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Accueil du site → Doctorat → Afrique du Sud → < 2000 → Towards improved livestock production off sweet grassveld.

University of KwaZulu-Natal (1984)

Towards improved livestock production off sweet grassveld.

Danckwerts, Jock Eric.

Titre : Towards improved livestock production off sweet grassveld.

Auteur : Danckwerts, Jock Eric.

Université de soutenance : University of KwaZulu-Natal

Grade : Doctor of Philosophy 1984

Résumé et résultats
i. There is little difference in the quality of -herbage consumed by animals of the same breed and class in the False Thornveld. ii. The quality of herbage (measured in terms of organic matter digestibility and crude protein content) consumed by animals changes negligibly within periods of occupation of two weeks. 288 iii. Forage digestibility drops as the season progresses from spring through to winter. In contrast, crude protein content of forage changes little with time of year. iv The quality of forage consumed by animals was higher on veld in moderate than on veld in good condition in the investigation reported in this chapter. However, this is not necessarily considered to be a general rule. v. The phosphorus content of herbage consumed by animals in the False Thornveld is higher than the requirement listed in feeding standards at all times of the year. vi During periods of occupation, herbage apparently disappears linearly with time until insufficient availability restricts daily intake per head. Thereafter, the rate of herbage disappearance diminishes. vii. From a point of view of animal production, I they should be moved from one camp and into the next when intake per head becomes noticeably availability. restricted through insufficient viii. Cattle tend initially to avoid partially grazed tufts within a species in favour of ungrazed plants, but will return to preferred species before ttempting even partial grazing of all less preferred species. ix. Grazed tillers, as opposed to tufts, are very rarely • re-grazed within periods of occupation of two weeks. x. Bite height within species remains fairly constant as periods of occupation progress and forage availability diminishes, provided initial herbage availability is less than 2000kg per ha. xi. Intensity (height) of grazing can probably not be manipulated by varying the duration of periods of occupation in rotational grazing systems in the veld type. xii. A large number of ungrazed tillers remain in the sward even after fairly severe defoliation. 289 xiii. The suggested rotational grazing and resting programme appears to be reasonably compatible with adequate animal performance. Animals will, however, have to undergo some stress when camps to be rested are severely utilised before the rest commences. xiv. The adage "move animals when nearly all (80% to 90%) of the tufts of the most preferred species have been grazed, and animals have commenced grazing (10% to 20%) the less preferred species" seems appropriate for use during the normal grazing rotation in the False Thornveld

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