Cryopreservation of horse semen with a liposome and trehalose added extender

The aim of the study was to evaluate the effect of cryopreserved equine semen in the presence of trehalose-loaded liposomes on the integrity and function of sperm cells. Six ejaculations of five stallions collected with an artificial vagina were used. The ejaculates were diluted with INRA 96® 2:1 v/v and transported at 22 °C to the laboratory. Before cryopreservation, the semen was diluted with INRA Freeze® to obtain the following treatments: T1) INRA Freeze® (control), T2) INRA Freeze® + liposomes, T3) INRA Freeze® + liposomes+trehalose. Data were analysed using the Kruskal Wallis test. The percentages of sperm with intact DNA were 54.5, 57.9, and 64.8% for T1, T2 and T3, respectively (P>0.05). When evaluating the acrosomal and capacitation state after filtering with Percoll®, the percentages of spermatozoa without acrosome reaction and without capacitation were 67.8, 79.2 and 68.1% in T1, T2, and T3, respectively (P>0.05), while the capacitated sperm without acrosome reaction and without capacitation was similar in T1 (47%) and T3 (32%) (P>0.05), and lower in T2 (16%) before filtering with Percoll®. The use of liposomes and liposome-trehalose did not affect on the functional status and nuclear chromatin of the equine sperm after freezing, but it did affect the percentage of capacitated sperm without acrosome reaction after selecting the thawed semen using the Percoll® gradient

Embryo development after ICSI, using spermatozoa from bovine testicular tissue treated with three membrane-destabilizing agents

ABSTRACT Objective: To determine differences in embryo development of bovine oocytes fertilized by frozen/thawed spermatozoa (F/T), or by intracytoplasmic sperm injection (ICSI) using F/T or spermatozoa from fresh (FTT) or cryopreserved testicular tissue (CTT) using three spermatozoa membrane destabilizers. Methods. Treatment (TRT) 1- In vitro fertilization (FIV) with F/T, TRT-2 ICSI with F/T, TRT-3 ICSI with FTT, TRT-4 ICSI with CTT. The spermatozoa membranes were destabilized using Triton X-100 (TX), Lysolecithin (LL) or Heparin--Glutathione (Hep-GSH). Embryo cleavage at 48 h and grade 1 and 2 blastocyst on day 8 post fertilization were recorded. The comparison among main effect means were analyzed based on the least significant difference of Fisher. Results. At D8 there was no difference in percentage of blastocyst formation among ICSI TRTs (F/T 13 ± 3, FTT 6 ± 3 and CTT 6 ± 3 p>0.05), but they were lower than control (FIV 23 ± 5). With Hep-GSH destabilizer, there was a lower cleavage at 48 h than the LL and TX (35± 5, vs 50± 5 and 56± 5 p<0.05). Cleavage at 48 h was better for the ICSI with F/T and LL, while for D8, the best percentage to blastocyst was for TX. Conclusion. It is possible to produce blastocysts using ICSI with spermatozoa obtained from fresh or cryopreserved testicular tissue. Sperm cells treated with TX or LL produced more BL than those treated with Hep-GSH. More experiments using spermatozoa obtained from different sources are necessary to improve embryo development after ICSI. Keywords:  ICSI, Vitrification, Testicular tissue, Oocytes, Bovine, Fertilization.R Objective. To determine the differences in the embryo development of bovine oocytes fertilized with frozen/thawing (F/T) spermatozoa or with the intracytoplasmic sperm injection (ICSI) of F/T, spermatozoa from fresh testicular tissue (FTT), and cryopreserved testicular tissue (CTT), using three spermatozoa membrane-destabilizing agents. Methodology. Four treatments were used. Treatment (TRT-1): In vitro fertilization (IVF) with F/T. TRT-2: ICSI with F/T. TRT-3: ICSI with FTT. TRT-4: ICSI with CTT. The spermatozoa membranes were destabilized with Triton X-100 (TX), Lysolecithin (LL), and Heparin-Glutathione (Hep-GSH). Embryonic division was recorded at 48 h and grade 1 and 2 blastocysts (BL) were recorded 8 days (D8) after the fertilization. The means were compared using Fisher’s least significant difference method. Results. At D8, the blastocysts formation between ICSI treatments (F/T 13 ± 3, FTT 6 ± 3, and CTT 6 ± 3, p>0.05) were lower than control (IVF 23 ± 5). There was a lower cleavage at 48 h using Hep-GSH than when LL and TX were used (35 ± 5 vs 50± 5 and 56± 5, p<0.05). Embryo division at 48 h obtained better results with the ICSI + F/T and LL treatment, while the highest blastocyst percentage at D8 was obtained using TX. Conclusions. Blastocysts can be produced through ICSI, using spermatozoa from fresh or cryopreserved testicular tissue. The spermatozoa treated with TX and LL produced a higher percentage of BL than the spermatozoa treated with Hep-GSH. Further experiments should be carried out using spermatozoa obtained from different sources, in order to improve embryo development after the ICSI

