Frequent human‐poultry interactions and low prevalence of Salmonella in backyard chicken flocks in Massachusetts

The backyard chicken (BYC) movement in the USA has increased human contact with poultry and subsequently, human contact with the pathogen Salmonella. However, to date, there have been few studies assessing prevalence of Salmonella in backyard flocks, despite the known public health risk this zoonotic bacterium poses. The objective of this study was to characterize human‐BYC interactions and assess the prevalence of Salmonella among BYC flocks. We interviewed 50 BYC owners using a structured questionnaire to determine flock and household characteristics that facilitate contact with BYC and that may be associated with Salmonella in the BYC environment. Composite faecal material, cloacal swabs and dust samples from 53 flocks housed on 50 residential properties in the Greater Boston, Massachusetts area were tested for Salmonella using standard culture techniques and confirmed using Matrix‐Assisted Laser Desorption/Ionization‐Time of Flight Mass Spectrometer. Microbroth dilution and whole genome sequencing were used to determine phenotypic and genotypic resistance profiles, respectively, and sequence results were used to determine multilocus sequencing type. No owners self‐reported a diagnosis of salmonellosis in the household. Over 75% of a subset of owners reported that they and their children consider BYC pets. This perception is evident in how owners reported interacting with their birds. Salmonella enterica subspecies enterica serotype Kentucky ST152 (serogroup C)—a strain not commonly associated with human infection—was confirmed in one flock, or 2% of tested flocks, and demonstrated resistance to tetracycline and streptomycin. We detected Salmonella at low prevalence in BYC. Further study of the health effects of exposure to zoonotic gastrointestinal pathogens such as Salmonella among families with BYC is warranted.     

Lachrymal antibody response of specific pathogen free chickens and chickens with maternal immunity after infectious bronchitis virus vaccination

Lachrymal fluid specific IgG and IgA were detected by ELISA in chickens with specific maternal antibodies and in chickens free of antibodies (SPF), after vaccination at 1 day of age with the H-120 vaccine strain of infectious bronchitis virus. Samples were obtained at 3 day intervals and until Day 37 of age. Optical densities were in all instances low but significant differences could be detected within and between the experimental groups. Both class-specific immunoglobulins showed a similar kinetic pattern. Nevertheless, the SPF group increased its IgA level on Day 13 while chickens with maternal immunity increased their level on Day 16. The antibody levels of both IgG and IgA were also different, being higher in the SPF group. In both chicken groups, higher levels of IgA than IgG were detected.     

Cycle Synchronization and Induction in Zebu Cattle with Chlormadinone Acetate in Differing Dosage Forms: Effects of Season

Contents Two different formulations and dosing regimens of Chlormadinone (CAP) were used for estrous cycle synchronization or for estrous cycle induction in cows with lactational anestrus, in open field trials with purebred Zebu (Brahman) cattle in the tropics (Gulf coast area of Central Mexico). In trial 1, during the dry season (February) animals received a single injection of 50 mg CAP in oily solution i. m., followed 10 days later by 5 daily oral doses of 10 mg CAP in raw sugar. In trial 2, during the rainy season (August) animals received 10 mg CAP/day orally for 15 days in an oily solution as a top dressing on raw sugar. In both trials, animals in heat were inseminated over a 30 day period. Data from 107 (61 lactating and 46 dry) cows were evaluated in trial 1, and from 214 lactating cows in trial 2. Synchronization of estrus within 3 to 8 days occurred in 67.4 % and 52,5 % of the dry and of the lactating cows in trial 1, and in 53,3 % of lactating cows in trial 2. 21.7 % of the dry and 41.0 % of the lactating cows in trial 1 and 37,9 % of the cows in trial 2 had their first heat 17 to 27 days after CAP withdrawal, indicating that they may have shown silent heat during the initial synchronization period. In the spring, conception rates from breeding during days 1 to 8 after CAP were low (33.3 %), but increased for animals bred on days 17 to 27 (54.5 %). In the summer, in congruence with the overall seasonal decline of fertility observed in Zebu cattle, the initially low conception rate from breeding on days 1–7 (27,1%) remained low for animals bred during days 18 to 27 (29.8%). Inhalt Induktion und Synchronisation von Sexualzyklen beim Zeburind mit Chlormadinonazetat in verschiedenen Darreichungsformen: Einfluβ der Jahreszeit. Zur Zyklussynchronisation bzw. Zyklusinduktion bei Zeburindern unter tropischen Haltungsbedingungen (mexikanische Golfküste) wurde Chlormadinonazetat (CAP) in zwei verschiedenen Darreichungsformen und Applikationsarten angewandt. Im 1. Feldversuch, wiihrend der Trockenzeit (Februar), wurden 50 mg CAP in öliger Lösung i. m. injiziert; 10 Tage später wurden 10 mg CAP in Rohrzucker täglich für fünf Tage verabreicht. Im 2. Feldversuch, während der Regenzeit (August) erhielten die Tiere 10 mg CAP in öliger Lösung auf eine Rohrzuckerration zur oralen Aufnahme, für 15 Tage. In beiden Versuchen wurden alle in Brunst kommenden Tiere während der ersten 30 Tage nach Medikation besamt. Im ersten Versuch kamen 107 Tiere zur Auswertung (61 laktierende und 46 trocken stehende Kühe), im 2. Versuch insgesamt 214 laktierende Zebukühe mit dem Kalb bei Fuss. Im 1. Versuch rinderten, synchronisiert zwischen dem 3. und 8. Tag, 67,4 % der trockenstehenden und 52,5 % der laktierenden Kühe; im Versuch 2, 53,5 % der in Laktation stehenden Tiere. Von den trokkenstehenden Tieren in Versuch 1 rinderten jedoch 21,7% und von den laktierenden Tieren 41,0 % erst zwischen dem 17. und 27. Tag nach letzter CAP-Gabe; im 2. Versuch waren es 37,9 %. Es wird angenommen, daβ diese Tiere unmittelbar nach CAP-Anwendung stillbrünstig waren. Ein Vergleich der Konzeptionen aus Besamungen vom Tag 1 bis 8 und vom Tag 17 bis 27 zwischen Versuch 1 und Versuch 2 zeigt einen Anstieg der Konzeptionsrate im Frühjahr von 33,3 % (Tag 1–8) auf 54 % (Tag 17–27), während im Sommer die Rate von 27,1 % (Tag 1–8) nicht weiter ansteigt (29,8 %: Tag 18 bis 27). Dies entspricht der Erfahrung, daβ beim Zeburind die Fertilität mit dem Frühjahr zunimmt, nach Beginn der Regenzeit jedoch bald abzusinken beginnt.     

