About Freemartins:
- In animal husbandry, cattle that are born exhibiting characteristics of both sexes are called freemartins.
- Freemartins are sterile female cattle that result from the twinning of a male and a female within the same uterus.
- This phenomenon occurs in approximately 90% of such twin pregnancies in cattle.
- The key reason is the exchange of blood between the male and female foetuses during gestation.
- Genetically, freemartinism is attributed to the sharing of cells carrying the Y chromosome from the male twin with the female twin.
- This chromosome triggers the development of male reproductive organs in the male foetus, while the female foetus, affected by the presence of male hormones, experiences incomplete development of its reproductive system.
- The end result is that the freemartin has an underdeveloped or non-functional reproductive tract.
- Freemartins can’t reproduce, so farmers often identify them through physical and/or behavioural traits to cull them from the breeding herd to improve reproductive efficiency.
Key facts about chromosome
- It is a thread-like structure located inside the nucleus of animal and plant cells.
- Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).
- It is passed from parents to offspring.
- DNA contains the specific instructions that make each type of living creature unique.
- In humans, in addition to the 22 pairs of chromosomes in each, we have a pair of sex chromosomes called X and Y.
- All biological males have X and Y chromosomes, and all biological females have two X chromosomes.
