Temporary Immunity of Blackbelly Lambs Reinfected with Trichostrongylus colubriformis

Background: Trichostrongylus colubriformis is one of the most prevalent gastrointestinal nematodes of sheep in warm climates. In this nematode species, anthelmintic resistance (AR) has been reported, which has motivated the search for alternative methods to control it. One practice is to increase the immune response level through the selection of animals with natural resistance, such as Blackbelly sheep. The aim of this study was to investigate the response of IgA and IgG in serum and saliva and the level of cells involved in the acquired resistance in Blackbelly lambs after single artificial reinfection with a resistant strain of Trichostrongylus colubriformis.Materials, Methods & Results: Sixteen weaned lambs grazed for one month in nematode-contaminated grasslands. All the lambs were treated with Albendazole and Levamisole; later, they were stabled for two months. After that, eight lambs were re-infected with 6000 larvae of T. colubriformis and other eight lambs remained naturally infected. In addition, eight nematode-free lambs raised in cages, served as negative control. Blood samples were taken fortnightly to determine packed cell volume (PCV, %), plasmatic protein (g dL-1), as well as absolute and differential leukocytes. The eggs per gram of feces (EPG) were recorded. An indirect ELISA against T. colubriformis Ag was performed to determine the IgG and IgA levels. All data were analyzed by repeated measures. The EPG in the re-infected group increased after 34 days (625 ± 287), while in the naturally infected group it remained close to 200 ± 158 throughout the study. The control lambs did not show any infection. The PCV (29.4 ± 3.4 %), basophils (44 ± 74), lymphocytes (8443 ± 2845) and monocytes (77 ± 91) counts were not affected by infection. The IgA OD against T. colubriformis increased significantly after 15 days post-infection (dpi) in the re-infected lambs (1.69 ± 0.5, 80% with regards to standard). With IgG was not possible to distinguish the effect of infection.Discussion: Highly persistent infection of T. colubriformis was observed for at least four months in the naturally infected group despite having been treated with anthelmintics. It is a significant problem because this species has a high prevalence in the region of study and shows anthelmintic resistance. For such reason, is important to evaluate the ability of the animal to develop an immune response. In other study, a natural reduction in the fecal egg count (FEC) was indicated at 100 dpi in the same species, but in the present work, the FEC could not be reduced until around 120 days when the naturally infected lambs were evaluated. The larger number of neutrophils and leukocytes in both the naturally infected and re-infected groups implies a sustained response for a long time. While the higher counts of eosinophils only in the re-infected group were produced as an immediate response to infection with T. colubriformis. Similarly, with a single infection of T. colubriformis, in Santa Ines sheep the infected lambs showed significantly higher levels of serum IgA than the control group. In this case, differences in IgA activity were observed between the re-infected lambs and the other groups at fifteen dpi, but the basal levels of IgA in the naturally pre-infected lambs were maintained at least five weeks after infection. In conclusion, an increase in the peripheral immune response in lambs re-infected with T. colubriformis resulted from the increase in IgA levels in serum and saliva, and increase in the number of peripheral eosinophils, total leukocytes and neutrophils. Re-infected lambs had a higher level of IgA than naturally infected lambs and control lambs, making possible to promote the immune response with a single re-infection with Trichostrongylus colubriformis

Efectos no genéticos sobre las características productivas de corderos de pelo alojados en corrales elevados con piso de rejilla en el trópico subhúmedo de México