Evaluation of the enzyme-linked immunosorbent assay for detecting Brucella abortus antibodies.

The specificity of enzyme-linked immunosorbent assays (ELISA) corresponds to conventional methods for detecting brucella antibodies in bovine serum. The ELISA test detected brucella antibodies early in only 12.5% of the cattle sera tested. Also, the sensitivity of ELISA was comparable to complement-fixation and Rivanol methods, but less sensitive than the standard tube agglutination method.     

Long-term biological effectiveness of Pochonia chlamydosporia var. catenulata against Meloidogyne incognita infection in a crop rotation systemi

The aim of this study was to determine the effectiveness of Pochonia chlamydosporia var. catenulata and the bacteria Tsukamurella paurometabola strain C-924 (HeberNem?), to control Meloidogyne incognita infection in a crop rotation system (cucumber, tomato and pepper) under greenhouse production during six crop cycles. We determined gall index, prevalence, intensity of disease, and number of juvenile nematodes in soil. At the end of the sixth cycle, plants protected with P. chlamydosporia showed a reduction in gall index (≤2), prevalence, and median (42%) intensity of disease similar or more pronounced than those observed in plants protected with T. paurometabola (80%). Both treatments were more efficient at reducing galling than at reducing prevalence and therefore reduction of intensity of disease was mainly due to the reduction in galling. The hydrolytic activity of P. chlamydosporia and its resistant spores make this fungus one of the best options for the long-term control of RKNs by decreasing egg masses or galls. Pochonia chlamydosporia var. catenulata is an important part of a potential biological control strategy in rotation systems of vegetable crop and can be used for long-time IPM strategies in Cuba and the Caribbean.     

Organic carbon and stable C isotope in conservation agriculture and conventional systems

Conservation agriculture might have the potential to increase soil organic C content compared to conventional tillage based systems. The present study quantified soil organic carbon (SOC) and soil C derived from C₃ (wheat) and C₄ (maize) plant species using δ¹³C stable isotope. Soil with 16 y of continuous application of zero tillage (ZT) or conventional tillage (CT), monoculture (M) or rotation (R) of wheat and maize, and with (+r) and without retention (−r) in the field of crop residues were studied in the central highlands of Mexico. The highest SOC content was found in the 0-5 cm layer under ZTM and ZTR with residues retention. The soil cultivated with maize showed a higher SOC content in the 0-10 cm layer with residue retention than without residue. In the 10-20 cm layer, the highest SOC content was found in the CT treatment with residue retention. The SOC stock expressed as equivalent soil mass was greatest in the 0-20 cm layer of the ZTM (wheat and maize) and ZTR cultivated treatments with residue retention. After 16 y, the highest content of soil δ¹³C was found in ZTM + r and CTM + r treated soil cultivated with maize; −16.56‰ and −18.08‰ in the 0-5 cm layer, −18.41‰ and −18.02‰ in the 5-10 cm layer and −18.59‰ and −18.72‰ in the 10-20 cm layer respectively. All treatments had a higher percentages of C-C₃ (derived from wheat residues or the earlier forest) than C-C₄ (derived from maize residues). The highest percentages of C-C₄, was found in ZTM + r and CTM + r treated soil cultivated with maize, i.e. 33.0% and 13.0% in 0-5 cm layer, 9.1% and 14.3% in the 5-10 cm layer and 5.0% and 6.8% in 10-20 cm layer, respectively. The gross SOC turnover was lower in soil with residue retention than without residues. It was found that the ZT system with residue retention and rotation with wheat is a practice with a potential to retain organic carbon in soil.     

