HAM QUALITY AND ITS RELATIONSHIP TO CARCASS QUALITY I. Ultrasonic and other measurements Unto Uusisalmi Department ofAnimal Breeding, University of Helsinki Received January 28, 1971 Abstract. Ham quality and its relationship to carcass quality were studied in Landrace and Yorkshire pigs at the Puistola testing station. The research material was as follows: 1) ultrasonic and other measurements and points evaluation of 236 live pigs in three weight classes, and conventional carcass evaluation of these pigs; 2) ultrasonic and other measurements and points evaluation of 97 live pigs, determinations of the specific weight of the ham, and the dissection results on the left half of the carcass. The subjective points evaluation of ham performed on the live pigs did not correlate with the subjective points evaluation made on the carcasses. Nor did the exterior measurements made on the ham provide sufficient information about the slaughter quality of the ham. By means of stepwise multiple regression analysis, estimations were obtained for the skin -f- -fat and meat + bone components of the most valuable part of the carcass and of the ham. In these estimations the most important were the dissection results and specific weight of the ham and the ultrasonic measurements. The statistically significant effect of the slaughter weight emerged to such an extent that corrections according to slaughter weight were found necessary in the dissection analysis. The ham, like the back, is one of the most valuable parts of the pig’s carcass. The ham quality has consequently been a matter of interest to animal breeders for decades. Ham quality of both live animals and carcasses was evaluated in points up to the 19605. The development of technical equipment and methods of measurement has gradually brought about a change in the evaluation of the ham by introducing objective methods. Objective measurements of ham quality that make use of technical devices include linear measurements, measurements ofareas, determinations of specific weight, ultrasonic meas- urements and isotope measurements. Increasing use has been made of various degrees of cutting and dissection of the ham and the carcass as a means of comparing the results obtained in the above ways and also as a direct method of ham evaluation (Blendl 1966 and Partanen 1969). The aim of the present study is to analyse the possibilities of measuring the slaughter quality of the ham 1) on live pigs at various stages of development, and 2) on the carcass; https://www.c-info.fi/en/info/?token=IouBZ4l_gtPlPz98.PRTTOE1jtk6dkLRTDqUsgw.8b6q-knR8mal83vQ4zpJbsM1aES7J9fhHbiv1U_kKfrhGJsoBlnCBuVU040h4SUB-2Cca7ynjogBr2C8yZdSsfTGH0AhN1d3HefvjRa1OAvkHy_fDmt_3zbY1KXthVvQTJ6Wr4fYS6LdD_LjaxU3Xi2hFfbRgIXL4BVE9A 130 and 3) to compare the methods of measurement as expressions of carcass quality; and 4) to examine the relationship between the ham quality and the carcass quality. It should be pointed out that this study does not examine the possibility of employing the isotope method in the measurement of ham quality. Preliminary tests have been made with K4O isotope (Takanen & Uusisalmi 1967, Maijala & Uusisalmi 1967) but further tests had to be abandoned owing to cost and other practical reasons. Material and methods The ultrasonic and other measurements made on Landrace and Yorkshire progeny testing pigs (n = 118 (J + 118$) at the Pig Husbandry Experiment Station at Puistola in 1965—66, in live weight classes of 20 kg, 60 kg and 90 kg. The final measurements were made one day before slaughter. Conventional carcass evaluation was made one day after slaughter. The ultrasonic and other measurements made on live progeny testing pigs (n = 97 $) at Puistola in 1966—67 and the carcass evaluation results on