The effects of feed restriction and lying deprivation on pituitary–adrenal axis regulation in lactating cows

Abstract In order to examine the effects of moderate feed restriction and periodic lying deprivation on pituitary–adrenal axis function in lactating dairy cows, 32 non-pregnant Jersey cows were allocated to two levels of feeding (4% vs. 3% of body weight of dry matter daily) and lying restriction (free lying vs. prevention of lying from 15:00 to 06:45 h daily) in a 2×2 factorial plan for 7 days. There were no feeding×lying interactions, and feeding level did not affect plasma cortisol concentrations, adrenocorticotrophic hormone (ACTH) and cortisol responses to challenge with 15 μg corticotrophin-releasing hormone (CRH), or ACTH and cortisol responses to CRH following the administration of 0.3 mg dexamethasone. Compared with free-lying animals, lying-restricted cows had increased basal plasma cortisol concentrations, and reduced ACTH and cortisol responses following CRH challenge relative to pre-challenge baselines. Lying-restricted cows also had an increased plasma cortisol/ACTH ratio for the total area under the hormone response curves following CRH. Dexamethasone administration prior to CRH challenge produced a similar result to CRH challenge alone, indicating that there were no differences between lying-restricted and free-lying cows in negative feedback sensitivity of the pituitary to glucocorticoids. In conclusion, 7 days of moderate feed restriction did not appear to alter pituitary–adrenal axis function, whereas periodic lying deprivation reduced pituitary responsiveness to CRH and increased plasma cortisol/ACTH ratio following CRH challenge.

[1]  I. Heuser,et al.  The combined dexamethasone/CRH test: a refined laboratory test for psychiatric disorders. , 1994, Journal of psychiatric research.

[2]  T. Friend,et al.  Change in adrenal response from free stall competition. , 1979, Journal of dairy science.

[3]  R. Spencer,et al.  Dexamethasone suppression of corticosteroid secretion: evaluation of the site of action by receptor measures and functional studies , 2000, Psychoneuroendocrinology.

[4]  A. H. Kirton,et al.  Relationships of Circulating Cortisol Levels with Growth Rate and Meat Tenderness of Cattle and Sheep , 1980 .

[5]  K. Svennersten-Sjaunja,et al.  Profiles of the hormones somatostatin, gastrin, CCK, prolactin, growth hormone, oxytocin and cortisol. II. In dairy cows that are milked during food deprivation , 1996 .

[6]  D. Broom,et al.  Stress and Animal Welfare , 1993, Springer Netherlands.

[7]  Koolhaas,et al.  Long‐Lasting Deficient Dexamethasone Suppression of Hypothalamic‐Pituitary‐Adrenocortical Activation Following Peripheral CRF Challenge in Socially Defeated Rats , 1999, Journal of neuroendocrinology.

[8]  M. Crowe,et al.  Indoor space allowance: effects on growth, behaviour, adrenal and immune responses of finishing beef heifers , 1997 .

[9]  E. Borell,et al.  Altered adrenocortical response to acute stressors or ACTH(1-24) in intensively housed pigs. , 1989, Domestic animal endocrinology.

[10]  D. Boggs,et al.  Effects of dietary energy level on luteinizing hormone and adrenal function in the post partum beef cow. , 1991, Theriogenology.

[11]  B. Allolio,et al.  Development of a non-extracted 'two-site' immunoradiometric assay for corticotropin utilizing extreme amino- and carboxy-terminally directed antibodies. , 1984, The Biochemical journal.

[12]  L. Pedersen,et al.  Deprivation of Lying Down Affects Behaviour and Pituitary-Adrenal Axis Responses in Young Bulls , 1999 .

[13]  G. W. Snedecor.  Statistical Methods , 1964 .

[14]  J. Ladewig,et al.  Behavior, episodic secretion of cortisol, and adrenocortical reactivity in bulls subjected to tethering , 1989, Hormones and Behavior.

[15]  L. Munksgaard,et al.  Behavioral and pituitary adrenal-axis responses of dairy cows to social isolation and deprivation of lying down. , 1996, Journal of animal science.

[16]  I. Colditz,et al.  The Effect of Dexamethasone on Some Immunological Parameters in Cattle , 1999, Veterinary Research Communications.

[17]  Richard L. Hauger,et al.  CRF receptor regulation and sensitization of ACTH responses to acute ether stress during chronic intermittent immobilization stress , 1990, Brain Research.

[18]  A. E. Ainsley,et al.  Genstat 5 Reference Manual , 1987 .

[19]  H. Klemcke.  Responses of the porcine pituitary-adrenal axis to chronic intermittent stressor. , 1994, Domestic animal endocrinology.

[20]  W. Vale,et al.  Diminished responsiveness of the hypothalamic-pituitary-adrenal axis of the rat during exposure to prolonged stress: a pituitary-mediated mechanism. , 1987, Endocrinology.

[21]  H. Dobson,et al.  Effect of various veterinary procedures on plasma concentrations of cortisol, luteinising hormone and prostaglandin F2 alpha metabolite in the cow , 1986, Veterinary Record.

[22]  C. Fossum,et al.  Influence of experimentally induced endogenous production of cortisol on the immune capacity in swine , 1994, Veterinary Immunology and Immunopathology.

[23]  T. Jenkins,et al.  Effect of dietary energy restriction on metabolic and endocrine responses during the estrous cycle of the suckled beef cow. , 1990, Journal of animal science.