G.L. Parsons

Experimental assessment of the pathogenicity of eight avian influenza A viruses of H5 subtype for chickens, turkeys, ducks and quail.

Clinical signs, death, virus excretion and immune response were measured in 2-week-old chickens, turkeys, quail and ducks infected by intramuscular, intranasal and contact routes with eight influenza viruses of H5 subtype. Six of the viruses: A/chicken/Scotland/59 (H5N1), ck/Scot; A/tern/South Africa/61 (H5N3), tern/SA; A/turkey/Ontario/ 7732/66 (H5N9); ty/Ont; A/chicken/Pennsylvania/1370/83 (H5N2); Pa/1370; A/turkey/Ireland/83 (H5N8); ty/Ireland, and A/duck/Ireland/ 113/84 (HSN8); dk/Ireland, were highly pathogenic for chickens and turkeys. Two viruses, A/chicken/Pennsylvania/1/83 (H5N2), Pa/1 and A/turkey/Italy/ZA/80 (H5N2), ty/Italy, were of low pathogenicity. Ck/Scot was more pathogenic for chickens than turkeys while ty/Ont was more pathogenic for turkeys than chickens. Other viruses showed little difference in their pathogenicity for these two hosts. No clinical signs or deaths were seen in any of the infected ducks. Only two viruses, dk/Ireland and ty/Ireland, produced consistent serological responses in ducks, although intramuscular infection with tern/SA and ty/Italy resulted in some ducks with positive HI titres. These four were the only viruses reisolated from ducks. Quail showed some resistance to viruses which were highly pathogenic for chickens and turkeys, most notably to ck/Scot and ty/Ont and to a lesser extent tern/SA and Pa/1370. Transmission of virus from intranasally infected birds to birds placed in contact varied considerably with both host and infecting virus and the various combinations of these.

Isolation of a European bat lyssavirus type 2 from a Daubenton's bat in the United Kingdom

European bat lyssavirus type 2 (EBLV-2) has been isolated once previously from a bat in the UK in June 1996. In September 2002, a Daubentons bat (Myotis daubentonif) found in Lancashire developed abnormal behaviour, including unprovoked aggression, while it was in captivity. Brain samples from the bat were tested for virus of the Lyssavirus genus, which includes EBLV-2 (genotype 6), and classical rabies virus (genotype 1). A positive fluorescent antibody test confirmed that it was infected with a lyssavirus, and PCR and genomic sequencing identified the virus as an EBLV-2a. Phylogenetic comparisons with all the published sequences from genotype 6 showed that it was closely related to the previous isolate of EBLV-2 in the UK and suggested links to isolates from bats in the Netherlands. The isolation of EBLV-2 from a bat found on the west coast of England provides evidence that this virus may be present within the UK Daubentons bat population at a low prevalence level.

Risk factors associated with travel to rabies endemic countries

Increased travel to exotic destinations around the world is escalating the risk that an emerging virus may be imported into the UK. Rabies should be considered in the differential diagnosis of any encephalitic illness presenting in an appropriate epidemiological context. Molecular diagnostic tests that can rapidly discriminate rabies from other suspected infections will influence the use of anti-rabies prophylaxis for potential contacts with the victim. In 2001, the UK had two confirmed human rabies cases, imported from the Philippines and Nigeria, respectively. In case one, hemi-nested reverse transcriptase polymerase chain reaction (hn-RT-PCR) and automated sequencing confirmed the presence of rabies virus (RABV) within both the saliva and skin specimens within 36 h of sample submission. Subsequent phylogenetic analysis using a partial sequence of the nucleoprotein (N-) gene segment demonstrated that the virus was closely related to that of canine variants currently circulating in the Philippines. In the second case, the fluorescent antibody test and reverse transcriptase polymerase chain reaction (RT-PCR) confirmed the diagnosis on post-mortem tissue. Phylogenetic analysis of two genomic segments of this isolate confirmed that it was a classical RABV (genotype 1) of the Africa 2 subgroup. These cases have highlighted the capability of molecular diagnostic tests for the rapid identification and subsequent genotyping of RABV to host and geographical location. In the first instance, rabies diagnosis often rests on clinical and epidemiological grounds. Negative tests, even late in the illness, do not exclude the diagnosis as these tests are never optimal and are entirely dependent on the nature and quality of the sample supplied. For this reason, rapid molecular detection and virus typing will be essential in considering the appropriate medical treatment regimen for a patient. In addition, an early diagnosis may decrease the number of unnecessary contacts with the patient and reduce the requirement for invasive and costly interventions. Rabies should form part of a differential diagnosis for any patient presenting with a history of travel to a rabies endemic country and displaying an undiagnosed encephalopathy.

Isolation of EBLV-2 in a Daubenton's bat (Myotis daubentonii) found in Oxfordshire.

