Effects of dietary yeast extract on turkey stress response and heterophil oxidative burst activity

1. Effective nutritional approaches to counteract the negative effects of stress may provide food animal producers with useful alternatives to antibiotics. In this study, turkeys were fed on a standard diet, or the same diet supplemented with yeast extract (YE), to determine if YE would improve disease resistance in a stress model.

2. At 16 weeks of age, half of the birds were exposed to a bacterial challenge using a coarse spray of the pen environment. A subset of control and challenged birds was also treated with dexamethasone (Dex) prior to challenge (Dex/challenge). At 18 weeks, another subset was subjected to a 12?h transport stress protocol (Challenge/transport). All birds were bled and necropsied the morning after transport. The numbers and proportions of blood cells and the heterophil oxidative burst activity (OBA) were determined. Serum corticosterone (Cort) levels of male birds were measured using a commercial ELISA kit. Body weight and gain were increased by YE during week 1.

3. YE decreased mortality and bacterial isolation following Dex/challenge only in females. Cort levels in male turkeys were decreased by YE and Dex treatment. OBA was higher in males and in birds given YE and was reduced by challenge and transport.

4. These results suggest there may be gender differences in the turkey stress response and that dietary YE has potential for modulating the impact of stress on innate immunity of turkeys.     

Salmonella pullorum in the common pheasant (Phasianus colchicus)

In 1996, pullorum disease due to Salmonella enterica serovar Gallinarum biovar pullorum (Salmonella pullorum) was diagnosed in pheasants on a gamebird rearing enterprise in south-west Scotland. The gross pathology and bacteriological findings are described, as are the results of screening for S pullorum on the site in 1997. The causal organism was readily isolated from the lung, liver, yolk sac and heart blood on direct culture, but less readily from the digestive tract or by the use of selective media. The bacteria recovered from the pheasants were identified as S pullorum phage type 7, a phage type previously associated with pheasants rather than domestic fowl, and the organisms were most probably introduced to the site by the movement of carrier pheasants.     

Comparison of Tifton 85 and Coastal bermudagrasses for yield, nutrient traits, intake, and digestion by growing beef steers.

A study was undertaken to compare Tifton 85 (T85) and Coastal (CBG) bermudagrasses for effects of cultivar and age at harvest on yields of DM and digestible DM, in vitro digestion, nutrient content, cell wall composition, in situ digestion kinetics, and feed intake and digestion by growing beef steers. In Exp. 1, T85 and CBG forages staged for growth in May or July of 1993 were harvested at 3, 4, 5, 6, 7, and 8 wk from subplots. Tifton 85 bermudagrass had 7.1% greater DM yield, 18.2% higher (P < .05) digestible DM yield, and 7.1% greater IVDMD than CBG, and, after 5 wk of forage growth, IVDMD of both T85 and CBG decreased with increased age at harvest (P < .05). In Exp. 2, T85 and CBG forages staged for growth in July 1997 were harvested at 2, 3, 4, 5, 6, and 7 wk from subplots. Even though T85 had higher concentrations of NDF and ADF than CBG, T85 had 34.1% higher DM yield, 47.9% higher digestible DM, 55.0% higher digestible NDF, 91.7% higher digestible ADF, greater IVDMD, in vitro NDF and ADF disappearances, and higher in situ DM and NDF digestion (P < .05). Coastal bermudagrass had higher concentrations of lignin and lower concentrations of total neutral sugars, arabinose, glucose, and xylose than T85 (P < .05). In vitro digestibilities of DM, NDF, and ADF were lower and concentrations of ADF and lignin were greater for 7- vs 6-wk harvests of both T85 and CBG (P < .05). In Exp. 3, T85 and CBG forages staged for growth in July 1997 were harvested as hay at 3, 5, and 7 wk from .8-ha pastures and fed to 36 individually penned growing beef steers (initial BW = 244 kg) to quantify ad libitum intake without supplementation. Tifton 85 bermudagrass had lower concentrations of lignin and ether-linked ferulic acid and greater concentrations of NDF, ADF, hemicellulose, and cellulose than CBG (P < .05). Steers fed T85 had higher (P < .05) digestion of DM, OM, NDF, ADF, hemicellulose, and cellulose than steers fed CBG. Digestion of NDF, ADF, hemicellulose, and cellulose decreased (P < .05) with increased age at harvest for both cultivars. In conclusion, T85 produced more DM and had more digestible nutrients in vitro, in situ, and in vivo than CBG, and 3 and 5 wk of growth would be recommended ages to harvest either cultivar.     