the same animals. After the conventional carcass evaluation the left half of the carcass was cut and dissected in the manner presented by Uusisalmi (1969 a). The specific weights of the ham and the shoulder were determined. Stepwise multiple regression analysis (SCC 1966) was done to explain the thickness of the back fat, the area of the musculus longissimus dorsi and the skin + fat components and meat -(- bone components of the ham and the most valuable part of the half carcass. In processing the material, use was made of a free model in which the programme selects as a new explanatory variable the variable that produces the greatest increase in the correlation coefficient. The programme employs the F-test as criterion for the factor to be added (F 2.000) or dropped (F < 2.000). Results 2 3 6 p i g s. Tables 1 and 2 show the averages, the standard deviations and the pheno- typical correlations of the ham points of carcass evaluation, the ham points obtained on live pigs (in live weight classes of 90, 60 and 20 kg) and some external measurements. The relationships between the ham points obtained on live pigs and the ham points obtained from carcass evaluation and the external measurements were slight, all the correlation coefficients being between 0.23 and —O.ll. Table 3 shows an estimationfor the area of the m. long, dorsi. This model was calcu- lated from the results of measurements on live pigs, by means of stepwise multiple re- gression analysis. The following measurements pertaining to the ham part occur therein as optional explanatory variables in the second, third and fourth places: width at haun- ches, fat measurement at 12 cm left of midline of back rump, and the ham points at live weight of 90 kg. The coefficient of the multiple determination of the m. long, dorsi, how- ever, is modest (R 2 = 0.287; R 2 % = 28.7) at nine steps. In a previous study Uusisalmi (1967) has presented an estimationfor back fat (R 1 % = 75.3) in carcass evaluation, calculated from ultrasonic and other measurements on live pigs by means of stepwise multiple regression analysis. This estimation did not include 131 Table 1. Averages and standard deviations of ham points from carcass evaluation, and of ham points and some external measurements of live pigs in various weight classes, at the Puistola Pig Husbandry Experiment Station (n = 236) in 1965—66. 90 kg live weight 60 kg live weitht 20 kg live weight X S X S X S Carcass evaluation Shape and size of hams, points (scale 9—15) 12.56 0.58 Live pigs Ham points (scale I—s)1 —5) 3.34 0.69 3.23 0.73 3.23 0.74 Width at haunches, cm 26.28 1.17 23.62 1.31 16.98 1.53 Measurement at haunches, cm 48.61 0.88 46.39 1.17 Ham measurement, cm 108.80 3.56 95.17 3.70 68.07 4.18 Table 2. The correlation of the ham points of the carcass evaluation with the ham points and some ex- ternal measurements obtained on live pigs at various classes of live weight at the Puistola testing station, n = 236. Characteristic from carcass evaluation Ham points live v Width at hauenhes weight classes live weight classes 60 kg 20 kg 90 kg 60 kg 20 kg90 kg Y,X Ya Y, Y, Y 6 Ye Shape and size of hams 0.09 0.18 —0.03 0.23 0.20 —O.ll Measurement at haunches Ham measurement live weight classes live weight classes 90 kg 60 kg 20 kg 90 kg 60 kg 20 kg X Y, Y„ Y, YlO Y„ Yj, Shape and size of hams 0.19 0.14 —0.02 0.00 —0.17 r > 0.13 signif. at 5 % level r > 0.17 » 1 % » r > 0.22 » 0.1 % » other measurement results pertaining to the ham than the three fat measurements on the rump. 9 7 pigs. Table 4 shows how the skin + fat part of the ham was explained by means of stepwise multiple regression analysis. The optional explanatory variables were the evaluation and measurement results obtained on live pigs, the results of