Orally dosing steers with Lactipro (Megasphaera elsdenii) decreases the quantity of roughages fed during finishing

The cost of roughages is relatively high in comparison to their contribution of nutrients to feedlot diets. Widespread drought has affected roughage supplies in the cattle-feeding regions of the United States, further increasing the cost of roughages for feedlots. Despite their relatively high cost, roughages are incorporated into finishing diets to maintain rumen function and to manage ruminal acidosis. The greatest proportion of roughage is utilized early in the feeding period when cattle are being transitioned from forage-based diets to concentrate-based diets, allowing ruminal microbes to adapt gradually to higher levels of starch and sugars. If cattle are not properly adapted to concentrate-based diets, undesirable lactic acid-producing microorganisms, such as Streptococcus bovis, can rapidly proliferate and produce large excesses of lactic acid in the rumen. This condition can precipitate feedlot acidosis, which can have serious consequences for health and performance of cattle. Lactipro (MS Biotec, Wamego, KS) is a probiotic drench containing Megasphaera elsdenii, which is a lactate-utilizing bacterium that prevents lactic acid accumulations in the rumen of grain-fed cattle. Lactipro has been used successfully to accelerate the adaptation of cattle from roughage-based diets to concentrate-based diets. The objective of this study was to determine if Lactipro could be utilized to eliminate the step-up period for feedlot cattle, and in so doing decrease the amount of roughage required during the finishing period

Experimental Searches for the Axion and Axion-Like Particles

Four decades after its prediction, the axion remains the most compelling solution to the strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This article reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the µeV range and may plausibly be extended up to 100 µeV. Within the past several years, however, researchers have realized that axions are pervasive throughout string theories, but with masses that fall naturally in the neV range, for which an NMR-based search is under development. Both searches for axions emitted from the Sun's burning core and purely laboratory experiments based on photon regeneration have recently made great progress, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large gains in sensitivity and mass reach. Furthermore, each modality has been exploited in order to search for more generalized axion-like particles, which we also discuss in this review. We are hopeful, even optimistic, that the next review of the subject will concern the discovery of the axion, its properties, and its exploitation as a probe of early universe cosmology and structure formation

Hydrated lime matrix decreases ruminal biohydrogenation of flaxseed fatty acids

Omega-3 fatty acids are essential nutrients for humans, but dietary intake of these nutrients by many Americans is inadequate due to low consumption of omega-3-rich foods such as fish, walnuts, and flaxseed. In contrast, per capita consumption of red meat is relatively high, but these products normally contain only small amounts of omega-3 fatty acids. Feeding cattle diets that contain omega-3 fatty acids has consistently increased the proportion of the desirable fats that accumulate in beef. Unfortunately, the proportion of dietary omega-3 fats that are deposited into beef tissues is relatively low, because microorganisms within the rumen biohydrogenate the unsaturated omega-3 fatty acids extensively to produce the saturated fats that are characteristic of beef fat. Encapsulation of fats has been proposed as a method for improving efficiency of transfer of omega-3 fats into beef. Encapsulation processes apply a protective barrier on the surface of fats or fat-containing feeds, which theoretically decreases fats’ susceptibility to microbial biohydrogenation. Protective coatings must remain intact to retain their functionality, and physical damage to the coatings that occurs with normal handling can result in poor efficacy because the core material is exposed to microorganisms in the rumen. Embedding feed particles within a homogeneous protective matrix constitutes a potentially useful alternative to protective surface barriers. The matrix is created by mixing feed particles that are to be protected with a suitable matrix material that is resistant to microbial digestion and subsequently forming the mixture into pills. In cases where physical damage occurs, exposure of the core material is confined to the broken surface, and the remainder of the matrix retains its ruminal stability. The objective of this study was to determine if embedding flaxseed within a matrix of hydrated dolomitic lime could be used as a method to decrease biohydrogenation of polyunsaturated omega-3 fatty acids, thus improving efficiency of omega-3 fatty acids absorption into the bloodstream

On a Light Spinless Particle Coupled to Photons

A pseudoscalar or scalar particle $\phi$ that couples to two photons but not to leptons, quarks and nucleons would have effects in most of the experiments searching for axions, since these are based on the $a \gamma \gamma$ coupling. We examine the laboratory, astrophysical and cosmological constraints on $\phi$ and study whether it may constitute a substantial part of the dark matter. We also generalize the $\phi$ interactions to possess $SU(2) \times U(1)$ gauge invariance, and analyze the phenomenological implications.Comment: LaTex, 20p., 6 figures. Changes in sections 4, 5 and figure 2, our bounds are now more stringent. To be published in Physical Review

