Analysis of the productive and immune response of lambs infected with gastrointestinal nematodes and fed with saccharin

Objective: To determine the productive traits and immune response in Blackbelly lambs infected with gastrointestinal nematodes (GIN) fed with saccharin. Design / methodology / approach: Three treatments (T) were randomly assigned to 18 Blackbelly lambs, with an initial live weight (LW) of 13.9 + 3.2 kg. In T1 anthelmintic + base diet (CTah) was used; T2 without anthelmintic + base diet (STah) and T3 were grazing lambs without anthelmintic (STPS). The experimental design was completely randomized with measures repeated over time and the averages of the treatments were compared using Lsmeans. Evaluations included live weight (LW), egg per gram of feces (EPG), packed cell volume (PCV), total plasma protein (TPP), differential leukocyte count (WBC), and IgA level by ELISA with Haemonchus contortus and Trichostrongylus colubriformis antigens Results: The STah and CTah lambs showed a higher number of EPG (885 ± 142) and LW (29.73 ± 5.06 kg). While grazing lambs (STPS) showed the lowest PCV (26.4 ± 0.5%) compared to STah and CTah lambs (27.4 to 28.4%), caused by the high prevalence of H. contortus. The IgA level in grazing lambs was from 20.2 to 24.5% with respect to the positive standard, RPS, while the stabled lambs (STah and CTah) showed values ??close to 5% RPS. Study limitations / implications: Due to anthelmintic resistance problems, it was not possible to keep lambs free of infection in grazing, so this group was not included. Findings / conclusions: Feeding with saccharin allows increasing the resilience of sheep and achieving adequate weight gains in parasitized lambsObjective: Determine the productive and immune response of Blackbelly lambs infectedwith gastrointestinal nematodes (GIN) and fed with saccharin.Design/ methodology/ approach: A total of 18 Blackbelly lambs, with an initial live weight (LW) of 13.9 + 3.2 kg, were randomly assigned to three different treatments (T): T1, anthelmintic treatment + basal diet (CTah); T2, basal diet without anthelmintic treatment (STah); and T3, grazing lambs without anthelmintic treatment (STPS). This experiment followed a completely randomized design with repeated measures over time; mean values were compared using Lsmeans. The parameters evaluated included live weight (LW), fecal egg count per gram (FEC), packed-cell volume (PCV), plasma protein (PP), white blood celldifferential count (LEU), and IgA concentration by ELISA with Haemonchus contortusand Trichostrongylus colubriformis antigens.Results: STah and CTah lambs showed higher FEC (885 ± 142) and LW (29.73 ± 5.06kg). Grazing lambs (STPS) had lower PCV (26.4 ± 0.5%) compared to the STah andCTah lambs (27.4 to 28.4%) due to the high prevalence of H. contortus. The IgAconcentration in grazing lambs ranged from 20.2 to 24.5% of the positive standardserum titer. The feedlot lambs (STah and CTah) showed values close to 5%.Study limitations/ implications: Due to anthelmintic resistance problems, it wasimpossible to maintain grazing lambs free of infection; therefore, this group was notincluded.Findings/ conclusions: Saccharin increases sheep resilience and achieves adequateweight gains in parasitized lambs

Descripción de los sistemas intensivos de engorda de corderos en Yucatán, México

El objetivo del estudio fue describir los sistemas intensivos de engorda de corderos en el Estado de Yucatán, México. El estudio se desarrolló de marzo a junio de 2013. Se aplicó una encuesta a productores o responsables de 34 granjas, seleccionadas por conveniencia. La información fue analizada a través de tablas de frecuencias, medidas de tendencia central y análisis de varianza obtenidos con el paquete estadístico STATGRAPHICS® Centurion XV. Los resultados mostraron que los sistemas intensivos de engorda de corderos se diferencian básicamente por dos tipos de alojamiento: a) corrales a nivel del suelo (SICS) y b) corrales elevados con piso de rejilla (SICE). Los genotipos están formados por la cruza de razas Pelibuey, Dorper y Katahdin, principalmente (93.94 %). La alimentación se basa en la utilización de concentrados de marcas comerciales (47.06 %), elaborados en la granja (47.06 %) y elaborados por proveedores informales (5.88 %). El manejo sanitario consiste en la vacunación (79.41 %) y desparasitación de los animales (100 %). Se encontró, un mejor comportamiento productivo de los corderos de engorda en SICE comparado con aquellos de SICS. La venta de corderos en pie (91.18 %) es la principal fuente de ingresos económicos, con un precio de $29.75/kg. La mayoría de los productores (67.65 %) comercializan a sus animales en la unidad de producción. Es necesario hacer una evaluación prospectiva de los SICE y los SICS desde el punto de vista productivo y económico

