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Purpose: Agricultural losses caused by pests have a profound impact on African and Asian countries. In this context, the whitefly Bemisia tabaci is an important global pest and attacks many vegetables. However, conventional pesticides cause unwanted effects on the environment and consumers, in addition to the development of resistance. Therefore, sustainable resources have been used and researched, including those of natural origin. Research Method: The objective of this review was to compile and discuss studies of essential oils found in Asian and African countries with action against B. tabaci. For this, scientific studies on active essential oils were searched in databases such as Scopus, Web of Science, Google Scholar, and Science Direct. Findings: The work explored essential oils from 48 different species belonging to 19 families. Notably, the families Asteraceae, Lamiaceae, Lauraceae, Myrtaceae, and Poaceae presented the highest number of studies. Among the evaluated oils, Allium sativum oil demonstrated potent fumigant insecticidal action. Similarly, essential oils from Cinnamomum camphora, Thymbra spicata, Rosmarinus officinalis, and Laurus nobilis exhibited high activity against pests. Promising essential oils with high potency against pests also include Mentha pulegium, Mentha viridis, and Syzygium aromaticum. Research Limitations: Despite the diversity of active essential oils against B. tabaci, further studies on the development and stability of formulations must be carried out. Originality/value: This review highlighted the abundance of active essential oils in Africa and Asia as natural resources for sustainable pest management in the B. tabaci control. [ABSTRACT FROM AUTHOR]

Sin resumen

A pesar de la comprobada capacidad de mejorar el desempeño en los cerdos, el uso de antimicrobianos como promotores de crecimiento viene siendo progresivamente restringido en diversos países. Las nuevas reglamentaciones tienden a buscar nuevas alternativas al uso de antibióticos y quimioterapéuticos como promotores de crecimiento. Una de estas alternativas son los nutraceúticos que constituyen una de las opciones investigadas. El objetivo del trabajo fue evaluar los efectos antimicrobianos del orégano sobre la digestibilidad aparente de los nutrientes, en la ganancia diaria de peso, conversión alimenticia y presentación de diarreas en lechones recién destetados. Fueron estudiados tres grupos de lechones de 21 días de edad de la raza F1 (Landrace x Large White), durante cuatro semanas de los cuales uno de dichos grupos fue tomado como grupo control (alimento comercial), y los otros dos grupos con alimento fabricado en la granja a diferentes concentraciones de orégano (0,03 y 0,06 % respectivamente). Las dietas fabricadas son a base de harina de maíz y soya suplementados con los aminoácidos y minerales esenciales para la dieta del lechón. El proyecto tuvo duración de un mes en el cuales se midió semanalmente el peso ganado por los animales y la conversión alimenticia de los mismos; de igual forma se comparó la eficacia del orégano con respecto a una dieta normal de concentrado. Los resultados del estudio mostraron diferencias significativas entre los grupos estudiados, en cuanto a las variables ganancia diaria de peso, índice de conversión y presentación de diarreas. Se llegó a una conclusión muy significativa donde las alternativas para los antibióticos promotores de crecimiento mejoran los parámetros productivos en lechones además, del efecto antimicrobiano que poseen.

