Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The study assessed the effect of non-aqueous extracts of Artemisia ludoviciana mexicana and Chenopodium vulvaria on an experimental infection with Hymenolepis diminuta in mice. Twenty (20) mice were infected with 10 cysticercoids each, which were obtained from Tenebrio molitor fed with feces from infected rats. Egg excretion was monitored for 30 d. Subsequently, the mice were divided into four groups (n= 5): control with DMSO, nitazoxanide (50 mg/kg), Artemisia (375 mg/kg), and Chenopodium (375 mg/kg). Egg shedding began on day 12 postinfection, with a peak between d 19 and 21. After 24 h of treatment (d 30), excretion decreased by 50 %, and at 72 h, by 70 % in the nitazoxanide and Chenopodium groups. At 33 d, the recovery of adult worms was 50 % in the groups with extracts and 25 % in the nitazoxanide group, with damage to the integument and uterine branches. The extracts increased the roughness of the integument without affecting the scolex. The extracts reduced the parasite load, but more studies are required to determine their cestocidal effect or if they only favor the expulsion of the parasite. In addition, it is necessary to evaluate their impact on gastroenteric nematodes. The absence of adverse reactions suggests their potential use in the control of cestodes.

The purpose was to evaluate the chemical composition and adaptation potential of L. hexandra under crude oil stress conditions, through the rhizobacterial population, crude protein accumulation, neutral detergent fiber, acid detergent fiber, and lignin in foliage of young plants emerging from the main tillers of the plant at different growth ages (d 180 and 360), as well as the production of young plants in the tillering stage, and the aerial and root dry matter. The results showed that crude oil concentrations in the soil significantly affected the population of Azotobacter spp. (0.361*); however, those of Azospirillum spp. and Pseudomonas spp. were inhibited, while both populations increased with time extension (0.778*, 0.767*). Likewise, the synthesis of crude protein (0.551**) and lignin in the foliage (0.354*) and the production of young plants in the tillering stage (0.465**), as well as of root dry matter (0.362*) were increased, indicating a strategy of L. hexandra to survive and adapt to soil contamination by crude oil. Nevertheless, the chemical composition was affected by the age of the grass, in which the percentage of neutral detergent fiber (0.832**), acid detergent fiber (0.741**), and lignin (0.661**) increased, while that of crude protein decreased (-0.497**).

Bees as pollinators are crucial for global crop production and for maintaining ecosystem biodiversity. Nevertheless, like other pollinators, they are threatened by various factors, among which the indiscriminate use of pesticides stands out. These are substances that, depending on the dose acquired, could affect the foraging behavior, longevity, and learning of bees, and can accumulate in the products of the hive. Studies on the presence of pesticides in honey and wax in the Yucatán Peninsula are limited. For this reason, this research aimed to identify and quantify the presence of pesticides in honey and wax from honeybee colonies in municipalities of the Yucatán Peninsula. Between June and October 2023, a total of 31 samples of honey and 31 of wax were collected in the three states of the Yucatán Peninsula, from apiaries near agricultural or fruit crops and apiaries located in areas of primary vegetation. The samples were analyzed by gas chromatography with triple quadrupole mass spectrometry (GC-MS/MS) detection. The honey had traces of two pesticides, whereas residues of 11 pesticides were identified in the wax. The pesticides with the highest frequency and quantity were cis-1,2,3,6-tetrahydrophthalimide and coumaphos. It is concluded that honeycomb wax presented a greater quantity and diversity of pesticide residues, mainly those samples collected in apiaries near agricultural crops.