Factores que influyen sobre algunas variables productivas en corderos finalizados en corrales elevados con piso de rejilla

La finalización intensiva de corderos en corrales elevados con piso de rejilla permite que los animales se mantengan en un ambiente sano, con menos carga parasitaria, protección de los depredadores, reducción en el gasto energético y un mejor microclima, sin embargo, poco se conoce sobre el comportamiento productivo de los corderos bajo este sistema de producción. La identificación de los factores que influyen sobre el comportamiento productivo de los corderos en este tipo de alojamiento es crucial para mejorar su productividad. El objetivo de este estudio fue determinar los efectos de granja, año y época del año sobre algunas variables productivas de corderos finalizados en corrales elevados con piso de rejilla en el trópico subhúmedo de México. Se analizaron 882 datos de la ganancia diaria de peso post-destete (GDP), del peso corporal final (PCF) y del periodo de finalización (DE) de corderos machos de cuatro granjas (granja A, n = 166; granja B, n = 122; granja C, n = 350; granja D, n = 244). El modelo estadístico incluyo los efectos fijos de la granja (A, B, C y D), de la época del año (lluvia y seca) y del año (2010, 2011, 2012 y 2013) sobre GDP, PCF y DE. El modelo incluyó el peso corporal inicial como covariable. Las medias generales para GDP, PCF y DE fueron 263 g, 35 kg y 77 días, respectivamente. La granja afectó (P<0.001) todas las variables evaluadas. La época del año afectó (P<0.001) PCF y DE, pero no GDP. El año afectó (P<0.001) todas las variables evaluadas. La interacción granja × época del año afectó (P<0.001) PCF y DE, pero no GDP. En conclusión, el comportamiento productivo de corderos finalizados en jaulas elevadas en el trópico subhúmedo de México, fué afectado por la granja, el año y parcialmente por la época del año y la interacción granja × época del año

Technologies and strategies for improving hair lamb fattening systems in tropical regions: a review

Abstract: This paper addresses a literature review of lamb fattening systems in tropical regions of Mexico and other countries. In semi-intensive systems, lamb feeding is based on grasslands, and supplementation may or may not be offered; in intensive systems, lamb feeding is based on concentrated feeds. Local fodder resources could be a viable option for lamb fattening due to their low cost and the better quality and healthy meat resulting from this feeding strategy. It is suggested that further evaluations of tropical fodder resources be developed, focusing on nutritional quality, availability and possible use. Several hair sheep breeds (Pelibuey, BlackBelly, Katahdin and Dorper and their crossbreeds) have been investigated under those systems. However, there remains a lack of definition on which could be the most suitable Cross-breeding strategy in different regions of the country. The raised slatted-floor cages used in intensive lamb fattening systems were just recently introduced in Mexico, and hence, there is no scientific evidence regarding their productive and economic evaluation. Therefore, there is a need to strengthen knowledge and generate technology with precise goals and objectives. By doing so, it is possible to deliver technological options with strong scientific bases that are economically viable, socially equitably and ecologically acceptable.Resumen: Este artículo es una revisión sobre los sistemas de engorda de corderos en regiones del trópico Mexicano y otros países. La alimentación de los corderos en los sistemas de engorda semi-intensivos está basada en el pastoreo con o sin suplementación, mientras que, en los sistemas intensivos está basada en concentrados. Los recursos forrajeros locales podrían ser una opción viable para la engorda de corderos, por sus bajos costos y la carne sana y de mejor calidad que resulta de esta estrategia de alimentación. Se sugiere desarrollar futuras evaluaciones de recursos forrajeros tropicales, con base en su calidad nutricional, disponibilidad y posibilidad de utilización. Diferentes razas de ovinos de pelo (Pelibuey, BlackBelly, Katahdin y Dorper y sus cruzas) han sido estudiadas en estos sistemas, pero falta definir la mejor estrategia de cruzamientos en las diferentes regiones del país. Los corrales elevados con piso de rejilla para los sistemas de engorda intensiva de corderos fueron introducidos recientemente en México y no existe evidencia científica sobre su evaluación productiva ni económica. Por lo tanto, es necesario fortalecer la generación de conocimiento y tecnología con metas y objetivos precisos, que proporcionen al productor soluciones tecnológicas con sólidas bases científicas y que al mismo tiempo sean económicamente viables, socialmente aceptables y ecológicamente sostenibles

