An original system for the continuous monitoring of antimicrobial use in poultry production in France

Data collection at the flock level on a continuous basis, for antimicrobial use surveillance purposes, provides a complex challenge. Using existing on-farm records, produced as part of the regulations for meat inspection, a sampling scheme was implemented to collect on a simple, representative and continuous basis, the forms providing history of antimicrobial consumption of poultry flocks slaughtered in Brittany. Relational database-stored information provided by the forms includes treatment purpose, antimicrobial drug administered, age at treatment and treatment duration. The aim of this study was to collect information describing antimicrobial drug use quantitatively and qualitatively, by computing the frequency of antimicrobial use according to species, therapeutic class, treatment purpose, duration, and animal age at treatment. A study was carried out to check the validity of farmers' declarations. Examples of data and results are presented such as the relative importance of the different antimicrobial classes in relation to the live weight treated, which shows that beta-lactams and tetracyclines are the main classes used in broilers and turkeys respectively. Average bird weight at treatment was 0.5 kg for a broiler and 3 kg for a turkey. Nevertheless, several 'at-risk' periods could be identified. Initial results after 1 year of data collection showed that this surveillance system provides valid, detailed and useful data about antimicrobial drug use in poultry production at a low cost and with only a moderate time involvement.     

Prevalence and epizootiology of equine salmonellosis.

Feces from 1,451 horses entering a veterinary hospital over a 13-month period were cultured for salmonella. A total of 46 horses (3.2%) yielded 1 or more salmonella-positive fecal cultures. Twenty horses were found to be excreting salmonella in the feces on admission, and 5 of these later had severe diarrhea associated with enteric salmonellosis. Abdominal surgery and other severe stresses were associated with all cases of severe enteric salmonellosis. Serotypes of salmonella isolated included Salmonella agona (15), S anatum (14), S typhimurium (7), S typhimurium var copenhagen (4), S infantis (2), S montevideo (1), S meleagridis (1), S drypool (1), and an unnamed Salmonella serotype (1). Seven deaths were attributed to 4 serotypes (S typhimurium, 3; S anatum, 2; S typhimurium var copenhagen, 1; and S montevideo, 1). A marked seasonal incidence is isolations was found with isolations highest in later summer to early fall and lowest in the spring. It was also found that horses can shed salmonella intermittently, and a minimal of 5 consecutive negative fecal cultures is recommended before considering a horse not to be infected with salmonella.     

Bovine salmonellosis: experimental production and characterization of the disease in calves, using oral challenge with Salmonella typhimurium.

A highly virulent strain of Salmonella tyhimurium was given orally to produce disease experimentally in 21 normal colostrum-fed calves 3 to 9 weeks old. The challenge inoculum varied from 10(4) to 10(11) organisms. The disease was characterized by fever, depressed attitude, and decreased appetite. Many calves given larger challenge dose levels also had diarrheic feces containing mucus, fibrin, and blood. Fecal cultures were positive for salmonella. Septicemia occurred in some calves (9 of 15 calves cultured were positive). Eleven calves died and 10 calves survived challenge exposure. Survival was inversely related to the size of the challenge inoculum and directly related (although to a lesser degree) to age of the calf. White blood cell total and differential counts were variable. Both neutropenia and neutrophilia were observed. Plasma proteins decreased markedly in calves with diarrhea, probably indicating fecal protein loss. Fibrinogen increased during the acute stages of diarrhea.     

Surface phosphatase activity of Sitka spruce mycorrhizas from a serpentine site

The p-nitrophenyl phosphatase activity of mycorrhizal roots of Sitka spruce from a phosphorus deficient site was inversely proportional to the concentrations of 0.5 n acetic acid-extractable phosphorus in the decaying organic matter from which the roots were removed. This is interpreted as the derepression of phosphatase synthesis under conditions of inorganic P deficiency and is discussed in relation to the possible roles of mycorrhizal surface phosphatase activity.     

