| dc.description.abstract | 1. Torsken ved Vest-Grønland vokser senere enn vanlig etter at den er blitt kjønnsmoden. Hanfisken er ca. 5 cm lengere enn hunfisk av samme alder. Gjennomsnittsalderen var høy - 11.85 år - og lengden 77.2 cm. 2. Leveren var meget liten og fettfattig med en gjennomsnittlig lever og fettprosent på henholdsvis 2.54 g/100 g fisk og 30.0 g/100 g lever. Pr. kg fisk ga huntorsken ca. 1.4 ganger så meget lever og ca. 2.6 ganger mer tran enn hantorsken. 3. Denne magre lever vil gi meget lite tranutbytte ved vanlig damping. En må derfor benytte andre tranutvinningsmetoder (f. eks. en separatormetode). 4. Fettprosenten i leveren øker regelmessig med leverinnholdet. 5. Gjennomsnittlig var vitamin A- innholdet i tranen ca. 10 300 internasjonale enheter vitamin A pr. g (E3265Å = 5.42, faktor 1900), og vitamin A-reserven ca. 27 mg vit. A/kg rundfisk. 6. Opptil 12-13 år er vitamin A-reserven lik for begge kjønn og stiger linjert med ca. 1.65 mg vit. A/kg rundfisk pr. år. For eldre årganger stiger hunfiskens vitamin-reserve sterkere med alderen. 7. Forutsatt at vitamin A-reserven for en bestemt gjennomsnittsalder er den samme hvert år kan vitamin A-innholdet i tranen approksimativt beregnes av leverprosenten. ENGLISH 1. The cod at West-Greenland grows much slower than the Norwegian cod after maturity. After maturity and at a definite age the female is about 5 cm longer than the male. The average age of the fish in the 1949 season was high- 11.85 years- and the length 77,2 cm. 2. The livers were very small with low fat content. The average liver content was 2.54 g/100 g fish and the fat content of the livers 30.0 g/lOOg liver. On the average, the females gave about 1.4 times as much liver and about 2.6 times as much fat as the males. 3. These small livers yield too little fat with the usual steam rendering process. Other methods must be used, for example a centrifuge process. 4. The fat content of the livers increases with increase in the percentage of liver in the fish. 5. The vitamin A-reserve is equal for both sexes up to the age of 12 to 13 years, and rises linearly with the age of the fish with about 1.65 mg vitamin A/kg fish per year. For older fish (over 13 years) the females vitamin A-reserve rises faster with advancing age than does that of the male. 6. On the average the vitamin A-content of the liver oil in the 1949 season was about 10 300 international units per g. (E3265Å = 5.42, factor 1900), and the vitamin A-reserve ca. 27 mg vit. A/kg fish. 7. If the vitamin A-reserve of the West-Greenland cod of a definite age is the same each year, the vitamin A-content of the liver oil can be approximately predicted on the basis of the quantity of liver occurring in the fish. | |
