Brazil reports the birth of the country’s first genetically modified calves

Brazil’s agricultural research organization Embrapa has announced the birth of the country’s first genetically modified calves, which were born from embryos fertilized in vitro.

The achievement, carried out in cooperation with the Brazilian Angus Association, marks an important milestone for Brazil’s livestock sector. The project aims to develop cattle breeds that are more resilient to high temperatures and climate change using CRISPR/Cas9 gene-editing technology.

A total of five Angus calves were born between late March and early April 2025. Initial results indicate successful gene editing in at least two of them. Genetic sequencing conducted by Embrapa Gado de Leite in Minas Gerais confirmed the effectiveness of the method and showed that the edited animals possess the desired trait of short, smooth hair, which provides greater heat tolerance.

The technology is considered innovative for livestock production and is expected to improve the adaptation of high-yielding breeds such as Angus and Holstein to the country’s tropical conditions. Animals are expected to experience less heat stress, leading to better welfare and higher productivity.

Gene editing was performed using CRISPR/Cas9, often referred to as “precision genetic improvement.” According to Embrapa researcher Luiz Sérgio de Almeida Camargo, the tool is scientifically adapted from a natural system found in bacteria. “CRISPR/Cas9 works like a pair of genetic scissors capable of precisely editing DNA sequences and can be used to improve animal health and welfare, as well as economically desirable traits,” he explained.

The technology allows beneficial mutations to be introduced directly into embryos, eliminating the need for traditional breeding methods that can take several generations to fix desired traits. The project focused on editing the prolactin receptor gene, which is linked to body temperature regulation in cattle.

Mutations in this gene result in shorter, smoother hair, helping animals maintain lower body temperatures. This trait is naturally present in some breeds adapted to tropical climates in Latin America but is absent in purebred, high-performing breeds such as Angus and Holstein.

Camargo said that the two edited calves show short, smooth hair due to more than 90% gene editing in hair follicles. He noted that the results are already sufficient for the animals to express the desired characteristics, while research continues to improve efficiency.

Gene editing was carried out on embryos using a process known as zygote electroporation. Short electrical pulses temporarily open the zygote’s membrane, allowing gene-editing molecules to enter the cell. This technique is considered less invasive and more practical than other traditional methods, and Embrapa’s studies suggest it is more efficient and cost-effective.

The new Angus line is expected to be less susceptible to heat stress and to show improved productivity and reproductive performance in hot and humid climates. Such adaptation is becoming increasingly important in light of projected global warming scenarios.

Moreover, preserving the Angus breed with its core productive traits while adding greater heat tolerance represents a strategic advance for Brazilian livestock production, which seeks to combine meat quality with environmental adaptability.

Tags: Brazil, cattle, GM