TY  - JOUR
T1  - Daily Cortisol Profile in Lactating and Non-Lactating Dairy Goats (<I>Capra hircus</I>)
AU - , L. Alvarez AU - , F. Galindo 
JO  - Research Journal of Animal Sciences
VL  - 2
IS  - 3
SP  - 72
EP  - 77
PY  - 2008
DA  - 2001/08/19
SN  - 1993-5269
DO  - rjnasci.2008.72.77
UR  - https://makhillpublications.co/view-article.php?doi=rjnasci.2008.72.77
KW  - Cortisol
KW  -goats
KW  -cortisol daily profile
KW  -diurnal
KW  -nocturnal
AB  - The objective of the present study was to determine the daily plasma cortisol pattern in domestic lactating and non-lactating goats. In a total of 12 multiparous goats (6 lactating, 6 non-lactating), 4 daily blood samples were taken over the course of 12 days, beginning at different times, in order to cover two, 24 h periods. Lactating  goats  were  at their 4th month of lactation and were hand-milked daily at 07:30-08:30 h since parturition. Repeated measures ANOVA, Tukey-Kramer and student&#8217;s t-tests were used, considering diurnal (07:00-18:00 h) and nocturnal hours (19:00-06:00 h) as well as the condition of lactation. Higher levels of cortisol (45 nmol L <SUP>1</SUP>) were found during diurnal hours, followed by important and sustained decreases (6-16 nmol L <SUP>1</SUP>). A  pair  of  smaller  peaks appeared between 23:00-24:00 h, followed by a decrease that was maintained until 06:00 h, at which time high levels of cortisol returned (26 nmol L <SUP>1</SUP>). Daily average cortisol values were similar between lactating (16.6±1.8) and nonlactating goats (16.5±1.8; nmol L <SUP>1</SUP>; p&gt;0.05). Diurnal cortisol was higher (p = 0.003) than nocturnal (19.6±1.9vs. 13.5±1.1 nmol L <SUP>1</SUP>). Daily cortisol levels are similar between lactating and non-lactating domestic goats at their fourth month of lactation and cortisol levels undergo significant changes during the day, with higher concentrations in diurnal compared to nocturnal hours.
ER  -