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Do lambs perceive regular human stroking as pleasant? Behavior and heart rate variability analyses.

Coulon M, Nowak R, Peyrat J, Chandèze H, Boissy A, Boivin X - PLoS ONE (2015)

Bottom Line: Stroking by humans is beneficial to the human-animal relationship and improves welfare in many species that express intraspecific allogrooming, but very few studies have looked at species like sheep that do not express such contact except around parturition.Heart rate and heart rate variability were recorded and analyzed by 2-min slots over the same interval based on three measures: mean heart rate value (HR), root mean square of successive differences (RMSSD) and standard deviation of all intervals measured between consecutive sinus beats (SDNN).All behavioral variables were highly correlated with the main component axis of the PCA analyses: the more the animals stayed in contact with their caregiver, the less they moved and the more their ears were hanging.

View Article: PubMed Central - PubMed

Affiliation: INRA, Unité Mixte de Recherche 1213 Herbivores, Site de Theix, 63122 Saint-Genès-Champanelle, France; Clermont Université, VetAgro Sup, Unité Mixte de Recherche Herbivores, BP 10448, 63000 Clermont-Ferrand, France.

ABSTRACT
Stroking by humans is beneficial to the human-animal relationship and improves welfare in many species that express intraspecific allogrooming, but very few studies have looked at species like sheep that do not express such contact except around parturition. This study investigated the way lambs perceive regular human tactile contact using behavioral and physiological responses. Twenty-four lambs were reared and bucket-fed in groups of four. All were stroked daily by their familiar caregiver. At 8 weeks of age, the lambs were individually tested in their home pen but in a 1×1m open-barred pen after a 15 h period of habituation to physical separation from peers while remaining in visual and auditory contact. Half of the lambs received stroking by their caregiver for 8 min and half were exposed to their caregiver's immobile presence. Heart rate and heart rate variability were recorded and analyzed by 2-min slots over the same interval based on three measures: mean heart rate value (HR), root mean square of successive differences (RMSSD) and standard deviation of all intervals measured between consecutive sinus beats (SDNN). Behavioral responses (ear postures of the lamb and time spent in contact with the familiar caregiver, on the knees of the familiar caregiver, and moving) were recorded throughout the test. Lamb HR decreased continuously while in the presence of their caregiver. Lambs being stroked showed slower HR and higher RMSSD which reflected positive emotional states compared to lambs left unstroked. All behavioral variables were highly correlated with the main component axis of the PCA analyses: the more the animals stayed in contact with their caregiver, the less they moved and the more their ears were hanging. This first component clearly differentiates lambs being stroked or not. Behavioral and physiological observations support the hypothesis that gentle physical contact with the caregiver is perceived positively by lambs.

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Related in: MedlinePlus

Diagram of the home pen with the small pen where the 8-week-old tested lamb was isolated to test behavioral and cardiac responses to tactile contact (solid lines: opaque wooden fences and dotted lines: open-barred fences).The barriers of the 1x1 m testing area could be open as mentioned by the curved arrows.
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pone.0118617.g001: Diagram of the home pen with the small pen where the 8-week-old tested lamb was isolated to test behavioral and cardiac responses to tactile contact (solid lines: opaque wooden fences and dotted lines: open-barred fences).The barriers of the 1x1 m testing area could be open as mentioned by the curved arrows.

Mentions: This experiment used 24 female Romane lambs born within one week. The lambs were ear-tagged and weighed at birth, left with their mothers for 12 hours in order to ensure adequate ingestion of colostrum, then separated from them to be reared artificially as per standard farming practices. Immediately after separation, the lambs were randomly allocated into groups of four and housed in a straw-bedded home pen (2×2 m, Fig. 1). A single stockwoman, wearing blue coveralls, spent the first two days training the lambs to suckle from a bucket fitted with four teats (i.e. six training sessions per pen, even if the lambs had already learned to suckle). Each lamb underwent three 30 sec—training session, after which they suckled without any further assistance. The lambs were fed a combination of milk replacer and water (250 g of powder/liter of ‘Cremagneau-Chevreau’ from Nutrilia-Sanders) over two meals given at 08:00 and 17:00 h. The bucket was introduced from outside the pen and left in the pen for 45 min. Opaque wooden fences separating the groups meant that the lambs had no visual or direct physical contact between groups but could still hear lambs from other pens. All other husbandry procedures (bedding, preparing milk distribution, veterinary treatment, etc.) were performed by another male stockperson wearing green coveralls. Two lambs had to be removed from the experiment due to health issues.


