Spatial distribution models of seroreactive sheep to Leptospira spp. in Veracruz, Mexico

Leptospirosis is an infectious zoonotic disease of special importance in tropical regions of the world and is closely related to climatic conditions. In Mexico, at least eight Leptospira serogroups are known to affect sheep, but little is known about their distribution. The aim was to analyze the spatial distribution of seroreactive sheep to eight serogroups of Leptospira spp. through ecological niche modeling from the state of Veracruz. We carried out a cross-sectional, multi-stage, and stratified epidemiological study, sampling 405 sheep in different regions of the state (north, center, and south). The sera were analyzed using the Microscopic Agglutination Test (MAT) to identify seropositivity to eight Leptospira serogroups (Icterohaemorrhagiae, Pyrogenes, Grippotyphosa, Canicola, Pomona, Hardjo, Wolffi, and Tarassovi). Management variables in the sampled herds were evaluated through a survey among the producers, which was analyzed using the Chi-square test for cross-tabulation. Geospatial modeling was conducted using MAXENT and 19 climatic variables and the validation was carried out using the area under the curve (AUC). No positive animals were found for Pomona in any area of Veracruz and there was only one case of seroreactivity to Grippotyphosa. The total seroprevalence found was 53.83% (95% CI: 48.84-58.75). The main serogroup found was Sejroe (55.31%, 95% CI 50.32 - 60.20%), followed by Canicola (8.64%, 95% CI 6.17 - 11.92%), Icterohaemorrhagiae (4.69%, 95% CI 2.93 - 7.36%), Tarassovi (3.95%, 95% CI 2.35 - 6.47%), Pyrogenes (2.47%, 95% CI 1.26 - 4.64%), Australis (0.99%, 95% CI 0.32 - 2.69%) and Grippotyphosa (0.25%, 95% CI 0.01 - 1.59%). The predictive model for Australis was not significant. Acceptable predictive models (AUC>0.7-0.8) were found for Canicola, Icterohaemorrhagiae, Pyrogenes, and Tarassovi; while for Sejroe it was excellent (AUC> 0.85); consequently, the climatic variables that most contributed to the model were those related to precipitation. The potential distribution of Pyrogenes, Icterohaemorrhagiae, and Canicola was located to a greater extent in the three regions; Pyrogenes and Tarassovi were distributed mostly in the north and central regions and Sejroe is mostly located in the center and south of the state. Ecological niche modeling could support epidemiological control and surveillance programs for affected sheep herds in the state of Veracruz. This article is protected by copyright. All rights reserved.

Efficacy and Cost of Trap-Bait Combinations for Capturing Rhynchophorus palmarum L. (Coleoptera: Curculionidae) in Ornamental Palm Polycultures

Ornamental palms are an economically important component of international trade yet have recently experienced yield losses in Mexico due to red ring and bud rot diseases, which are spread by Rhynchophorus palmarum L. Considering that massive capture is a common strategy to control this pest and the cost of commercial traps and baits could be inaccessible for small farmers, an inexpensive trap-bait combination is desired. In this study, 16 trap-bait combinations for capturing R. palmarum were assessed in ornamental palm polycultures over the course of 1 year. An expensive yellow bucket trap combined with aggregation pheromone + insecticide + banana was compared with inexpensive, handmade trap-bait combinations. A total of 4712 weevils were collected in all traps, of which 52.7% were male and 47.3% female. The efficacy of the handmade trap made from a colorless polyethylene bottle and baited with banana + pineapple + sugarcane + sugarcane molasses was similar to that of the yellow bucket trap baited with aggregation pheromone + insecticide + banana. These two trap-bait combinations remained effective even when the R. palmarum population significantly decreased during the dry, warm season. The affordable handmade trap baited with food attractants and without insecticides was highly efficient in capturing R. palmarum and therefore represents an effective tool for monitoring weevil populations. As ornamental crops have recently gained greater economic importance in the studied region, the use of a novel and cheap trap-bait combination could offer great benefits to producers and form part of the integrated management of R. palmarum.

Soybean, palm kernel, and animal-vegetable oils and vitamin E supplementation effect on lipid oxidation stability of sous vide chicken meat

There is an increasing demand in precooked chicken meat products for restaurants and catering services. Because cooked chicken meat develops lipid oxidation relatively fast, sous vide chicken meat was studied to assess its shelf-life. Six hundred Cobb x Ross broilers were fed for 6 wk with a basal corn-soybean meal diet including soybean, palm kernel, or animal-vegetable oil, each supplemented with 33 or 200 mg/kg of dl-alpha-tocopheryl acetate. Broilers were randomly assigned into 6 treatments and 4 repetitions with 25 birds each. Boneless breast or thigh muscle pieces were dissected into 5 x 5 x 5 cm cubes, vacuum-packed, cooked in water bath (until 74 degrees C internal temperature), chilled, and stored at 4 degrees C for 1, 5, 10, 25, and 40 d. For each storage day, each pouch contained 3 pieces of meat, either breast or thigh. Thiobarbituric acid reactive substances analysis, to quantify malonaldehyde (MDA) values, was conducted to estimate the lipid oxidation development. Nonheme iron values of cooked meat were analyzed. Fatty acid methyl esters analysis was performed in chicken muscle to determine its fatty acid composition. There was no interaction between dietary fat and vitamin E level in all of the variables studied except in nonheme iron. Dietary fat significantly influenced the fatty acid composition of the muscle (P < 0.01), but it did not affect the MDA values, regardless of differences in the muscle fatty acid composition between treatments. Supplementation of the high level of vitamin E significantly reduced the MDA values in both breast and thigh meat (P < 0.01). The maximum MDA values were observed at d 40 of storage in thigh and breast meat in animal-vegetable and soybean oil treatments with the low levels of vitamin E, 0.91 and 0.70 mg/kg, respectively. Nonheme iron values in thigh meat differed between treatments at 1 or 25 d of storage but not in breast meat. In conclusion, refrigerated sous vide chicken meat has a prolonged shelf-life, which is enhanced by dietary supranutritional supplementation of vitamin E.