diplomsko delo
Abstract
Namen diplomskega dela je bil pregledati literaturo povezano z osvetlitvijo in vzrejo telic, predvsem njihovo rastjo, razvojem vimena in nastopom spolne zrelosti. V večini raziskav se je pokazal pozitiven vpliv dolgodnevne osvetlitve (16 ur svetlobe in 8 ur teme) v primerjavi z naravno ali kratkodnevno osvetlitvijo (8 ur svetlobe in 16 ur teme) na rast telic. Dolgodnevna osvetlitev vpliva na sproščanje različnih hormonov, predvsem se zmanjša sproščanje melatonina in poveča sproščanje IGF-1 in prolaktina. To vodi do povečane rasti predvsem skeleta in mišičnega tkiva ter zmanjšanja rasti maščobnega tkiva. Te razlike so bolj opazne pri mlajših živalih. Podaljšanje osvetlitve vodi tudi do večjega razvoja vimena, predvsem parenhimskega tkiva, kar posledično lahko vodi tudi do povečanja mlečnosti. Vpliv podaljšane osvetlitve se pokaže tudi pri zgodnejšem pojavu prvega estrusa in pubertete.
Keywords
govedo;telice;vzreja;osvetlitev;diplomske naloge;
Data
Language: |
Slovenian |
Year of publishing: |
2021 |
Typology: |
2.11 - Undergraduate Thesis |
Organization: |
UL BF - Biotechnical Faculty |
Publisher: |
[A. Bevk] |
UDC: |
636.2(043.2) |
COBISS: |
76613123
|
Views: |
207 |
Downloads: |
23 |
Average score: |
0 (0 votes) |
Metadata: |
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Other data
Secondary language: |
English |
Secondary title: |
Effect of photoperiod on growth and development of heifers |
Secondary abstract: |
The aim of B. Sc. Thesis was to review the literature on the photoperiod and rearing of heifers, especially their growth, mammary gland development and onset of puberty. Most studies have shown a positive effect of long day photoperiod (16 hours of light and 8 hours of darkness) compared to natural and short day photoperiod (8 hours of light and 16 hours of darkness) on heifer growth. The long photoperiod affects the release of several hormones, most notably decreased melatonin and increased IGF-1 and prolactin. This results in increased growth, especially of skeletal and muscle tissue, and decreased growth of fat tissue. The differences are more evident in younger animals. Prolongation of the photoperiod leads to increased growth of mammary glands, especially parenchymal tissue, which may result in higher milk yield. The influence of a longer photoperiod is also reflected in an earlier onset of the first estrus and puberty. |
Secondary keywords: |
cattle;heifers;rearing;photoperiod; |
Type (COBISS): |
Diploma project paper |
Study programme: |
0 |
Embargo end date (OpenAIRE): |
1970-01-01 |
Thesis comment: |
Univ. v Ljubljani, Biotehniška fak., Oddelek za zootehniko |
Pages: |
VIII, 18 str. |
ID: |
13403729 |