Malformações e morte embrionária em ruminantes causadas pela ingestão de Mimosa tenuiflora (jurema preta)

Abstract

Malformations caused by the ingestion of Mimosa tenuiflora have been reported in sheep, goats and cattle in the semiarid of the Brazilian Northeastern. This paper reports malformations diagnosed in ruminants, from 2000 to 2008, by the Federal University of Campina Grande in Patos, State of Paraíba. During the period 47 (3.48%) out of 1.347 ascensions were diagnosed as malformations. Of these, 35 were caused to the ingestion of M. tenuiflora and 12 were sporadic cases of unknown causes.Malformations caused by the ingestion of M. tenuiflora occurred during the whole year, being more frequent in sheep supplemented with concentrates and ingesting the plant in early gestation, after first rains, when M. tenuiflora is the main green forage. Main malformations were arthrogryposis, micrognatia, palatoschisis, microphtalmia and hypoplasia or aplasia of the incisive bones. They occur mainly in degraded areas with larger availability of the plant and lesser variety of other species. To determine the teratogenic effect of M. tenuiflora, the plant was administered to goats in different gestation periods. For pregnancy diagnosis ultrasonographic examinationwas accomplished every 15 days after mating. None of the goats of Group 1, that ingested M. tenuiflora during 1-30 days of gestation was pregnant, demonstrating that the plant causes embryonic death. Other two goats of Group 2 (30-60 days of gestation) were not pregnant on day 45 after mating, suggesting late embryonic loss or abortion. The other goats of that group and goats from groups 3-5 (60-90, 90-120 and 120-150 days of gestation) and from control group delivered normal kids, except one goat in Group 4, that aborted, and one from Group 5, that was found died. It is concluded that M. tenuiflora, besides causing malformations, also causes embryonic death. The failure in reproducing malformations can be due to the high dose of the unknown active principle of the plant causing fetal death in side of malformations. Another possibility is that to induce malformations goats have to ingest the plant during the whole gestation, as it was observed in a previous experiment.