Effects of groundnut hay (GNH) supplementation and trypanosome infection on diet selection and grazing behaviour of N'Dama cattle in the late dry season in The Gambia were studied. 20 multiparous lactating cows were allocated to 2 groups: infected and control. The 10 cows in the infected group were intradermally injected with a Trypanosoma congolense clone known as ITC 84. Supplementary feeding with GNH commenced 14 days after infection and continued for 10 weeks. The start of supplementation coincided with peak parasitaemia, when the infected and control groups were each divided into 2 sub-groups of 5. Cows received fresh GNH 0 or 2 kg/day. Each of the 10 infected cows (5 supplemented and 5 unsupplemented) were paired with a comparable control for the duration of the trial and followed at least 3 times (range 3-5). Every 5 minutes, throughout the 9- to 10-h grazing day, a record was made of 4 activities and, if the cow was feeding, the feed item identified. The distance travelled was also measured. Cattle spent 78% of their time feeding on grasses, of which Hyparrhenia rufa and Andropogon gayanus were the dominant species. Neither infection nor GNH supplementation had any effect on the diet selected. Based on the mean distance travelled, the energetic cost of walking was estimated to be 10% of the ME required for maintenance. Trypanosome infection had no significant effect on grazing behaviour. However, cows supplemented with GNH spent a greater proportion of the day resting (P<0.01); this was particularly evident in the final 2 grazing periods of the day. There was also an interaction (P<0.05) between GNH supplementation and infection in the early afternoon when the infected group supplemented with GNH spent a greater proportion of time resting and less time feeding.
|Publication Title||Applied Animal Behaviour Science|
|Author Address||Natural Resources Institute (NRI), Central Avenue, Chatham Maritime, Chatham, Kent ME4 4TB, UK.|
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