Costo del intervalo interparto en la producción bovina tropical del sureste de México: Cost of the calving interval in tropical bovine production in southeastern Mexico

Objective: The aim was to analyze the cost of the calving interval (CI) in cattle production in humid tropic of south-eastern Mexico and to predict the possible economic losses of farms in the humid tropics. Design/methodology/approach: Tropical farms corresponding to 1,200 cattle of the breeds: Simmental, Simbrha, Brahman and F1 crosses, grazing was analyzed. &nbsp;One-way ANOVA was used to compare costs among breeds. Linear regression was used to obtain the relationship between cow age and CI. Results: The cost of a day without pregnancy reached US$0.99 (± 0.05), and a cow that did not calve for one year represented an investment loss of US$359.00 (± 11.72) dollars in relation to production costs. Limitations on study/implications: The income obtained from the sale of a calf at weaning and milk amounted to US734.10 (± 16.98) dollars. Findings/conclusions: No significant differences were found between the races (p <0.05) and the CI, however, there was a positive relationship (r=0.9326, r2= 0.8698, p<0.05) between the CI and the increase in the age of the cow.Objetivo: El objetivo fue analizar el costo del Intervalo Interparto (IIp) en la producción de ganado vacuno del sureste de México, y predecir las posibles pérdidas económicas en las granjas tropicales. Diseño/metodología/aproximación: Se analizaron granjas tropicales correspondientes a 1,200 bovinos de las razas: Simmental, Simbrha, Brahman y cruzas F1, en pastoreo. Se utilizó el ANOVA unidireccional para comparar los costos entre las razas. La regresión lineal se utilizó para obtener la relación entre la edad de la vaca y el IIp. Resultados: El costo de un día sin preñez alcanzó los US 0,99 (± 0,05), y una vaca que no parió durante un año representó una pérdida, para el productor, de US $359.00 (± 11,72), en relación con los costos de producción. Limitaciones del estudio/implicaciones: Los ingresos obtenidos de la venta de un becerro al destete y la leche generada, ascendieron a US$734.10 (± 16.98) dólares. Hallazgos/conclusiones: No se encontraron diferencias significativas entre las razas (p &lt;0.05) y el IIp, sin embargo, hubo una relación positiva (r = 0.9326, r2 = 0.8698, p &lt;0.05) entre el IIp y el incremento de la edad de la vaca

Procedure before the Competition Agency

U radu se analizira postupak koji se vodi radi utvrđivanja narušenja tržišnog natjecanja. Takav je postupak u nadležnosti Agencije za zaštitu tržišnog natjecanja. Svrha takvog postupka je utvrditi je li došlo do sprječavanja, ograničavanja ili narušavanja tržišnog natjecanja. Postupak koji se vodi pred AZTN upravni je postupak. U tom smislu, predmetni se postupak suštinski ne razlikuje od “klasičnog” upravnog postupka, ali postoje neke razlike koje su baš zbog toga i posebno regulirane u Zakonu o zaštiti tržišnog natjecanja te se u radu želi ukazati na njih. U radu se daje cjelokupan i zaokružen prikaz postupka pred Agencijom za zaštitu tržišnog natjecanja potkrijepljen primjerima radi lakšeg razumijevanja. Rad se bazira na Zakonu o zaštiti tržišnog natjecanja te aktima Agencije za zaštitu tržišnog natjecanja. Na temelju takvog prikaza može se zaključivati je li opravdano što Agencija ima tako velike ovlasti u tim postupcima o čemu se spore mnogi teoretičari. Rad je koncipiran tako što je podijeljen u nekoliko cjelina gdje svaka predstavlja određeni stadij postupka. U prvoj cjelini govori se o načinu pokretanja postupka i osobama koje mogu biti stranke u takvom postupku. Sljedeća cjelina stavlja naglasak na prikupljanje podataka od strane Agencije što joj omogućuje donošenje ispravne odluke. Nakon toga slijedi obrada radnji koje prethode samoj usmenoj raspravi. U završnim cjelinama riječ je o odlukama koje Agencija može donositi te o sudskoj zaštiti. Na kraju rada iznose se zaključci i osobni osvrt na važnost djelotvorne primjene prava tržišnog natjecanja.In this thesis is analyzed the procedure for determinating violation of market competition. That kind of procedure is in the jurisdiction of Competition Agency. The purpose (point) of this procedure is to determine if there was prevention, restricition or violation of market competition. The procedure before the Competition Agency is administrative procedure. There for, the subject matter does not differentiate from the ''classic'' form of administrative procedure, but there are some differences that are specially regulated in the Law of protection of Market Competition and they are pointed out in this thesis. The thorough representation of the procedure before Competition Agency is given in this thesis substantiated with examples for easier understanding. The thesis is based on the Law of protection of Market Competition and Competition Agency's acts. Based on that representation, it can be concluded if the Agency's wide authority is justified in that kind of procedures, on which many theorists dispute. The thesis is conceived in several sections that represent specified parts of the procedure. In the first section is shown the inititaion and the presumptive parties of the procedure. Next section emphasize the gathering of information from the Agency itself, which enables it to provide the correctly decisions. After that section, follows processing of acts that precede the hearing. The final sections present possible Agency's decisions and the protection provided by court. At the end of thesis are drawn conclusions and the personal review of the importance of effective use of Right on Market Competition

