This study evaluated the productive performance and carcass traits of broiler chickens during the warm season in dry tropical conditions. Two hundred, 1-day-old chicks were used. Birds were fed on reduced (RED) and standard (STD) diets, and two essential oils (EOs) levels, 0 and 200 ppm. The RED diets were formulated with 10% less energy and 10% less protein than STD diets. In the starter phase, weight gain was greater (p < 0.01) in birds fed STD than birds fed RED. In the starter phase, productive variables were not affected (p ≥ 0.14) by EOs. In the finisher phase, greater feed intake (p = 0.02) and higher weight gain (p = 0.04) were observed in chickens on STD. Feed conversion ratio was similar (p = 0.97) for STD and RED. Throughout this study (1–42 d), greater feed intake (p = 0.02) and higher weight gain (p < 0.01) were found in chickens on STD. Feed conversion ratio was similar (p = 0.51) for STD and RED. Broiler chickens on EO-supplemented diets had better feed conversion (p ≥ 0.08). Hot carcass weight was greater (p < 0.01) in birds on STD. Greater yields of leg-thigh (p = 0.01), back (p = 0.01), and wings (p < 0.01) were observed in RED. Carcass yields, breast yield, pH, and meat temperature were not influenced (p ≥ 0.14) by nutrient concentrations in the diet. Carcass evaluations were not affected (p ≥ 0.11) by EOs. Body temperature was lower (p = 0.03) in birds receiving RED, however EOs had no effect (p ≥ 0.22) on body temperature. For the length of the study, at 20:00 h, broiler chickens fed on RED diets showed lower (p = 0.04) body temperatures. In conclusion, broiler chickens were under heat stress during the study, and body temperatures were reduced in chickens fed on RED diets or with EOs. Diet modification or EO-supplementation may improve feed conversion, though RED diets may have a negative effect on weight gain or carcass values.

Anthropogenic activities directly and indirectly affect the life cycle of Kemp's ridley turtles (Lepidochelys kempii). The transport of sea turtle eggs in boxes helps to establish new nesting areas and increases the possibility of turtle survival. This study aimed to compare the effects of two types of transport boxes on egg incubation, hatching rate and turtle emergence: a conventional plastic crate-type box with polystyrene nets as egg protection, and an experimental plywood box with convoluted (egg carton) foam as egg protection. Both boxes were used to transport eggs from 40 in situ nests (n = 20 nests transported by each box system, with 89–97 eggs per nest) to the Tepehuajes station (Tamaulipas, Mexico), during the nesting season from 23 April to 31 May 2000. Incubation period, and hatching and emergence rates for both box systems were compared using Student's t-test. The results showed that the experimental box had a significant positive effect on hatching and emergence rates when compared with the conventional plastic box, representing a feasible alternative for nest translocation procedures.

La transferencia de embriones (TE) en sistemas de producción bovina ha mostrado limitaciones y desafíos para alcanzar su éxito, especialmente cuando se habla de lograr las gestaciones después de la TE, ya que esto impacta tanto indicadores reproductivos, productivos e incluso económicos. El objetivo del presente estudio fue determinar los factores asociados a los porcentajes de gestación entre hembras bovinas nulíparas y multíparas sometidas a TE, así como la estimación económica de los servicios de TE en sistemas de producción de carne bajo condiciones de trópico seco. Se analizaron los registros de TE de 221 hembras, clasificadas en vacas nulíparas (n = 145) y vacas multíparas (n = 76) cruzas Bos taurus y Bos indicus, mantenidas en un sistema extensivo. Los porcentajes de gestación entre multíparas (33%) y nulíparas (30%) fueron iguales (p > 0.05), sin embargo, las nulíparas requirieron hasta tres servicios de TE para alcanzar los mismos porcentajes de gestación que las vacas multíparas (OR = 2.31; IC 95% 1.28-4.16; p = 0.005). La valoración económica mostro una pérdida de hasta el 74% en gestaciones con un servicio y de 67% con tres servicios. La etapa del embrión transferido tuvo efecto en los porcentajes de gestación (OR = 1.92; IC 95% 1.21-3.05; p = 0.006) mientras que la condición corporal, tamaño y posición del cuerpo lúteo no mostraron efecto (p > 0.05) sobre los porcentajes de gestación. Las hembras nulíparas requirieron hasta tres servicios de TE para lograr los mismos porcentajes de gestación que la multíparas, la mayor pérdida económica se observó al realizar hasta tres servicios de TE, mientras que la etapa del embrión fue el único factor predictor a lograr la gestación de las hembras.