conventional carcass evaluation, and the specific weight of the ham (a total of 32 characteristics). The specific weight of the ham, which was included at the first step, alone explained 61.9 per cent of the total variation of the skin -f- fat part of the ham. The estimation 132 Table 3. Area of the m.long. dorsi explained by means of stepwise multiple regression analysis. The op- tional explanatory variables are the ultrasonic measurements, external mesurements and results of points evaluation on live pigs at the weight of 90 kg, a total of 30 characteristics (n = 236). Step Characteristics Cumulative r R R 2 % 1 Side fat 9 cm left —0.43 0.427 18.2 2 Width at haunches 0.18 0.465 21.6 3 Rump 12 cm left (fat) —0.13 0.491 24.2 4 Ham points 0.20 0.504 25.4 5 Measurement behind shoulders —0.13 0.514 26.4 6 Shoulder 12 left (fat) —0.29 0.520 27.0 7 Muscle depth 9 cm left 0.28 0.527 27.7 8 Side fat 8 cm left —0.37 0.531 28.2 9 Circumference of carcass —0.04 0.536 28.7 r > 0.13 signif. at 5 % level r > 0.17 » at 1 % » r > 0.22 » at 0.1 % » Fig I. Width and measurement at the haunches. The sites of ultrasonic measure- ments at the ham. 133 Table 4. Skin ■+■ fat part of the ham is estimated by means of stepwise multiple regression analysis. Op- tional explanatory variables are results of measurements and determinations on live animals, of conven- tional carcass evaluation and specific weight of ham. n = 97. Step Characteristics Cumulative r R R 2 % 1 Specific weight of ham —0.79 0.787 61.9 2 Rump 12 cm left (fat on live pigs), mm 0.60 0.816 66.6 3 Carcass weight, kg 0.16 0.832 69.2 4 Back fat (from carcass), mm 0.62 0.845 71.4 5 Feed consumption, fu/kg 0.26 0.854 72.9 6 Rump 15 cm left (fat on live pigs), mm 0.26 0.859 73.8 7 Ham measurement (on live pigs), cm 0.16 0.864 74.6 r > 0.20 signif. at 5 % level r > 0.26 » » 1 % » r > 0.33 » » 0.1 % » Table 5. Meat + bone part of the ham is estimated by means of stepwise multiple regression analysis. Optional explanatory variables are results of measurements and determinations oh live animals, of con- ventional carcass evaluation and specific weight of ham. n = 97. Step Characteristics Cumulative r R R 2 % 1 Carcass weight, kg 0.55 0.547 29.9 2 Fat/meat ratio, % —0.54 0.758 57.5 3 Wither (fat on live pigs), mm —0.45 0.780 60.8 4 Length of carcass, cm —0.20 0.795 63.2 5 Hams (points of live pigs) 0.37 0.814 66.3 6 Rump b (fat on live pigs), mm —0.32 0.826 68.2 7 Depth of muscle 8 cm (on live pigs), mm 0.32 0.837 70.1 8 Witdh at haunches, cm 0.22 0.941 70.7 9 Rump 15 cm left (fat on live pigs), mm —0.15 0.844 71.2 r > 0.20 signif. at 5 % level r > 0.26 » » 1 % » r > 0.33 » » 0.1 % » also includes the following measurements of the ham obtained with ultrasonic apparatus: rump 12 cm left and rump 15 cm left. Altogether, the R 2 % rose to 74.6. The meat -f- bone part of the ham (Table 5) is explained in terms of the same 32 characteristics as was the skin + fat part. As fifth were included in the model the ham of live pigs. Thus the points evaluation of the ham of live pigs, too, seems to be of signi- 134 ficance in the evaluation of the ham quality. The model further includes three other measurement results pertaining directly to the ham. Altoghether, the R 2 % rose to 71.2. Table 6 shows the multiple correlation of the dissection results of the various parts of the carcass, with the estimations of skin -f- fat and meat -f- bone parts of ham. Between the estimation of the skin + fat part of the ham and the skin + fat component of the most valuable part of the carcass, R = 0.84 and R 2 % = 71.2; between the estimation of the meat -|- bone part of the ham and the meat + bone component of the most valuable part of the carcass, R = 0.82 and R 2 % = 67.1. The estimations calculated