Introduction:
The Chhandogya Upanishad is one of the oldest and most important Upanishads in Hindu philosophy. It is a part of the Sama Veda and contains teachings on various aspects of life, spirituality, and philosophy. While it covers a wide range of topics, it does not include the practice of animal sacrifices.

Explanation:
The Chhandogya Upanishad is primarily concerned with the nature of the self (Atman) and its relationship with the ultimate reality (Brahman). It provides insights into various spiritual practices and moral principles that can lead individuals towards self-realization and liberation.

Teachings included in the Chhandogya Upanishad:
1. Non-violence (Ahimsa): The Upanishad emphasizes the importance of non-violence in thought, word, and action. It teaches that harming others ultimately harms oneself and promotes peaceful coexistence.

2. Dana (Charity): The Upanishad encourages the practice of charity and selfless giving. It promotes the idea that by sharing one's wealth and possessions with others, one can cultivate virtues like compassion, generosity, and detachment from material possessions.

3. Tapas (Austerity): The Upanishad extols the practice of tapas, which involves self-discipline, self-control, and self-sacrifice. It teaches that through tapas, individuals can purify their minds and bodies, develop inner strength, and attain spiritual growth.

Exclusion of Animal Sacrifices:
Unlike some other ancient Hindu texts, the Chhandogya Upanishad does not endorse or prescribe animal sacrifices as a means of attaining spiritual goals. Instead, it focuses on the importance of ethical conduct, meditation, self-realization, and understanding the nature of the self.

Conclusion:
The Chhandogya Upanishad is a profound spiritual text that encompasses a wide range of teachings and practices. While it emphasizes non-violence, charity, and austerity, it does not include the practice of animal sacrifices. This reflects the Upanishad's emphasis on inner transformation, self-realization, and ethical living as the means to attain spiritual enlightenment.