The producers must observe feed efficiency (FE) and profitability in feedlot cattle under scenarios of high production costs associated with feeding. most efficient persistant way to change FE is using genetic tools. However, selection slow compared the use addititves, which work stabilize ruminal pH, induce beneficial changes rumen microbial population, increase energy protein metabolism. lite...

Introduction Ionophores have been used extensively in the beef industry in Canada since 1977. Until recently, there has been no label indication for use of ionophores in lactating dairy cattle. Ionophores are feed additives that alter rumen microbial populations through ion transfer across cell membranes. In Canada, the label warning prohibiting the use of Rumensin premix in lactating dairy ca...

AIMS To examine the effects of ionophores on Salmonella and Escherichia coli O157:H7 in pure and mixed ruminal fluid cultures. METHODS AND RESULTS Four Salmonella serotypes (Dublin, Derby, Typhimurium, and Enteriditis) and two strains of E. coli O157:H7 (ATCC 43895 and FDIU 6058) were cultured in the presence of varying concentrations of ionophores (monensin, lasalocid, laidlomycin propionate...

Ionophores (such as monensin, lasalocid, laidlomycin, salinomycin and narasin) are antimicrobial compounds that are commonly fed to ruminant animals to improve feed efficiency. These antimicrobials specifically target the ruminal bacterial population and alter the microbial ecology of the intestinal microbial consortium, resulting in increased carbon and nitrogen retention by the animal, increa...

interpreted by using a variety of schemes involving Ni(III)/Ni( I and Ni( I I I ) /Ni( I I ) /Ni( I ) / Ni(0)22 formal oxidation states. In all these schemes, the assignment of Ni(l1l) to the oxidized forms of the enzymes is based on the observation of hyperfine in 61Ni-labeled enzymes, the similarity of the EPR spectra to EPR spectra of tetragonal Ni(II1) coordination compounds, and the associ...

a new series of noncyclic ionophores containing two to four furan units (ia to iiib) i.e. 1,1-difurylethane (ia), 2,5-bis(methylfurfuryl)furan (iia) and 1,1’ ethyledenebis[5-(methylfurfuryl)furan] (iiia), 2,2-difurylpropane (ib), 2,5-bis (dimethylfurfuryl)furan(iib), 2,2’-isopropylidenebis[5-(dimethylfurfuryl)furan] (iiib) have been synthesized by the condensation of furan with acetaldehyde and...

Three novel phenyltelluroalkoxyl functionalized tweezer-like calix[4]arenes 6-8 and two monophenyltelluropropoxyl functionalized calix[4]arenes 10 (cone conformer) and 12 (partial cone conformer) were synthesized and characterized. They are good Ag(+)-selective ionophores in ion-selective electrodes evaluated by electromotive force measurements of polymer membrane electrodes. The tweezer-like i...

A new series of noncyclic ionophores containing two to four furan units (Ia to IIIb) i.e. 1,1-difurylethane (Ia), 2,5-bis(methylfurfuryl)furan (IIa) and 1,1’ ethyledenebis[5-(methylfurfuryl)furan] (IIIa), 2,2-difurylpropane (Ib), 2,5-bis (dimethylfurfuryl)furan(IIb), 2,2’-isopropylidenebis[5-(dimethylfurfuryl)furan] (IIIb) have been synthesized by the condensation of furan with acetaldehyde and...

X-537 A and A 23187, two antibiotics which form liphophilic complexes with divalent cations, function as ionophores in vesicular fragments of sarcoplasmic reticulum (SR). Addition of either ionophore to SR preloaded with calcium in the presence of adenosine triphosphate (ATP), causes rapid release of calcium. Furthermore, net calcium accumulation by SR is prevented, when the ionophores are adde...