This study aimed to determine the effects of space allowed (SA), season of the year (SY) and year (YR), and simple interactions on productive traits of hair lambs housed in raised slatted floor cage (RFC). Data from initial weight (IW, kg), final weight (FW, kg), adjusted weight at 90 days (FWA, kg), daily weight gain (DWG, g) and finalization period (FP) of 982 lambs were evaluated. Data for FW, FWA and DWG was analysed using general linear models and FP using survival analysis. The model included fixed effects of SA (0.47-0.53, 0.56-0.60, 0.64-1.13 m2/animal), SY (dry, rainy, north) and year (2012, 2013), the simple interactions and IW as a covariate. Mean IW, FW, FWA, DWG were 14.29±3.52, 35.75±3.11, 40.50±5.91 kg, and 286± 50 g, respectively, with 72.15± 14.45 of FP. The SA affected FW, FWA and DWG, SY affected only FW and YR affected significantly all the study variables. Lambs in spaces of 0.47-0.53 m2 have a higher probability or risk (1.986) to extend the FP. In conclusion, SA, SY, and YR had effect on the productive traits of hair lambs housed in RFC; lambs with larger SA were more productive in a shorter finalization period than those with smaller SA.El presente estudio tuvo como objetivo determinar los efectos del espacio de alojamiento (SA), la época del año (SY) y el año (YR), así como las interacciones simples sobre las características productivas de corderos de pelo alojados en corrales elevados con piso de rejilla (RFC). Se utilizaron datos del peso inicial (IW, kg), el peso final (FW, kg) y el peso ajustado a los 90 días (FWA, kg), la ganancia diaria de peso (DWG, g) y el periodo de finalización (FP) de 982 corderos. La información del FW, FWA y DWG se analizó usando modelos lineales generales y del FP usando análisis de supervivencia. El modelo incluyó efectos fijos de SA (0.47-0.53, 0.56-0.60 y 0.64-1.13 m2/animal), SY (seca, lluvia y norte) y año (2012 y 2013), las interacciones simples e IW como covariable. Los corderos tuvieron una media de IW, FW, FWA, DWG de 14.29± 3.52; 35.75 ± 3.11 kg; 40.50± 5.91 kg; y de 286± 50 g, respectivamente, con 72.15± 14.45 de FP. El SA afectó FW, FWA y DWG, SY afectó solo FW, y YR afectó significativamente todas las variables de estudio. Los corderos en espacios de 0.47-0.53 m2 tienen mayor probabilidad o riesgo (1.986) de prolongar la FP. En conclusión, SA, SY e YR tuvieron efecto sobre las características productivas de los corderos de pelo alojados en RFC; los corderos con mayor SA fueron más productivos en un periodo de finalización más corto que aquellos con menor SA

Rentabilidad de la engorda de corderos alojados en corrales elevados y a nivel del suelo en el sureste de México

The aim of this study was to compare the profitability of fattening lambs under two types of housing in the subhumid tropics of Mexico. Data on production parameters and production costs of 32 lambs, 16 housed in raised pens and 16 in pens at ground level, were analysed to determine the cost-benefit relationship and profitability. The cost-benefit ratio and the profitability of fattening lambs in raised pens were superior compared to fattening lambs in pens at ground.El objetivo del presente trabajo fue comparar la rentabilidad de la engorda de corderos bajo dos tipos de alojamiento en el trópico subhúmedo de México. Se analizaron datos de parámetros productivos y costos de producción de 32 corderos, 16 alojados en corrales elevados y 16 en corrales a nivel del suelo, para determinar la relación costo-beneficio y la rentabilidad. La relación costo-beneficio y la rentabilidad en crianza en corrales elevados fueron superior en comparación con la crianza en corrales a nivel del suelo

Physico-chemical, sensory and texture properties of an Aged Mexican Manchego-style cheese produced from hair sheep milk

Articulo publicadoThe objective of this study was to evaluate the physicochemical and texture changes of the Manchego-style cheese produced from hair sheep (Pelibuey) throughout 180 days of ripening, as well as consumer’s acceptance. Cheese pH was constant from 1 to 180 days of ripening. Moisture, water activity, fat, elasticity and hardness decreased from day 1 to day 180, while protein, trichloroacetic acid-soluble N and free amino acid increased. Cheese lightness decreased as ripening time increased, while elasticity and hardness decreased. Principal Component Analysis was useful in discriminating cheeses according to their physicochemical composition and that allowed cheeses to be classified in two groups according to their ripening time and this resulted in those with less than 60 days and those with more than 90 days of ripening. Compared with cheeses ripened at 1 and 90 days, aged cheeses at 180 days reduced scores for appearance, color, odor, taste, texture and overall acceptance. Overall, Manchego-style cheeses from hair sheep had the usual ripened-cheese physicochemical changes.The authors are grateful for the assistance of engineer Walter Lanz Villegas, who granted access to the facilities of the Centro de Integracion Ovina del Sureste (CIOS). We also thank D. Arcos-Alvarez, E. Bautista-Diaz, R. Espinosa-Mendoza and R. I. Narváez-Ballesteros for their technical assistance. The first author is grateful for the research grant provided by the National Council of Science and Technology of Mexico (CONACYT) for his postgraduate studies at the Universidad Juárez Autónoma de Tabasco, Mexico

Emisión de metano en ovinos alimentados con Pennisetum purpureum y árboles que contienen taninos condensados