Elephant herpes virus--a problem for breeding and housing of elephants]

Herpesvirus infections which take a fatal turn on African elephants as well as on Asian elephants seem to occur increasingly not only in the USA but also in European stocks. The endotheliotropic herpesvirus causes a rapidly progressing and severe disease which makes any therapeutical effort unsuccessful and finally results in death of the animal, especially in young Asian elephants. As all attempts to culture the virus failed up to now, molecular biological procedures have to be used more often for diagnostical purpose together with the common methods of pathology, virology, and electronmicroscopical evaluation. This is a report on the case of 'KIBA', an eleven year old male elephant at the Zoological Garden Berlin, infected with the endotheliotropic elephants herpesvirus. 'KIBA' was born at the Zoo in Houston, Texas, and raised within his herd. Upon arriving in Berlin in November 1997 he adapted to the new premises and climate and new social circumstances without any problems. In June 1998 he already serviced three females of his new herd several times. In August 1998 he died after passing a peracute progression of the disease after residenting in Berlin for only 9 months. The dissection of the animal revealed some evidence on an agent damaging the endothelium. Major signs indicating this agent were bleedings in several serous membranes, mucosa and on the the right atrium, as well as other parts of the myocardium. Furthermore there have been ulcerations at various localisations of the whole digestive tract. Slightly basophilic intranuclear inclusion bodies have been found histologically in endothelial cells of different organ samples. An examination of altered organ-material by electronmicroscopy made some herpesvirus-like particles visible. A virological investigation first revealed evidence of giant cell formations with solitary basophilic intranuclear inclusion bodies in different cell cultures, however, without any distinct cytopathogenic effect. Supported by molecular biological procedures the infection of 'KIBA' could be verified as the elephants herpesvirus. By means of PCR and subsequent sequence analysis a DNA-sequence typical for the elephants herpesvirus could be obtained which showed an identity of 97% with the terminase sequence of the elephant herpesvirus described by American authors. The deduced amino acid-sequences were 100% identical. To the terminase of the human cytomegalovirus, the elephant sequence had an identity of 53% (similarity: 74%). Based on the cooperation of ILAT, Institute of Veterinary-Pathology/Free University Berlin, Robert-Koch-Institut Berlin, and Zoological Garden Berlin, the cause of 'KIBA's' death could be discovered immediately. Possible implications of this case especially on breeding and keeping elephants are discussed briefly.     

Drug disposition and dosage determination of once daily administration of gentamicin sulfate in horses after abdominal surgery.

OBJECTIVE: To evaluate pharmacokinetics of once daily i.v. administration of gentamicin sulfate to adult horses that had abdominal surgery. DESIGN: Prospective study. ANIMALS: 28 adult horses that underwent abdominal surgery for colic. PROCEDURE: 14 horses were treated with each dosage of gentamicin (i.e., 6.6 or 4 mg/kg, i.v., q 24 h) and blood samples were collected for pharmacokinetic analysis. Plasma gentamicin concentrations were measured by use of a fluorescence polarization immunoassay. Pharmacokinetic analysis measured the elimination half-life, volume of distribution, and gentamicin total systemic clearance. Treatment outcome, CBC, and serum creatinine concentrations were recorded. RESULTS: 1 horse in the high-dosage group died. All other horses successfully recovered, and did not develop bacterial infection or have evidence of drug toxicosis resulting in renal injury. Mean pharmacokinetic variables for gentamicin administration at a high or low dosage (i.e., 6.6 or 4 mg/kg, i.v., q 24 h) were half-life of 1.47 and 1.61 hours, volume of distribution of 0.17 and 0.17 L/kg, and systemic clearance of 1.27 and 1.2 ml/kg/min, respectively. Mean serum creatinine concentration was 1.74 and 1.71 for the high and low dosages, respectively, and serum creatinine concentration was not correlated with gentamicin clearance. CONCLUSIONS AND CLINICAL RELEVANCE: Gentamicin administration at a dosage of 4 mg/kg, i.v., every 24 hours, will result in plasma concentrations that are adequate against susceptible bacteria with a minimum inhibitory concentration (MIC) of < or = 2.0 micrograms/ml. Gentamicin administration at a calculated dosage of 6.8 mg/kg, i.v., every 24 hours will result in optimum plasma concentrations against susceptible bacteria with a MIC of < or = 4.0 micrograms/ml.     

