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The effect of dietary linoleic acid on the firmness of backfat in pigs of 85 kg live weight
Author(s) -
Whittington Frances M.,
Prescott Nicola J.,
Wood Jeffrey D.,
Enser Michael
Publication year - 1986
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740370807
Subject(s) - linoleic acid , food science , chemistry , zoology , biology , fatty acid , biochemistry
Three groups of 15 female pigs were fed diets containing 0.8%, 1.1%, or 1.8% linoleic acid from 20 to 35 kg followed by 1.0%, 1.2% or 1.4% linoleic acid respectively from 35 kg to slaughter at 85 kg live‐weight. Pigs grew at similar rates on all three diets and had similar proportions of carcass fat. The mean proportions of linoleic acid in the backfat lipids were 8.6%, 11.0%, and 13.9% respectively as the amount of the diet increased. There was a significant correlation between the concentration of linoleic acid in the inner backfat lipid and P 2 backfat thickness for those animals on the high and medium linoleic acid diets but not for those on the low diet. Backfat from pigs fed the high linoleic acid diet was softer than that from the other two groups of pigs which could not be distinguished using the subjective finger probe method. Using a mechanical probe backfat consistency was distinguished between all three groups and was inversely correlated ( r =−0.775, P <0.001) with the concentration of linoleic acid in the lipid. However, none of the pigs had fat which was too soft for bacon production based on either consistency data or linoleic acid content. If 15% linoleic acid is taken to be the maximum acceptable in bacon, then extrapolation of the regression of linoleic acid concentration on backfat thickness suggested that only the 1.4% linoleic acid diet is likely to result in unacceptably soft fat as pigs become leaner. However, this high concentration, although frequently present in current feeds, is not necessary since it is twice that recommended for normal growth and development of pigs.