Do lambs perceive regular human stroking as pleasant? Behavior and heart rate variability analyses.

Coulon M, Nowak R, Peyrat J, Chandèze H, Boissy A, Boivin X - PLoS ONE (2015)

Diagram of the home pen with the small pen where the 8-week-old tested lamb was isolated to test behavioral and cardiac responses to tactile contact (solid lines: opaque wooden fences and dotted lines: open-barred fences).The barriers of the 1x1 m testing area could be open as mentioned by the curved arrows.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4340872&req=5

pone.0118617.g001: Diagram of the home pen with the small pen where the 8-week-old tested lamb was isolated to test behavioral and cardiac responses to tactile contact (solid lines: opaque wooden fences and dotted lines: open-barred fences).The barriers of the 1x1 m testing area could be open as mentioned by the curved arrows.
Mentions: This experiment used 24 female Romane lambs born within one week. The lambs were ear-tagged and weighed at birth, left with their mothers for 12 hours in order to ensure adequate ingestion of colostrum, then separated from them to be reared artificially as per standard farming practices. Immediately after separation, the lambs were randomly allocated into groups of four and housed in a straw-bedded home pen (2×2 m, Fig. 1). A single stockwoman, wearing blue coveralls, spent the first two days training the lambs to suckle from a bucket fitted with four teats (i.e. six training sessions per pen, even if the lambs had already learned to suckle). Each lamb underwent three 30 sec—training session, after which they suckled without any further assistance. The lambs were fed a combination of milk replacer and water (250 g of powder/liter of ‘Cremagneau-Chevreau’ from Nutrilia-Sanders) over two meals given at 08:00 and 17:00 h. The bucket was introduced from outside the pen and left in the pen for 45 min. Opaque wooden fences separating the groups meant that the lambs had no visual or direct physical contact between groups but could still hear lambs from other pens. All other husbandry procedures (bedding, preparing milk distribution, veterinary treatment, etc.) were performed by another male stockperson wearing green coveralls. Two lambs had to be removed from the experiment due to health issues.

Bottom Line: Stroking by humans is beneficial to the human-animal relationship and improves welfare in many species that express intraspecific allogrooming, but very few studies have looked at species like sheep that do not express such contact except around parturition.Heart rate and heart rate variability were recorded and analyzed by 2-min slots over the same interval based on three measures: mean heart rate value (HR), root mean square of successive differences (RMSSD) and standard deviation of all intervals measured between consecutive sinus beats (SDNN).All behavioral variables were highly correlated with the main component axis of the PCA analyses: the more the animals stayed in contact with their caregiver, the less they moved and the more their ears were hanging.

View Article: PubMed Central - PubMed

Affiliation: INRA, Unité Mixte de Recherche 1213 Herbivores, Site de Theix, 63122 Saint-Genès-Champanelle, France; Clermont Université, VetAgro Sup, Unité Mixte de Recherche Herbivores, BP 10448, 63000 Clermont-Ferrand, France.

ABSTRACT
Stroking by humans is beneficial to the human-animal relationship and improves welfare in many species that express intraspecific allogrooming, but very few studies have looked at species like sheep that do not express such contact except around parturition. This study investigated the way lambs perceive regular human tactile contact using behavioral and physiological responses. Twenty-four lambs were reared and bucket-fed in groups of four. All were stroked daily by their familiar caregiver. At 8 weeks of age, the lambs were individually tested in their home pen but in a 1×1m open-barred pen after a 15 h period of habituation to physical separation from peers while remaining in visual and auditory contact. Half of the lambs received stroking by their caregiver for 8 min and half were exposed to their caregiver's immobile presence. Heart rate and heart rate variability were recorded and analyzed by 2-min slots over the same interval based on three measures: mean heart rate value (HR), root mean square of successive differences (RMSSD) and standard deviation of all intervals measured between consecutive sinus beats (SDNN). Behavioral responses (ear postures of the lamb and time spent in contact with the familiar caregiver, on the knees of the familiar caregiver, and moving) were recorded throughout the test. Lamb HR decreased continuously while in the presence of their caregiver. Lambs being stroked showed slower HR and higher RMSSD which reflected positive emotional states compared to lambs left unstroked. All behavioral variables were highly correlated with the main component axis of the PCA analyses: the more the animals stayed in contact with their caregiver, the less they moved and the more their ears were hanging. This first component clearly differentiates lambs being stroked or not. Behavioral and physiological observations support the hypothesis that gentle physical contact with the caregiver is perceived positively by lambs.

Show MeSH
Related in: MedlinePlus