Factors Affecting Growth And Body Measurements Of The Grasscutter (Rodentia: Thryonomyidae)

Abstract

Overall mean body weights (0.138 ± 0.06 and 0.513 ± 0.03 kg), body lengths (17.24 ±0.30 and 21.68 ± 0.65 cm), heart girths (12.57 ± 0.18 and 16.83 ± 0.90 cm), and height-at-withers (7.39 ± 0.14 and 9.86 ± 0.52 cm) of the grasscutter (Thryonomys swinderianus Temminck) at brth and 60 days of age, respectively, were recorded. Litter size and sex significantly influenced body weight and linear body measurements in the grasscutter. Mean birth weight (0.173 ± 0.02 kg) of rats born singles was significantly different from that of twin births (0.135 ± 0.08 kg) and triplets (0.135 ± 0.09 kg) (P < 0.05). Male grasscutters with a mean brth weight of 0.148 ± 0.01 kg were heavier (P < 0.05) than the females, which weighed 0.128 ± 0.02 kg. Average daily weight gain forthe first 60 days for males (0.007 kg/d) was significantly different from that of females (0.005 kg/d) (P < 0.05). Parity had no significant effect on the rat's birth weight, weight at 60 days of age, and average daily weight gain for the first 60 days. Litter size, sex and parity did not have significant effect on the linear body measurements of the grasscutter at brth (P > 0.05). However litter size and sex had significant influence on body length and heart girth of the grasscutter at 60 days ofage (P < 0.05). At 60 days the mean body length (23 ± 0.28 cm) and heart girth (18.13 ± 0.23 cm) of rats born singles were longer and larger than those of twins (21.66 ± 0.89 and 16.82 ± 0.76 cm) and triplets (21.59 ± 0.96 and 16.71 ± 0.80). Males also have longer body length and larger heart girth than females at that age.

Keywords: Grasscutter, Growth, Body Weight, Linear Measurements

Animal Research International Vol. 1 (3) 2004 pp. 176-180