SCREENING OF THE ACARICIDAL EFFICACY OF PHYTOCHEMICAL EXTRACTS ON THE CATTLE TICK Rhipicephalus (Boophilus) microplus (Acari: ixodidae) BY LARVAL IMMERSION TEST

The objective of the study was to determine the acaricidal efficacy of selected native plants from Yucatán, Mexico on acaricide resistant larvae of Rhipicephalus (Boophilus) microplus. Methanolic extracts from roots, leaves, stems, and stem barks of 15 plants were tested using the modified larval immersion test. A final concentration of 10% (100 mg/ml) of plant crude-extract was used. The percentage mortality from different plants and extracts were: Petiveria alliacea  leaves (95.7±2.9 %) and stems (99.2±0.5 %); Diospyros anisandra leaves (87.9±8.6 %) and stem bark (98.8±1.0 %); Havardia albicans leaves (93.0±12.0 %), Caesalpinia gaumeri (90.1±4.8 %) and Capraria biflora (86.6±9.9 %), stems of Solanum tridinamum (98.0±1.7 %) and Solanum erianthum (97.8±1.8 %), stem bark of Bursera simaruba (99.1±0.7 %) and Cassearia corymbosa (99.5±0.5 %); and the root of Ocimum micrantun (87.0±3.2 %). We concluded that plants from Yucatan, Mexico showed a high acaricidal efficacy that could be used to control R. (B.) microplus acaricide resistant larvae. P. alliacea, Havardia albicans and Caesalpinia gaumeri were of the most encouraging plants to be used as an acaricide. Further studies are needed to evaluate these plants on adult ticks (in vivo conditions) and to identify the active compound(s) on R. (B.) microplus

Comparing different maize supplementation strategies to improve resilience and resistance against gastrointestinal nematode infections in browsing goats

The effect of maize grain supplementation on the resilience and resistance of browsing Criollo goat kids against gastrointestinal nematodes was evaluated. Five-month-old kids (n = 42), raised worm-free, were allocated to five groups: infected + not supplemented (I-NS; n = 10), infected + maize supplement at 108 g/d (I-S108; n = 8), maize supplement at 1% of body weight (BW) (I-S1%; n = 8), maize supplement at 1.5% BW (I-S1.5%; n = 8), or infected + supplemented (maize supplement 1.5% BW) + moxidectin (0.2 mg/kg BW subcutaneously every 28 d) (T-S1.5%; n = 8). Kids browsed daily (7 h) in a tropical forest for 112 days during the rainy season. Kids were weighed weekly to adjust supplementary feeding. Hematocrit (Ht), hemoglobin (Hb), and eggs per gram of feces were determined fortnightly. On day 112, five goat kids were slaughtered per group to determine worm burdens. Kids of the I-S1.5% group showed similar body-weight change, Ht and Hb, compared to kids without gastrointestinal nematodes (T-S1.5%), as well as lower eggs per gram of feces and Trichostrongylus colubriformis worm burden compared to the I-NS group (P > 0.05). Thus, among the supplement levels tested, increasing maize supplementation at 1.5% BW of kids was the best strategy to improve their resilience and resistance against natural gastrointestinal nematode infections under the conditions of forage from the tropical forest

Comparing different maize supplementation strategies to improve resilience and resistance against gastrointestinal nematode infections in browsing goats

The effect of maize grain supplementation on the resilience and resistance of browsing Criollo goat kids against gastrointestinal nematodes was evaluated. Five-month-old kids (n = 42), raised worm-free, were allocated to five groups: infected + not supplemented (I-NS; n = 10), infected + maize supplement at 108 g/d (I-S108; n = 8), maize supplement at 1% of body weight (BW) (I-S1%; n = 8), maize supplement at 1.5% BW (I-S1.5%; n = 8), or infected + supplemented (maize supplement 1.5% BW) + moxidectin (0.2 mg/kg BW subcutaneously every 28 d) (T-S1.5%; n = 8). Kids browsed daily (7 h) in a tropical forest for 112 days during the rainy season. Kids were weighed weekly to adjust supplementary feeding. Hematocrit (Ht), hemoglobin (Hb), and eggs per gram of feces were determined fortnightly. On day 112, five goat kids were slaughtered per group to determine worm burdens. Kids of the I-S1.5% group showed similar body-weight change, Ht and Hb, compared to kids without gastrointestinal nematodes (T-S1.5%), as well as lower eggs per gram of feces and Trichostrongylus colubriformis worm burden compared to the I-NS group (P > 0.05). Thus, among the supplement levels tested, increasing maize supplementation at 1.5% BW of kids was the best strategy to improve their resilience and resistance against natural gastrointestinal nematode infections under the conditions of forage from the tropical forest