to explain the two components of the ham are thus also good measurements for the skin + fat and meat bone components of the most valuable part of the carcass. Tables 7 and 8 show the estimations for the skin -)- fat and meat + bone components of the most valuable part of the carcass. The optional explanatory variables were the Table 6. The multiple correlation of the following dissection results with the characterics included in the estimations of skin+fat and meat + bone parts of ham. Cf. tables 4 and 5. Dissection results Characteristics of estimations of a) skin+fat of ham b) meat+ bone of ham R R» % R R s % Skin + fat of ham, g 0.864 74.6 0.682 46.5 Meat + bone of ham, g 0.715 51.1 0.844 71.2 Skin + fat of shoulder, g 0.514 26.4 0.619 38.3 Meat + bone of shoulder, g 0.638 40.7 0.589 34.7 Skin fat of ham + shank, g 0.861 74.1 0.614 37.7 Meat + bone of ham + shank, g 0.712 50.7 0.851 72.4 Ham + shank, g 0.667 44.5 0.727 52.9 Skin + fat of the most valuable part, g 0.844 71.2 0.774 59.9 Meat + bone of the most valuable part, g 0.790 62.4 0.819 67.1 Ham, % of carcass 0.363 13.2 0.601 36.1 Skin + fat of back, g 0.722 52.1 0.710 50.4 Meat -|- bone of back, g 0.533 28.4 0.613 37.6 Fat of ham, g 0.874 76.4 0.652 42.5 Meat of ham, g 0.709 50.3 0.874 71.7 Bone of ham, g 0.611 37.3 0.571 32.6 Ham, g 0.670 44.9 0.743 55.2 Fat % of ham 0.894 79.9 0.738 54.5 Meat % of ham 0.841 70.7 0.779 60.7 Characteristics included in estimations: a) Specific wt. of ham b) Carcass weight Rump 12 cm left (fat on live pigs) Fat/meat ratio, % Carcass weight Wither (fat on live pigs) Back fat (from carcass) Length of carcass Feed consumption Hams (points from carcass) Rump 15 cm left (fat on live pigs) Rump b (fat on live pigs) Ham measurement Depth of muscle 8 cm (on live pigs) Witdh at haunches Rump 15 cm left (fat on live pigs) 135 Table 7. Skin+fat component of the most valuable part of the carcass (hams+carrö-fback-(-fore back-f shoulders-(-kidney fat) is estimated by means ofstepwise multiple regression analysis. Optional explanatory variables are results ofmeasurements and determination on live animals, ofconventional carcass evaluation and specific weights of ham and shoulders, a total of 29 characteristics, n = 97. Cumulative Step Characteristics r R R* % 1 Specific weight of ham —0.72 0.719 51.7 2 S. o. 1., mm 0.60 0.813 66.1 3 Live weight, kg 0.36 0.840 70.5 4 Back fat (from carcass), mm 0.72 0.859 73.8 5 Specific weight of shoulder —0.68 0.877 76.8 6 Rump 12 cm left (fat on live pigs), mm 0.61 0.885 78.3 7 S. o. 1. (dropped from model), mm 0.60 0.884 78.1 8 Carcass weight, kg 0.20 0.886 78.5 9 Hams (points of live pigs) —0.16 0.890 79.1 10 Rump 12 cm left (dropped from model) 0.59 0.893 79.7 11 Carcass weight, kg 0.20 0.892 79.6 12 Wither (fat on live pigs), mm 0.52 0 894 80.0 r > 0.20 signif. at 5 % level; r > 0.26 signif. at 1 % level; r > 0.33 signif. at 0.1 % level Table 8. Meat-(-bone component of the most valuable part of the carcass is estimated by means of stepwise multiple regression analysis. Optional explanatory variables are results of measurements and determi- nations on live animals, of conventional carcass evaluation and specific weight of ham and shoulder, n = 97. Cumulative Step Characteristics r R R* % 1 M. long, dorsi, cm* 0.61 0.605 36.6 2 Carcass weight, kg 0.54 0.727 52.9 3 Back fat (from carcass), mm —0.46 0.823 67.8 4 Specific weight of ham 0.55 0.846 71.5 5 Hams (points from carcass) 0.25 0.854 73.0 6 Rump 6 cm left (fat on live pigs), mm —0.41 0.859 73.8 7 S. o. I. (from carcass), mm —0.32 0.865 74.8 r > 0.20 signif. at 5 % level; r > 0.26 signif. at 1 % level; r> 0.33 signif. at 0.1 % level measurement results and ponits evaluation results oflive animals, the results of conventio- nal