Contents Bovine oocytes and embryos produced in vitro were studied to determine the mitochondrial pattern of distribution, segregation and activity using DIOC 6 and Jc-1 fluorescence. The highest fluorescence level observed in mature oocytes was taken as 100% activity and six activity levels were estimated as follows: (1) 0%, (2) 1-15%, (3) 16-30%, (4) 31-50%, (5) 51-75% and (6) 76-100%. Three patterns of mitochondrial distribution were found: (1) diffused throughout the cytoplasm in oocytes and embryos, (2) pericytoplasmic in oocytes and embryos, and (3) perinuclear only in embryos. The segregation of mitochondria in blastomeres showed two distinct patterns: (1) symmetrical with an even mitochondrial population, and (2) asymmetrical with different numbers of mitochondria in each blastomere. In immature oocytes, mitochondrial activity was very low and the distribution was diffuse or negligible, while in mature oocytes the activity was high and the distribution was diffuse or pericytoplasmic. Competent embryos up to the 16-cell stage showed intermediate levels of activity (16-50%) but activity decreased thereafter up to the blastocyst stage. Non-competent embryos showed low levels of activity (1-15%) at all stages. These results suggest that mitochondria might play an important role during early development and that a minimum threshold of activity regulates the potential competence for reaching the blastocyst stage.

Excessive human population growth, uncontrolled use of natural resources, including deforestation, mining, wasteful systems, biodiversity reduction by agriculture, and damaging climate change affect the existence of all animals, including humans. This discussion is now urgent and people are rethinking their links with the animals we use for clothing, food, work, companionship, entertainment, and research. The concepts of one health, one welfare, and one biology are discussed as a background to driving global change. Nothing should be exploited without considering the ethics of the action and the consequences. This review concerns domesticated animals, including those used for human consumption of meat, eggs, and milk; horses kept for work; and dogs kept for company. Animal welfare includes health, emotional state, and comfort while moving and resting, and is affected by possibilities to show behavior and relationships with others of the same species or with humans. We show some examples of the relations between humans and domesticated animals in the environmental context, including zoonotic diseases, and consider the consequences and the new paradigms resulting from current awareness.

SUMMARYOne of the biggest obstacles in the in vitro embryo production for basic research, commercial purposes, or conservation, is the blockade of the early cleavage, which occurs on a species-specific manner in a particular stage of development. To explain this phenomenon some causative factors have been postulated such as: disturbances in chromatin, cytoskeleton rearrangement, oxidative stress and mitochondrial damage. The latter has received considerable attention because mitochondrion is a source of reactive oxygen species (ROS), and oxidative stress is a critical mediator of physiological and pathological states. Over the past years it has been shown that hydrogen peroxide (H 2 O 2 ) is a pivoting molecule able to trigger cell death by different mechanisms that may or may not involve the transcription factors such as NFκB-p53, and is executed by effector caspases. It is believed that mitochondria may play an important role as a producer or as a target of H 2 O 2 , and as a mediator in apoptotic death of embryos. The purpose of this review is to present the state of the art about apoptosis triggered by oxidative stress and mediated by mitochondria in in vitro produced bovine embryos, as part of the explanation for the low efficiency in this process.Palabras clave: apoptosis, NFκB, potencial transmembranal mitocondrial, p53.

A study of the in vitro fermentation dynamics of the forages star grass (Cynodon plectostachyus; E), Guinea grass (Megathyrsus maximus; G) and Leucaena leucocephala (L), available in intensive silvopastoral systems (ISS) was carried out. Samples of these forages were harvested in ISS set in tropical dry forest in the Valle del Cauca, Colombia. With these forages, ten mixes or different treatments were generated: E100, G100, L100, E33G66, E66G33, L33E66, L66E33, L33G66, L66G33 and L33E33G33. The shorter lag phase was observed with L100 (7.02 h) and E33G66 (7.11 h), lower (α= 0.05) than that of L33E66 (10.22 h) and G100 (9.85 h). The maximum production of gas (a) ranged between 97.34 and 253 ml/ g substrate for L100 and G100, respectively. The lowest HIP value was obtained with L100 (23.3 hours) and the gas accumulated to that point was 35.08 ml, which coincides with the lower value. The treatments that most accumulated gas were the grasses alone or their mixtures and those with the least accumulated gas included leucaena. Regarding FP, after 24 hours of incubation, the greater values occurred with L100 and mixtures that included leucaena. It is concluded that the inclusion of Leucaena was associated with decreases in the lag phase time and maximum gas production rates and with high values of FP, characteristics that may be associated with more efficient fermentation processes.

