The effect of maternal-fed omega-3 fatty acids on the cognition and fearfulness of their offspring: A study of broiler and egg-laying chickens
dc.contributor.advisor | Widowski, Tina | |
dc.contributor.author | Whittle, Rosemary | |
dc.date.accessioned | 2023-05-12T16:23:54Z | |
dc.date.available | 2023-05-12T16:23:54Z | |
dc.date.copyright | May-23 | |
dc.date.created | 2023-04-20 | |
dc.degree.department | Department of Animal Biosciences | en_US |
dc.degree.department | Campbell Centre for the Study of Animal Welfare | en_US |
dc.degree.grantor | University of Guelph | en |
dc.degree.name | Doctor of Philosophy | en_US |
dc.degree.programme | Animal Biosciences | en_US |
dc.description.abstract | Commercial poultry diets are deficient in omega-3 fatty acids (n-3 FA) essential for embryonic brain development. Feeding n-3 FA to broiler and layer breeder chickens may directly benefit them and could increase their offspring's health, welfare, and productivity. This thesis aimed to assess the effects of maternal feeding n-3 FA on the brain size and n-3 FA concentration, cognition, and fearfulness of layer and broiler offspring. Ross 708 broiler breeders were fed a control (n-6 to n-3 ratio 26.1:1) or flaxseed (4.81:1) diet during the rearing and laying period, resulting in four maternal diet combinations (control-control, control-flaxseed, flaxseed-control, flaxseed-flaxseed). Two strains of layer breeders, ISA Brown and Shaver White, were also fed a control (7.56:1) or flaxseed (5.31:1) diet. Layer and broiler offspring were assessed for brain size and docosahexaenoic acid (DHA) concentration, performance in two types of learning tests (T-maze and discrimination tasks), fear response to a novel object and social isolation. Although maternal feeding of n-3 supplemented diets resulted in significantly greater brain-to-body weight ratios in broiler offspring and decreased brain n-6: n-3 FA ratio in layer offspring, we found little evidence that maternal flaxseed diets resulted in differences in offspring cognition or fearfulness. There were sex-specific effects of maternal diet on broiler offspring vocalisation rate during a social isolation test and participation in a T-maze test. However, no effect of maternal diet was found on layer offspring behaviour. We found several effects of strain on behaviour in the layers. White chickens participated more in T-maze tests as chicks and were likelier to reach the learning criteria in both a T-maze test and discrimination learning task when tested as pullets and adults. Brown chicks vocalised more during social isolation, whereas white chicks spent more time motionless. In a novel object test, brown chickens were observed more frequently on elevated platforms than white chickens indicating greater avoidance of the novel object. We suggest further exploration into the optimal n-6 to n-3 FA ratios for poultry diets using diets closer to the 1:1 ratio found in wild precocial birds. | en_US |
dc.description.embargo | 2024-04-20 | |
dc.description.sponsorship | Natural Sciences and Engineering Research Council in Canada | |
dc.description.sponsorship | O & T Farms Ltd. | |
dc.description.sponsorship | Alltech, Ontario Agri-Food Innovation Alliance | |
dc.description.sponsorship | Egg Farmers of Canada | |
dc.identifier.uri | https://hdl.handle.net/10214/27570 | |
dc.language.iso | en | en_US |
dc.publisher | University of Guelph | en |
dc.rights.license | All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated. | |
dc.subject | Laying hen | en_US |
dc.subject | Broiler | en_US |
dc.subject | Maternal diet | en_US |
dc.subject | Omega-3 | en_US |
dc.subject | Cognition | en_US |
dc.subject | Fear | en_US |
dc.subject | Breeder | en_US |
dc.subject | Chicken | en_US |
dc.title | The effect of maternal-fed omega-3 fatty acids on the cognition and fearfulness of their offspring: A study of broiler and egg-laying chickens | en_US |
dc.type | Thesis | en |
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