Comparison of indirect fluorescent antibody test and enzyme linked immunosorbent assay in the detection of exposure of cattle to Theileria parva in Kenya.

Appraisal of the indirect fluorescent antibody test (IFAT) and antigen enzyme linked immunosorbent assay (ELISA) serological tests as carried out to detect cattle exposed to Theileria parva at the National Veterinary Research Centre, Muguga (NVRC), Kenya is reported. Using sera from T. parva naive cattle and cattle experimentally exposed to T. parva, the two tests were appraised in terms of their sensitivity and specificity. IFAT and ELISA had the same sensitivity of 90% while ELISA had a higher specificity (90%) than IFAT (80%). A comparison was also made of the capability of the two tests to detect exposure of dairy cattle to T. parva prior to immunization against East Coast fever (ECF). The positive outcome from the IFAT was significantly higher (chi 2 = 30.36; P < 0.001) than that from the ELISA. The agreement between the two tests was low (Kappa = 0.21). The two tests indicated a higher risk of ECF in the study area than was expected. Indications are that the ELISA has been effectively adopted at NVRC.     

Effects of sire growth potential, growing-finishing strategy, and time on feed on performance, composition, and efficiency of steers.

Beef production systems that increase use of unharvested forages and use animals with greater potential for gain affect age and size of animals placed on a finishing regimen. This experiment was conducted to evaluate effects of genetic potential for gain, age at the start of a finishing period, and time on feed on composition, quantity, and quality of beef produced and efficiency of production during finishing. Crossbred cows were bred by AI to Charolais or Line 1 Hereford bulls that represented potentially high (HG) or moderate growth (MG) rates, respectively, to produce spring- or fall-born calves. Steer calves from these matings were placed on an individually fed finishing diet at three ages (A). Spring-born steers were started at 6 or 18 mo of age (A6 and A18), and fall-born steers were started at 12 mo of age (A12). Slaughter times (T) were at 0, 90, 180, and 270 d for A6; 68, 136, and 204 d for A12; and 0, 45, 90, and 135 d for A18. Data collected on each animal included feed intake, growth, chemical composition of the complete body and carcass, and quantitative and qualitative assessment of the meat produced. Four steers of each sire group were slaughtered in each of the 11 A-T treatment groups, and the experiment was repeated for 2 yr in the A12 groups and 3 yr in the A6 and A18 groups (n = 237). Steers sired by HG bulls were larger and produced larger carcasses and more carcass protein than MG-sired steers (S, P < .05 or .01). Steers sired by MG bulls were fatter, had higher quality grades, and accumulated fat at a faster rate than HG-sired steers, and this effect was greater in older steers (G and GA, P < .05 or .01). Sire growth potential did not affect gain, intake, live weight efficiency, tenderness, or taste panel scores (P > .2). Steers sired by HG bulls were more efficient at producing carcass weight and carcass protein at A12 and A18 than were MG-sired steers. At the end of the finishing period, older (A18), HG-sired steers were too large with insufficient fat by current industry standards, and younger (A6), MG-sired steers were too small. Our conclusions are that both HG- and MG-sired steers can produce acceptable carcasses for current market standards with comparable efficiencies of live-weight gain, but the growing and finishing strategy must be adapted to the genotype.