Comparative Assessment of Growth Structure and Litter Size of Grasscutter (Thryonomys Swinderianus Temminck, 1872) Bred In Captivity

Abstract

Cane rats under domestication and multiplication in Forestry Research Institute of Nigeria, Ibadan were assessed for their population growth, structure and analysis over a period of five years (2009-2013). On the basis of weight gain, fecundity and docility, thirty-two (32) female grass cutter were selected for reproduction. A buck (male) was provided with one to three does (females) for mating and the mating group continued to live together until pregnancy was observed. These animals were housed in floor hutches constructed with 6-inch hollow blocks. The off springs were monitored for sex ratios and population growth and data generated were subjected to analysis using both continuous statistics of percentages and inferential statistics of X².  Continuous statistics results revealed that more cases of parturition occurred during rainy season than dry season probably due to high quality forage that is always available during the season but inferential statistics did not establish it  Analysis also showed that more female grass cutter were produced than males on yearly basis but mortality affected more females than males probably because the stress of continuous parturition coupled with age may weaken their   resistance against diseases and environmental fluctuations. Also, mortality figure was higher during wet than dry season, implying that the animals need more care and medical care during rainy season. These observations are subjects of further research.

Keywords. Cane rat, domestication, parturition, litter, sex ratio, mortality.