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Fat quality in lean pigs

172 pages
Agricultural and fisheries research
Animal production
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Meat Research Institute
Special Report No.2
Fat Quality in Lean Pigs
Commission of the European Communities Meat Research Institute Special Report No. 2
A Workshop in the
CEC Programme of Coordination of Research on Animal Husbandry,
held in Brussels, Belgium, 20-21
September 1983
Edited by J.D. Wood
AFRC Meat Research Institute
Langford, Bristol, UK
Sponsored by the Commission of the European Communities,
Directorate-General for Agriculture. Coordination of
Agricultural Research Meal Research Institute Special Re|x>rts are issued by
the Agricultural and Food Research Council
Meat Research Institute
BS18 7DY, UK
Document No. EUR 8901 EN of the
Commission of the European Communities,
Directorate-General Information Market and Innovation,
© ECSC, EEC, EAEC, Brussels and Luxembourg, 1984
All rights reserved. No part of this publication may be produced,
stored in a retrieval system or transmitted in any form or by any
means, mechanical, photocopying, recording, or otherwise, without
prior permission.
Legal Notice
Neither the Commission of the European Communities nor any person
acting on behalf of the Commission is responsible for the use which
might be made of the following information. CONTENTS
Page No.
Preface 1
Observations on fat quality in Irish pigmeat 3
S.N. Reid
Eat quality in pigmeat - U.K. 9
J.D. Wood
Pig fats and the manufacture and storage of meat products 15
J.II. Houben and B. Krol
Variations in the fat composition of raw and cooked pigmeat 27
J.P. Girard
Eat quality in lean pigs 36
D. KCihne
Fat quality in pigmeat with special emphasis on cured and
seasoned raw hams 43
P. Santoro
Some experience on measuring the quality of pork fat 47
P.A. Barton-Gade
The relationship between the composition and consistency of
pig backfat - 53
M. Enser
On the role of essential fatty acids in the metabolism of fat and
fatty acids in pigs 58
K. Christensen
Hormones and fat deposition in pigs 69
Influence of fatty acid intake on the fatty acid composition
of the backfat in pigs 74
F. Berschauer
The energy value of dietary fats in pig rations and their
influence on lipogenesis 83
R.O. De Wilde
Energy value of vegetable fats for pigs and poultry 88
W. Eeckhout, G. Fontaine and R. Deschrijver
Feeding effects on fat deposition and fat quality 9
A. Madsen
Environmental effects on carcass traits in the pig 104
W.H. Close
Genetic effects on fat deposition and fat quality in growing
lean pigs 109
S.H.M. Metz
Effects on the distribution of fat deposition 117
P. Walstra, P.L. Bergstrom and G. Mateman
Genetic and sex effects on fat deposition and quality 126
G. Gcri
Sex effects on the deposition and quality of fat in
lean pigs 130
B. Desmoulin
Sex differences in fat composition 145
P. Allen
Conclusions 161
List of participants3 PREFACE
This publication contains the proceedings of a workshop on 'fat
quality in loan pigs' held in Brussels, Belgium on 20-21 September 1983.
In most European countries during the last 20 years, pigmeat has
become considerably leaner because of the demands of consumers. The
trend has also been valuable to producers because of the lower feed costs
of lean compared with fat tissue. In some countries, however, meat
traders are now saying that the reduction in fat content has gone far
enough. These people believe that further reductions will lower the
quality of the carcass tissues in various ways and lead to lower
consumer satisfaction. There has been little work on this topic but
most of the criticisms of lean pigs centre on the quality of the fat
tissues themselves. Thus, very lean pigs are said to have soft,
'floppy' backfat which has an unsightly grey colour and tends to
'separate' relatively easily from muscle.
