An in vitro rumen incubation method to study exsheathment kinetics of Haemonchus contortus third-stage infective larvae.

This study developed and evaluated an in vitro rumen incubation (IVRI) method to describe the exsheathment kinetics of Haemonchus contortus third-stage infective larvae (L3) in ruminal liquor (RL). The specific objectives were (i) to standardize the IVRI method to facilitate the contact between L3 and RL as well as the larval recovery, and (ii) to apply the IVRI method to describe the exsheathment kinetics of H. contortus and to select the best fitting nonlinear model. Incubation devices containing H. contortus larvae were incubated according to the IVRI technique in cattle RL or PBS. The incubation conditions included RL mixed with a nitrogen-rich media, maintained at 39 °C, with pH = 7.0, vented with CO2 and manual agitation. The larvae were recovered after 0, 1, 3, 6, 9, 12, and 24 h. The exsheathed and ensheathed larvae were counted to estimate the exsheathment (%) in RL or PBS. Exsheathment in RL was analyzed with nonlinear regression models: Exponential, Gompertz, Logistic, Log-Logistic, and Weibull. The models' fit was compared to select the one that best described the exsheathment kinetics. The exsheathment in RL reached 6.52%, 20.65%, 58.22%, 69.24%, 73.08%, and 77.20% in 1, 3, 6, 9, 12, and 24 h, respectively. Although the Gompertz, Weibull, and Logistic models were adequate to describe the observed exsheathment, the Log-Logistic model had the best fit. The IVRI method using bovine RL represents a suitable tool for the study of the in vitro exsheathment kinetics of H. contortus L3.

Composition of Slow-Growing Male Chicken's Meat and Bone Quality as Affected by Dietary Moringa oleifera Lam. Meal.

This study investigated the impact of Moringa oleifera Lam. meal (MOM) on meat nutritional properties and bone quality of slow-growing layer-type male chickens raised in semi-intensive conditions. A total of 198, 72-d-old Dominant Blue D 107 male chickens, with an average weight of 1093 ± 15.2 g, were randomly assigned to three dietary treatments supplemented with 0, 3, and 6% of MOM that corresponded to T1, T2, and T3, respectively. Each treatment, consisting of six replicated floor pens of 11 birds, had access to the outdoors for 49 days. The results showed that breast muscle ash percentage was significantly greater (P ≤ 0.05) in T2 in comparison to the T1 group. Meat dry matter, protein, and fat content were not influenced by the treatments (P > 0.05). Regardless of the treatments, oleic acid (C18:1N9C) was numerically more abundant in the breast than in the leg muscle. Alternatively, femoral and tibial lengths were shorter (P ≤ 0.05) in birds fed 3% MOM than the two other groups. Moreover, birds fed with MOM had greater tibial diameter (P ≤ 0.05) than those that were fed without MOM. In addition, bone ash content and phosphorous amount were significantly higher (P ≤ 0.05) in birds fed 6% MOM compared to those fed without MOM. The data of this study indicate that up to 6% of MOM may be added to the diet of slow-growing layer-type male chickens raised with outdoor access under tropical conditions to improve bone quality traits.

In vitro anthelmintic activity of five tropical legumes on the exsheathment and motility of Haemonchus contortus infective larvae.

This study investigated the in vitro anthelmintic (AH) activity of five tropical legume plants [Arachis pintoi CIAT 22160 (A.p. 22160), Gliricidia sepium, Cratylia argentea (C.a. Yacapani), C. argentea CIAT 22386 (C.a. 22386), C. argentea Veranera (C.a. Veranera)] against Haemonchus contortus infective larvae and the role of tannins/polyphenolic compounds in the AH effect. Lyophilized leaf extracts of each plant were evaluated using the Larval Exsheathment Inhibition Assay (LEIA) and the larval migration inhibition assay (LMIA). The role of tannins/polyphenolic compounds in the AH effect was evaluated in both assays using polyethylene glycol (PEG) to remove tannins from the solutions. At the highest concentration (1200µg of extract/ml), A. pintoi 22160, C.a. Yacapani, C.a. Veranera and C.a. 22386 completely inhibited the exsheathment process of H. contortus (P<0.01). At the same concentration (1200µg of extract/ml), the inhibition of larval migration for C.a. 22386, C.a. Veranera and G. sepium was 66.0%, 35.9% and 39.2% (relative to the PBS control), respectively. In both bioassays (LEIA and LMIA), the AH effect shown by each plant was blocked after the addition of polyethylene glycol (PEG), corroborating the role of tannins/polyphenolic compounds.

Determinación de L-canavanina por cromatografía líquida de alta resolución en fase reversa y por colorimetría / Measurement of L-canavanine by reverse phase high performance liquid chromatography and by an spectrofotometric method

Introducción. Para estudiar la toxicidad y el efecto metabólico de la canavanina en animales o plantas se depende de la disponibilidad de métodos sensibles, específicos y rápidos de análisis. Materiales y métodos. Se desarrolló un método para medir la concentración de L-canavanina por cromatografía líquida en fase reversa utilizando DABS-C1 como agente de derivación y se compararon los resultados con aquellos obtenidos por colorimetría por el método de Rosenthal. Cinco muestras de canavalia fueron utilizadas para validar la técnica. Resultados y discusión. La derivación con DABS-C1 permitió la determinación de éste aminoácido sin interferencia con otros aminoácidos. No se encontraron diferencias entre las concentraciones de L-canavanina en granos de Canavalia ensiformis cuando se midió por estos 2 métodos. El análisis colorimétrico puede ser empleado como una herramienta confiable de primera elección. Debido al alto costo que involucra el análisis por HPLC deberá ser empleado cuando exista evidencia de interferencia en el método colorimétrico de compuesto y/o metabolitos presentes en la muestra