The effect of dietary supplementation with 1% L-glutamine and a combination of 1% L-glutamine and 0.5% a-arginine on intestinal health was examined in weaned rabbits. A basal diet was formulated to meet nutrient recommendations. Another 2 diets were formulated by adding 1% (as-fed basis) Gln or a mixture of 1% (as-fed basis) Gln + 0.5% (as-fed basis) Arg (Gln-Arg) to the basal diet. In Exp. 1, a total of 357 rabbits were blocked by litter and assigned at random to the experimental diet to determine mortality (119 per diet) and growth performance (35 per diet; from weaning at 25 to 56 d of age). Rabbits were fed the experimental diets for a 2-wk period and thereafter received a commercial diet. Rabbits weaned at 25 d (blocked by litter and assigned at random to diets) were slaughtered at 35 d and used to determine apparent ileal digestibility of DM, CP, and AA (Exp. 2, a total of 60 rabbits), intestinal morphology, N-aminopeptidase and myeloperoxidase intestinal activity, the expression of PPAR[gamma] at the ileum and kidney, serum immunoglobulin in healthy and sick rabbits (Exp. 3, a total of 24 rabbits), and ileal and cecal microbial composition by PCR-RFLP (Exp. 4, a total of 45 rabbits). Dietary treatment did not affect ADG, ADFI, or G:F, during the entire fattening period. Supplementation with Gln reduced mortality during the first 2 wk and the whole fattening period from 18.5 to 8.4% (P = 0.023) and from 31.9 to 20.2% (P = 0.039), respectively, whereas no effect was detected for Arg supplementation. Among all the variables studied, the reduction on mortality due to Gln was related to a reduced intestinal colonization (Eimeria lesions) and changes on microbial ecosystem in the ileum and cecum, reducing the frequency of detection of Clostridium spp. (from 86.7 to 33.3%, P = 0.003) at the ileum, and Helicobacter spp. at the ileum (from 86.7 to 46.7%, P = 0.003) and at the cecum (from 86.7 to 46.7, P = 0.028), whereas no effect was detected for Arg supplementation. In conclusion, 1% L-Gln supplementation to postweaned rabbit diets decreased fattening mortality and modified the intestinal microbiota (although no consistent effects were observed on mucosal histology or inflammatory and systemic immune response). Diets containing a combination of 1% Gln and 0.5% Arg were of little additional benefit. Key words: arginine, glutamine, intestinal microbiota, mucosal integrity, rabbit doi: 10.2527/jas.2008-1698

The effect of neutral detergent-soluble fiber level on gut barrier function and intestinal microbiota was examined in weaned rabbits. A control diet (AH) containing 103 g of neutral detergent-soluble fiber/ kg of DM included alfalfa hay as main source of fiber. Another diet (B-AP) was formulated by replacing half of the alfalfa hay with a mixture of beet and apple pulp resulting in 131 g of soluble fiber/kg of DM. A third diet (OH) was obtained by substituting half of the alfalfa hay with a mix of oat hulls and a soybean protein concentrate and contained 79 g of soluble fiber/kg of DM. Rabbits weaned at 25 d and slaughtered at 35 d were used to determine ileal digestibility, jejunal morphology, sucrase activity, lamina propria lymphocytes, and intestinal microbiota. Suckling 35-d-old rabbits were used to assess mucosa morphology. Mortality (from weaning to 63 d of age) was also determined. Villous height of the jejunal mucosa increased with soluble fiber (P = 0.001). Rabbits fed with the greatest level of soluble fiber (BA-P diet) showed the highest villous height/ crypt depth ratio (8.14; P = 0.001), sucrase specific activity (8,671 [micro]mol of glucose/g of protein; P = 0.019), and the greatest ileal starch digestibility (96.8% ; P = 0.002). The opposite effects were observed in rabbits fed decreased levels of soluble fiber (AH and OH diets; 4.70, 5,848 [micro]mol of glucose/g of protein, as average, respectively). The lowest ileal starch digestibility was detected for animals fed OH diet (93.2%). Suckling rabbits of the same age showed a lower villous height/crypt depth ratio (6.70) compared with the B-AP diet group, but this ratio was higher than the AH or OH diet groups. Lower levels of soluble fiber tended (P = 0.074) to increase the cellular immune response (CD8+ lymphocytes). Diet affected IL-2 production (CD25+, P = 0.029; CD5+CD25+, P = 0.057), with no clear relationship between soluble fiber and IL-2. The intestinal microbiota biodiversity was not affected by diets (P [greater than or equal to] 0.38). Rabbits fed the B-AP and AH diets had a reduced cecal frequency of detection compatible with Campylobacter spp. (20.3 vs. 37.8, P = 0.074), and Clostridium perfringens (4.3 vs. 17.6%, P = 0.047), compared with the OH diet group. Moreover, the mortality rates decreased from 14.4 (OH diet) to 5.1% (B-AP diet) with the increased presence of soluble fiber in the diet. In conclusion, increased levels of dietary soluble fiber improve mucosal integrity and functionality. Key words: immune response, intestinal microbiota, mucosa integrity, rabbit, soluble fiber