Bhartiya Krishi Anusandhan Patrika, 36(4): 344-346 DOI: 10.18805/BKAP371 A Study on Morphological Growth and Development of Swiss Albino Mice, Wistar Rat and Dunkin Hartley Guinea Pigs K. Abhijeet 1 , Y.B. Rajeshwari 2 , Vivek M. Patil 2 , R.Y. Ranjith 3 , S.M. Ali 3 , G.S. Shaswath 3 , S.K. Bhandekar 4 , Akash Katiyar 5 , K.D. Masood 3 , Prabha Karan 6 Central Poultry Development Organization and Training Institute, Hessarghatta, Bangalore-560 088, Karnataka, India. Received: September 2021 Accepted: December 2021 ABSTRACT Background: Baseline information on the morphological development of laboratory animals is very scanty. Hence the present study was undertaken to understand the morphological development of experimental animals. Methods: An experiment was conducted at Biogen animal facility, Bangalore in the year 2018 to study the morphological changes with regard to growth and developmental parameters in Swiss albino mice and Wistar rats and body weight in guinea pigs. Ten Swiss albino mice and Wistar rats in advanced pregnancy of similar age groups and comparable litter sizes in the previous kindlings were selected for the experiment, where as five guinea pigs males and females each were selected with same age group. During the study period, litter weight and size at birth and at weaning, time of initiation and completion (full growth of hair) of hair growth, time of opening of eyes and ears recorded in Swiss albino mice and Wistar rats whereas body weight at birth, 3 rd day, 6 th day, 9 th day, 12 th day and 15 th were recorded in Dunkin Hartley guinea pigs. Result: The results of Swiss albino mice indicated that the average litter weight (grams) and litter size at birth ranged from 1.39 and 7.50 respectively. The average time taken from initiation and full growth of hair covering on body was 7.50 to 15.30 days. Eyes and ears opened at 7.90 and 8.20 days respectively. Average weight of male and female recorded at weaning (25 days) 19.38 and 15.12 respectively and the litter size at the weaning was 9.70 whereas, livability percent was recorded 87.81 at the end of the trial. The results of Wistar rats indicated that the average litter weight (grams) and litter size at birth ranged from 5.07 and 11 respectively. The average time taken from initiation to full growth of hair covering on body was 9 to 16.20 days. Eyes and ears opened at 12.20 days, average weight (grams) of male and female recorded at weaning (25 days) 78.03 and 63.09 respectively. The litter size at the weaning was 9.70. The livability percent was recorded 88.02 at the end of the trial. The results of Dunkin Hartley guinea pigs indicated that the average body weight (grams) of female at birth, 3 rd day, 6 th day, 9 th day, 12 th day, 15 th (Weaning period) ranged from 94.88, 109.34, 123.94, 139.74, 152.14 and 166.66, respectively. On the other hand, average body weight (grams) of male at birth, 3 rd day, 6 th day, 9 th day, 12 th day, 15 th (Weaning period) ranged from 145.38, 155.42, 170.50, 185.54, 200.64 and 215.7, respectively. Key words: Dunkin hartley guinea pig, Growth pattern, Litter size, Swiss albino mice, Wistar rat. *Corresponding author's E-mail: dr.abhikumar0501@gmail.com 1 Central Poultry Development Organization and Training Institute, Bangalore-560 088, Karnataka, India. 2 Department of Livestock Production Management, Veterinary College Hebbal, Bangalore-560 024, Karnataka, India. 3 Veterinary College, Hebbal, Bangalore-560 024, Karnataka, India. 4 Central Cattle Breeding Farm, Hessarghatta, Bangalore-560 088, Karnataka, India. 5 Central Poultry Development Organization, Nayapalli, Bhubaneswar-751 012, Odisha, India. 6 First Class Veterinary Hospital, Girihinda Chowk-811 105, Govt of Bihar, India. INTRODUCTION Laboratory mice, rats and guinea pigs are the animals which are very extensively used in many of research area especially in the field of transplantation and cancer studies. Baseline information on the morphological development of Swiss albino mice, Wistar rats and Dunken Hartley guinea pigs maintained in India are very scanty. Hau and Van Hoosier (2005) reported that Swiss albino mice are an out bred strain with good breeding ability and strong maternal instinct. Swiss albino mice mainly used in the research area like oncology, pharmacology, immunology and ageing. Wistar rat strain was selected by Donaldson in 1906 at the Wistar Institute (USA), from a batch belonging to Chicago University (Lindsay, 1979; Russel et al., 1981). The Wistar rat is an out bred stock, used in all fields of medical and biological research. Its longevity and high rate of spontaneous tumors make it an ideal choice for ageing studies. It is an albino strain, easy-to-handle, it is however slower learner than Long Evans rat. Swiss Albino mice are usually used in toxicology studies. It is not often used in R&D studies. Swiss mice being an out bred animal is suitable for toxicology as it has genetic variability between animals