Publication Date

1997

Description

This experiment was designed to determine the thickness of saltbush (Atriplex amnicola) stem grazed by sheep, grazing pressure on saltbush in the presence of understorey and the effect of season on the nutritive value of saltbush. Four 0.9 ha plots of Atriplex amnicola were grazed by a group of 10 Merino wethers each. The results indicated that the maximum diameter of stem selected by sheep under extreme conditions was only 1.5 mm. The number of stems chewed per 0.1m2 quadrat were 0.8, 9.6, 20.1 and 18.0 (P<0.05) after 2, 4, 6 and 8 wk. From January to June the nitrogen content (14 to 30 gkg-1) and DMD (0.65 to 0.72) of saltbush leaves remained high. These results suggest that in the presence of understorey the grazing pressure on saltbush was least and increases when the feed from understorey was exhausted. The nutritional value of saltbush did not deteriorate severely during the summer and autumn period.

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Grazing Sheep on Revegetated Saline Pastures: Effects of Season and Grazing on Morphology and Nutritive Value of Saltbush

This experiment was designed to determine the thickness of saltbush (Atriplex amnicola) stem grazed by sheep, grazing pressure on saltbush in the presence of understorey and the effect of season on the nutritive value of saltbush. Four 0.9 ha plots of Atriplex amnicola were grazed by a group of 10 Merino wethers each. The results indicated that the maximum diameter of stem selected by sheep under extreme conditions was only 1.5 mm. The number of stems chewed per 0.1m2 quadrat were 0.8, 9.6, 20.1 and 18.0 (P<0.05) after 2, 4, 6 and 8 wk. From January to June the nitrogen content (14 to 30 gkg-1) and DMD (0.65 to 0.72) of saltbush leaves remained high. These results suggest that in the presence of understorey the grazing pressure on saltbush was least and increases when the feed from understorey was exhausted. The nutritional value of saltbush did not deteriorate severely during the summer and autumn period.