Prediction of water retention properties of clayey soils: validity of relationships using a single soil characteristic

Abstract. Regression equations successfully allowed the calculation of water retained at—0.3 × 10⁵ Pa and–15 × 10⁵ Pa matric potentials from single soil characteristics, such as bulk volume or clay content, in clayey horizons derived in similar ways from a single parent material. It is possible to use these regression equations on other soils with similar clay fabrics. The fabric is expressed numerically using the pore volume associated with clay particles.     

Protein and lipid sources affect cholesterol concentrations of juvenile Pacific white shrimp, Litopenaeus vannamei (Boone)

Two experiments were conducted to evaluate the effects of protein and lipid sources on cholesterol, AA, and fatty acid content, and on biological performance of juvenile Pacific white shrimp, Litopenaeus vannamei (Boone). In Exp. 1, seven isonitrogenous and isocaloric diets were prepared using fish meal; soybean meal; casein; fish meal + soybean meal; fish meal + casein; soybean meal + casein; and fish meal + soybean meal + casein. In Exp. 2, seven isonitrogenous and isocaloric diets were prepared using fish oil; soy oil; poultry fat; fish oil + soy oil; fish oil + poultry fat; soy oil + poultry fat; and fish oil + soy oil + poultry fat. Nine shrimp (average BW 570 mg) were stocked per 60-L tank, with three tanks per diet in each experiment. Shrimp were fed to apparent satiation twice daily for 28 d. Protein sources affected shrimp cholesterol, feed consumption, feed efficiency, protein consumption, protein efficiency ratio, and crude body fat (P < or = 0.05), but not weight gain, survival, hepatosomatic index, body protein, ash, and AA composition. Body (without hepatopancreas) cholesterol concentrations were the highest in shrimp fed the diet containing fish meal (0.81%), lowest for those fed the casein diet (0.64%), and intermediate in the other dietary treatment groups (range 0.71 to 0.74%). Lipid source also affected shrimp body cholesterol, body fatty acid profiles, and fatty acid profiles in the hepatopancreas (P < or = 0.05), but not growth performance, body protein, fat, ash, and cholesterol concentrations in the hepatopancreas. Shrimp fed the fish oil diet had the highest body cholesterol (0.75%), whereas those fed the soy oil or poultry fat diets were lowest (0.66 and 0.65%, respectively). Results indicate that by replacing fish meal and fish oil with soybean meal and soy oil, shrimp growth performance is not affected, but body cholesterol concentration is reduced.     

Effect of strenuous exercise and ex vivo TLR3 and TLR4 stimulation on inflammatory gene expression in equine pulmonary leukocytes

The effects of strenuous exercise and ex vivo stimulation of TLR3 and TLR4 pathways on the expression of six inflammatory genes in equine pulmonary leukocytes were investigated. The genes tested were interferon-beta (IFN-β), interleukin-1-beta (IL-1β), interleukin-6 (IL-6), interferon gamma-induced protein 10 (IP-10), chemokine (c-c motif) ligand 5 (RANTES) and tumor necrosis factor-alpha (TNF-α). We hypothesized that strenuous exercise would modulate basal gene expression on one hand and modulate the response to bacterial lipopolysaccharide (LPS) and to polyinosinic:polycytidylic acid (Poly IC) on the other hand. Eight young Thoroughbred mares were selected for the experiment. Bronchoalveolar lavages were performed on horses 48 h before and 24h after the completion of treadmill exercise until fatigue. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was used to quantify cytokine expression in pulmonary leukocytes. Target gene expression was normalized to the expression of three housekeeping genes (HKG). There were no significant differences in the mRNA expression of the six cytokines between pre-exercise and post-exercise cells. LPS and Poly IC induced respectively significant increases of TNF-α, IFN-β, IL-6, IL-1β, and TNF-α, IFN-β, IP-10 and RANTES, both before and after exercise. However, exercise induced a significant decrease of the genes response to LPS and Poly IC. These findings may suggest that strenuous treadmill exercise exerts a deleterious effect on part of the pulmonary immune response in horses 24h following an intense physical activity.