Expressão e positividade dos transportadores de cálcio Calbindin-D28k e TRPV6 e morfometria do Sistema Digestório e Reprodutor de codornas de postura submetidas a estresse térmico e suplementação com metionina

Abstract

The objective of this study was to verify if methionine supplementation in high temperature heat stress situations can minimize the deleterious effects on egg production in Japanese quails. For this purpose, 504 Japanese quails in production phase (second cycle) were used, distributed in a completely randomized design in a 3x4 factorial scheme, with three levels of methionine (100%, 110% and 120%) and four temperature ranges (20, 24, 28 and 32°C). It was first evaluated by immunohistochemical positivity and gene expression by real time PCR whether the calcium transporters, calbindin-D28k and TRPV6 acting on calcium uterus absorption, resorption and deposition, respectively. in duodenum and jejunum, kidney and uterus would be changed under such conditions (heat stress and methionine supplementation). It has been seen that methionine supplementation generally does not increase the positivity or gene expression of both genes in the aforementioned tissues, thus not reversing the deleterious effects in cases of heat stress. Exception to the uterine glands, which presented in immunohistochemistry, a higher positivity in animals supplemented at temperatures of 20 and 32ºC, evidencing the positive effect of supplementation for production of such birds, especially at temperature already considered heat thermal stress, such as that of 32ºC previously mentioned. Morphometric studies of the digestive system (height and width of the villus, crypt depth, villus: crypt ratio, villus area, number of goblet cells, stock) were also performed for the first time in heat stress quail and methionine supplemented. hepatic glycogen and steatosis) and breeding (height of uterine primary folds and number of secondary folds), which did not present significant results upon methionine supplementation, since the significant results were obtained at thermoneutral temperatures for the birds. It is concluded that the use of methionine supplementation is justifiable, with the objective of reversing the deleterious effects on the production of laying quails subjected to thermal stress, as there were alterations of calbindin and TRPV6 in the magnesium and kidney, production sites. eggshell and calcium resorption respectively, reversing part of the deleterious effects caused by heat and thus proposing improvements in the quality and production of these birds.