the control of Nematopsis gametocysts in the white shrimp L. vannamei.