It is a rare opportunity for a student to write “Fore ward” to his own teacher. In a broad sense this book will be very suitable for the students who have problems in understanding due to unfortunate standard of English. Considering this in mind the authors have prepared this Animal Physiology and Biochemistry book with easy standard of English for better understanding of the students. The authors particularly express heartfelt thanks to our beloved Rev. Fr. Sylvester Moraise President St. Jude’s College Thoothoor for his blessings splendid encouragement and valuable suggestions. We also express our profound gratitude to Rev. Fr. Lucian Thomas Secretary St. Jude’s College Thoothoor for his blessings moral support and indebted suggestions.