Wet faeces produced by sheep fed dried spineless cactus pear cladodes in balanced diets
Cactus pear cladodes in ruminant diets are characterized by the production of wet faeces and assumed to be diarrhoea. Incremental levels of sun-dried and coarsely ground spineless cactus pear (Opuntia ficus-indica var. Algerian) cladodes were used to substitute part of the lucerne hay in balanced sheep diets. Feed and water intake and faeces and urine excretion were determined with 24 Dorper wethers. The four diets (T0, T12, T24 and T36) comprised respectively (air dry basis) 0, 120, 240 or 360 g/kg sun-dried, coarsely ground Opuntia cladodes; 660, 535, 410 or 285 g/kg coarsely ground lucerne hay; 300 g/kg yellow maize meal; 0, 5, 10 or 15 g/kg feed grade urea; and 40 g/kg molasses meal. The wethers drank significantly more water with increasing inclusion of Opuntia in the diets, while urine excretion showed little increase. Food intake and faeces dry matter (DM) excreted remained the same for all diets, but the DM content of the faeces decreased with higher levels of Opuntia inclusion. The wetter faeces produced by the sheep lacked the customary foul smell associated with diarrhoea and this is ascribed to the water-binding capacity of the mucilage in Opuntia. Although more definitive research is needed, it is concluded that the wetter faeces produced by the sheep on diets T12, T24 and T36 were not diarrhoea induced by the sun-dried and coarsely ground Opuntia cladodes, but the result of larger quantities of water that were not reabsorbed from the lower digestive tract.
Keywords: Cactus pear; diarrhoea; feed intake; mucilage; water intake
South African Journal of Animal Science Vol. 36 (5) 2006: pp.10-13