Publications by authors named "Celio Freitas"

Artificial reproduction in dairy cattle is challenged by summer temperatures in tropical environments. We describe a treatment based on mild temperature increases to induce thermotolerance and improve the embryo's performance under heat stress conditions. A protocol was established to induce upregulation of heat shock protein A (HSPA, formerly known as HSP70) but not impair embryonic development.

View Article and Find Full Text PDF

Vitrification is a superior method for cryopreservation of IVF embryos, but due to complicated warming protocols, it is not commonly used for commercial bovine embryos routine. To overcome the need of laboratory embryo preparation during warming, we developed an in-straw warming protocol compatible with most vitrification devices for embryo transfer without sucrose gradient steps and embryo evaluation. Surprisingly, one of the tested protocols improved embryo survival (95.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

Heat stress is an important issue in the global dairy industry. In tropical areas, an alternative to overcome heat stress is the use of crossbred animals or synthetic breeds, such as the Girolando. In this study, we performed a genome-wide association study (GWAS) and post-GWAS analyses for heat stress in an experimental Gir × Holstein F population.

View Article and Find Full Text PDF

Rhipicephalus (Boophilus) microplus is the main cattle ectoparasite in tropical areas. Gir × Holstein crossbred cows are well adapted to different production systems in Brazil. In this context, we performed genome-wide association study (GWAS) and post-GWAS analyses for R.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: In tropical countries, losses caused by bovine tick Rhipicephalus (Boophilus) microplus infestation have a tremendous economic impact on cattle production systems. Genetic variation between Bos taurus and Bos indicus to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (Bos indicus) x Holstein (Bos taurus) cross.

View Article and Find Full Text PDF

In vitro embryo production (IVP) has been suggested to result in a greater proportion of male calves, longer gestation and heavier offspring than artificial insemination in Bos taurus cattle. Despite the increasing use of IVP in tropical countries, its effects upon these traits in Bos indicus have not been conclusively investigated. Gyr is a B.

View Article and Find Full Text PDF