Livestock-Forest integrated system attenuates deleterious heat stress effects in bovine oocytes.

Global warming poses significant challenges to the fertility of tropical dairy cattle. One promising approach to mitigate heat stress effects on reproductive function and reduce the carbon footprint is the use of integrated livestock-forest (ILF) systems. The aim of this study was to investigate the effects of two different systems, namely Full Sun (FS) and ILF, on maternal hyperthermia and oocyte quality of Holstein and Girolando heifers during the tropical summer season.

Reproductive development of dairy heifers in an integrated livestock-forest system during the summer.

This study aimed to assess the cortisol, body and reproductive development of prepubertal Holstein and Holstein-Gir ¾ heifers at 27 months of age maintained in an integrated livestock-forest (ILF) system for 60 summer days compared to the monoculture system in full sun (FS). The ILF system promoted changes (=0.02) in the cortisol levels of Holstein-Gir ¾ heifers and did not affect weight gain in any of the breed groups studied.

Outstanding Gir oocyte donors: How does individual factor affect in vitro embryo production efficiency?

The oocyte donor plays a pivotal role in bovine in vitro embryo production (IVP) success. The individual factor affects blastocyst/oocyte ratio and determine the existence of outstanding performing animals. The aim of this study was to assess the extent of individual factor effect to IVP efficiency, in a population of Gir oocyte donors.

Imputation accuracy for genomic selection using embryo biopsy samples in Gir.

The aim of this study was to establish a platform for genomic selection of in vitro-fertilized (IVF) Gir embryos. Multiple displacement amplification (MDA)-based embryo biopsy samples were genotyped, and genomic estimated breeding values (GEBV) for milk yield (305MY) were calculated. The concordance of GEBV and accuracy between embryo biopsies and the respective liveborn were assessed.

Challenges in the use of nanostructures as carriers of nucleic acids in clinical practice.

The delivery of nucleic acids to cells is considered a crucial step for the success of genetic modifications aimed at therapeutic purposes or production of genetically modified animals. In this context, nanotechnology is one of the most promising fields of science, with the potential to solve several existing problems. Nanostructures have desirable characteristics to be used as carriers, such as nanometric size, large surface area, cell internalization capacity, prolonged and controlled release, among others.

Erratum to: Daily vaginal temperature in Girolando cows from three different genetic composition under natural heat stress.

[This corrects the article DOI: 10.1093/tas/txab138.].

Daily vaginal temperature in Girolando cows from three different genetic composition under natural heat stress.

The present trial evaluated the effect of crossbred composition and Temperature and Humidity Index (THI) on vaginal temperature (VT) of Girolando dairy cows maintained under tropical pasture during warm seasons. The VT was monitored along 41 to 96 h in 615 Girolando cows with different Holstein (H) × Gir genetic composition (1/2 H = 284, 3/4 H = 248, and 7/8 H = 83) from six Brazilian farms in the summer of 2016 and 2017. VT of each cow at each hour of the day and the respective THI were averaged per hour across all monitoring days to generate an averaged value for VT and THI during 24 h.

Heat shock during in vitro maturation of bovine oocytes disturbs bta-miR-19b and DROSHA transcripts abundance after in vitro fertilization.

While microRNAs (miRNAs) are a class of non-coding RNAs important for embryo development, the relationship between them and heat stress during oocyte maturation has not yet been established. This study investigated the effect of heat shock during in vitro maturation (IVM) on the abundance of bta-miR-20a, -27b, -103, -21-5p, -19b, -1246 miRNAs and DROSHA and DICER1 mRNAs, previously reported for being involved in oocyte maturation, response to heat stress and miRNA biogenesis. Oocytes were exposed for 12h to heat shock during IVM, fertilized in vitro and the presumptive zygotes cultured for eight days.

Chromium supplementation improves glucose metabolism and vaginal temperature regulation in Girolando cows under heat stress conditions in a climatic chamber.