carcass evaluation, and the specific weights of the shoulder and the ham (a total of 29 characteristics). In the estimation explaining the skin + fat component, the specific weight of the ham (R 2 % =51.7) was included first; and, in the estimation explaining 136 the meat + bone component, fourth. Further, the ham points from carcass evaluation still occur almost significantly in the meat + bone estimation. The R 2 % of the skin + fat component has risen to 80.0 and that of the meat -|- bone component to 74.8. Con- versely, it can be seen from Table 9 that the characteristics occurring in the estima- tions calculated for the skin -(- fat and meat -)- bone components of the most valuable part of the carcass measure the skin -f- fat of the ham (R 2 % = 71.6) and the meat + bone of the ham (R 2 % = 59.6). Estimations have been constructed for the skin + fat and meat -f- bone components of the most valuable part of the carcass (Uusisalmi 1969 b) from the same measurement results as in Tables 7 and 8, with the difference, however, that the skin -)- fat and meat + Table 9. The multiple correlation of the following dissection results with the characteristics included in the estimations of skin+fat and meat+bone components of the most valuable part of carcass. Cf. tables 7 and 8. Dissection results Characteristics of estimations of a) skin+fat component b) meat+bone component R R 2 % R R 2 % Skin+ fat of the most valuable part, g 0.894 79.9 0.864 74.6 Meat+bone of the most valuable part, g 0.794 63.7 0.865 74.8 Most valuable part of carcass, g 0.829 68.7 0.837 70.0 Skin+fat component, % of carcass 0.881 77.6 0.859 73.8 Meat+ bone component, % of carcass 0.816 66.6 0.839 70.4 The most valuable part, % of carcass 0.306 9.4 Skin+fat of shoulder, g 0.870 75.7 0.664 44.1 Meat+bone of shoulder, g 0.669 44.8 0.646 41.7 Skin+fat of shoulder+shank, g 0.860 74.0 0.676 45.7 Meat+ bone of shoulder + shank, g 0.634 40.2 0.615 37.8 Shoulder+shank, g 0.634 40.2 0.435 18.9 Skin+fat of ham, g 0.846 71.6 0.826 68.2 Meat+bone of ham, g 0.734 53.9 0.772 59.6 Skin+fat of ham+shank, g 0.849 72.1 0.838 70.2 Meat+bone of ham+shank, g 0.723 52.3 0.766 58.7 Ham+shank, g 0.678 46.0 0.708 50.1 Skin+fat of back, g 0.777 60.4 0.756 57.2 Meat +bone of back, g 0.605 36.6 0.689 47.5 Skin+fat of back parts, g 0.790 62.4 0.756 57.2 Meat +bone of back parts, g 0.629 39.4 0.682 46.5 Back parts, g 0.501 25.1 0.531 28.2 Characteristics included in estimations: a) Specific wt. of ham b) M. long, dorsi Back fat (from carcass) Carcass weight Specific wt. of shoulder Back fat (from carcass) Shoulder 12 left (fat on live pigs) Specific wt. of ham Carcass weight Hams (points from carcass) Hams (points from live pigs) Shoulder 6 cm left (fat on live pigs) Rump 12 cm left (fat on live pigs) S. o. 1. (from carcass) Wither (fat on live pigs) 137 bone parts of the ham were added to the explanatory variables of the 1969 b study. In the skin + fat estimation of the most valuable part of the carcass there was first included the skin + fat of the ham (R 2 % = 57.2); and in its meat + bone estimation the meat + bone of the ham (R 2 % = 68.6) was included first and the specific weight of the ham second. Altogether, the R 2 % of the skin + fat estimation for the most valuable part of the carcass was thus 82.1 at the sixth step and 85.0 at the twelfth step for the meat + bone estimation. Adding the results of the dissection of the ham to the results of the evaluation of the live animal and of the carcass and to the determinations of specific weight, thus improves the information (by 7.5—13.8 %) obtained concerning the fattiness and the meatiness of the most valuable part of the carcass. Discussion It was established earlier that the points evaluation of the ham made on