This study aimed to evaluate the effects of milk replacer (MR) feeding on carcass characteristics, meat quality, and fatty acid profile in suckling goat kids through a meta-analysis. The electronic databases Scopus, Web of Science, PubMed, and Google Scholar were used to identify the articles required for the meta-analysis using the PRISMA methodology. The data used in this meta-analysis were obtained from 13 English-language articles published in peer-reviewed journals between January 2005 and May 2026. All data were analyzed using random-effects models. Feeding with MR did not affect (p > 0.05) body weight at slaughter, hot carcass weight, or hot carcass yield of suckling kids. However, a lower renal fat weight (p < 0.05) was observed in kids fed MR. On the other hand, feeding with MR did not affect (p > 0.05) meat pH at 24 h, lightness (L*), redness (a*), yellowness (b*), Chroma (C*), Hue (H°), Warner-Bratzler shear force, or the moisture, protein, fat, collagen, and ash content in the meat of suckling kids. Nevertheless, a lower water-holding capacity (p < 0.05) was observed in the meat of kids fed MR. Feeding with MR did not affect (p > 0.05) the concentration of caproic, caprylic, lauric, myristic, myristoleic, palmitoleic, heptadecanoic, oleic, alpha-linolenic, arachidonic acid, behenic acids, total saturated fatty acids, total monounsaturated fatty acids, and total polyunsaturated fatty acids. However, lower concentrations (p < 0.05) of capric, pentadecanoic, palmitic, stearic, and arachidic acids were observed in the meat of suckling kids fed MR. In contrast, higher concentrations (p < 0.05) of linoleic acid were observed in the meat of suckling kids fed MR. In conclusion, the use of milk replacer in suckling kids preserves growth, carcass traits, and most meat quality attributes, while reducing renal fat deposition and selectively modifying the fatty acid composition toward a higher linoleic acid content.

To determine the effect of anesthesia and tranquilization on the stress response of tilapia (Oreochromis nilotica) during a handling procedure. We assess three anesthetics: ketamine, MS222, and clove oil; and two tranquilizers: xylazine, and medetomidine, which were administrated by submersion in adult tilapia. Our results showed a significant difference in cortisol levels between treatments after handling procedure (P = 0.0002), where xylazine had the highest cortisol levels compared to the other treatments. We also found differences between induction and recovery times in the different treatments. Then, animals exposed to xylazine took longer to present induction effects, than the other treatments (P < 0.0001). For recovery times, ketamine presents the longest recovery times, than clove oil and MS222, but not when compared to animals exposed to medetomidine and xylazine (P = 0.0019). We observed paleness in animals exposed to medetomidine.

Los tumores de células redondas (TCRs) son un grupo de tumores heterogéneos que se originan de células hematopoyéticas (mastocitoma, linfosarcoma, plasmocitoma e histiocitoma) a excepción del tumor venéreo transmisible y melanoma. Diagnosticarlos lo más tempranamente es vital, pues su comportamiento biológico difiere drásticamente. Aunque existen investigaciones sobre su prevalencia en distintos países incluyendo México, es importante realizar estudios epidemiológicos locales, ya que se reporta que los resultados varían dependiendo de la población y área geográfica evaluada. Por lo anterior, el objetivo del presente trabajo fue describir la frecuencia y ciertas características epidemiológicas de TCRs diagnosticados en el Departamento de Patología de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad Autónoma de Tamaulipas, y dos laboratorios privados entre 2020 y 2024. De los 1,325 tumores evaluados, 411 correspondieron a TCRs (31%). De estos, 167 fueron mastocitomas (40.6%), 118 TVT (28.7%), 59 linfomas (14.4%), 59 melanomas (14.4%) y 8 histiocitomas (1.9%). Las hembras y machos se afectaron de manera similar (p>0.05). La mayor frecuencia se observó en perros entre 6 y 10 años (42.1%) (p<0.05), donde los mestizos fueron más afectados (27.98%) (p0.05).