This study aimed to evaluate chromium supplementation on productive, reproductive, and metabolic parameters at lactating Girolando cows subjected to heat stress conditions in a climatic chamber. Thirty-six lactating Girolando cows were subjected to two sequential trials. In trial 1 (thermoneutral environment), the effect of chromium supplementation was evaluated (0 vs.

Oocyte origin affects the in vitro embryo production and development of Holstein (Bos taurus taurus) - Gyr (Bos taurus indicus) reciprocal cross embryos.

A reciprocal crossbred embryo production approach was used to assess effects of maternal breed on embryo development in tropical conditions (average temperature 22.0 °C and 77.9% relative humidity).

Easy In Vitro Synthesis of Optimised Functioning Reporter mRNA from Common eGFP Plasmid.

The extensive growth in number and importance of experiments and clinical-aimed techniques based solely or majorly on the activity of RNA strands, e.g. CRSPR/Cas9 and siRNA, has put emphasis on the necessity of standardisation of experiments with RNA.

Post implantation development reveals that biopsy procedure can segregate "healthy" from "unhealthy" bovine embryos and prevent miscarriages.

Embryo biopsy has been performed in bovine in vivo produced embryos for the last twenty years, but little could be done with few embryonic cells in the past. Recently, advances in single cell analysis enabled a wide range of applications using embryo biopsy, from morphology to genetics analysis and different omics-techniques, which are promising for in vitro-fertilized (IVF) embryos. The aim of this study was to address if biopsy procedure would affect post implantation development of IVF blastocyts.

Sperm pretreatment with heparin and l-glutathione, sex-sorting, and double cryopreservation to improve intracytoplasmic sperm injection in bovine.

In bovine, intracytoplasmic sperm injection (ICSI) remains inefficient partially due to low levels of sperm decondensation. The aim of this study was to determine whether the injection of normal size sperm pretreated with heparin (Hep) and l-glutathione (GSH), the use of sex-sorted sperm, the double round of sperm freezing/thawing (re frozen), or the combination of these approaches can improve sperm decondensation and embryo development after ICSI in cattle. Cleavage and blastocyst rates were evaluated on days 2 and 7 post ICSI.

Insulin influences developmental competence of bovine oocytes cultured in α-MEM plus follicle-simulating hormone.

The aim of this study was to evaluate the dose-response effect of insulin, plus follicle-simulating hormone (FSH) at a fixed concentration, in a serum-free defined culture medium (DCM) on the in vitro maturation of bovine cumulus-oocyte complexes (COCs). For oocyte nuclear maturation, the expression levels of GDF9, GLUT1, PRDX1 and HSP70.1 transcripts related to oocyte and embryo developmental competence were analysed.

Developmental competence and expression of the MATER and ZAR1 genes in immature bovine oocytes selected by brilliant cresyl blue.

The objective of this work was to evaluate the selection of immature bovine oocytes by brilliant cresyl blue dye (BCB) and expression of transcripts MATER and ZAR1. Cumulus-oocyte complexes (COCs) from slaughterhouse ovaries were exposed to BCB diluted in mDPBS and incubated for 60 min at 38.5 degrees C in humidified air.

Post-biopsy bovine embryo viability and whole genome amplification in preimplantation genetic diagnosis.

Objective: To evaluate the effect of the biopsy of 8-cell to 16-cell bovine embryos on their subsequent development and the effect of whole genome amplification (WGA) on removed blastomeres.

Design: Randomized study.

Setting: Molecular genetics and animal reproduction laboratories.

Short intervals between ultrasonographically guided follicle aspiration improve oocyte quality but do not prevent establishment of dominant follicles in the Gir breed (Bos indicus) of cattle.

The aim of the present study was to evaluate oocyte recovery and embryo yield using two different ovarian follicular aspiration schedules in donor cows of the Gir breed. Pluriparous, non-lactating Gir cows (n = 14) were randomly allocated to one of two groups, one of which had aspirations of ovarian follicular contents conducted once a week (TVFA-1x) and the other twice weekly (TVFA-2x), for nine consecutive weeks. Before follicle aspiration, follicular population was recorded in three classes according to size (> 6 mm, 6-9 mm and > 9 mm).