תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםGlasser, T. A. and Markovics, A.
Goat breeds differ in their behavior towards tannin-rich plants: on the Carmel heights of Israel, Pistacia lentiscus, containing 20 % of PEG-binding tannins, forms 17 % of the DM ingested by Damascus, but only 6% of the DM ingested by Mamber goats. P. lentiscus tannins are deleterious to nitrogen balance but act as anthelmintics. Therefore, like many natural chemicals, they are either toxins or drugs, depending on dose and duration of the treatment. This prompts the question: do goats learn to self-medicate by modifying intake of the plant when they are afflicted with gastro-intestinal nematodes? We examined if infection with gastro-intestinal nematodes (GIN) - 10,000 L3 of mixed-species larvae triggers an increased consumption of tannin-rich P. lentiscus in 29 young goats that were exposed, before and during infection, to hay only or hay plus P. lentiscus. The infection was characterized by a decrease in plasma cell volume value (P < 0.005) and a decline in growth rate (P < 0.01). The consumption of P. lentiscus resulted in a sharp decrease in fecal egg count compared to the hay diet (P < 0.0001). On the other hand, feeding with P. lentiscus impaired the protein balance of the goats, as evidenced by decreased blood urea concentration (P < 0.0001). A preference test between hay and P. lentiscus revealed that infected Mamber goats consumed more P. lentiscus than noninfected counterparts (3.2 and 3.7 g DM kg BW-1, P < 0.02) but this effect was not significant in Damascus goats (3.6 g DM kg BW-1 for both treatments). Infected goats with previous exposure to P. lentiscus did not eat more of the plant than non-infected counterparts (approximately 3.6 g DM kg BW-1 for both, P < 0.5), but infection with previous exposure to hay did result in increased consumption of P. lentiscus (2.9 and 3.6 g DM kg BW-1, P < 0.01). Our results suggest that: 1. Goats that routinely ingest P. lentiscus in great amounts demonstrate passive self-medication through high and constant consumption of anthelmintic tannins; 2. Goats with less propensity to consume P. lentiscus, such as Mamber goats, exhibit active selfmedication behavior and increase the consumption of the plant only when the worm load increases; 3. Active self-medication can be explained by the neophilic behavior of sick animals and 4. self-medication of GIN-afflicted goats is a complex process, encompassing previous foraging habits affected by breed and education.
Glasser, T. A. and Markovics, A.
Goat breeds differ in their behavior towards tannin-rich plants: on the Carmel heights of Israel, Pistacia lentiscus, containing 20 % of PEG-binding tannins, forms 17 % of the DM ingested by Damascus, but only 6% of the DM ingested by Mamber goats. P. lentiscus tannins are deleterious to nitrogen balance but act as anthelmintics. Therefore, like many natural chemicals, they are either toxins or drugs, depending on dose and duration of the treatment. This prompts the question: do goats learn to self-medicate by modifying intake of the plant when they are afflicted with gastro-intestinal nematodes? We examined if infection with gastro-intestinal nematodes (GIN) - 10,000 L3 of mixed-species larvae triggers an increased consumption of tannin-rich P. lentiscus in 29 young goats that were exposed, before and during infection, to hay only or hay plus P. lentiscus. The infection was characterized by a decrease in plasma cell volume value (P < 0.005) and a decline in growth rate (P < 0.01). The consumption of P. lentiscus resulted in a sharp decrease in fecal egg count compared to the hay diet (P < 0.0001). On the other hand, feeding with P. lentiscus impaired the protein balance of the goats, as evidenced by decreased blood urea concentration (P < 0.0001). A preference test between hay and P. lentiscus revealed that infected Mamber goats consumed more P. lentiscus than noninfected counterparts (3.2 and 3.7 g DM kg BW-1, P < 0.02) but this effect was not significant in Damascus goats (3.6 g DM kg BW-1 for both treatments). Infected goats with previous exposure to P. lentiscus did not eat more of the plant than non-infected counterparts (approximately 3.6 g DM kg BW-1 for both, P < 0.5), but infection with previous exposure to hay did result in increased consumption of P. lentiscus (2.9 and 3.6 g DM kg BW-1, P < 0.01). Our results suggest that: 1. Goats that routinely ingest P. lentiscus in great amounts demonstrate passive self-medication through high and constant consumption of anthelmintic tannins; 2. Goats with less propensity to consume P. lentiscus, such as Mamber goats, exhibit active selfmedication behavior and increase the consumption of the plant only when the worm load increases; 3. Active self-medication can be explained by the neophilic behavior of sick animals and 4. self-medication of GIN-afflicted goats is a complex process, encompassing previous foraging habits affected by breed and education.
