Experimental poisoning by Enterolobium contortisiliquum in sheep

Abstract

Ingestion of Enterolobium contortisiliquum pods causes digestive disturbances, secondary hepatogenous photosensitization and abortions in ruminants. Pods were administered to sheep via a ruminal cannula to characterize acute poisoning. In Experiment 1, a single dose of 12g/kg of body weight (BW) was administered to three sheep in one experiment. One sheep died, and the other two recovered after presenting clinical signs. In Experiment 2, 10g/kg BW were administered daily to 15 sheep until the onset of clinical signs or for three consecutive days. Fourteen sheep showed mild to severe signs after the ingestion of 1-3 doses. Two sheep died, and the others recovered. Clinical signs in both experiments were diarrhea, anorexia, rumen atony, apathy, dehydration and tachypnea. The main macroscopic findings were an orange, frothy ruminal content witch contained pods fragments. The intestinal content was liquid. Detachment of the mucosa from the submucosa and ballooning degeneration of mucosal cells were observed histologically in the forestomachs. Evaluation of ruminal contents revealed acute lactic ruminal acidosis (ALRA). Bromatological analysis of E. contortisiliquum pods revealed 537.8g/kg DM (dry matter) of non-fibrous carbohydrates, which is sufficient to cause ALRA. Only one sheep in Experiment 2 had liver failure, characterized by jaundice, elevated serum activity of liver enzymes and histological lesions in liver biopsies. It is concluded that the administration of E. contortisiliquum pods in forage--fed sheep at doses of 10g/kg BW or higher may cause ALRA. The induction of liver failure in one sheep suggests that liver damage may occur in those sheep that do not develop acidosis.

Poisoning by Enterolobium contortisiliquum pods in calves showing photosensitization and digestive lesions

“…Spontaneous cases of ruminal acidosis occur in ruminants fed with large amounts of non-fiber carbohydrates (corn, wheat and barley) without prior adaptation (Nagaraja and Titgemeyer, 2007). As was already experimentally demonstrated (Bacha et al, 2017;, the pods of E. contortisiliquum have a high content of non-fiber carbohydrates which triggers ruminal acidosis. Drops in ruminal pH are associated with the accumulation of lactic acid, which potentially leads to ruminal acidosis (Hobson and Stewart, 1997).…”

“…Acute ruminal acidosis is the first clinical manifestation of naïve sheep fed with pods of E. contortisiliquum (Bacha et al, 2017; and also in cattle (Leal et al, 2017). Sheep may die at this stage or recover, but photosensitization wasn't seen; however, in cattle, those which recovered had photosensitization Poisoning by Enterolobium contortisiliquum… (Leal et al, 2017), as observed in the calves of the current outbreak, since the plant is highly hepatotoxic (Leal et al, 2017).…”

“…are well-developed trees, and intoxication occurs by ingestion of the pods that fall spontaneously to the ground or fall along with twigs that are torn by the wind, are pruned, or are reached by the animals in the lower parts of the tree (Grecco et al, 2002;Mendonça et al, 2009). Digestive disorders with or without photosensitization were experimentally reproduced by feeding cattle (Mendonça et al, 2009, sheep (Leal et al, 2017;Bacha et al, 2017; and goats (Benicio et al, 2007) with the pods of E. contortisiliquum. The reported digestive clinical signs of E. contortisiliquum poisoning are usually described as non-specific and include diarrhea, anorexia, ruminal atony, apathy, and dehydration (Grecco et al, 2002;Mendonça et al, 2009).…”

“…Recently, based on experimental studies done in sheep fed with the pods of E. contortisiliquum at our laboratory (Bacha et al, 2017;, it was determined that such digestive signs results from ruminal acidosis due to the high content of non-fiber carbohydrates in the pods. Bromatological analysis of pods from E. contortisiliquum (Bacha et al, 2017) revealed 1:2.2 ratio between neutral detergent fiber corrected for protein and non-fiber carbohydrates, which is much higher than the 1:1 recommended ratio (Poore et al, 1993) to prevent depression in fiber digestion and preserve normal ruminal function. These results support the hypothesis that fermentable carbohydrates (starches and sugars) in the non-fermentable carbohydrate fraction of E. contortisiliquum pods may induce acute lactic ruminal acidosis.…”

“…Additionally, the gross and histopathological ruminal changes were characterized. The characterization of the digestive lesions of E. contortisiliquum poisoning as resultant from ruminal acidosis was yet unreported until the experiments performed by Bacha et al (2017) and . The aim of this paper is to describe an outbreak of photosensitization and digestive lesions suggestive of ruminal acidosis in calves associated to ingestion of E. contortisiliquum pods in order to further confirm previous experimental studies.…”