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.

Metabolizable energy balance in hair sheep lambs artificially infected with Haemonchus contortus.

In sheep, infection with Haemonchus contortus may increase the need for energy, and this demand may vary according to the infection level. In this study, the energy intake, digestibility, and energy retention of lambs artificially infected with different levels of H. contortus were estimated. A total of 24 hair sheep lambs reared parasite-free were experimentally infected with H. contortus at one of three infection levels: non-infected (n = 6); infected with 300 infective larvae (L3) of H. contortus/kg body weight (BW) (n = 9); and infected with 500 H. contortus L3/kg BW (n = 9). The lambs were fed for an individual weight gain of 100 g/day, and intake of organic matter (OMI) and gross energy (GEI), digestible (DEI) and metabolizable energy (MEI) were measured weekly. The digestibility of organic matter (OMD) and GE (GED) and the metabolizable energy (ME) balance adjusted to zero nitrogen balance (MEadj) were measured for each lamb during the prepatent and patent periods of infection. From day 21 post-infection (PI), the individual eggs per gram (EPG) of feces and the total number of eggs in feces (TEF) were estimated weekly. After humane slaughter on day 42 PI, the worm burden (WB) was determined. Correlation and regression analyses were performed to estimate the relationships between the parasitological variables (L3, EPG, TEF and WB) and the response variables (OMI, GEI, DEI, MEI, OMD, GED, MEadj). During the prepatent period, there were no significant relationships of L3 with the response variables (OMI, GEI, DEI, MEI, OMD, GED, ME, MEadj). Similarly, during the patent period, no relationship was evident between infection (EPG, TEF or WB) and OMI, GEI, DEI, GED, OMD, ME or MEadj. Thus, the gradient of H. contortus infection examined in the present study did not influence energy balance in hair sheep lambs, and infection did not impose any detectable energy cost. Further studies are needed to fully assess the impact of H. contortus infection on energy metabolism in hair sheep.

Composition, Mineral and Fatty Acid Profiles of Milk from Goats Fed with Different Proportions of Broccoli and Artichoke Plant By-Products.

In the Mediterranean region, artichoke and broccoli are major crops with a high amount of by-products that can be used as alternative feedstuffs for ruminants, lowering feed costs and enhancing milk sustainability while reducing the environmental impact of dairy production. However, nutritional quality of milk needs to be assured under these production conditions and an optimal inclusion ratio of silages should be determined. This work aimed to evaluate the effect of three inclusion levels (25%, 40%, and 60%) of these silages (artichoke plant, AP, and broccoli by-product, BB) in goat diets on milk yield, composition, and mineral and fatty profiles. Treatments with 60% inclusion of AP and BB presented the lowest milk yield. No differences were found on the milk mineral profile. Inclusion of AP in the animals' diet improved the milk lipid profile from the point of view of human health (AI, TI) compared to BB due to a lower saturated fatty acid content (C12:0, C14:0, and C16:0) and a higher concentration of polyunsaturated fatty acids (PUFA), especially vaccenic acid (C18:1 trans11) and rumenic acid (CLA cis9, trans11), without any differences with the control treatment.

Ensiling Process in Commercial Bales of Horticultural By-products from Artichoke and Broccoli.

Wastes from artichoke and broccoli crops and cannery industries represent an environmental problem. A viable option to this problem is ensiling them for use as ruminants feed. The aim of this study was to characterise the ensiling process of broccoli and artichoke by-products and assess their suitability to be part of the ruminant diet, as well their minimum shelf life. Twenty-one commercial round bale silos (300 kg and 0.64 m3) of each by-product were made. Samples were analysed at days 0, 7, 15, 30, 60, and 200 to determine microbial populations, fermentation metabolites, nutritional components, and phytosanitary residues. Feedstuffs showed good suitability for ensiling, and stabilisation was achieved on day 30. The variables with the greatest significant differences among sampling times were microbial populations and fermentative components. There were no important dry matter losses, and some significant differences were observed in the nutritional composition, especially in crude protein and fibrous fractions, but they were not relevant for the loss of nutritional quality of silages. The phytosanitary residues determined on day 200 were below the maximum residue limits set by European legislation. So, ensiling these by-products in commercial round bale silos is a suitable and profitable technique that allows their preservation for a long time (200 days).

Digestibility of Duddingtonia flagrans chlamydospores in ruminants: in vitro and in vivo studies.

