M. Candekpotokar et al., EFFECTS OF AGE AND OR WEIGHT AT SLAUGHTER ON LONGISSIMUS-DORSI MUSCLE- BIOCHEMICAL TRAITS AND SENSORY QUALITY IN PIGS/, Meat science, 48(3-4), 1998, pp. 287-300
The effect of increasing either age alone through feed restriction, or
both age and weight at slaughter, on the quality of the longissimus d
orsi muscle (LM) was investigated. Starting at 83 days of age and 32 k
g, 80 pigs were allotted within litter to four experimental groups. Al
l pigs were free of RYR1 mutated gene. Pigs were fed either ad libitum
(A100, A130) or restricted 30% (R100, R130) and slaughtered at either
100 kg (A100, R100) or 130 kg (A130, R130) body weight. Restricting f
eed intake in order to increase age at the same weight resulted in slo
wer growth, better feed efficiency and increased leanness, whereas inc
reasing age and weight simultaneously elicited slower growth, reduced
feed efficiency and fatter carcasses. Intramuscular fat (IMF) and musc
le collagen concentration were reduced by restricted feeding. Increase
in both age and weight of pigs resulted in lower water, and higher pr
otein and IMF concentrations. Although pigs were free of RYR1 gene, th
e PSE condition (defined as pH1 less than or equal to 5.9) developed i
n 25 carcasses, with a higher incidence in restricted pigs. PSE animal
s were excluded from the subsequent analysis of meat quality data. Fee
d restriction resulted in higher drip loss and lower a and c* (satura
tion index) values. Longer myofibril fragments in muscle of restricted
pigs on day I post mortem are indicative of slower maturation, while
longer fragments on day 4 in heavier pigs, suggest that the extent of
post mortem tenderisation could be negatively affected by the elevatio
n of slaughter weight. Feed restriction had no significant effect on m
eat sensory quality, whereas increase in both age and weight resulted
in lower tenderness, chewiness and mouth coating scores. Our results i
ndicate that increasing age at a given body weight, via feed restricti
on, reduced IMF and collagen concentrations, and the rate of post mort
em proteolysis, however, this had no significant impact on pork qualit
y assessed after 4 days of ageing. On the other hand, increasing both
age and weight at slaughter could alter pork texture, in spite of elev
ated IMF concentration. (C) 1998 Elsevier Science Ltd. All rights rese
rved.