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United States Department of Agriculture

Agricultural Research Service

Title: Maternal Ingestion of Locoweed. I. Effects on Ewe-Lamb Bonding and Behaviour

Authors
item PFISTER, JAMES
item Astorga, J - UNIV TECNICA ALTIPLANO
item PANTER, KIP
item STEGELMEIER, BRYAN
item Molyneux, Russell

Submitted to: Small Ruminant Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 12, 2005
Publication Date: November 14, 2005
Citation: Pfister, J.A., Astorga, J.B., Panter, K.E., Stegelmeier, B.L., Molyneux, R.J. 2005. Maternal ingestion of locoweed. i. effects on ewe-lamb bonding and behaviour. Small Ruminant Research 65:51-63

Interpretive Summary: Livestock that consume locoweed (Oxytropis sericea) show erratic behaviors and may die. The purpose of this study was to determine if locoweed eaten during gestation would affect the behavior of ewes and lambs at birth. Twenty-nine Columbia-Targhee ewes were divided into two feeding treatments: (1) locoweed (L, n=15), fed as a 10% locoweed pellet at 6 lbs./day from day 100 to 130 of gestation, or (2) controls (C, n=14) fed 6 lbs./day of alfalfa hay. Lamb birth weights were reduced about 25% from maternal locoweed ingestion. Locoweed had a major effect on maternal-infant bonding, primarily because lambs were poisoned. Only 1 lamb born to L ewes was able to nurse without assistance within 120 min. Lambs born to L ewes took longer to stand, to find the mother's udder, and to suckle. Interesting, although lambs were severely affected at birth, behavioral anomalies largely disappeared within 10 days following parturition. Locoweed affected ewes also, with locoweed ewes showing increased motor activity. There were few behavioral differences induced by locoweed up to 30 min after birth, when L ewes became inattentive to lambs. After the first (human assisted) suckling bout, L ewes were attentive toward both their own and alien lambs. Both L and C dams were equally aggressive toward alien lambs. These results indicate that lamb survival after maternal locoweed exposure will depend greatly on human intervention. If locoweed-exposed lambs survive the first 24 to 48 hours after birth, then the prognosis for survival improves greatly.

Technical Abstract: This study investigated whether exposure of ewes to locoweed (Oxytropis sericea) during gestation would affect ewe behavior during parturition, ewe-lamb bonding and related behaviors post partum, and maternal responsiveness of ewes to alien and own lambs. Twenty-nine nulliparous Columbia-Targhee ewes bearing a single fetus were divided into two feeding treatments: (1) locoweed (L, n=15), fed as a 10% locoweed pellet at 3 kg/day from day 100 to 130 of gestation, or (2) controls (C, n=14) fed 3 kg/day of alfalfa hay. Lamb birth weights were reduced about 25% from maternal locoweed ingestion. There was a distinct lack of maternal-infant bonding due to locoweed intoxication of lambs. Only 1 lamb born to L ewes was able to nurse without assistance within 120 min. Lambs born to L ewes took longer to stand (P < 0.05), to initiate teat-seeking behavior (P < 0.03), and to suckle (P < 0.0007). The behavioral toxicosis did not persist in lambs, as behavioral anomalies largely disappeared within 10 days following parturition. Locoweed-intoxicated ewes in general had an increased propensity (P < 0.1) for locomotor activity, notably during fetal expulsion, and longer fetal expulsion times (P < 0.1). There were few behavioral differences induced by locoweed up to 30 min post partum, when L ewes became inattentive to lambs (P < 0.1). After the first (human assisted) suckling bout, L ewes were attentive toward both their own and alien lambs. Both L and C dams were equally aggressive toward alien lambs. These results indicate that lamb survival after maternal locoweed exposure will depend greatly on human intervention. If locoweed-exposed lambs survive the first 24 to 48 hours after birth, then the prognosis for survival improves greatly.

Last Modified: 9/10/2014
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