Hematological and blood biochemical reference information is important to establish physiological status of freshwater stingray populations and improve care and management protocols in artificial environments. Here, we used a commercial freshwater stingray with high mortality rates in the market (Potamotrygon magdalenae), as an example to understand how artificial environments and handling protocols influence physiological status of captive freshwater stingrays. To this purpose, blood from five adult males and six adult females was collected to perform complete blood counts and blood chemistry analyses. All sampled animals showed good body condition with no differences between sexes. Differences between sexes were only found for the differential count of lymphocytes. Red blood results were consistent with previously studied potamotrygonids while white blood results showed higher values of leukocytes, thrombocytes, heterophils and lymphocytes in P. magdalenae compared to other Potamotrygonids. All types of leukocytes described for elasmobranchs were found except neutrophils and basophils. Blood metabolites showed an influence of ex situ diet in total protein, triglycerides and cholesterol. Glucose results were consistent while urea showed lower levels than those recorded for other freshwater stingrays. These results highlight the importance of physical, physiological and health analysis in freshwater stingrays as a part of welfare assessment to improve monitoring protocols and survival rates in public or private aquaria.

The aim of this study was to evaluate the possible relationships between reproductive parameters and Anti Mullerian Hormone (AMH) levels in two closely related bovine species. AMH levels and the reproductive parameters of 50 water buffaloes (Bubalus bubalis) and 50 Zebu cattle (Bos indicus) of the same age and raised in similar conditions were evaluated. Clinical data were obtained from the farm in specialized designed format, and AMH was measured by ELISA. The results show that Zebu cattle had higher AMH levels than water buffaloes (P<0.0001), while water buffaloes exhibited better reproductive parameters: days open to pregnancy (P<0.0001), parity (P<0.0005), age at first calving (P<0.0001), and intercalving period (P<0.0001). Although both species have different reproductive parameters, no correlations were found between AMH and the reproductive parameters evaluated in either species. Finally, pregnant Zebu cattle and water buffalo showed a tendency to have lower AMH levels than non-pregnant counterparts. The results are paradoxical as the species with lower AMH levels exhibited better reproductive parameters, suggesting that the reproductive parameters within the herd do not depend solely on the ovarian reserve of females.

La adaptación de un animal al medioambiente está influenciada por varios factores, entre ellos los métodos utilizados para la reproducción, producción y sacrificio. El objetivo de este estudio fue evaluar el comportamiento individual de machos cebú en corrales presacrificio y relacionarlo con el pH de la carne. Un total de 150 novillos de la raza Brahman, entre 24 y 27 meses de edad y un peso promedio de 447,4±35,4 kg, fueron estudiados en su etapa previa al sacrificio, evaluando los comportamientos agonistas de cada individuo durante seis horas posteriores al desembarque en la Central Ganadera de Medellín. El método utilizado para medir el comportamiento fue un registro continuo en el momento de ocurrencia de alguno de los comportamientos agonistas. Fueron estimadas las relaciones entre el tiempo de transporte (TT), el tiempo de ayuno (TA), el peso vivo (PV), la temperatura ambiental, humedad relativa, y la temperatura superficial (ventral (TV) y dorsal (TD)), con el pH de la carne a las 24 horas post mortem y los comportamientos agonistas de los animales. Se concluye que un TT superior a 20 horas desde la finca hasta la planta de sacrificio, y un TA mayor a 38 horas, implican un aumento en la actividad y la agresividad de los animales durante su espera en corrales. La TV y TD al momento de llegada al corral, influencian el descenso apropiado del pH de la carne. Los cambios en temperaturas superficiales a diferentes momentos, pueden aumentar el comportamiento agresivo, y además, PV superiores a 447 kg al momento del sacrificio, pueden afectar el descenso adecuado del pH.

For years the study of the differences in reproduction between bovines have been restricted to describe the consequences not the causes, it is very easy to find differences in parameters such as embryo/oocyte morphology, metabolism, cleavage rate, but it is quite difficult to find papers trying to explain the reason of this differences and it is not possible to identify their influence in the reproductive parameters and answer to reproductive biotechnologies. The idea that the quantity of follicles and oocytes in ovaries impacts on fertility is a long-held tenet in reproductive biology Follicle formation occurs during fetal life in ruminants and primates. The establishment of the pool of primordial follicles is critical to a female's reproductive success, but very little is known about how this important developmental process is regulated. It has been reported is has been reported in buffaloes the effect of season in the gene expression of oocytes and follicles However, until now very few studies has been attempted to evaluate this fundamental hypothesis, it is possible to think that animals with low follicle count such buffaloes has lower fertility than cattle but this must be demonstrated. The aim of this review is to present evidence related to the differences in reproductive potential in two closely related bovines: buffaloes (Bubalus bubalis) and cattle (Bos taurus and Bos indicus), with special emphasis in the role of antimullerian hormone (AMH) and discuss their possible role in the application of reproductive biotechnologies.