FISHERY BULLETIN' : \ OL. 09. NO- I 



Table 



-Rates of gain, utilization of feed, and quantity of oil consumed by pigs fed diets containing 

 various percentages of menhaden oil. 



criterion of evaluation indicate that tlie.se cri- 

 teria did not differ significantly. 



Development of Carcasses 



The .yield of lean cuts was obtained as an 

 accumulative value for the four commercial lean 

 cuts — namely, hams, loins, shoulders (picnics), 

 and Boston butts. Ci'os.s-sectional measure- 

 ments of the longlsi^hnus dorsi muscle of the 

 loin were obtained by cutting- the loin at the 

 10th rib, tracing- the muscle area onto pajjer, 

 and measuring the perimeter of the area by 

 means of a ])lanimeter to convert the encom- 

 passed area to square centimeters. The thick- 

 ness of the backfat was based on an average of 

 three measurements taken at positions opposite 

 the first rib, the last rib. and the last lumbar 

 vertebra. 



Table 4 presents the data on the dressing per- 

 centage, lean-cut percentage, loiu/lssiiniis dorsi 

 area, and backfat thickness obtained from pigs 

 fed the various diets containing menhaden oil. 

 The analyses of variance for each criterion of 

 evaluation indicate that no significant differ- 

 ences occurred among these factors that reveal 

 the growth reaction of the pigs to their diet. 



Thus the pigs develojied uniformly during the 

 feeding trials. Consequently any differences 

 that may be found in the fatty acid composition 

 of the tissues should be related to the oil in the 

 diet rather than to markedly different growth 

 of the pigs. 



RELATION OF DEPOSITIONAL PATTERNS 

 TO FATTY ACIDS IN OIL FED TO PIGS 



In this section, we are concei-ned with the fol- 



lowing three sulyects: (1) the differences 

 found in the degree of saturation both within 

 and among tissues, (2) the fatty acids identified, 

 and (3) the relations of the quantity of fatty 

 acids fed to the quantity deposited in the var- 

 ious tissues. 



Differences Found in Degree of Saturation Both 

 Within and Among Tissues 



Described here are (1) the tissue samjiles 

 used, (2) the extraction of lipids, (.3) the prep- 

 aration of methyl esters, and (4) the quantita- 

 tive gas-liquid-chromatographic technique. 



Samples were taken from the outer and the 

 inner backfat tissue, the lo)igissi>nus dorsi, and 

 the liver in the following manner. From each 

 animal, a sample of backfat was obtained dor- 

 sally to the 10th to 12th ribs. This sample was 

 then divided into the "outer" and "inner" fat 

 layers. Samples of the muscle were taken from 

 the eye of the Io)u/issimiis dorsi at the 10th rib. 

 Samples of the liver were taken from the right 

 central lobe. All samples were i)!aced in vials, 

 Ijrotected with nitrogen, and held at —20° C 

 until the lipids were extracted from them. 



The lipids were extracted from the samples 

 by the homogenization of the tissue in a mechan- 

 ical blender with a 2: 1 mixture of chloroform 

 and methanol for 2 min. The solvent mixture 

 was added in the proportion of 5 ml of mixture 

 to 1 g of sami^le. The slurry was filtered through 

 a Buchner funnel, and the filter paper and the 

 nonfilteral)le portion were re-extracted for an- 

 other 2-min period. The filtrate was evaporated 

 in a rotary vacuum evaijorator over a 60° C wa- 

 ter bath. The dried sample was redissolved in 



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