Ruminal fermentation and nutritive value assessment of selected Acacia species in vitro [electronic resource].

Includes reference.

This study aimed to evaluate the nutritional value of the fresh shoots of 14 Acacia species (A. coriacea, A. cuthbertsonii, A. ineguilatera, A. iteaphylla, A. Mmpeana. A. ligulata, A. microbotrya, A. nilotica, A. oswaldii. A. pruinocarpa. A. saligna, A. sclerosperma, A. seyal and A. Victoria) that were imported to be cultivated in Saudi Arabia, and to determine the potentiality of these species as ruminant feed resources in comparison with alfalfa hay and wheat straw. Chemical analysis and in vitro gas production technique were used as the basis for this evaluation. The crude protein (CP) content among tested Acacia spp. ranged from 8.0 to 16.7% and it was comparable in A. iteaphylla with that of alfalfa hay, the values were 16.7 and 17.1% in A. iteaphyllal and alfalfa hay, respectively. Among the tested Acacia spp. A. ineguilatera had the highest condensed tannin (CT) values. Which ranged from 10.4 to 77.0 mg/g dry matter (DM). Metobolizabole energy (ME, MJ/ kg DM) of the tested Acacia spp. ranged from 4.35 to 6.69 MJ/ kg DM, which could supply the animals with 5384% of the ME as in alfalfa hay. The CT/CP ratio in Acacia spp. showed a negative correlation with either organic matter digestibility (OMD. %⁻ r = -0.71. P < 0.01), potential gas production (r= -0.71. P < 0.01), ammonia production (r = -0.86. P <0.01) or total volatile fatty acid concentrations (r = -0.72, P < 0.01). To ease the evaluation of the nutritive value of Acacia spp. the following equations could be applied. OMD (%) = 36.5 + 0.02CP + 0.3 NDF - 0.75CT; (r = 0.75; P< 0.001); ME (MJ/kg DM) = 5.8 + 0.14CP + 0.02NDF-0.71CT; (r = 0.79; P <0.001). [Where NDF is neutral detergent fiber and CT was expressed as mg/g DM].

Summary in Arabic.

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