The Mexican hairless pig (MHP) is a subpopulation of creole pigs characterized by being hardy and resistant to diseases and having a high quality of meat, which gives it outstanding genetic qualities. Signals in the genome, derived from genetic selection, can be used to associate with genes and quantitative trait loci (QTL). The present study aimed to determine if there are selection signals (SSs) in the MHP genome, as well as to associate candidate genes (CG) and QTL with regions showing SS. A total of 107 pigs were genotyped with the GGP Porcine 50k BeadChip, and SSs were determined using the integrated haplotype score (iHS) method, with which significant SSs (P<0.0001) were observed in 20 markers distributed on chromosomes 3, 5, 6, 7, 8, 16, and 17. Chromosome 8 presented greater conservation and intensity, with possible association with response to selection in recent generations; small, less delimited haplotypes were observed on chromosomes 3 and 7 as an indicator of natural selection or adaptation. CGs were related to characteristics associated with the immune system, adaptation, behavior, obesity, embryonic implantation and development, meat quality, growth, development, and feed efficiency. One hundred forty-six (146) QTL were associated, which are related to behavior, conformation, fatness, immune capacity, and reproduction. There are SSs in the MHP, which can be used in genetic conservation and improvement programs.

This study aimed to evaluate the effect of the partial substitution of soybean meal with guanacaste (Enterolobium cyclocarpum) pods on the productive performance and carcass and meat traits of finishing lambs. The evaluation was carried out with 16 lambs (East Friesian x Blackbelly) randomly distributed to two experimental diets with 0 and 19 % guanacaste pods, which were previously vaccinated, dewormed, and adapted for 15 d to the individual cages. The feeding trial lasted 60 d, during which time live weight and feed intake were recorded. At the end of the trial, the lambs were slaughtered, and hot and cold carcass weight, yield, and classification were evaluated. In the meat (Longissimus dorsi), acidity, texture, and color were determined. Lamb weight, feed intake, and carcass and meat traits were similar in lambs fed with and without guanacaste. It is concluded that adding 19 % of guanacaste pods to the diet for finishing lambs does not affect the productive performance or modify traits of meat and carcass quality, so it can be considered a viable alternative for feeding sheep in dry seasons.

The increase in human population will be directly proportional to the demand for food that must meet the global requirements, which implies the urgency of ensuring food quality, maintaining its attributes and nutritional values without contributing to increase bacterial resistance. In recent years, bacteriophages have gained relevance due to their high specificity and to their being regarded as environmentally friendly for the biological control of pathogens in food. Multiple scientific evidence has revealed a great effectiveness of bacteriophages in significantly decreasing the bacterial count of pathogens associated with the food industry. Moreover, in recent years, several international companies have begun to produce and commercialize phage-based products for application in food products. This review highlights recent research on the use of bacteriophages in raw or cooked meat from different animals, ready-to-eat foods, food handling surfaces, and packaging materials to combat foodborne pathogens most frequently reported in outbreaks, including Salmonella, Escherichia coli, Campylobacter, and Listeria monocytogenes. In addition, phage products that are marketed by several companies for use in food decontamination are mentioned.

Dos experimentos evaluaron las respuestas del ganado Bos indicus alimentado con monensina (MON), extracto de Stryphnodendron adstringens (BBT), una mezcla de aceites esenciales (MAE) y una mezcla de aceites funcionales (MAF). Los aditivos alimentarios se añadieron a una ración mezclada total (RMT) con una proporción de forraje a concentrado de 20:80. En el experimento 1, con una duración de 104 días, se utilizó un diseño de bloques completos al azar. Se asignaron ciento catorce (114) toros mestizos (336 ± 26 kg PC) a cuatro tratamientos: MON (30 mg/kg MS), BBT (1,500 mg/kg MS), MAE (118 mg/kg MS) y MAF (250 mg/kg MS). MON resultó en la menor ingesta de materia seca. La ganancia diaria promedio, el peso corporal final y las características de la canal fueron similares en todos los tratamientos. La eficiencia alimenticia fue 13 %, 11 % y 4 % mayor con MON en comparación con BBT, MAE y MAF, respectivamente. En el experimento 2 se empleó un cuadrado latino de 5×5 con cinco novillos Bos indicus fistulados ruminalmente para probar los mismos cuatro tratamientos y una dieta control sin aditivos. Cada período duró 14 días. La digestibilidad aparente de los nutrientes y las concentraciones de ácidos grasos volátiles y NH3-N fueron similares entre los tratamientos. BBT y MAF presentaron los valores de pH ruminal más bajos (6.54) y más altos (6.75), respectivamente. La monensina mostró una eficiencia alimenticia superior a pesar de tener perfiles de digestibilidad de nutrientes y fermentación ruminal similares en comparación con los aditivos fitogénicos.