Detection of fragments arising from >10 GeV electron-nucleus collisions

Much is understood about the interaction of both high energy electrons with nucleons and lower energy electrons with nucleons and nuclei. Although a number of experiments involving high energy inelastic scattering of electrons from quarks bound in nuclei have been performed, many interpretations of the data are still discussed. A project called PEGASYS was conceived at PEP to further investigate this physics. Unfortunately, the termination of PEP operations curtailed this experiment and much of the physics remains unexplored. In this paper we present some details of one proposed part of this project (tagged nuclear structure functions) and some considerations made in designing a detector suitable for observing very low momentum nuclear fragements around a cold-cluster gas target

Altering dietary calcium does not influence tenderness in cattle fed Zilmax

Tenderness is a key contributor to the sensory attributes of beef, and production practices that decrease tenderness are generally viewed as unfavorable. Zilmax (Merck Animal Health, Summit, NJ) is a potent beta-adrenergic agonist that results in dramatic improvements in carcass weight when fed to cattle, normally for a period of 20 days prior to harvest. Zilmax increases muscle mass at the expense of body fat, and these changes can have favorable effects on retail yield and overall value of beef carcasses. One of the unfavorable side effects of Zilmax is a decrease in meat tenderness. Aging of beef is one means of improving tenderness. During the aging process, proteolytic enzymes degrade the myofibrillar proteins that contribute to the perceptions of tough meat. Activity of these enzymes is stimulated by the presence of calcium ions, and various strategies aimed at increasing intracellular concentrations of calcium have been investigated as a means of improving beef tenderness. The purpose of this experiment was to determine if dietary calcium could be manipulated during the period of Zilmax supplementation as a means of improving meat tenderness. To do this, we eliminated supplemental calcium from the diet in hopes of inducing the secretion of parathyroid hormone. Parathyroid hormone stimulates the mobilization of calcium deposited in skeletal tissue, and we hypothesized that by decreasing dietary calcium we could potentially increase bone mobilization, and in so doing increase the supply of calcium available to proteolytic enzymes within skeletal muscle to enhance activity of these enzymes post-mortem

Orally dosing steers with Lactipro (Megasphaera elsdenii) decreases the quantity of roughages fed during finishing

The cost of roughages is relatively high in comparison to their contribution of nutrients to feedlot diets. Widespread drought has affected roughage supplies in the cattle-feeding regions of the United States, further increasing the cost of roughages for feedlots. Despite their relatively high cost, roughages are incorporated into finishing diets to maintain rumen function and to manage ruminal acidosis. The greatest proportion of roughage is utilized early in the feeding period when cattle are being transitioned from forage-based diets to concentrate-based diets, allowing ruminal microbes to adapt gradually to higher levels of starch and sugars. If cattle are not properly adapted to concentrate-based diets, undesirable lactic acid-producing microorganisms, such as Streptococcus bovis, can rapidly proliferate and produce large excesses of lactic acid in the rumen. This condition can precipitate feedlot acidosis, which can have serious consequences for health and performance of cattle. Lactipro (MS Biotec, Wamego, KS) is a probiotic drench containing Megasphaera elsdenii, which is a lactate-utilizing bacterium that prevents lactic acid accumulations in the rumen of grain-fed cattle. Lactipro has been used successfully to accelerate the adaptation of cattle from roughage-based diets to concentrate-based diets. The objective of this study was to determine if Lactipro could be utilized to eliminate the step-up period for feedlot cattle, and in so doing decrease the amount of roughage required during the finishing period

Dosing high-risk calves at processing with Lactipro decreases the number of calves treated for bovine respiratory disease

Bovine respiratory disease is the leading cause of cattle mortalities in U.S. feedlots. In addition to costs associated with death loss and medical treatments, cattle affected by respiratory disease typically have suboptimal performance. Lightweight calves coming into the feedlot are at high risk for respiratory disease due to the stress associated with weaning, transportation, feed and water deprivation, commingling, castration, and other factors. Calves often have no experience eating from feed bunks and may be unfamiliar with the types of feeds used in feedlots. At the same time, the cattle are susceptible to acidosis due to the concentrate-based diets that are fed, which also can have unfavorable effects on feed intake and performance. Moreover, symptoms of acute acidosis, which include poor appetite, increased respiration rate, lethargy, depression, loss of muscle tone, nasal and ocular discharge, and diarrhea, can be difficult to distinguish from clinical symptoms of respiratory disease. Therapies designed to address respiratory disease are generally ineffective for treating acidosis, inevitably leading to the perception that antibiotic treatments have only limited efficacy. Moreover, acidosis can increase susceptibility of cattle to respiratory disease. Acidosis is most logically dealt with through preventive measures. We hypothesized that Lactipro (MS Biotec; Wamego, KS), a source of the lactate-utilizing bacterium Megasphaera elsdenii, could decrease the incidence of feedlot acidosis in newly arrived feedlot calves. By preventing acidosis, we speculated that clinical symptoms similar to those associated with respiratory disease would be less prevalent, thus decreasing the number of animals inappropriately diagnosed and treated for respiratory disease. Our objective was to determine if dosing cattle with Lactipro at processing would decrease morbidity and mortality in lightweight calves after arrival at the feedlot