Reproduction and mortality of breeds cattle in subtropical climate of Argentina

[ES] El ambiente tropical provoca bajos índices reproductivos en el ganado bovino, por lo tanto, el objetivo de la investigación fue evaluar el efecto del ambiente sobre los índices de reproducción bovina. La investigación se realizó en la Estación Experimental Agropecuaria (EEA) Corrientes, Argentina. Se analizaron los datos de 3,082 registros del hato; del año 1991 hasta el año 2009 de tres razas: Hereford (HR), Braford (BF) y Brahman (BH). Se evaluaron dos variables: la primera, la pérdida de los productos a partir de su diagnóstico hasta el momento del parto (DP) y la segunda, inicia del día de su nacimiento hasta su destete en 205 d (PD). Para analizar los datos se realizó un diseño completamente al azar y un análisis de correlación. Las pérdidas se observaron durante la gestación para vacas BH y BF (P < 0.05), la humedad relativa no presentó efecto sobre la gestación y días al destete. Hubo correlación entre la humedad y la radiación con las vacas HR y BF que no se preñaron, las vacas BH no presentaron ninguna relación.SILos autores agradecen al Instituto Nacional de Tecnología Agropecuaria de Argentina por las facilidades prestadas para realizar esta investigació

Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

P. 1-14The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.S

Tetramerosis en paloma doméstica (Columba Liva L.) por Tetrameres (Petrowimeres) Fissispina Diesing, 1861 (Nematoda, Tetrameridae)

p. 287-299Se describe el brote agudo de tetramerosis en palomas con elevado número de bajas, producido por Tetrameres (Petrowimeres) fissispina Diesing, 1861, en Asturias. Los síntomas observados fueron: anorexia, adelgazamiento progresivo, apatía, ligera palidez de mucosas, heces de normales a diarréicas y de color marrón-verdoso. Las lesiones anatomopatológicas se limitaba casi exclusivamente al proventrículo, destacando la presencia de formaciones rojizas de localización intraglandular, que se correspondían con las hembras parásito. El examen histopatológico reveló una clara atrifia por compresión de las glándulas parasitadas, así como infiltrados inflamatorios. El tratamiento con cloruro de tetramisol resultó eficaz a las dosis de 20 mg por paloma y día, durante tres díasN

Reproducción y mortalidad de razas bovinas en clima subtropical de Argentina

Abstracts: Tropical environmental climate causes low reproductive rates in cattle, so the objective of the present study was to evaluate the possible effects of the climate on the reduction of the rates of bovine reproduction. The work was carried out in the Experimental Agriculture Station (EAS) in Corrientes, Argentina, where, 3,082 bovine herd records data were analyzed from 1991 to 2009, three breeds, Hereford (HR), Braford (BF) and Brahman (BH). It was evaluated the percentage of losses from the diagnosis of gestation until the delivery (DP) and from the delivery until the weaning to the 205 d (PD). Data were analyzed by analysis of variance in a completely randomized design and with an analysis of correlation. The greater losses (P 0.05) between DP and PD. There was a correlation between the humidity and the radiation with the cows that were not in gestation (HR and BF), the cows BH not presented any relation.Resumen: El ambiente tropical provoca bajos índices reproductivos en el ganado bovino, por lo tanto, el objetivo de la investigación fue evaluar el efecto del ambiente sobre los índices de reproducción bovina. La investigación se realizó en la Estación Experimental Agropecuaria (EEA) Corrientes, Argentina. Se analizaron los datos de 3,082 registros del hato; del año 1991 hasta el año 2009 de tres razas: Hereford (HR), Braford (BF) y Brahman (BH). Se evaluaron dos variables: la primera, la pérdida de los productos a partir de su diagnóstico hasta el momento del parto (DP) y la segunda, inicia del día de su nacimiento hasta su destete en 205 d (PD). Para analizar los datos se realizó un diseño completamente al azar y un análisis de correlación. Las pérdidas se observaron durante la gestación para vacas BH y BF (P < 0.05), la humedad relativa no presentó efecto sobre la gestación y días al destete. Hubo correlación entre la humedad y la radiación con las vacas HR y BF que no se preñaron, las vacas BH no presentaron ninguna relación

MOESM3 of Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

Additional file 3 Box-plot graph T. gondii burdens measured at the same period post infection and comparing between the three groups at the placenta and foetal viscera. Box-plot graphs represent the median burden, the lower and upper quartiles (boxes) and minimum and maximum values (whiskers). (*) indicates P < 0.05 significant differences between groups in each period post infection

MOESM4 of Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

Additional file 4 Individual frequency of parasite DNA detection in infected animals. Table showing the individual frequency of parasite DNA detection in infected animals

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health