Carcass Classification Measurements in Pigs as Affected by the Operator and Abattoir

The aim of the present study was to test a possible way of statistical checking of the measurement uncertainty in pig carcass classification; i.e. to monitor deviations between operators when measuring fat and muscle thickness used for meat percentage calculation. For that purpose, data were obtained from the official classification body Bureau Veritas for the year 2009, which comprised eight operators working in five abattoirs. An analysis of covariance was performed using a model with the effects of the operator, carcass weight as a covariate and their interaction. The equality of the regression lines (regression coefficients and intercepts) was tested for various operators. Regression lines differed significantly between the operators, however all pairwise comparisons were not conclusive since the operators work only in one or two abattoirs, the abattoirs have different suppliers i.e. different origin of pigs. In order to differentiate between the operator and the abattoir effect we further compared i) different operators working in the same abattoir and ii) same operator working in different abattoirs. The deviations in measurements of muscle and fat (often reflected also in meat percentage) were more important in the case of the same operator working in different abattoirs, than in the case of different operators working in the same abattoir

TEORETICAL AND PRACTICAL ASPECTS OF IMMUNOCASTRATION

Due to animal welfare problems and strong public opposition a ban on surgical castration of male piglets is foreseen in EU until the end of 2018. To cope with this major change in pig production, intensive research of possible alternatives is carried out, in particular fattening of entire (EM) and immunocastrated (IC) males. Present publication is focused on the immunocastration; its physiological principles and impact on metabolism, growth performance, carcass and meat quality, animal welfare, economics and public acceptability. Although current trends indicate that rearing of EM is more likely to become a regular practice for the provision of fresh meat market, immunocastration offers a good alternative, especially interesting for fattening pigs to higher age and weight (e.g. more extensive systems) due to the efficient elimination of boar taint and advantages in animal welfare and meat quality

Performance of Krškopolje pigs in extensive and intensive production systems

An observational study of growth performance was performed with Krškopolje pigs reared in extensive (EXT) and intensive (INT) production system. Pigs in INT system (n=6) were housed indoors and received a complete feed mixture, while EXT pigs (n=6) were kept in combined indoor/outdoor system and were fed a traditional meal (cooked root crops) and a mixture of ground grains. Growth performance and meat quality traits of longissimus dorsi (LD) muscle of pigs were assessed. Pigs were monitored from 86 to 224 days of age and were weighed 4-times (at 86, 129, 195, 224 days) with 4 growth stages (25-45, 45-75, 75-90 and 90-120 kg) considered. Overall INT pigs achieved 49 % higher daily gain and were heavier at slaughter than EXT pigs (88 vs. 120 kg, P<0.001). Growth rate of INT and EXT pigs was similar (443 vs. 464 g/day) from 25-45 kg, whereas EXT pigs grew slower than INT pigs in the periods 45-75 and 75-90 kg (445 vs. 853 and 505 vs 893 g/day, respectively). In the last period (90-120 kg) only INT pigs were monitored and they exhibited a decline in growth rate (580 g/day) compared to the previous two periods. Due to higher body weight (BW) at slaughter, INT had thicker backfat than EXT pigs (40 vs. 22 mm, P<0.000), however at equal BW (88 kg), no differences were noted. EXT pigs exhibited lower CIE L* (P=0.044) and higher CIE a* (P=0.003) colour parameters of LD (i.e. darker, redder LD colour), indicative of more oxidative muscle metabolism of EXT pigs

Performance of Krškopolje Pigs in Extensive and Intensive Production Systems

An observational study of growth performance was performed with Krškopolje pigs reared in extensive (EXT) and intensive (INT) production system. Pigs in INT system (n=6) were housed indoors and received a complete feed mixture, while EXT pigs (n=6) were kept in combined indoor/outdoor system and were fed a traditional meal (cooked root crops) and a mixture of ground grains. Growth performance and meat quality traits of longissimus dorsi (LD) muscle of pigs were assessed. Pigs were monitored from 86 to 224 days of age and were weighed 4-times (at 86, 129, 195, 224 days) with 4 growth stages (25-45, 45-75, 75-90 and 90-120 kg) considered. Overall INT pigs achieved 49 % higher daily gain and were heavier at slaughter than EXT pigs (88 vs. 120 kg, P<0.001). Growth rate of INT and EXT pigs was similar (443 vs. 464 g/day) from 25-45 kg, whereas EXT pigs grew slower than INT pigs in the periods 45-75 and 75-90 kg (445 vs. 853 and 505 vs 893 g/day, respectively). In the last period (90-120 kg) only INT pigs were monitored and they exhibited a decline in growth rate (580 g/day) compared to the previous two periods. Due to higher body weight (BW) at slaughter, INT had thicker backfat than EXT pigs (40 vs. 22 mm, P<0.000), however at equal BW (88 kg), no differences were noted. EXT pigs exhibited lower CIE L* (P=0.044) and higher CIE a* (P=0.003) colour parameters of LD (i.e. darker, redder LD colour), indicative of more oxidative muscle metabolism of EXT pigs