Potassium Current Is Not Affected by Long-Term Exposure to Ghrelin or GHRP-6 in Somatotropes GC Cells

Ghrelin is a growth hormone (GH) secretagogue (GHS) and GHRP-6 is a synthetic peptide analogue; both act through the GHS receptor. GH secretion depends directly on the intracellular concentration of Ca2+; this is determined from the intracellular reserves and by the entrance of Ca2+ through the voltage-dependent calcium channels, which are activated by the membrane depolarization. Membrane potential is mainly determined by K+ channels. In the present work, we investigated the effect of ghrelin (10 nM) or GHRP-6 (100 nM) for 96 h on functional expression of voltage-dependent K+ channels in rat somatotropes: GC cell line. Physiological patch-clamp whole-cell recording was used to register the K+ currents. With Cd2+ (1 mM) and tetrodotoxin (1 μm) in the bath solution recording, three types of currents were characterized on the basis of their biophysical and pharmacological properties. GC cells showed a K+ current with a transitory component sensitive to 4-aminopyridine, which represents ~40% of the total outgoing current; a sustained component named delayed rectifier , sensitive to tetraethylammonium; and a third type of K+ current was recorded at potentials more negative than −80 mV, permitting the entrance of K+ named inward rectifier (KIR). Chronic treatment with ghrelin or GHRP-6 did not modify the functional expression of K+ channels, without significant changes () in the amplitudes of the three currents observed; in addition, there were no modifications in their biophysical properties and kinetic activation or inactivation

Breeding soundness examination and herd proficiency of local genetic groups of bulls in tropical environment conditions in Veracruz, Mexico

With the aim of assessing bull fertility before or during its use for reproduction under tropical weather conditions where heat stress is present, and correlating it to herd parameters, BSE was carried out to determine which genetic groups of bulls have better reproductive performance. 223 bulls from different genetic groups, Zebu bulls (N = 72), European bulls (N = 58), and Crossbred Bulls (N = 93), were evaluated in situ over a two-year period, 2018–2019. Bull (age, corporal conditions, libido, and scrotal circumference), semen (concentration, motility and volume), herd (pregnancy rate and calving intervals) and environmental variables (THI, season, sampling month and spermatogenesis month) were analysed with One-Way ANOVA, as well as with factorial, multiple regression, and multivariate analysis. Zebu and European bulls have a higher libido than crossbreed bulls (p 7) show high correlation (R = 0.70 p  .05). Heat stress did not directly affect bull reproductive performance; Zebu bulls and crossbreeds showed better herd parameters (p < .05).Highlights Bull breeding soundness examination and herd proficiency. Herd proficiency of local genetic groups of bulls in tropical conditions. Breeding soundness examination in tropical environment conditions

La investigación universitaria y sus contribuciones en Mesoamérica

La Universidad Autónoma de Chiapas a través de su Proyecto Académico 2014-2018, reafirma su compromiso con el desarrollo de nuestra región, al establecer líneas de desarrollo de nuestra región, al establecer líneas de desarrollo institucional, donde la vinculación de la investigación ocupa un lugar preponderante; en este sentido, a partir de 2015, junto con la comunidad académica internacional, se unió a la Agenda 2030 para el Desarrollo sostenible de la ONU y priorizó los 17 Objetivos de Desarrollo Sostenible (ODS) y sus 169 metas, con la finalidad de dar soluciona los grandes desafíos sociales, económicos y medioambientales que enfrenta la sociedad. Este libro es la recopilación de trabajos realizados por académicos de diversas Instituciones de Educación Superior y Centros de Investigación, de manera multidisciplinaria, interinstitucional e internacional, los cuales han permitido compartir intereses en diversas líneas de generación y aplicación del conocimiento

La investigación universitaria y sus contribuciones en Mesoamérica

La Universidad Autónoma de Chiapas a través de su Proyecto Académico 2014-2018, reafirma su compromiso con el desarrollo de nuestra región, al establecer líneas de desarrollo de nuestra región, al establecer líneas de desarrollo institucional, donde la vinculación de la investigación ocupa un lugar preponderante; en este sentido, a partir de 2015, junto con la comunidad académica internacional, se unió a la Agenda 2030 para el Desarrollo sostenible de la ONU y priorizó los 17 Objetivos de Desarrollo Sostenible (ODS) y sus 169 metas, con la finalidad de dar soluciona los grandes desafíos sociales, económicos y medioambientales que enfrenta la sociedad. Este libro es la recopilación de trabajos realizados por académicos de diversas Instituciones de Educación Superior y Centros de Investigación, de manera multidisciplinaria, interinstitucional e internacional, los cuales han permitido compartir intereses en diversas líneas de generación y aplicación del conocimiento