There are important implications if such claims are true. The
direction of large-scale breeding programmes might have to be changed,
processing techniques modified, heavier carcass weights considered and
so on but as a first step it was thought necessary to review the current
position in the various EEC countries, determine whether there was
indeed a widespread problem and consider possible solutions. Experts
in production, nutrition, processing, biochemistry and physiology were
therefore brought together in this workshop to share knowledge of the
factors controlling fat growth in pigs and the implications for further
reductions in fatness. For convenience the workshop was conducted in
A parts: an introductory part on fat quality in pigmeat in which a range
of national views and experiences was considered followed by:
biochemistry and physiology; feeding effects; and genetic and sex
effects. The workshop was financed by the Commission of the European
Communities from the Directorate General for Agriculture budget for
coordination of agricultural research. Representatives from the
different member states of the European Community participated in the
workshop which was formally introduced by Professor A.J. Bailey,
Director, Agricultural and Food Research Council Meat Research
Institute, Langford, Bristol, U.K.
J.D. Wood
S.N. Reid
Meat Research Department
The Agricultural Institute
Co. Dublin
As in other countries over the past ten years, there has been a
significant movement in Ireland to the production of lighter, leaner pigs
for slaughter at commercial pig processing plants. In 1982 out of
1.4 x 10 pig carcasses graded in Irish plants, 76.5% were placed into
the top lean 'A special' (AS) grade compared to 66.6% in 1977 and
48.17" in 1973. With changing trends in carcass composition and quality,
processors are obviously interested in any differences in processing
characteristics that will affect economic returns and consumer
acceptability of the end-product. At the introduction of non-castration
policies by pig producers to provide better production returns, the
industry became acutely aware of the lower yields in processing boar
carcasses into bacon sides and also of the quality differences existing
between these and other carcasses.
The trend towards the use of leaner pigs has raised questions
regarding the quality of the fat on lean carcasses. Although general
comments regarding the softer fat on lean carcasses are often made,
the extent of the problem and the economic importance of this and other
fat quality defects have not been quantified. In preliminary work in
this area an assessment was made of the fat quality on a limited number
of lean pork carcasses and bacon sides and also to get an insight of
industry views, a survey of processor opinions on the existence and
significance of lower fat quality in lean pigs was carried out.
A total of one hundred and forty one lean pork carcasses (76 boar
and 63 gilt) from five factories were subjectively assessed for firmness,
colour and presence of splitting of the back fat tissues. All carcasses
had been classified by factory personnel on the day of slaughter into the
'A special' (AS) grade, which is reserved for carcasses of 38 - 68 kg
weight-range with maximum back fat measurements of 22, 24 and 42 mm
for loin, mid-back (last rib) and shoulder sites respectively.
I'valuations were carried out after overnight chilling as the carcasses
3 TABLE 1 Fat depth measurements* on very lean (VLC) and lean
(LC) pork carcasses (mm)
No of carcasses Loin Mid-back Shoulder
Boar 33 8.9 10.5 11.1 43 17.8 28.0 30.4
Gilt 24 41 9.7 12.9 12.1 18.0 29.6 32.1
* Means - measurements include skin thickness
TABLE 2 Assessment of fat firmness* on very lean (VLC) and
lean (LC) pork carcasses
, , .,,-, , n Significance of
Lean category VLC LC . .= . c
3 ' Lean effect Se> Sex effect
Boar 3.0 3.4
Gilt 3. 3.66 4. 4.00 NS P < .05
Boar 3.2 3.7
Gilt 3.6 6 4. 4.3 3 P <: .05 NS
Boar 4.2 4.4
Gilt 5. 5.00 5. 5.00 NS P< .01
"Mean scores on scale 1, very soft to 7, very hard
TABLE 3 Assessment of fat colour* on very lean (VLC) and lean
(LC) pork carcasses
Lean category VLC LC , „ . c rr .
Lean effect Sex effect
Boar 4.4 3.5
Gilt 4. 4.5 5 4. 4.11 P P < .0011 NS
Boar 4.3 3.9
Gilt 4.66 4. 4.22 N NS S NS
Boar 4.2 4.0
Gilt 4. 4.66 4. 4.44 N NS S NS
'Assessment on scale 1, very grey to 7, very white