The nutritive value of fruits (pods with seeds) from four Acacia spp. compared with extracted noug (Guizotia abyssinica) meal as supplements to maize stover for ethiopian highland sheep

Abstract

Forty Menz rams weighing 20 to 22 kg and aged 13 to 18 months were individually offered 1·0 kg/day chopped maize stover and one of five supplements over a 70-day growth trial followed by a 10-day metabolism trial. The amounts of supplement offered were designed to supply 4·4 g nitrogen per day and with stover, sufficient nutrients to allow growth rates of 50 g/day. The control supplement, 80 g dry matter (DM) per day extracted noug (Guizotia abyssinica) meal, was compared with 194 to 212 g DM per day of fruits (pods (carpels) with seeds) of Acacia tortilis, A. albida, A. nilotica and A. sieberiana. For the control and four Acacia supplements respectively, mean growth rates were 32, 32, 21, 16, 4 (s.e.6) g/day and mean stover intakes 483, 430, 401, 347, 320 (s.e. 74) g DM per day. The low growth rates and intakes with A. sieberiana and to a lesser extent A. nilotica were probably related to their content of phenolic compounds including insoluble proanthocyanidins which may have lowered the digestibility of neutral-detergent fibre and nitrogen. A. tortilis and A. albida would appear to be of comparable nutritive value to noug meal as supplements to maize stover. Unlike noug meal Acacia fruits are widely available in rural areas of Africa. Further research is required to identify other tree species suitable for use as supplements and how to overcome the anti-nutritional factors.

Nutritive value of Acacia tree foliages growing in the Limpopo Province of South Africa

“…From our study, NDF levels varied between 438.4 and 621.7 g/kg DM among the different species. Wide variations in NDF levels in browse have been observed in other studies Tanner et al, 1990;Kaitho et al, 1997;Larbi et al, 1998;Maasdorp et al, 1999;Hove et al, 2001). The higher NDF levels recorded in our study could be due to the inclusion of petioles in the foliage of all species tested.…”

Semi arid browse forages: Their antinutritive substances and in sacco neutral detergent fibre and organic matter degradability

“…The values for phenolic compounds in this study were lower compared to that reported by Osuga et al [35]. Phenolic compounds are the largest single group of secondary plant compounds (SPCs), and total phenolics in plants can reach up to 40% of the dry matter [36]. In grasses, the major phenolic is lignin that is bound to all plant cell walls, and is a significant limiting factor in their digestion in the rumen [34].…”

In vitro biological activity of tannins from Acacia and other tree fruits: Correlations with colorimetric and gravimetric phenolic assays

“…Trees, especially those of the Acacia genus, are adapted to a low moisture environment (Timberlake et al, 1999) thus offer a reliable source of feed in the form of leaves and fruits. Many Acacias produce potentially nutritious fruits with up to 20% crude protein (Tanner et al, 1990;Kibon & Maina, 1993;Ncube & Mpofu, 1994;Mlambo et al, 2008), which could be used to supplement low quality roughage in the long dry season. However, anti-nutritional factors, such as tannins, are known to be a significant component of many browse tree species (Aganga & Mosase, 2001;Mlambo et al, 2008).…”