Aversão alimentar condicionada no controle de surtos de intoxicações por Ipomoea carnea subsp. fistulosa e Turbina cordata em caprinos

Abstract

Pesq. Vet. Bras. 32(8):707-714, agosto 2012 707 RESUMO.-A aversão alimentar condicionada é uma técnica que pode ser utilizada em animais para evitar a ingestão de plantas tóxicas. A técnica foi utilizada em uma fazenda para controlar a intoxicação por Turbina cordata e em outra para controlar a intoxicação por Ipomoea carnea subsp. ϔistulosa. Os caprinos eram presos à noite, e na manhã do dia seguinte lhes era ofertada a planta verde, recém-colhi- Conditioned food aversion is used to train livestock to avoid the ingestion of toxic plants. This technique was used to control Turbina cordata poisoning in goats in one farm, and to control Ipomoea carnea subsp. ϔistulosa poisoning in another farm. The goats were penned at night and the next morning the green plants were offered for 10 minutes. Goats that ingested any amount of the plant were treated through a gastric tube with 175mg of LiCl/kg body weight. In the ϐlock in which the poisoning by T. cordata was occurring, the goats were averted every two months during the period that the plant was found in the pastures. During the experiment, from December 2009 to April 2011, new cases of poisoning were not observed, and there was a progressive decrease in the number of goats that ingested the plant and were averted. In the farm where I. carnea poisoning was occurring, most of the goats were averted in December 2010, 15-20 days before the ϐirst rains. The goats of this ϐlock did not ingest the plant spontaneously in the ϐield until September-October 2011, when, due to the dry season, there was a severe forage shortage, and the goats started to ingest the plant in the ϐield. Later, despite three aversive treatments with 21 days intervals, the goats continued to ingest the plant and some animals became poisoned. In conclusion, conditioned food aversion was effective in to control intoxication by T. cordata. The technique was also effective in conditioning goats to avoid consuming I. carnea during the rainy season, but not during the dry season, with low forage availability in the ϐield. The differences in these results seem to be due to the epidemiology of both poisonings: T. cordata is senescent and unavailable during most of the dry period, and green biomass is typically available either at the very end of the dry season, for a short period of time, and during the rainy season when there is no shortage of forage. In contrast, I. carnea grows in wet areas near water sources, and stays green during the dry period when there is a lack of other forage.

Biópsia hepática como método diagnóstico para intoxicação por plantas que contém swainsonina

“…Além da família Fabaceae, swainsonina tem sido identificada em duas outras famílias de plantas: Convolvulaceae (Solanaceae) Malvaceae (Malvales) (Huang et al 2003, Cook et al 2009). Algumas plantas que contém swainsonina são lactescentes e os animais que as consomem podem ser identificados por apresentarem manchas (nódoas) na boca ocasionadas pela lactescência da planta (Pimentel et al 2012). Porém, na maioria das vezes, essa avaliação é insuficiente e inespecífica por se aplicar a várias plantas lactescentes, em sua maioria, desprovidas de toxicidade.…”

Conditioned food aversion to control poisoning by Ipomoea carnea subsp. fistulosa in goats

“…Another possibility may be the removal of goats that ingest the plant followed by the induction of aversion in each naïve replacement goat if it begins to eat I. carnea. This technique was applied successfully to control poisoning in goats by T. cordata, another swainsonine-containing plant (PIMENTEL et al, 2012). The use of other techniques such as removal of plants by pulling, plowing or using herbicides, or building fences to prevent animal access is economically infeasible on Marajo Island because most areas remain fl ooded for long periods each year, the production system is very extensive, and access may be diffi cult.…”

“…Averting young animals so that the aversion is maintained in the herd could be done every two months by offering the plant in the stalls or by observation of the animals during grazing. This technique was successfully used by PIMENTEL et al (2012) to control T. cordata poisoning. Another important point is the availability of forage, particularly for livestock producers to avoid overgrazing and to provide, when possible, supplemental feed during the dry season.…”

“…Another important point is the availability of forage, particularly for livestock producers to avoid overgrazing and to provide, when possible, supplemental feed during the dry season. In an outbreak of poisoning I. carnea, in the state of Paraiba, the aversion was effective in preventing consumption during the rainy season, even in animals that had ingested the plant for long periods, but the goats began again to ingest the plant during the dry season because of the severe shortage of forage (PIMENTEL et al, 2012).…”

“…Currently, there is no treatment for poisoning cases and control methods are ineffi cient (OLIVEIRA et al, 2009). Conditioned food aversion can be used in ruminants to avoid eating poisonous plants (RALPHS AND OLSEN, 1990;PFISTER et al, 2002;ALMEIDA et al, 2009;PIMENTEL et al, 2012). In Brazil, lithium chloride (LiCl) has been used to induce aversion to consumption of Amorimia rigida (BARBOSA et al, 2008;PACIFICO DA SILVA & SOTO-BLANCO, 2010), Leucaena leucocephala (GORNIAK et al, 2008) Turbina cordata and I. carnea (PIMENTEL et al, 2012).…”