live pigs in various weight classes hardly correlated with the subjective points evaluation in carcass evaluation. The ham points of the carcass evaluation were obtained from official progeny testing, and the evaluation of the live pigs was carried out by the author together with the director of the Puistola Pig Husbandry Experiment Station or some other member of the staff. The exterior measurements taken of the hams of live pigs also correlated poorly with the ham points of the carcass evaluation. Many research workers (Bratzler and Margetum 1953, Kuhn 1957, Haring and Sieburg 1957, Fewson and Le Roy 1959, Pedersen 1961) have come to the result that a points evaluation and exterior measurements carried out on live pigs do not show a sufficient correlation with the carcass quality established from the carcass. It has, likewise, been shown that conventional carcass evaluation in respect of the ham has been merely a subjective judgement. It emerges, on the other hand, that indirectly the ham quality has been affected, e.g. by measurements of back fat and side fat and measurements of the area of the m. long, dorsi. Conventional carcass evaluation gave no confirmation of he ultrasonic measurements made on ham (236 pigs). The weight and the ratio between meat and fat of the hams were not known. The need to dissect the carcasses was obvious. In the second stage of the study the left half of the carcass was dissected. The ham points obtained on live pigs correlated with the skin + fat component of the most valu- able part of the carcass as follows: r = —0.16; and with the meat + bone component as follows: r = 0.34. It was found, on the other hand, that measurements made with ultrasonic instrument on live pigs at the hams at distances of 6 and 12 cm from the midline of the back were of significance in establishing the fattiness of the ham. The correlations of these measurements with the fat of the ham were r = 0.47 and r = 0.60. The points evaluation of the ham done on live pigs was also found to be of significance in determining the meatiness of ham: r = 0.38. It should be emphasized that slaughter weight had a very significant or a significant effect on the skin -)- fat part and the meat -(- bone part of the ham and on the ham points. The present study established the great importance of the specific weight of the ham for the measurement of the skin + fat part of the ham and the skin + fat component of the most valuable part of the carcass. The specific weight of the ham is a better measure of the fattiness of the ham than is e.g. the average back fat or the 5.0.1. (Uusisalmi 1969 b). 138 It may be mentioned that the specific weight of the shoulder in this material is smaller. It does appear, however, in an estimation constructed for the skin -f- fat component of the most valuable part, at the second step. The skin -f- fat component of the ham was first in the estimation. The inclusion of the meat + bone part of the ham in the stepwise multiple regeression analysis caused an increase of c. 10 per cent in the information obtained about the meat -f- bone component of the most valuable part of the carcass as compared with the information obtained about the meat + bone component by means of measurement of the live animal, conventional carcass evaluation and the specific weight of the ham. Estimations were made by stepwise multiple regression analysis in which measurements made on live animals, results of carcass evaluation and dissection results are concurrently present as optional explanatory variables. This was done because it was thought that selection of insemination boars may be made in the future as follows: The first test of phenotype of young boars will be performed at an earlier stage than at present. Most