Post-partum anestrus is a problem on farms, and its duration depends on the frequency and intensity of suckling which affects reproduction and production efficiency to become a determining economic factor. The aim of this study was to determine the post-partum reproductive response in ewe to a "male effect" with an ovulation induction protocol of five days using progesterone and the application of a metabolic restorative (MR; Metabolase ®). One hundred and twenty females were randomly assigned to one of four treatments: T1: Continuous suckling (CS; n = 29), T2: CS + MR (n = 29), T3: CS + Male Effect (ME; n = 32), and T4: CS + MR + ME. The percentage of females in ovulation, weight changes among females and lambs, the onset of estrus, calving, fecundity, and prolificacy were also determined. The ovulation percentage was higher in CS + ME and CS + MR + ME (75.0 and 73.3%) than in the other treatments. Weight changes in females and lambs were different among periods. The onset of estrus was similar for CS and CS + MR (25.9 ± 1.9 and 25.7 ± 0.7 h, respectively). The calving percentage was higher for CS + MR (86.2%) than other treatments. Male presence positively affected the postpartum cyclic ovarian re-establishment and the metabolic restorative could even improve the fertility of hair ewes in continuous suckling with similar hormone protocol. ______________________________________________________________________________________

Livestock systems can contribute to food security by making use of available resources not suitable for human consumption such as Cucurbita argyrosperma Huber residue (CR). The aim of this pilot study was to evaluate preference and physicochemical characteristics of CR silages and their effect on milk production and milk composition from cows in a dual-purpose system in Campeche, Mexico. Three completely randomized experiments were performed. In experiment 1, physicochemical characteristics of four CR plus hay grass silages were evaluated: CR-77, CR-71, CR-65 and CR-59, containing 77%, 71%, 65% and 59% of CR, with 25%, 30%, 35% and 40% of estimated dry matter (DM), respectively. In experiment 2, silages intake preferences were determined in cattle. In experiment 3, the effect of CR silage or corn silage on milk production and milk composition of grazing cows in a dual-purpose system was evaluated. The results in experiment 1 showed that DM content differed between treatments (p < 0.05), ranging from 27.35% (CR-77) to 41.81% (CR-59) and estimated DM was similar to the actual values. pH and temperature were also different (p < 0.05). pH was different between CR-71 (4.01) and CR-59 (4.43), and temperature between CR-77 (28.87 °C) and CR-65 (29.5 °C). Crude protein (CP) was very low in all silages (<4%), particularly in CR-59 (2.8%) (p < 0.05), and neutral detergent fiber (NDF) was significantly (p < 0.05) higher with CR-65 and CR-59 (average: 79.6%) than CR-77 and CR-71 (average 75.1%). There were no differences in intake preference (experiment 2), milk production (average 3.7 L) or milk composition (average protein: 3.27%, fat: 2.26%, lactose: 5.23%, solids non-fat: 9.17%) (experiment 3) (p > 0.05), but differences in DM intake of silages in experiment 3 were observed (p < 0.05). Even with the limitations of this pilot study, it is feasible to produce silages with CR with a good fermentation process as a feeding alternative for cows in a dual-purpose system in Campeche, Mexico.

En México, el cultivo de cítricos tiene una importancia alimentaria, social y cultural que llega a regir la vida familiar y la dinámica comunitaria en las regiones y están siendo afectadas por el cambio climático. El objetivo de esta investigación fue medir la percepción de los citricultores, ante el efecto del cambio climático. Se aplicó una encuesta participativa a 65 productores de cítricos de Campeche, México. Se midieron variables sobre ocurrencia de eventos asociados al cambio climático, daño directo a las plantas, percepción del aumento de fenómenos meteorológicos, cambio tecnológico y socioeconómico. Los encuestados son hombres (86.3%), de edad mayor y escolaridad básica. El 55% de los participantes posee tierra ejidal y 44% propiedad privada. El rendimiento promedio de los cítricos es bajo debido a la falta de sistemas de riego tecnificado y a los efectos del cambio climático, particularmente el aumento de la temperatura y el descenso de la precipitación. Los productores poseen un total de siete tipos de cultivos en sus parcelas, sin correlación con el tamaño de propiedad (r= 0.032), ni con el área destinada al cultivo (r= 0.33). El 66.6% de los participantes ha escuchado sobre el cambio climático siendo la fuente de información la televisión. El 69.6% ha percibido cambios mayores en el clima, lo que ha motivado a realizar cambios en el tipo de labranza (McNemar.test χ2= 10.56, p< 0.01**). Así, los efectos del cambio climático están incidiendo en las prácticas de manejo de los cítricos en Campeche; sin embargo, son acciones reactivas y se requieren de investigaciones que cuantifiquen y valoren los daños por este fenómeno y se diseñen estrategias para contrarrestar sus efectos en el mediano y largo plazo.

Estudio preliminar sobre la inhibición in vitro de nematodos gastrointestinales de ovinos con extractos acuosos de plantas forrajeras