Cardiovascular, endocrine and behavioural responses to suckling and permanent separation in goats.
BACKGROUND
Suckling can be a peaceful or vulnerable event for goats and kids, whereas, separation is suggested as stressful. The aim of this study was to investigate physiology and behaviour in these two different situations in dairy goats.


METHODS
Four studies were performed with seven goats kept with their first-born kid in individual boxes. The goats were videotaped and heart rate and arterial blood pressure were recorded every minute by telemetry from parturition until 24 hours after separation. One to two days after parturition, Study 1 was performed with analyses of heart rate and blood pressure around a suckling. In Study 2, performed 3-5 days after parturition, blood sampling was done before, during and after suckling. Study 3 was performed 4-6 days post partum, with blood sampling before and after a permanent goat and kid separation. In addition, vocalisations were recorded after separation. Blood samples were obtained from a jugular vein catheter and analysed for plasma cortisol, β-endorphin, oxytocin, and vasopressin concentrations. Study 4 was performed during the first (N1) and second nights (N2) after parturition and the nights after Study 2 (N3) and 3 (N4). Heart rate, blood pressure and time spent lying down were recorded.


RESULTS
The kids suckled 2 ± 0.2 times per hour and each suckling bout lasted 43 ± 15 s. In Study 1, heart rate and blood pressure did not change significantly during undisturbed suckling. In Study 2, plasma cortisol (P ≤ 0.05 during suckling and P ≤ 0.01 five minutes after suckling) and β-endorphin (P ≤ 0.05) concentrations increased during suckling, but oxytocin and vasopressin concentrations did not change. In Study 3, the goats and kids vocalised intensively during the first 20 minutes after separation, but the physiological variables were not affected. In Study 4, heart rate and arterial blood pressure declined gradually after parturition and were lowest during N4 (P ≤ 0.05) when the goats spent longer time lying down than during earlier nights (P ≤ 0.01 during N1 and N3 and P ≤ 0.05 during N2).


CONCLUSIONS
Suckling elevated plasma cortisol and β-endorphin concentrations in the goats. The intensive vocalisation in the goats after separation, earlier suggested to indicate stress, was not accompanied by cardiovascular or endocrine responses.
von Walter
Louise Winblad
LW
Department of Anatomy, Physiology and Biochemistry, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden. louise.winblad@afb.slu.se
Lidfors
Lena
L
Madej
Andrzej
A
Dahlborn
Kristina
K
Hydbring-Sandberg
Eva
E
D000818:Animals; D000833:Animals, Suckling / Q000502:physiology* / Q000523:psychology; D001522:Behavior, Animal / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D006041:Goats / Q000502:physiology* / Q000523:psychology; D006339:Heart Rate / Q000502:physiology; D006854:Hydrocortisone / Q000097:blood; D010121:Oxytocin / Q000097:blood; D013312:Stress, Physiological / Q000502:physiology*; D013686:Telemetry; D014667:Vasopressins / Q000097:blood; D014743:Videotape Recording; D014828:Vocalization, Animal / Q000502:physiology; D001615:beta-Endorphin / Q000097:blood
D014667:Vasopressins; D010121:Oxytocin; D001615:beta-Endorphin; D006854:Hydrocortisone
Acta Physiol Scand. 1997 Nov;161(3):295-302
9401581
J Dairy Res. 1997 Aug;64(3):315-25
9275252
J Dairy Sci. 1998 Apr;81(4):939-49
9594382
Horm Behav. 2007 Jun;52(1):99-105
17482617
Theriogenology. 1981 Aug;16(2):185-93
16725631
Acta Physiol Scand. 1963 Nov;59:269-83
14078664
Physiol Behav. 1994 Oct;56(4):693-700
7800735
Theriogenology. 1981 Oct;16(4):469-75
16725658
J Endocrinol. 1972 Jan;52(1):177-88
5062212
Br Vet J. 1989 Sep-Oct;145(5):446-50
2790435
J Dairy Res. 2009 Feb;76(1):15-9
18922197
J Dairy Sci. 1992 Feb;75(2):443-8
1560139
Vet Res Commun. 2005 Jan;29(1):81-90
15727294
Dev Psychobiol. 2007 Jan;49(1):54-70
17186516
Acta Physiol Scand. 1999 Feb;165(2):135-41
10090324
Reprod Nutr Dev. 2000 May-Jun;40(3):271-81
10943606
Rev Reprod. 2000 Sep;5(3):153-63
11006165
Aust Vet J. 1992 Jul;69(7):161-3
1445079
Appl Anim Behav Sci. 2000 Mar 22;67(1-2):77-88
10719191
Res Vet Sci. 2006 Jun;80(3):343-8
16181650
J Anim Sci. 2007 Jun;85(6):1522-9
17339412
Acta Physiol Scand. 1963 Dec;59:299-318
14082601
J Endocrinol. 1999 Jan;160(1):75-85
9854179
Reprod Nutr Dev. 1999 Mar-Apr;39(2):231-44
10327451
J Dairy Res. 1993 Nov;60(4):449-56
8294603