Diet selection by Nguni goats in the Zululand Thornveld

Abstract

________________________________________________________________________________ AbstractThe aim was to determine diet selection of goats grazing/browsing in Zululand Thornveld. An experiment was done in spring (November 2007) and autumn (March/April 2008) at Owen Sitole College of Agriculture, KwaZulu-Natal. Diet selection was estimated using direct observation of animals and an indirect plant-based method. The browse species observed in the plant-based methods were: Gymnosporia senegalensis (Gs), Acacia nilotica (An), Acacia karroo (Ak), Scutia myrtina (Sm) and Dichrostachys cinerea (Dc). Selection was determined by observing at regular intervals 40 marked branches on 10 plants of each browse species. Direct observation of diet selection was done by observing two goats in a base herd of 24 castrated males when they were allowed to forage together in a paddock of 1 ha. Observations were made every minute for three hours in the morning and 1.5 hours in the afternoon. The relative abundance of the browse species in the veld was determined and used to estimate the selection index (utilization relative to availability). In both seasons, the three most selected species according to the plant-based observations were Sm, Ak and Dc. Consistently, An experienced moderate defoliation and Gs the least. However, on the basis of the selection index the species followed the order: An>Dc>Ak>Sm>Gs in spring and An>Sm>Dc>Ak>Gs in autumn. The selection index was negatively correlated to all fibre attributes although the correlation attained significance only for NDF, ADF and lignin but not for tannins and cellulose. Both methods did not rank species in the same order, thus suggesting the need for further methodological refinement. ________________________________________________________________________________

Effect of feeding level on production performance of lactating Red Maradi goats and post-natal performance of kids

“…The high DM, OM, NDF and ADF contents of refusals may be explained by differences in physical and chemical characteristics of feeds (Abdou et al, 2017) due to feeding behaviour of goats known to select feeds based on prehension ease, nutrient content and post-ingestive effects. This is in agreement with other works (Provenza et al, 2003;Basha et al, 2009;Glasser et al, 2012;Tshibangu et al, 2014).…”

Effects of season, browse species and polyethylene glycol addition on gas production kinetics of forages in the subhumid subtropical savannah, South Africa

“…Browse and shrub fodders are vital supplements for covering the seasonal shortage in ruminant feed availability and nutritive value . However, there is ample information on seasonal and species effects on the chemical composition of browse in subtropical savannah; for instance, the high variability in tannin (from <10 to >100 g kg −1 ) among species, even among species that are otherwise very similar (e.g. among deciduous species or among spiny species) or closely related (e.g.…”

“…among deciduous species or among spiny species) or closely related (e.g. among Acacia species), and the general trends in seasonal changes, such as crude protein increasing from around 100 g kg −1 in the dry season to as much as 150 g kg −1 in the wet season, neutral detergent fibre increasing from around 300–400 g kg −1 in the dry season to as much as 500–600 g kg −1 at the end of the wet season, and tannin being as much as 90% lower in the wet season than in the dry season, although in some species the opposite trend has been observed . The nutrient composition of browse is normally estimated by chemical analysis, but this does not give enough information about the true nutritive value of feed.…”

Effect of leaf type on browse selection by free-ranging goats in a southern African savanna

“…High foliar fibre content negatively affects browse nutritive value [ 9 , 21 , 22 ], because it constrains digestibility [ 23 ]. Hence, foliar fibre content (both neutral and acid detergent fibre) can be used to predict browse nutritive value for goats [ 9 ].…”