Changes in luteinizing hormone‐containing gonadotrophs after moulting induced by fasting and zinc in laying hens (Gallus domesticus)

Abstract

The purpose of the present study was to investigate egg production performance, immunohistochemical (IHC) identification, localization and morphological characterization of moulted hen's pars distalis luteinizing hormone (LH) gonadotrophs. This system has been validated for chicken LH by immunodetection of purified hormones on dot blots, western blotting and by specific labelling of cells on sagittal sections of chicken pituitaries. This study showed that egg production and egg weight increased significantly after zinc-induced moult when compared with fasting-induced moult. Luteinizing hormone-gonadotrophs are of numerous shapes and distributed throughout the adenohypophysis, with densely populated regions on the margins of pars distalis. Moulting of laying hens was associated with a significant increase in immunoreactive LH gonadotroph cell count and cell size, which peaked at the subsequent production stages. Zinc-induced moulting also caused a significant increase in LH gonadotroph cell size as compared with fasting-induced moulting. The nuclear size of LH-positive cells was distinct during decreased egg production. Our results validate the use of ovine LHbeta antibodies for the IHC localization of chicken LH gonadotrophs. This technology was further applied to the characterization of the shape and morphological changes of gonadotrophs as a function of the egg production status of the birds.

Alternative induced molting methods for feed withdrawal and their effect on post molt egg quality parameters of White Leghorn hens

“…These findings were in agreement with our results. In addition to this, dietary zinc-induced molting was proved to be better in improving the immune status (Sandhu et al 2008) as well as the production performance (Sandhu et al 2006) and the favourable alternate to the conventional fast molting procedures (Koch et al 2007, Koelkebeck andAnderson 2007). Shell weight was also increased after the 10 th week of molting, which has already been reported by Khajali et al (2008).…”

Dynamics of anterior pituitary immunoreactive gonadotrophs in moulted hens supplemented with protein, symbiotic and probiotics

“…() and Sandhu et al. (). The impact of under nutrition on the pituitary response in the animals is multidimensional as Herbert () observed a decrease in LH‐releasing hormone from the hypothalamus in low‐protein fed animals.…”

Gene Expression Profiles of LH, Prolactin and Their Receptors in Female Zi Geese (Anser cygnoides) during Development

“…LH, as well as follicle-stimulating hormone (FSH), is essential for sexual maturation and egg production. In birds, ovulation and oviposition are processes controlled by LH and sex steroids, including progesterone (SANDHU et al 2008). The expression profiles of LH in the pituitary and LHR in the ovary of geese during embryonic development and the egg-laying period have been studied extensively in avian species (BRUGGEMAN et al 2002;RANGEL et al 2006;NI et al 2007;GRZE-GORZEWSKA et al 2009).…”