SOIL MICROBIAL BIOMASS AND NITROGEN MINERALIZATION RATES ALONG AN ALTITUDINAL GRADIENT ON THE COFRE DE PEROTE VOLCANO (MEXICO): THE IMPORTANCE OF LANDSCAPE POSITION AND LAND USE

A study was conducted to examine the responses of microbial activity and nitrogen (N) transformations along an altitudinal gradient. The gradient was divided into three parts. Three areas were sampled: upper part (UP): coniferous forest, corn field, and abandoned corn field; middle part (MP): tropical cloud forest, grassland, and corn field (COL); and lower part (LP): tropical deciduous forest and sugarcane. The results showed that soil microbial biomass carbon (C) and basal respiration were significantly higher in MP and UP than in LP, whereas the microbial quotient (C_mic/C_org) was higher in LP and MP than in UP. The metabolic quotient (qCO₂) was similar among gradient parts evaluated. Net N mineralization, ammonification, and nitrification rates were higher in UP than MP and LP. We found that in UP, the forest conversion to cropland resulted in no significant differences in microbial activity and N transformation rates between land uses. In MP, microbial biomass C, ammonification, and net N mineralization rates decreased significantly with conversion to cropland, but C_mic/C_org and nitrification were higher in COL. Basal respiration and qCO₂ were significantly lower in COL when compared with other land uses. In LP, lower microbial biomass C, C_mic/C_org, and nitrification rates but higher ammonification and net N mineralization rates were observed in tropical deciduous forest than in sugarcane. No significant differences in basal respiration and qCO₂ were found between uses of LP. Clearly, then, soil organic C is not equally accessible to the microbial community along the gradient studied. Copyright © 2012 John Wiley & Sons, Ltd.     

Oil stability prediction by high-resolution (13)C nuclear magnetic resonance spectroscopy

(13)C NMR spectra of oil fractions obtained chromatographically from 66 vegetable oils were obtained and analyzed to evaluate the potential use of those fractions in predicting oil stabilities and to compare those results with oil stability prediction by using chemical determinations. The oils included the following: virgin olive oils from different cultivars and regions of Europe and north Africa; "lampante" olive, refined olive, refined olive pomace, low-erucic rapeseed, high-oleic sunflower, corn, grapeseed, soybean, and sunflower oils. Oils were analyzed for fatty acid and triacylglycerol composition, as well as for phenol and tocopherol contents. By using stepwise linear regression analysis (SLRA), the chemical determinations and the (13)C NMR data that better explained the oil stability determined by the Rancimat were selected. These selected variables were related to both the susceptibility of the oil to be oxidized and the content of minor components that most contributed to oil stability. Because (13)C NMR considered many more variables than those determined by chemical analysis, the predicted stabilities calculated by using NMR data were always better than those obtained by using chemical determinations. All these results suggest that (13)C NMR may be a powerful tool to predict oil stabilities when applied to chromatographically enriched oil fractions.     

Accuracy of genomic prediction of purebreds for cross bred performance in pigs

In pig breeding, as the final product is a cross bred (CB) animal, the goal is to increase the CB performance. This goal requires different strategies for the implementation of genomic selection from what is currently implemented in, for example dairy cattle breeding. A good strategy is to estimate marker effects on the basis of CB performance and subsequently use them to select pure bred (PB) breeding animals. The objective of our study was to assess empirically the predictive ability (accuracy) of direct genomic values of PB for CB performance across two traits using CB and PB genomic and phenotypic data. We studied three scenarios in which genetic merit was predicted within each population, and four scenarios where PB genetic merit for CB performance was predicted based on either CB or a PB training data. Accuracy of prediction of PB genetic merit for CB performance based on CB training data ranged from 0.23 to 0.27 for gestation length (GLE), whereas it ranged from 0.11 to 0.22 for total number of piglets born (TNB). When based on PB training data, it ranged from 0.35 to 0.55 for GLE and from 0.30 to 0.40 for TNB. Our results showed that it is possible to predict PB genetic merit for CB performance using CB training data, but predictive ability was lower than training using PB training data. This result is mainly due to the structure of our data, which had small‐to‐moderate size of the CB training data set, low relationship between the CB training and the PB validation populations, and a high genetic correlation (0.94 for GLE and 0.90 for TNB) between the studied traits in PB and CB individuals, thus favouring selection on the basis of PB data.