SIR, — Since 1987, we have undertaken passive surveillance in Great Britain for bat variants of rabies virus ([Harris and others 2006a][1]). In Europe, bat variants of rabies virus are classified as genotypes 5 and 6 (European bat lyssavirus [eblv] type 1 [eblv-1] and type 2 [eblv-2], respectively

Effects of megasphaera elsdenii on ruminal pH, ruminal concentrations of organic acids, and bacterial genomes following a grain challenge

Introduction Upon arrival in feedlots, cattle normally must be adapted to high-concentrate diets. The microbial population in the rumen of incoming cattle normally is suited to digestion of forages, and when cattle are transitioned onto concentrate diets, opportunistic bacteria that produce lactic acid can proliferate rapidly, leading to excesses of lactic acid in the rumen. High levels of lactic acid in the rumen may cause mild to severe acidosis. Megasphaera elsdenii is a lactate-utilizing bacterium that normally is present in rumens of cattle that have been adapted to high-grain diets, but numbers of the organism are relatively low during the step-up phase. Increasing the numbers of lactate-utilizing bacteria in newly arrived cattle by orally dosing with M. elsdenii may be a useful means of reducing the risk of ruminal acidosis in feedlot cattle. Our objectives were to evaluate ruminal parameters and determine efficacy of increasing ruminal populations of lactateutilizing bacteria in cattle following an abrupt diet change and administration of 10 mL (low dose), 100 mL (medium dose), or 1000 mL (high dose) of a culture containing 1.62 × 108 CFU/mL of live M. elsdenii compared with a control group given a placebo without live Megasphaera.

Effects of feeding low levels of crude glycerinwith or without other by-products onperformance and carcass characteristics offeedlot heifers

Introduction Expansion of the renewable fuels industries has increased availability of by-products that are well suited for use as cattle feed. Glycerin is among the principal by-products of biodiesel production, comprising approximately 10% (by weight) of the soybean oil that is used to manufacture soy-based diesel fuel. Our previous research evaluated effects of including between 0% and 16% glycerin in flaked-corn finishing diets and revealed that optimal growth performance was achieved with 2% glycerin addition. Our laboratory experiments have suggested that even lower levels of glycerin may be effective at stimulating digestion. Therefore, the objective of this study was to evaluate effects of low levels of glycerin in the diet on performance and carcass characteristics of finishing cattle. Furthermore, because distillers grains and other by-products are increasingly common in feedlot rations, we opted to evaluate glycerin in corn-based finishing diets as well as in diets that consisted of a combination of corn grain, distillers grains, and soybean hulls.

Effects of crude glycerin on ruminal metabolism and diet digestibility of flaked-corn finishing diets

Introduction Expansion of the biodiesel industry has increased supplies of crude glycerin available for livestock feeding. Catalyzed reactions between methanol and triglycerides from vegetable oils, such as soybean oil, yield biodiesel and a coproduct, crude glycerin. Approximately 10% of the weight of soybean oil used to produce biodiesel becomes glycerin. Limited work has been conducted to understand metabolism of glycerin in ruminant livestock. In previous studies at Kansas State University, feeding crude glycerin at 8% or less of the diet improved cattle performance. Subsequent laboratory experiments indicated that low levels of glycerin may improve ruminal fermentation. This study was conducted to determine whether adding low levels of glycerin to feedlot diets could affect diet digestibility.

Feed depredation by european starlings

Introduction European starlings (Sturnus vulgaris) were first introduced to the United States in the late 1800s. It is believed that the starlings were imported from Europe and released in New York City’s Central Park so that all of the birds mentioned in Shakespeare’s works would inhabit the new country. For the next 50 years, the starling population grew exponentially; by 1942, starlings had spread to the West Coast. Starlings are not considered migratory and remain in the same general area year round; however, some may migrate several hundred miles. During much of the year, the inconspicuous starlings disperse into small flocks and feed on seeds, fruits, and insects. During winter months, starlings form flocks of several hundred up to 750,000 birds that share feeding and roosting sites. These large flocks prefer to roost in coniferous trees, which provide protection from wind and adverse weather conditions. Previous research has documented that a 3-oz starling consumes nearly 2 lb of feed in a 30-day period. Commercial feedlots have been infested with large populations of starlings during winter months. The attraction to feedlots is due to open feed bunks that provide a convenient source of feed. Currently, there are limited means for controlling starlings in feedlots. The objective of our experiment was to compare susceptibility of different rations to depredation by starlings.

Increasing days on feed for heavy short-fedyearling stocker cattle improves carcasscharacteristics

Introduction With increasing feed costs, producers may be able to utilize forage resources to help cattle gain weight before entering a high-concentrate finishing phase. In theory, heavy stocker cattle need less time on feed before slaughter compared to lighter weight cattle; however, research determining the impact of a short feeding system on product quality is limited. Therefore, the purpose of this research was to investigate the impact of a shortened, high-concentrate feeding period on carcass characteristics and meat quality traits of heavy yearling stocker cattle.

Supplementing dried distillers grains with solubles to heavy yearling stocker cattle grazing native tallgrass pastures during late summer and fall improves animal performance and carcass characteristics

Introduction Grazing stocker cattle on low-quality forages is a common practice in Kansas; however, animal performance typically is modest. Due to the increasing availability of ethanol co-products, producers may be able to use dried distillers grains with solubles (DDGS) as a protein source to help increase body weight of stocker cattle grazing native tallgrass pastures during the late summer and fall. Therefore, the purpose of this research was to investigate the impact of feeding DDGS to heavy stocker cattle during late summer and fall and to document its effects on animal performance and subsequent carcass characteristics.