An attempt to predict conformation and fatness in bulls by means of artificial neural networks using weight, age and breed composition information

The present study aimed to predict conformation and fatness grades in bulls based on data available at slaughter (carcass weight, age and breed proportions) by means of counter-propagation artificial neural networks (ANN). For chemometric analysis, 5893 bull carcasses (n=2948 and n=2945 for calibration and testing of models, respectively) were randomly selected from the initial data set (n≈27000; one abattoir, one classifier, three years period). Different ANN models were developed for conformation and fatness by varying the net size and the number of epochs. Tested net parameters did not have a notable effect on models’ quality. Respecting the tolerance of ±1 subclass between the actual and predicted value (as allowed by European Union legislation for on-spot checks), the matching between the classifier and ANN grading was 73.6 and 64.9% for conformation and fatness, respectively. Success rate of prediction was positively related to the frequency of carcasses in the class.info:eu-repo/semantics/publishedVersio

The Effect of the Abattoir on Beef Carcass Classification Results

The aim of the present study was to test a possible way of monitoring cattle carcass classification using a statistical approach. For that purpose the analysis of covariance (ANCOVA by SAS) was used with the fixed effect of the abattoir, carcass weight (as a covariate) and their interaction. The analysis was based on the relationship between carcass weight and conformation or fatness grades. We tested if the regression lines of individual abattoirs differ from the average. The analysis comprised data for young bulls of Simmental breed slaughtered in Slovenia in the period from 2007 to 2010 (52,624 records). Results showed that in many abattoirs the assessment of conformation and fatness deviates significantly from the average, i.e. regression lines for several abattoirs differ significantly from the average (population) line. Differences were more important for the conformation than fatness. The statistical process control using the analysis of covariance can be used for additional monitoring of cattle carcass classification

Differences in Carcass and Meat Quality between Organically Reared Cocks and Capons

The aim of the present study was to compare carcass and meat quality traits of ecologically reared capons and cocks. The experiment comprised 60 layer-type Slovenian hybrid Prelux-G chickens. Half of the animals were caponized at the age of 52 days (app. 0.5 kg body mass) and another half were left entire males. All chickens were reared on the same farm respecting requirements for ecological farming. Chickens were fed commercial feed mixtures combined with the free access to pasture. After the slaughter (185 days), the chickens were dissected and main carcass parts were weighed. Meat quality (pH, colour, water-holding capacity) and chemical composition (protein, water, intramuscular fat) were determined. Birds of both groups had similar weight of carcass and body parts, except for weight of the thighs with drumsticks and off al weight, which were significantly lower in capons. The main differences in carcass traits appeared in the abdominal fat tissue. Capons had more abdominal fat. Meat physico-chemical characteristics (pH, drip loss) were similar in both groups, except for the colour. Capons had lighter (higher Minolta L*value) and less red (lower Minolta a* value) colour of meat as cocks. There was no difference between capons and cocks in the content of muscle proteins, water and intramuscular fat

Classification of dry-cured hams according to the maturation time using near infrared spectra and artificial neural networks

An attempt to classify dry-cured hams according to the maturation time on the basis of near infrared (NIR) spectra was studied. The study comprised 128 samples of biceps femoris (BF) muscle from dry-cured hams matured for 10 (n=32), 12 (n=32), 14 (n=32) or 16 months (n=32). Samples were minced and scanned in the wavelength range from 400 to 2500 nm using spectrometer NIR System model 6500 (Silver Spring, MD, USA). Spectral data were used for i) splitting of samples into the training and test set using 2D Kohonen artificial neural networks (ANN) and for ii) construction of classification models using counter-propagation ANN (CP-ANN). Different models were tested, and the one selected was based on the lowest percentage of misclassified test samples (external validation). Overall correctness of the classification was 79.7%, which demonstrates practical relevance of using NIR spectroscopy and ANN for dry-cured ham processing control. Key words: dry-cured ham, classification, near infrared spectroscopy, artificial neural network

Accuracy of Near Infrared Spectroscopy to Predict Quality of Pork and Pork Products Including Samples of Krškopolje and Turopolje Pigs

Study demonstrates the preliminary results of the evaluation of pork and pork products of local Slovenian (Krškopolje) and Croatian (Turopolje) pig breeds using near infrared spectroscopy (NIRS) conducted in the frame of European Union H2020 project TREASURE. For that purpose, samples from meat and products of two local pig breeds were collected, scanned with near infrared spectroscopy apparatus and chemically analysed (for proximate composition, fatty acids composition, proteolysis index, salt content and water activity). Data obtained were added to the database of previously collected samples and prediction models were recalibrated and reassessed. In general, NIRS calibration models are considered to be fit for purpose when the requirements (chemometric parameters) for screening purposes are met. In the present study, the quality of recalibrations using the samples from local pig breeds confirmed practical applicability for majority of studied quality traits. Further efforts are needed to enlarge the database with additional samples from local pig breeds to improve the robustness of the models and to test the calibrations on the independent sets of samples (i.e. with external validation)