Preweaning diet and stall weaning method influences on stress response in foals.

Abstract

The stress response of foals during weaning was examined in terms of a behavioral protocol and the responses of plasma ascorbate, serum cortisol, and the serum cortisol response to an ACTH challenge. The experimental plan was a 2 x 2 factorial of two preweaning diets and two stall weaning methods. Dietary groups included foals raised on pasture supplemented with hay and a pelleted concentrate (PHC) and foals raised on pasture supplemented with hay only (PH). Stall weaning methods included foals placed in stalls singly or in pairs. Sex influences were also examined. The foals exhibited characteristic behavioral and physiological responses to weaning stress. Behavior scores indicated fewer outward signs of stress in single than in paired foals (P = .008) and tended to indicate fewer signs of stress in PHC than in PH foals (P = .15). No differences in plasma ascorbate concentrations were found among treatments. Responses of serum cortisol to an ACTH challenge were lower (representing adrenal depletion arising from stress) in PH than in PHC foals (P = .001) and in paired than in single foals (P = .058). Behavior scores were positively correlated with the response of serum cortisol to ACTH. Both behavioral data and the ACTH response indicated that foals may cope better with weaning when supplemented with concentrate before weaning or when placed singly in stalls rather than in pairs.

Total and free iodothyronines profile in the donkey (Equus asinus) over a 12-month period

“…The results did not exclude the fact that some stress conditions such as stabling or Symbols indicate significant ( ▲ P < 0.05; ▲▲ P < 0.01) differences in average hormone compared to previous month management (Hoffman et al 1995;Malinowski et al 1996;Christensen et al 1997;Moons et al 2005) and diet (Messer et al 1995;Sticker et al 1995;Powell et al 2000) may determine higher T 4 , fT 3 and fT 4 concentrations in both barren and pregnant donkeys than data reported in horses. Stress conditions may be induced by blood drawing which was always performed in donkeys that were out to pasture.…”

Effects of prompt versus stepwise relocation to a novel environment on foals' responses to weaning in domestic horses (Equus caballus)

“…Given these potential repercussions of abrupt weaning, various alternative methods have been subjected to detailed research (reviewed in Apter and Householder, 1996;Waran et al, 2008), including gradual weaning (Rogers et al, 2004), partial separation allowing fence-line contact between mothers and foals (McCall et al, 1985), weaning in pairs (Hoffman et al, 1995;Malinowski et al, 1990) or groups (Heleski et al, 2002), weaning in paddocks with the possibility of grazing (Heleski et al, 2002;, weaning with a presence of some unrelated adult horse(s) (Henry et al, 2012), and feeding different diets at the time of weaning (Coleman et al, 1999;McCall et al, 1985;. These more weaning techniques that mimic parts of natural weaning appear to be associated with lower levels of stress in both mother and foal, but the various studies undertaken are not easily comparable owing to different methodologies and differences in measures recorded.…”

“…Evaluation of stress levels in foals has been based on various indicators, including the foals' behavior [including locomotion, vocalization, or abnormal behavior (Heleski et al, 2002;Henry et al, 2012;Houpt et al, 1984)]; activity (McCall et al, 1985); blood cortisol levels (Berger et al, 2013;Hoffman et al, 1995;Houpt et al, 1984;Malinowski et al, 1990;McCall et al, 1987); salivary levels of cortisol and other compounds (Erber et al, 2012;Henry et al, 2012;Moons et al, 2005); growth rates (Coleman et al, 1999;Erber et al, 2012;Rogers et al, 2004;Warren et al, 1998); and weanlings' trainability, tractability, and responses to a novel object . Stress affects normal biological functions (e.g., growth) through biological responses that are used to redress stressful situations (Moberg, 1987;Morgan and Tromborg, 2007).…”

Exploring aggression regulation in managed groups of horses Equus caballus

“…The highest reactions are observed for foals weaned singly in a box. When paired with a peer, foals exhibit less stress reactions but aggressions do arise and can lead to injuries (Hoffmann et al, 1995). Other practices, such as the progressive retrieval of mares from the group (Holland et al, 1996), keeping foals at pasture in groups (Heleski et al, 2002) or still more so introducing adults with the weanlings (Henry et al, in press) all lead to lowered expressions of stress, including lowered levels of aggression.…”