El objetivo fue evaluar el efecto de los taninos condensados (TC) contenidos en el follaje de arbóreas tropicales, sobre el consumo de materia seca y orgánica (CMS, CMO), la digestibilidad de la materia seca (DMS) y emisiones de metano (CH4) en ovinos alimentados con una ración basal de pasto Pennisetum purpureum. Cuatro ovinos de pelo con un peso vivo promedio de 21.6±2.0 kg se sometieron a cuatro tratamientos en un diseño cuadro latino 4 x 4. Los tratamientos fueron P. purpureum (PP), P. purpureum + Havardia albicans (PPHA), P. purpureum + Bursera simaruba (PPBS), y P. purpureum + Acacia pennatula (PPAP); el follaje de las arbóreas se incluyó en 300 g/kg de MS de la ración. El consumo, la digestibilidad y la producción total de metano entérico se midieron por periodos de 23 h. La producción de metano se midió en cajas de respiración de circuito abierto. El consumo y digestibilidad de la MS y materia orgánica (MO) entre los tratamientos PP, PPHA, PPBS y PPAP no se afectaron por la inclusión de los follajes de arbóreas en la ración (P>0.05). Cuando la producción de CH4 se expresó en L/kg del CMS, CMO o consumo de fibra detergente neutro los resultados fueron similares entre tratamientos (PP, PPHA, PPBS y PPAP) (P>0.05). Se concluye que los TC contenidos en el follaje de Havardia albicans, Acacia pennatula y Bursera simaruba no afectaron las emisiones de CH4 al nivel de incorporación de 30 % de la MS; tampoco se observaron efectos en el CMS, CMO, DMS y concentración molar de ácidos grasos volátiles

Effect of feeding lactating ewes with <i>Moringa oleifera</i> leaf extract on milk yield, milk composition and preweaning performance of ewe/lamb pair

The objective this study was to evaluate the effect of different doses of Moringa oleifera leaf extract (MOE) on milk production and milk composition in ewes and on preweaning performance of their lambs. Twenty-four lactating ewes were housed individually with their lambs and assigned to four groups in a completely randomized design. The treatments included a basal diet without MOE (MOE0) or a basal diet supplemented with either 20 mL MOE per ewe per day (MOE20), 40 mL MOE per ewe per day (MOE40) or 60 mL MOE per ewe per day (MOE60). Over 45 days, milk production was recorded weekly and individual milk samples were collected for chemical analysis. Milk yield, fat-corrected milk and daily yields were similar among the four treatments. The supply of MOE did not affect ewe weaning efficiency and average daily gain or litter weaning weight of the lambs. Overall, the results from this study showed that dietary supplementation of hydroalcoholic extracts of Moringa oleifera leaves at doses of 20, 40 or 60 mL/ewes/d in lactating ewes does not have negative effects on milk yield, milk composition or lamb performance

Using plant-based compounds as preservatives for meat products: a review

The susceptibility of meat and meat products (MP) to oxidation and microbial deterioration poses a risk to the nutritional quality, safety, and shelf life of the product. This analysis provides a brief overview of how bioactive compounds (BC) impact meat and MP preservation, and how they can be utilized for preservation purposes. The use of BC, particularly plant-based antioxidants, can reduce the rate of auto-oxidation and microbial growth, thereby extending the shelf life of MP. These BC include polyphenols, flavonoids, tannins, terpenes, alkaloids, saponins, and coumarins, which have antioxidant and antimicrobial properties. Bioactive compounds can act as preservatives and improve the sensory and physicochemical properties of MP when added under appropriate conditions and concentrations. However, the inappropriate extraction, concentration, or addition of BC can also lead to undesired effects. Nonetheless, BC have not been associated with chronic-degenerative diseases and are considered safe for human consumption. MP auto-oxidation leads to the generation of reactive oxygen species, biogenic amines, malonaldehyde (MDA), and metmyoglobin oxidation products, which are detrimental to human health. The addition of BC at a concentration ranging from 0.025 to 2.5% (w/w in powdered or v/w in oil or liquid extracts) can act as a preservative, improving color, texture, and shelf life. The combination of BC with other techniques, such as encapsulation and the use of intelligent films, can further extend the shelf life of MP. In the future, it will be necessary to examine the phytochemical profile of plants that have been used in traditional medicine and cooking for generations to determine their feasibility in MP preservation