of the boars will then be castrated in order to reduce the costs of testing. The uncastrated boars will then be reared in experimental-station conditions until the semen is obtained from them. Naturally, the problems of collecting and storing the semen will have to be solved before that time. After the semen has been obtained, the boars will be slaughtered and the carcasses evaluated and dissected to the extent necessary. The semen of the prime boars will be used expediently. In aiming at the stated objective, there will probably be reason to continue with research into the determination of the ham and its components. REFERENCES Blendl, H. M. 1966. Objektive Methoden zur Bestimmung des Schlachtkorperwertes beim Schwein als Hilfsmittel fur die zuchterische Selektion. Z-kunde 38: 234—246. Bratzler, L. J. & Margerum, Jr., E. P. 1953. The relationship between live hog scores and carcass measurements. J. Anim. Sci. 12: 856—858. Fewson, D. & Le Roy, H. L. 1959. Körpermessungen am lebenden Schwein als Basis zur Abschätzung des Fleisch- und Fettanteils. Z. Tierzucht. u. Z.-Biol. 73: 297—310. Haring, F. & Sieburg, H. 1957. Methoden zur Bestimmung des Schlachtwertes am lebenden Schwein. Z-kunde 29: 291—303. Kuhn, J. 1957. Untersuchungen iiber Beziehungen zwischen der äusseren Form des Schweines und seiner wichtigsten Mast- und Schlachtleistungen anhand der bisher erschienenen in- und ausländischen Literatur. Diss. Bonn. Lakanen, E. & Uusisalmi, U. 1967. Lihan radioaktiivisuusmittaus ja sen hyväksikäyttö. Koetoim. j'a Käyt. 24: 9, 12. Maijala, K. & Uusisalmi, U. 1967. Erfarenheter av bestämmandet av skinkornas kvalitet med hjälp av K4O och nägra mätningar. Nord. Jordbr. forsk. 49; 365. Partanen, J. 1969. Mastleistungspriifungen in Finnland. Europäische Vereinigung fur Tierzucht, Schweinekomission, Helsinki 24. Juni 1969. Pedersen, O. K. 1961. Die Bedeutung des Exterieurs fur den Schlachtkorperwert beim Schwein. Z. Tierziicht. u. Z.-Biol. 75: 23—33. SCO 1966. Valikoiva regressioanalyysi (multiple stepwise regression analysis). State Computing Center. Dep. of Planning X 40, 1578. 139 Uusisalmi, U. 1967. Sian teurasominaisuuksien periytymisestä ja mittaamisesta (On the heritability and measurement of slaughter characteristics in pigs). Unpublished MS thesis, Univ. of Helsinki. » 1969 a. Vorläufige Ergebnisse iiber das Messen der Schlachteigenschaften beim Schwein. J. Sci. Agr. Soc. Finland 41: 50—59. » 1969 b. Carcass analysis as aid in pig breeding. Acta Agric. Scand. 19: 214—220. SELOSTUS KINKUN TEURASLAATU JA SEN YHTEYS RUHON TEURASLAATUUN I. TEURASLAADUN MITTAUKSET ELÄVISTÄ SIOISTA JA RUHOISTA Unto Uusisalmi Helsingin Yliopisto, Kotieläinten jalostustieteen laitos Mitattiin kinkun teuraslaatua ja sen yhteyttä ruhon teuraslaatuun maatiais- ja yorkshire-rotuisista kantakoesioista Puistolan koeasemalla vuosina 1965—67. 2 3 6 s i k a a. Elävistä eläimistä suoritettu kinkun pistearvostelu ja exteriöörimitat eivät sanottavasti korreloituneet ruhosta saatuun pistearvosteluun. Kinkun leikkely kudososiinsa osoittautui tarpeelliseksi ultraäänimittauksilla saatujen tulosten arvon toteamiseksi. 97 naarassikaa. Valikoivan regressioanalyysin avulla saatiin arvioita ruhon arvokkaimman osan sekä kinkun nahka + rasvalle ja liha + luulle. Arvioissa esiintyivät kinkun leikkelytulokset, ominais- painoja ultraäänimitat tärkeillä tiloilla. Ultraäänimitoista mm. silavamitta pakaralta (12 cm vasemmalle) korreloitu! erittäin merkitsevästi kinkun nahka + rasvaan (r = 0.60); samoin kinkun ominaispaino kinkun nahka + rasvaan (r = —0.79). Kinkun nahka rasva korreloitui erittäin merkitsevästi ruhon arvokkaimman osan nahka + rasva -komponenttiin (r = 0.76) ja kinkun liha + luu ruhon arvokkaim- man osan liha + luu -komponenttiin (r 0.83).