Albizia species

Abstract

Distribution: A. tanganyicensis occurs only in groups on rocky outcrops in the hot dry northern parts of the country, while A. versicolor can be found in mixed woodland, river banks and vleis.

Botanical description: Albizia tanganyicensis General:A small to medium-sized tree with a somewhat sparse, rounded or flattened crown. Bark is very distinctive: smooth, creamy white, peeling off in large reddish or yellowish white papery pieces. Leaves: The leaves with 3 - 6 pairs of pinnae and 4 - 13 pairs of leaflets per pinna. Reddish-brown at first, turning to dark grey-green. Flowers: Flowers in large powder puffs; white turning cream. Appearing before the leaves. Spring. Fruit: Pods flat, light brown, dehiscent.

Albizia versicolor General: A medium to large deciduous tree with a straight long stem and a rather spreading rounded crown. Leaves: Leaves with 1 - 3 pairs of pinnae; leaflets usually 2 - 5 pairs per pinna, elliptic to ovate, large, hairy above, rusty velvety below. New leaflets are dark reddish brown and older ones become dark green. Flowers: Flowers in large powder-puff heads. Creamy white and wither quickly. Nov/Dec. Fruit: Pods thin and flat, glossy. Colour changes from green to wine-red to pale brown, dehiscent.

Toxic principle: Pods contain a 4-methoxy derivative of pyridoxine. Stimulation of the central nervous system occurs. Unripe pods probably more toxic

Systems affected: Cardiovascular system.

Clinical signs: Problem in cattle, but also sheep and goats - acute poisoning syndrome. Signs observed within 3 hours. Death a few hours later.

CNS: Stimulation such as: • Hypersensitivity • Tetanic convulsions • Opisthotonus or orthotonus • Nystagmus • Hyperpyrexia (up to 44° C). Respiratory system: • Polypnoea • Dyspnoea • Froth around the mouth.

NB: Nervous suppression is not present.

Necropsy: Macroscopical findings: • Pods in rumen, characteristic broad, large, flat pods. • Cyanosis and congestion. • Petechial haemorrhages. • Obvious skeletal muscle degeneration• Heart and liver degeneration (parboiled appearance) Histopathology: • Slight CNS changes - too acute • Muscle, heart and liver degeneration confirmed, probably as result of high temperatures

Treatment: Vit B6 (pyridoxine HCl) 20 - 25 mg/kg administered twice with an interval of 8 hours