The effect of Saccharomyces cerevisiae as live cells (LC) or cells extract (CE) on in vitro gas production (GP) kinetics and ruminal fermentation parameters of a total mixed ration (TMR) consisting of commercial concentrate and alfalfa hay [1:1 dry matter (DM)] as a substrate was studied. The TMR was incubated with CE at 1, 2 and 4 mg/g or LC at 0.3, 0.6 and 0.9 mg/g DM for 96 h. Rumen GP was recorded after 6, 12, 19, 24, 48, 72 and 96 h of incubation. Interaction effects were observed (P<0.01) between treatment type and yeast dose for the asymptotic GP and methane (CH4) production. Incubation of yeast CE improved (P<0.01) the asymptotic GP compared to control and LC with greater effects (P<0.01) for the low and the intermediate doses. Yeast CE treatment was more effective (P<0.01) in GP than both of LC and control treatments with greater effect (P<0.01) for the low and the intermediate doses. Treatment type and yeast dose affected (P<0.01) CH4 production, metabolisable energy (ME), and short chain fatty acids (SCFA) without affecting in vitro DM degradability (IVDMD). Higher values (P<0.01) of CH4, ME, SCFA and IVDMD were observed for the yeast CE treatment. It could be concluded that adding yeast S. cerevisiae (CE and LC extract) improved GP and ruminal fermentation parameters, where CE at 0.3 and 0.6 mg/g DM was more effective than the yeast LC.

Twenty Katahdin × Pelibuey crossbreed male lambs, 3 to 4 months of age and 24 ± 0.3 kg of body weight, were used to study the anthelmintic effects of administering extracts of Salix babylonica L. (SB) and Leucaena leucocephala Lam. (LL). Lambs had not been treated with anthelmintics previously and were randomly allocated into four groups of five lambs each in a completely randomized design. Treatments were as follows: control (lambs fed on total mixed ration without extracts), SB (as control plus S. babylonica L. extract at 30 ml/day), LL (as control plus L. leucocephala Lam. extract at 30 ml/day), and SBLL (as control plus 30 ml/day of S. babylonica L. and L. leucocephala Lam. extracts in a 1:1 (v/v) mixture) for 63 days. Extracts were orally administered before the 8:00 a.m. feeding to each lamb. Rectal fecal samples were collected from each lamb at day 22 (P1), day 43 (P2), and day 63 (P3) of the experiment. Adult worm and egg counts were determined in each fecal sample immediately after collection. Plant secondary metabolites of total phenolics, saponins, and the aqueous fraction were 50 % lower in the SB versus LL extracts. Overall, the oral administration of extracts has improved the egg and worm count reductions in lamb feces by 54, 47, and 40 % for LL, SB, and SBLL, respectively, versus the control lambs. Reductions of worm egg counts in lamb feces were higher (P < 0.05) in P2 and P3 versus P1. Extracts of SB and LL or possibly isolated bioactive compounds could be a promising alternative to conventional anthelmintics to treat gastrointestinal parasites of small ruminants. Such treatments could be used in control strategies against gastrointestinal nematodes in organic and conventional production systems.

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The grapefruit (Citrus paradisi) is an important crop for citrus farming in Mexico. During June 2019, in a plantation in Iguala, Guerrero, Mexico, symptoms of anthracnose on grapefruit fruits were observed. Based on morphological and molecular characterisation, the fungus isolated from the anthracnose was identified as Colletotrichum gloeosporioides. Koch's postulates were verified and fulfilled. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose on grapefruit fruits in Mexico.

Los trips son una plaga de importancia económica en múltiples cultivos, entre ellos mango; altas densidades de trips causan pérdidas significativas. El manejo convencional se basa en el uso de insecticidas químicos sistémicos que acarrean inconvenientes como selección de resistencia, contaminación ambiental e intoxicaciones. El objetivo del estudio fue evaluar la efectividad insecticida de productos biorracionales, como alternativas de manejo de trips. Se utilizaron arboles de mango cv. manila en un diseño experimental completamente al azar; se aplicaron cinco tratamientos insecticidas, T1: Aceite parafínico, T2: extracto de ajo + extracto de chile picante + extracto de canela, T3: Extracto de neem + extracto de canela, T4: Extracto de aceite neem todos a 2.0 L/ha, T5: Spinetoram a 500 mL/ha y T6: testigo sin aplicación. Se realizó una evaluación previa y tres posteriores a la primera aplicación, se contabilizó y evaluó la cantidad de individuos por inflorescencia o brote vegetativo, con los datos de la fluctuación poblacional se realizó un análisis de varianza y comparación de medias (Tukey, p=0.05). Se destacó la presencia de Frankliniella invasor como especie dominante. En la primera evaluación, de manera consistente en todo el experimento Spinetoram (dosis 500 mL/ha) obtuvo las mejores eficacias de control; en la segunda y tercera fecha de evaluación T2: Extracto: ajo + chile + canela (dosis 2 L/ha) registro altos niveles de control. Aquellos tratamientos que con mezcla de extractos mantuvieron altos niveles de control. Dos aplicaciones semanales consecutivas, son suficientes para mantener bajas poblaciones de trips por 21 días.