Browsing by Autor "Adriana Morgado-Osorio"

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Biomasa aérea de Leucaena leucocephala [(Lam.) de Wit] y herbáceas acompañantes en la Cuenca Sur del lago de Maracaibo
(Asociación Latinoamericana de Producción Animal, 2022) Adriana Morgado-Osorio; Eduardo Chacón‐Madrigal; Luís Arriojas; Luis Paredes; Wilfre Machado
El objetivo de este estudio fue analizar la estructura y la composición química de la biomasa aérea de la Leucaena leucocephala (LL) y herbáceas acompañantes en épocas de lluvia y de sequía en la cuenca sur del lago de Maracaibo, Venezuela. El experimento se realizó en una finca comercial ubicada en el sur de la Cuenca del Lago de Maracaibo, Zulia, Venezuela. Se utilizaron dos potreros que tenían un banco de LL, siendo pastoreados por 24 becerros, cruces de animales criollos Bos taurus y Bos indicus, con edades entre 2 a 3 meses. La estimación de la biomasa, estructura y disponibilidad forrajera se realizó tomando las muestras de biomasa aérea de vegetación arbustiva y herbácea durante dos épocas del año (lluvia y sequia), iniciando el periodo experimental durante la época de lluvias. Se tomaron las muestras de biomasa aérea de vegetación arbustiva y herbácea los días 1, 3, 5 y 7 de la semana seleccionada en el período experimental. Se analizaron los datos mediante estadística descriptiva y multivariada. En la época de lluvia, la distribución en las fracciones hojas y tallos de la biomasa disponible (Ø < 6 mm) y no disponible (Ø > 6 mm) presentó valores de 187 ± 18.03 y 33 ± 12.21 kg MS/ha, respectivamente y de 195 ± 21.24 y 68 ± 31.00 kg MS/ha en la época seca. La proteína cruda presentó valores más altos en las hojas (lluvia: 26 % ± 12 vs. sequía: 35 % ± 18; P < 0.05) que en los tallos (lluvia: 8 % ± 3.5 vs. sequía: 10 % ± 6; P < 0.05). En relación a las herbáceas acompañantes, las especies encontradas en los potreros fueron similares en las dos épocas del año, la cobertura fue menor en la época de sequía que en la época de lluvias (7.30 cm ± 11.29 vs. 16.66 cm ± 10.96; P < 0.05). En conclusión, la composición química de las hojas de LL presentó valores de proteína cruda, calcio y fósforo más altos en la época seca que en la época de lluvia. La LL puede ser una alternativa de uso en épocas de sequía, habiendo un menor porcentaje de cobertura de herbáceas acompañantes en los potreros
Effect of season and parity on water buffalo calving distribution throughout the year in Venezuela
(Pontifícia Universidade Católica do Paraná, 2019) Héctor Nava-Trujillo; Robert Valeris-Chacín; J. Serna Hernandez; Mariano Duran Nuñez; Adriana Morgado-Osorio; Janeth Caamaño; Armando Quintero‐Moreno
The aim of this study was to determine the effect of season and parity on water buffalo calving distribution throughout the year in Venezuela. A retrospective study analyzing records of 3,192 crossbred (Murrah/Mediterranean) buffaloes including 7,790 calvings was carried out in Venezuela. Two seasons were evaluated according to the length of the photoperiod: September-February (short photoperiod; autumn-winter) and March-August (long photoperiod; spring-summer). Parity order was categorized in parity 1, parity 2, parity 3, and parity 4. Photoperiod was shorter between September and February in comparison with March-August (11.81 ± 0.08 h/day and 12.42±0.08 h/day, respectively, p < 0.05). Percentage of calving varied between the two seasons (p < 0.05), and 63.7% (95% Confidence Interval (CI): 62.5%-64.9%) of calving occurred during the season of short photoperiod in comparison with that of the season of long photoperiod (36.3%, 95% CI: 35.1%-37.5%), and this effect was observed in all parities. The proportion of calvings during the short photoperiod season was greater as parity increased. The percentage of calving during the short photoperiod season was lower in primiparous water buffalo cows in comparison with that of multiparous water buffalo cows; conversely, the percentage of calving during the long photoperiod season was higher in primiparous water buffalo cows in comparison with that of multiparous water buffalo cows. Eight percent of water buffalo cows having their first calving in the long photoperiod season had the next calvings during this season. In conclusion, results confirm the seasonal reproductive behavior of water buffaloes with a concentration of calvings during the months with short photoperiod; this seasonality becomes stronger as parity increases; even though a small percentage of water buffalo cows has the ability of calving constantly during long photoperiod.
Probability of pregnancy before ninety days postpartum in water buffaloes
(Asociación Latinoamericana de Producción Animal, 2021) Héctor Nava-Trujillo; Robert Valeris-Chacín; Adriana Morgado-Osorio; J. Serna Hernandez; Janeth Caamaño; Armando Quintero‐Moreno
This study aimed to determine the effect of parity and season of calving on the probability of water buffalo cows becoming pregnant before 90 days postpartum. A retrospective analysis of reproductive records of 1,465 water buffaloes with 3,181 pregnancies was carried out. Buffaloes were grouped according to parity in one, two, or three and more calvings. Season of calving was created with the following values: long photoperiod (March-August) and short photoperiod (September-February) and predicted probabilities from the mixed-effects logistic regression model were calculated, and a generalized linear mixed model was fitted with random intercepts to calculate the log odds of becoming pregnant ≤90 days postpartum. The probability of pregnancy ≤90 days postpartum was 0.3645, and this was lower in primiparous (0.2717) in comparison with two-calved (0.3863) and three or more calving buffaloes (0.5166). Probability of pregnancy ≤90 days postpartum increased 1.77 odds by each increase in parity. The probability of becoming pregnant ≤90 days postpartum was higher in water buffaloes calving during the short photoperiod season (0.4239 vs. 0.2474, P>0.000), and water buffaloes calving during the long photoperiod season only had 0.2645 odds to become pregnant than those calving during the short photoperiod season. The negative effect of long photoperiod was observed indifferently of parity. In conclusion, primiparity and the long photoperiod affect water buffalo cow's reproductive performance, decreasing pregnancy probability during the first 90 days postpartum.