Kikuyu (Pennisetum clandestinum) pasture for sheep. 1. Pasture quality and nutrient intake of ewes

Abstract

Irrigated kikuyu pasture was continuously grazed for 12 months by 30 South African Mutton Merino (SAMM) and 30 Merino ewes at a stocking density of 23 ewes ha−1. Herbage samples for chemical composition were obtained monthly either by quadrat cuts or by oesophageally fistulated (OF) wethers. Intake was determined with controlled chromium release devices on eight dry and eight producing ewes from each breed during the periods of late pregnancy (February) and lactation (March). Significant (P ≤ 0.05) differences in the OM, OMD, CP, ADF, and NDF contents of manually collected and OF‐selected samples occurred between months. The means for CP, OMD, ADF, and NDF of the OF‐samples were, respectively, 18.3%, 62.3%, 37.8%, and 74.1% (expressed on an OM‐basis). During February, SAMM ewes (1184 ± 66 g d−1) consumed 27% (P = 0.01) more OM than Merino ewes (930 ± 66 g d−1), while there was no difference in intake between dry and pregnant ewes. During March, there were no differences in intake between breeds or between dry and producing ewes. When intake was expressed on a metabolic mass basis, there were no significant differences between breeds, while dry ewes tended (P = 0.08) to consume more OM than pregnant ewes during February. During March, there were no significant differences in OMI/kg−1 W0.75 d−1 between SAMM and Merino ewes or between dry and lactating ewes. When intake was compared with the respective requirements for energy and protein, there were no deficiencies during pregnancy, and DOM and CP were inadequate during lactation.