The aim of the study was to determine if significant differences, in terms of grazing parameters, intake, animal performane and digestibility, existed between foggage of Cenchrus ciliaris cv. Molopo and Cenchrus ciliaris cv. Gayndah. A grazing trial as well as a partial digestibility study was done with sheep. The following parameters were used: grazing parameters (dry matter availability and structure of the grazing), qualitative and quantitative intake, animal production and partial digestiblity. The grazing trial was conducted over two years and further divided into two separate periods of utilisation, middle and late winter. The second trial was a partial digestibility experiment conducted during the second year. In terms of the production parameters of the two varieties: dry material production and sward length of C. ciliaris cv. Molopo was constantly higher than that of C. ciliaris cv. Gayndah. In the grazing experiment the quality of selected material did not differ between C. ciliaris cv. Gayndah and Molopo. Differences in most parameters were not significant. Experimental animals grazing Gayndah selected a diet with higher N- and NDF-concentrations, as opposed to animals grazing Molopo. The same trend continued during the second year but only for N-concentration. In terms of quantitative observations in the grazing experiment the intakes of the two varieties were high for the whole duration of the trial. Only during the "out"-phase of period 1 in 1991, animals on C. ciliaris cv. Molopo couldn’t maintain an intake to meet maintenance requirements. Experimental animals gained weight in the first period of grazing of the first year of the study but not during the rest of the trial. Although intake was high in the other periods, these intakes didn’t support growth or maintenance. This suggests that supplementation in the form of a lick could address possible deficiencies. In the partial digestion trial animals grazing C. ciliaris cv. Gayndah, as opposed to animals on cv. Molopo, selected a better quality material but quantitatively there were no significant differences. For both varieties the amount of organic material consumed wasn’t adequate to meet maintenance requirements. There were no significant differences in the partial digestibility of organic material or nitrogen. Animals on both varieties were in a negative nitrogen balance.
Dissertation (MSc Agric (Animal and Wildlife Sciences))--University of Pretoria, 2007.