title: The effect of ovariectomy on concentrations of plasma prolactin and LH and parental behavior in the domestic fowl.
abstract: The role of ovarian hormones in the expression of parental behavior and in the regulation of LH secretion was investigated in incubating commercial meat-type hens. After ovariectomy, incubating hens continued to incubate eggs normally and brooded day-old chicks given to replace eggs, in a manner similar to sham-ovariectomized control hens. The concentration of plasma LH increased significantly in incubating hens after ovariectomy while the concentration of plasma prolactin remained high. Plasma LH remained depressed in sham-ovariectomized incubating control hens. The increase in plasma LH in incubating hens after ovariectomy (3.92 +/- 0.7 ng/ml) was less than that following the ovariectomy of nonincubating, nonlaying hens (5.3 +/- 1.2 ng/ml). The two groups of hens differed in that plasma prolactin concentrations were high (527 +/- 7.4 ng/ml) in the incubating hens and low (70 +/- 9 ng/ml) in the nonincubating hens. Nest deprivation resulted in an increase in plasma LH in both ovariectomized and sham-ovariectomized incubating hens with a significantly larger increase occurring in the ovariectomized hens (8.5 +/- 1.41 ng/ml compared to 2.48 +/- 0.65 ng/ml). Nest deprivation resulted in a similar rapid decrease in plasma prolactin in both ovariectomized and sham-ovariectomized hens. Replacement of eggs with day-old chicks in ovariectomized or sham-ovariectomized incubating hens resulted in a rapid decrease in plasma prolactin and after 6 days, in an increase in plasma LH in the ovariectomized but not sham-operated hens. It is concluded that once incubation behavior is established, ovarian hormones are not required for its maintenance or the readiness to brood day-old chicks. Ovarian hormones do, however, suppress LH release during incubation while the high concentration of plasma prolactin supplements this suppression.
authors.affiliation: Department of Applied Biology, University of Central Lancashire, Preston, United Kingdom.
authors.forename: R W
authors.initials: RW
authors.lastname: Lea
authors.forename: M A
authors.initials: MA
authors.lastname: Richard-Yris
authors.forename: P J
authors.initials: PJ
authors.lastname: Sharp
mesh_terms: D000818:Animals; D002645:Chickens / Q000502:physiology*; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood*; D008425:Maternal Behavior / Q000502:physiology*; D010052:Ovariectomy; D011388:Prolactin / Q000097:blood*; D013997:Time Factors
chemical_list: D011388:Prolactin; D007986:Luteinizing Hormone