Perspectives of gene editing for cattle farming in tropical and subtropical regions

A Novel Quantification Method for Gene-Edited Animal Detection Based on ddPCR

As gene-editing technologies continue to evolve, gene-edited products are making significant strides. These products have already been commercialized in the United States and Japan, prompting global attention to their safety and regulatory oversight. However, the detection of gene editing still relies on qPCR, and there is a lack of quantitative detection methods to quantify gene-editing components in products. To ensure consumer safety and transparency, we developed a novel droplet digital PCR (ddPCR)-based detection method for gene-edited products. Primers and probes were designed targeting the editing sites of MSTN-edited cattle, and the method was evaluated for specificity, sensitivity, real sample testing, and detection thresholds. Our results demonstrate that this ddPCR method is highly specific, with a detection limit of 5 copies/µL, and it successfully detected MSTN edits in all 11 tested samples. Tests using both actual gene-edited cattle samples and plasmid DNA at concentrations of 5%, 1%, and 0.01% yielded consistent results, indicating the method's suitability for real-world applications. This ddPCR assay provides a sensitive and specific tool for detecting MSTN gene-edited cattle and determining the presence of gene-edited products, offering crucial support for regulatory monitoring of gene-edited animal-derived foods.

Application of Genomic Selection in Beef Cattle Disease Prevention

Genomic applications in beef cattle disease prevention have gained traction in recent years, offering new strategies for improving herd health and reducing economic losses in the livestock industry. Advances in genomics, including identification of genetic markers linked to disease resistance, provide powerful tools for early detection, selection, and management of cattle resistant to infectious diseases. By incorporating genomic technologies such as whole-genome sequencing, genotyping, and transcriptomics, researchers can identify specific genetic variants associated with resistance to pathogens like bovine respiratory disease and Johne's disease. These genomic insights allow for more accurate breeding programs aimed at enhancing disease resistance and overall herd resilience. Genomic selection, in particular, enables identification of individuals with superior genetic traits for immune function, reducing the need for antibiotic treatments and improving animal welfare. Moreover, precision medicine, powered by genomic data, supports development of tailored health management strategies, including targeted vaccination plans and antimicrobial stewardship. Incorporation of genomic tools in beef cattle management also offers the potential for early disease detection, facilitating proactive interventions that reduce the spread of infections. Despite challenges like cost, data interpretation and integration into current management systems, the potential advantages of genomic applications in disease prevention are substantial. As these technologies advance, they are anticipated to have crucial roles in improving sustainability (by enhancing herd performance), profitability (by improving overall herd longevity), and biosecurity (by decreasing the likelihood of disease outbreaks) of beef cattle production systems worldwide.

An overview of recent technological developments in bovine genomics

Cattle are regarded as highly valuable animals because of their milk, beef, dung, fur, and ability to draft. The scientific community has tried a number of strategies to improve the genetic makeup of bovine germplasm. To ensure higher returns for the dairy and beef industries, researchers face their greatest challenge in improving commercially important traits. One of the biggest developments in the last few decades in the creation of instruments for cattle genetic improvement is the discovery of the genome. Breeding livestock is being revolutionized by genomic selection made possible by the availability of medium- and high-density single nucleotide polymorphism (SNP) arrays coupled with sophisticated statistical techniques. It is becoming easier to access high-dimensional genomic data in cattle. Continuously declining genotyping costs and an increase in services that use genomic data to increase return on investment have both made a significant contribution to this. The field of genomics has come a long way thanks to groundbreaking discoveries such as radiation-hybrid mapping, in situ hybridization, synteny analysis, somatic cell genetics, cytogenetic maps, molecular markers, association studies for quantitative trait loci, high-throughput SNP genotyping, whole-genome shotgun sequencing to whole-genome mapping, and genome editing. These advancements have had a significant positive impact on the field of cattle genomics. This manuscript aimed to review recent advances in genomic technologies for cattle breeding and future prospects in this field.

Performance and nutritional status of Holstein crossbred cows in a selected area of Bangladesh under the existing farming system

Objectives

This study aimed to compare the body weight (BW), milk yield, nutritional status, and profitability of moderate genetic (MG) and high genetic (HG) merit of Holstein crossbred (HC) cows in a tropical region under the existing farming system.

Materials and Methods

Data was gathered from 204 nursing cows of MG (n = 99) and HG (n = 105) merit of HC cows throughout a year in the dairy zone Keraniganj, Bangladesh. HC cows of MG and HG merit contained 50.0%-67.7% and 75.0%-87.5% Holstein blood, respectively. Data on genetic merit, BW, lactation stage and number, daily milk yield, feed intake, feed, and milk price were documented. All variables were except genetic merit analyzed using one-way analysis of variance.

Results

HC cows of MG and HG merit had 433 and 493 kg BW (p < 0.01), and daily produced 11.99 and 14.06 kg milk (p = 0.07) with having 0.99 and 1.15 feed efficiency (p = 0.06), respectively but dry matter intake did not vary (p > 0.05). HC cows of both genetic merit daily offered surplus metabolizable energy and digestible crude protein through roughage and concentrate than their requirement (p > 0.05). The milk production cost of both genetic merit HC cows was alike (p > 0.05), whereas almost two times more profit was obtained in HG merit HC compared to MG merit HC cows (p < 0.05).

Conclusion

HC cows of HG merit showed superior potentiality of milk yield, profit, and feed efficiency, whereas MG merit HC cows revealed inferior feed efficiency and milk yield.

Editing microbes to mitigate enteric methane emissions in livestock

Livestock production significantly contributes to greenhouse gas (GHG) emissions particularly methane (CH4) emissions thereby influencing climate change. To address this issue further, it is crucial to establish strategies that simultaneously increase ruminant productivity while minimizing GHG emissions, particularly from cattle, sheep, and goats. Recent advancements have revealed the potential for modulating the rumen microbial ecosystem through genetic selection to reduce methane (CH4) production, and by microbial genome editing including CRISPR/Cas9, TALENs (Transcription Activator-Like Effector Nucleases), ZFNs (Zinc Finger Nucleases), RNA interference (RNAi), Pime editing, Base editing and double-stranded break-free (DSB-free). These technologies enable precise genetic modifications, offering opportunities to enhance traits that reduce environmental impact and optimize metabolic pathways. Additionally, various nutrition-related measures have shown promise in mitigating methane emissions to varying extents. This review aims to present a future-oriented viewpoint on reducing methane emissions from ruminants by leveraging CRISPR/Cas9 technology to engineer the microbial consortia within the rumen. The ultimate objective is to develop sustainable livestock production methods that effectively decrease methane emissions, while maintaining animal health and productivity.

Gene editing in small and large animals for translational medicine: a review

The CRISPR/Cas9 system is a simpler and more versatile method compared to other engineered nucleases such as Zinc Finger Nucleases (ZFNs) and Transcription Activator-Like Effector Nucleases (TALENs), and since its discovery, the efficiency of CRISPR-based genome editing has increased to the point that multiple and different types of edits can be made simultaneously. These advances in gene editing have revolutionized biotechnology by enabling precise genome editing with greater simplicity and efficacy than ever before. This tool has been successfully applied to a wide range of animal species, including cattle, pigs, dogs, and other small animals. Engineered nucleases cut the genome at specific target positions, triggering the cell's mechanisms to repair the damage and introduce a mutation to a specific genomic site. This review discusses novel genome-based CRISPR/Cas9 editing tools, methods developed to improve efficiency and specificity, the use of gene-editing on animal models and translational medicine, and the main challenges and limitations of CRISPR-based gene-editing approaches.