PhD theses

All Wageningen University PhD theses

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    Wageningen PhD theses

    This database contains bibliographic descriptions of all Wageningen University PhD theses from 1920 onwards. It is updated on a daily basis by WUR Library.

    Author abstracts and/or summaries are added to all descriptions. A link to the full text dissertation is added to the bibliographic description. In a few cases, no electronic version is available, mostly because of copyright issues.

    Hard copies of all theses are available for loan at WUR Library. To request them, click the link Request this publication in the full record presentation. This is a fee based service.

    mail icon WUR Library, 9 july 2012


Record number 104456
Title Over het effect van hyperthyreoidiseering bij witte leghorns
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door J.B. van der Meulen
Author(s) Meulen, J.B. van der
Publisher Gorinchem : Noorduyn
Publication year 1938
Description X, 161 p
Notes Proefschrift Wageningen
Tutors Grijns, Prof. Dr. G.
Graduation date 1938-07-12
Dissertation no. 110
Author abstract show abstract
Oral feeding of White Leghorn hens on a thyroid preparation generally had only a very small toxic effect when given in one dose. A higher death rate occurred when given in small doses on consecutive days.

The hens fell into a moult, varying from slight to complete, 7 or 8 days after thyroid feeding. Severity depended on dose, season and feeding. The sensitivity to moult induction increased gradually from January to May, reaching maximum in summer. During natural moult in September hens were almost insensitive to thyroid preparation. This resistance decreased gradually until February-March.

After giving thyroid preparation, 1-3 eggs were produced, then followed a temporary interruption in egg production, varying in length with the individual, but usually in almost direct proportion to the quantity given. The maximum interruption lasted about 1.5 months despite larger doses. After moulting this maximum diminished to about 3 weeks. After an induced moult the birds rarely moulted again in autumn; yet egg production ceased as usual. Thus advanced moult cannot increase winter production. After induced interruption, normal egg production was resumed.

The influence of thyroid feeding on moult periodicity was probably controlled by another mechanism than that on egg production. A hypothesis was drawn up to explain these mechanisms.

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Keyword(s) poultry / fowls / zoology
Categories Poultry
Publication type PhD thesis
Language Dutch; Flemish
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