BACKGROUND: The use of Duddingtonia flagrans as a tool for the biological control of gastrointestinal nematodes (GIN) is a promising alternative to anthelmintics. The chlamydospores of D. flagrans are orally dosed and their thick cell wall gives them the capacity to resist digestion and pass through the gastrointestinal tract (GIT). Chlamydospores reaching the faeces are able to germinate and trap nematode larvae. The efficacy of this control method is based on reducing the numbers of infective larvae leaving the faeces. Techniques have recently been developed for quantifying the numbers of chlamydospores in faeces. As the number of non-digested spores could be relevant in the design and optimization of dosing programmes for the control of GIN infective larvae, the aim of the present study was to estimate the loss of D. flagrans chlamydospores during their passage through the ruminant gastrointestinal tract using in vitro and in vivo techniques. RESULTS: After in vitro rumen digestion, chlamydospore recovery was not different from the quantity originally incubated (undigested spores) (P > 0.05). In vitro rumen+abomasum digestion caused nearly 36% loss of the chlamydospores originally incubated (P < 0.05). Germination of chlamydospores classified as viable was 24.3%. Chlamydospores classified as non-viable did not germinate. Rumen digestion resulted in more spore germination (R1 = 35.7% and R2 = 53.3%) compared to no digestion (time 0 h = 8.7%). Subsequent abomasal digestion reduced germination (R1+A = 25%) or stopped it (R2+A = 0%). In vivo apparent chlamydospore digestibility in sheep showed a loss of 89.7% of the chlamydospores (P < 0.05). CONCLUSIONS: The loss of chlamydospores was evident under in vitro and in vivo conditions. Negligible amounts of spores were lost during the in vitro rumen digestion. However, in vitro rumen+abomasum digestion resulted in a chlamydospore loss of approximately 36%. In vivo passage through the sheep GIT resulted in a total loss of 89.7% of the orally administered spores.

Cambios en la población de protozoarios ruminales por efecto de la inclusión de Canavalia ensiformis a la dieta de bovinos / Changes on rumen protozooa population induced by the inclusión of Canavalia ensiformis in cattle diets

Introducción. Canavalia ensiformis es una leguminosa que destaca por su contenido de nutrimentos. Sin embargo, posee numerosos compuestos tóxicos que pueden limitar su utilización. Se ha reportado efecto de estos compuestos in vitro sobre fauna ruminal, pero se desconoce su efecto tóxico in vivo. Objetivo. El objetivo del presente trabajo fue analizar los cambios en la población de protozoarios ruminales como respuesta al consumo de canavalia. Materiales y Métodos. Se emplearon cuatro bovinos con un peso de 264.5 Kg en un diseño doble conmutativo con arreglo factorial 2x2. Los animales fueron alimentados con pasto Taiwán ad libitum y canavalia o sorgo como suplemento (c. 27 por ciento de la dieta en base seca). Se colectó líquido ruminal después de tres semanas de adaptación a la dieta y se contaron las poblaciones de protozoarios ruminales. Los datos normalizados utilizando su log10 y fueron analizados mediante un modelo lineal general. Las medias fueron comparadas mediante la prueba de mínima diferencia significativa. Resultados. Se observó un incremento (p<0.05) en los conteos de protozoarios flagelados en las dietas que contenían canavalia (106.345 vs 105.247), pero los holotricos y entodinomorfos disminuyeron (103.717 vs 104.364 y 104.407 vs 104.933 respectivamente p<0.05). Las cuentas totales de protozoarios fueron mayores en dietas con canavalia si el total incluía flagelados (106.369 vs 105.575) y menores si los excluía (104.505 vs 105.093) (p<0.05).Discusión. Los cambios en las diferentes poblaciones de protozoarios son una respuesta de adaptación al consumo de canavalia. Los diferentes grupos de protozoarios ruminales parecen tener diferente respuesta y/o capacidad de adaptación a los tóxicos de la canavalia.

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

Estimación de la síntesis de proteína microbial en rumiantes a traves de la medición de los derivados de purina en orina / The estimation of microbial protein synthesis in rumiants using the urinary excretion of purine derivates

La presente revisión tuvo como objetivo recopilar y presentar información actualizada sobre la técnica de los derivados de purina en rumiantes domésticos. La técnica de los derivados de purina representa una alternativa simple y no invasiva para el estudio del aporte de N microbial a nivel intestino delgado en animales rumiantes. Existe información y modelos cuantitativos de respuesta para bovinos y ovinos que permiten el uso de esta técnica, y numerosos métodos analíticos publicados para el análisis de los derivados de purina. El método de los derivados de purina tiene la ventaja de no requerir animales quirúrgicamente preparados, pero tiene la desventaja de requerir colecta total de orina. El uso de submuestras de orina colectada a lo largo del día(s) junto con el índice `derivados de purina:creatinina' puede ser una alternativa a la colección total de orina, pero se necesita más información sobre este punto. La medición de los derivados purínicos en leche no parece ser una alternativa viable a la colección total de orina. Deben de validarse algunos de los parámetros en uso para el cálculo del flujo de nitrógeno microbial al intestino como son; la recuperación de purinas microbiales absorbidas como derivados purínicos en orina y la digestibilidad de la purina en intestino delgado en animales bajo condiciones de alimentación normal. No obstante, comparada con otras téncicas convencionales, la medición de los derivados de purina en orina representa una herramienta simple para profundizar en el estudio y entendimiento de la dinámica ruminal