College of Agriculture & Natural Resources
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Item EFFECTS OF ENVIRONMENTAL ENRICHMENTS ON WELL-BEING MEASURES IN COLONY-CAGED JAPANESE QUAIL (COTURNIX JAPONICA)(2022) Mathkari, Chirantana Vikas; Dennis, Rachel L; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Breeding purpose Japanese quail (Coturnix japonica) are often maintained in barren cages with little environmental complexity. These conditions can lead to unwanted social interactions and stress-related behaviors that can cause serious injury, mortality, and reduce productivity. Use of environmental enrichments has shown to improve poultry well-being; however, the optimal enrichments for quail have not been widely studied. The aim of this project was to evaluate the effectiveness of various enrichments on the well-being and productivity of breeding quail colonies (1 male, 2 females/cage). The enrichments studied were designed to reduce unwanted interactions and stress-related behaviors by either providing a shelter (protective enrichments) or by providing mental stimulation (stimulatory enrichments). In Experiment 1, using an incomplete Latin square design, each cage received one protective enrichment (Hut, Plastic leaves, or Grass), or one stimulatory enrichment (Mirror, Feeder toy, or Mat), or no enrichment (control) (average n=17/treatment). In Experiment 2, using an incomplete Latin square design, each cage received one of the following enrichment combinations: Hut + Mirror, Hut + Feeder toy, Hut + Mat, or only Hut (average n=14/treatment). Parameters measured included behaviors, body weight, Hen Day Egg Production (HDEP), egg weight, physical scores, and fecal corticosterone metabolites (FCM) levels. Measures were analyzed using a one-way ANOVA or Chi-square test on SAS 9.4. The results indicate that exposure to a single enrichment reduced stress-related damaging behaviors and increased resting; while exposure to a combination of enrichments reduced a larger variety of stress-related damaging behaviors more efficiently. Two of the three protective enrichments (Hut, Grass) exerted a notable impact on production, while combinations of protective and stimulatory enrichments were more efficient in decreasing physical scores as compared to a single enrichment. The Hut + Mat combination notably reduced the FCM levels as compared to only Hut. Our study identified enrichments which are optimal for improving breeding quail well-being, and exhibit the potential to improve the economics of the quail industry.Item SOMATOTROPIN RESPONSE TO CORTICOSTERONE AND THE THYROID HORMONE T3 DURING CHICK EMBRYONIC DEVELOPMENT: INVOLVEMENT OF TYPE I AND TYPE II GLUCOCORTICOID RECEPTORS(2004-05-17) Heuck, Kristina; Porter, Tom E; Animal SciencesCorticosterone (CORT) can stimulate growth hormone (GH) cell (somatotroph) differentiation and GH secretion on embryonic day (e) 12 but not e20 in the chicken. GH induction involves both glucocorticoid receptors (GR) and mineralocorticoid receptors (MR); however, this finding has been characterized only on e12. To further define changes in somatotroph responsiveness to CORT, pituitary cells obtained on e12-e20 were cultured with CORT alone and in combination with T3. GH secretion increased over basal with CORT treatment on e12, e14, e16, and e18, but not e20. Contributions of GR and MR in CORT responses were evaluated using GR and MR antagonists. Blocking both receptors was required to abolish the CORT response by e12 cells. The same treatment on e20 decreased GH secretion relative to basal. We conclude that positive somatotroph responses to CORT are lost during embryonic development and that both GR and MR mediate CORT-induced GH secretion by cultured somatotrophs.