Porcine parvovirus causes mummified fetuses and stillbirth. Immunization programs are based on commercial vaccines and feedback (oral administration of a macerate of parvovirus-mummified fetuses). The present study assessed the seroconversion of these two methods on a farm in Sonora, Mexico, with reproductive problems. Replacement gilts are divided into: T1, feedback at 24 wk of age and T2, commercial vaccine (porcine parvovirus) at 24 and 27 wk of age. Multiparous sows are split into: T3, feedback at weaning and T4, commercial vaccine 2 wk before farrowing. Serum samples were taken the week before administrating the treatments (T0) and three weeks later to evaluate the immune response. T1, T2, T3, and T4 seroconverted 90, 83, 78, and 50 %, respectively. The presence of the porcine parvovirus genome was analyzed by endpoint PCR, using specific indicators (genotypes 1 to 6) with the presence of porcine parvovirus 4, in samples of T1, T2, and T4, which are analyzed by next-generation sequencing and porcine parvovirus 4 is confirmed, in addition to the identification of other viruses, bacteria, fungi, and parasites. The presence of porcine parvovirus 4 emphasizes the importance of evaluating preventive medicine programs, under the specific conditions of each farm, to optimize the prevention of reproductive conditions since commercial vaccines may not be effective and feedback treatment may favor the dissemination of other pathogens that are present on the farm.

En el sistema familiar de producción leche, la prevalencia de partos asistidos y la retención de membranas fetales (RMF) es alta; sin embargo, no se ha determinado en qué medida estas condiciones afectan la prevalencia de enfermedades uterinas y el desempeño reproductivo. Este estudio tuvo como objetivo evaluar la presencia o ausencia de partos asistidos y RMF sobre la prevalencia de endometritis clínica (EC) y la tasa de concepción en la primera inseminación artificial posparto (TC1S) de vacas Holstein. Se realizó un estudio observacional de cohorte retrospectivo para examinar la relación entre el parto asistido, MFR, EC y TC1S. Los datos se analizaron mediante estadística descriptiva y regresión logística. La prevalencia de partos asistidos, RMF y EC fue de 4.8 %, 8.3 % y 16.8 %, respectivamente, y la TC1S general fue de 58.5 %. Las vacas con MFR tuvieron un riesgo 5.6 veces mayor de desarrollar EC (P=0.001), y las vacas con EC tuvieron un riesgo 5.4 veces mayor de no quedar gestantes en la primera inseminación artificial postparto a la TC1S (P<0.001). La prevalencia de parto asistido y MFR observada en este estudio fue menor a la reportada típicamente en este sistema de producción. No obstante, se confirmó que la RMF es un factor de riesgo significativo para la EC, y esta condición uterina impacta negativamente en el desempeño reproductivo en el sistema familiar de producción leche.

The structure of the pig movement network in the State of Mexico was analyzed. Through the analysis of social networks, the main municipalities of origin and destination that participated in the commercialization of pigs for the slaughter, fattening, breeding, and livestock fair markets were identified, evaluating their centrality and betweenness in the network. The data from pig movement records authorized by the National Service for Agrifood Health, Safety, and Quality (SENASICA, for its acronym in Spanish) correspond to the period from 2017 to 2021. The results indicated that the general structure of the network is highly centralized in a small number of municipalities, such as La Paz and Ecatepec de Morelos, which functioned as key nodes in the distribution of pigs. This centralization favored commercial efficiency by guaranteeing a constant flow to strategic markets, contributing to food security and economic growth in the most connected municipalities. Nonetheless, important risks were also identified, such as vulnerability to network interruptions, economic inequalities between municipalities, and the generation of bottlenecks in distribution. In addition, the low density of connections between municipalities could limit network cohesion, highlighting the need to diversify trade relationships and strengthen connectivity to reduce risks and promote a more equitable and resilient network.