Livestock Production Science 65 2000 239–248 www.elsevier.com locate livprodsci
Genetic parameters for lean meat yield, meat quality, reproduction and feed efficiency traits for Australian pigs
1. Description of traits and heritability estimates
a , b
a
S. Hermesch , B.G. Luxford , H.-U. Graser
a
Animal Genetics and Breeding Unit , joint Institute of NSW Agriculture and The University of New England,
University of New England , Armidale, NSW, 2351, Australia
b
Bunge Meat Industries , Corowa, NSW, 2646, Australia
Received 15 September 1998; received in revised form 12 November 1999; accepted 9 December 1999
Abstract
Data from 1799 Large White and 1522 Landrace boars were used to obtain heritability and litter effect estimates for performance, carcass and meat quality traits applying a REML procedure fitting an animal model. Analysed traits included
average daily gain from three to 18 weeks of age ADG1 and average daily gain, feed intake and feed conversion ratio from 18 to 22 weeks of age. Carcass traits included two backfat measurements and one muscle depth measurement taken on the
live animal using realtime ultrasound and on the carcass using Hennesy Chong equipment. Further carcass traits included weight of the whole back leg BLW and weight of the ham LMW. Meat quality traits included pH recorded 45 min and 24
h after slaughter, colour of the m
. longissimus dorsi and m. multifidus dorsi, drip loss percentage and intramuscular fat content. For ADG1 heritability and litter effect estimates were 0.1060.05 and 0.2060.04 in Large White and
0.4860.09 and 0.0860.04 in Landrace. Data structure might have limited simultaneous estimation of these two effects. Heritability estimates ranged from 0.13 to 0.2760.04 to 0.05 for further performance traits and from 0.45 to 0.6260.05 to
0.07 for backfat measurements. Heritability estimates were lower for Hennesy Chong measurements in comparison to realtime ultrasound measurements. Heritability estimates for BLW and LMW were 0.2260.05 and 0.3860.07. Estimates
of heritabilities for meat quality traits ranged from 0.14 to 0.3560.04 to 0.06.
2000 Elsevier Science B.V. All rights
reserved.
Keywords : Pigs; Production; Carcass; Meat quality traits; Genetic parameters
1. Introduction
For successful pig production enterprise all econ- omically important aspects of producing pork have to
Corresponding author. Tel.: 1 61-267-73-3787; fax: 1 61-
be considered. Besides efficient lean meat growth the
267-73-3266. E-mail address
: skahtenbmetz.une.edu.au S. Hermesch.
reproductive performance of the sow and marketing
0301-6226 00 – see front matter
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240 S
. Hermesch et al. Livestock Production Science 65 2000 239 –248
aspects of pork are of increasing importance. Histori- Performance records included the animal’s weight
cally, reproductive performance and meat quality at 21 days of age, at 18 weeks of age when the
characteristics were not considered as feasible breed- animal entered the test station and at 22 weeks of age
ing objectives due to low heritabilities, difficulty of recorded shortly before slaughter. The trait recorded
measurement and lack of economic importance before start of test was growth rate from three to 18
McPhee, 1982. However, decline in pork quality weeks of age ADG1. During this period of time
and lack of improvement in reproductive traits animals were group penned in contrast to station
suggests that these areas require greater considera- testing where animals were single penned. Traits
tion Ollivier et al., 1990. recorded in the test station included growth rate
Meat quality has become a major concern in pig ADG2, daily feed intake FDINT and feed conver-
production. In Australia, genetic improvement for sion ratio FCR. Pigs were fed ad libitum in both
meat quality has been achieved by selection against housing systems.
stress susceptible pigs using the halothane test. Carcass traits included real time ultrasound mea-
Studies in Europe showed that in the absence of the surements and measurements taken in the abattoir
halothane gene meat quality characteristics still have with a Hennesy Chong grading machine. Real time
a genetic variation of 20 which could be used in ultrasound measurements were recorded the day
breeding programs de Vries et al., 1994b. Meat before slaughter on the live animal and included fat
quality can be described through a range of charac- depth at the P2 site which is located 6.5 cm of the
teristics but the meat quality deficiency which is of mid line at the last rib LFDP2 and fat and eye
most concern to the consumer is pale, soft and muscle depth between the third and fourth last ribs
exudative meat PSE Jeremiah, 1994. Its signifi- LFD3 4, LMD3 4. After a lairage time of 18 h
cance to the Australian pork industry was shown by pigs were slaughtered and backfat and muscle depth
a PRDC survey PRDC, 1993. The genetic vari- were recorded on the same sites using a Hennesy
ability of traits describing PSE meat is unknown for Chong grading machine FDP2, FD3 4, MD3 4. In
Australian pigs. The objective of this study was to addition, total weight of the left back leg BLW and
obtain genetic parameters for meat quality, carcass lean meat weight of the back leg LMW were
and performance traits as well as reproductive traits obtained on the day after slaughter as additional
of the sow. Within this first paper heritability esti- carcass characteristics. To obtain lean meat weight,
mates for production, carcass and meat quality traits the left back leg was derinded, defatted and slash
obtained from a commercial breeding herd are boned, excluding the hock muscles.
presented. Meat quality traits consisted of pH measured 45
min after slaughter pH45. Meat quality traits recorded 24 h after slaughter were taken on a chop
2. Material and methods including the loin eye area and the belly, which was
