The cow eye
The purpose of this review was to study the cow’s eye physiology, focusing on how light affects the cow’s milk yield. It has been shown in studies that more hours of light per day (16 hours of light a day, as opposed to about 9-12 hours of light a day), increases milk yield for dairy cows. This revi...
| Autor principal: | |
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| Formato: | First cycle, G2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2019
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| Acceso en línea: | https://stud.epsilon.slu.se/14401/ |
| _version_ | 1855572401120608256 |
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| author | Tiilikainen, Hanna |
| author_browse | Tiilikainen, Hanna |
| author_facet | Tiilikainen, Hanna |
| author_sort | Tiilikainen, Hanna |
| collection | Epsilon Archive for Student Projects |
| description | The purpose of this review was to study the cow’s eye physiology, focusing on how light affects the cow’s milk yield. It has been shown in studies that more hours of light per day (16 hours of light a day, as opposed to about 9-12 hours of light a day), increases milk yield for dairy cows. This review contains suggestions on how this is connected with the physiology of the eye.
Vision is an important sense for most mammals and is used to check out the animals’ surroundings. Sensory neurons in the retina of the globe help in turning photons from the light into signals to the brain. The brain can then translate the information and start a range of responses in the animals. For instance, ganglion cells in the eye´s retina send signals to the pineal gland in the brain, to stimulate or inhibit production of melatonin.
Increased light hours decrease the secretion of melatonin, important for sleep patterns and regulation of seasonal reproduction. Artificial light seems to work as well as natural light, in this aspect. Studies have shown relations between longer photoperiods (16 hours of light per day) and elevated prolactin levels, which leads to increased milk production. However, in dry cows, short photoperiods (8 hours of light per day) show an increase in milk yield in the subsequent lactation. Studies also show connections between increased levels of the growth hormone bovine somatotropoin (BST) and longer photoperiods. |
| format | First cycle, G2E |
| id | RepoSLU14401 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2019 |
| publishDateSort | 2019 |
| record_format | eprints |
| spelling | RepoSLU144012019-04-26T01:01:00Z https://stud.epsilon.slu.se/14401/ The cow eye Tiilikainen, Hanna Animal husbandry Veterinary science and hygiene - General aspects The purpose of this review was to study the cow’s eye physiology, focusing on how light affects the cow’s milk yield. It has been shown in studies that more hours of light per day (16 hours of light a day, as opposed to about 9-12 hours of light a day), increases milk yield for dairy cows. This review contains suggestions on how this is connected with the physiology of the eye. Vision is an important sense for most mammals and is used to check out the animals’ surroundings. Sensory neurons in the retina of the globe help in turning photons from the light into signals to the brain. The brain can then translate the information and start a range of responses in the animals. For instance, ganglion cells in the eye´s retina send signals to the pineal gland in the brain, to stimulate or inhibit production of melatonin. Increased light hours decrease the secretion of melatonin, important for sleep patterns and regulation of seasonal reproduction. Artificial light seems to work as well as natural light, in this aspect. Studies have shown relations between longer photoperiods (16 hours of light per day) and elevated prolactin levels, which leads to increased milk production. However, in dry cows, short photoperiods (8 hours of light per day) show an increase in milk yield in the subsequent lactation. Studies also show connections between increased levels of the growth hormone bovine somatotropoin (BST) and longer photoperiods. Syftet med denna litteraturstudie var att studera koögats fysiologi, med fokus på hur ljus påverkar kornas mjölkavkastning. Det har tidigare visats i studier att fler ljusa timmar på dygnet (16 timmar per dygn, i stället för cirka 9-12 timmar per dygn), ökar mjölkavkastningen hos mjölkkor. Den här litteraturstudien innehåller förslag på hur detta är kopplat till ögats fysiologi. Synen är ett viktigt sinne för de flesta däggdjur, och används för att ta in information från djurets omgivning. Synceller i ögats näthinna hjälper till att omvandla fotoner ifrån ljuset till signaler som sedan överförs till hjärnan. Hjärnan kan därefter översätta informationen och starta olika responser hos djuren. Ett exempel är ganglieceller i ögats näthinna som sänder signaler till tallkottkörteln i hjärnan som stimulerar eller inhiberar produktionen av melatonin. Fler ljustimmar minskar även utsöndringen av melatonin, viktigt för sömn och säsongsmässig reglering av reproduktionen. Artificiellt ljus verkar fungera lika bra som naturligt ljus i detta fall. Studier har visat samband mellan längre fotoperioder (16 timmar ljus/dygn) och förhöjda prolaktinnivåer, vilket kan leda till ökad mjölkproduktion. Hos sinkor har det motsatta visats. Korta fotoperioder (8 timmar ljus/dygn) ger ökad mjölkproduktion i kommande laktation. Studier har även visat samband mellan ökade nivåer av tillväxthormonet bovint somatotropin (BST) och längre fotoperioder. 2019-04-23 First cycle, G2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/14401/7/Tiilikainen_H_180618.pdf Tiilikainen, Hanna, 2018. The cow eye : function and effect of light on milk yield. First cycle, G2E. Uppsala: (VH) > Dept. of Animal Nutrition and Management (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-650.html> urn:nbn:se:slu:epsilon-s-10361 eng |
| spellingShingle | Animal husbandry Veterinary science and hygiene - General aspects Tiilikainen, Hanna The cow eye |
| title | The cow eye |
| title_full | The cow eye |
| title_fullStr | The cow eye |
| title_full_unstemmed | The cow eye |
| title_short | The cow eye |
| title_sort | cow eye |
| topic | Animal husbandry Veterinary science and hygiene - General aspects |
| url | https://stud.epsilon.slu.se/14401/ https://stud.epsilon.slu.se/14401/ |