Ann. Anim. Sci., Vol. 11, No. 1 (2011) 27 40

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1 Ann. Anim. Sci., Vol. 11, No. 1 (2011) Possibilities of using ultrasonography in breeding work with pigs. Part I Analysis of ultrasonic, ultrasonographic and dissection measurements of the most numerous breeds of pigs raised in Poland M i r o s ł a w T y r a, M a g d a l e n a S z y n d l e r - N ę d z a, R o b e r t E c k e r t Department of Animal Genetics and Breeding, National Research Institute of Animal Production, Balice n. Kraków, Poland Abstract The aim of the study was to determine the usefulness of ultrasonographic measurements in breeding work focused on fatness and meatiness evaluation in pigs. The possibility of using ultrasonographic devices for both live and postmortem evaluation of animals was investigated. In this first paper in a series, we characterized and measured the test animals using different measurement techniques. Subjects were gilts (100 kg b.w.) tested in Polish Pig Performance Testing Stations (SKURTCh). A total of 476 animals representing Polish Large White (n = 151), Polish Landrace (n = 149), Pietrain (n = 84) and Duroc (n = 92) breeds were studied. On the day prior to slaughter, thickness of backfat and m. longissimus dorsi was measured using a PIGLOG 105 ultrasound device and an ALOKA SSD 500 ultrasonographic device at locations corresponding to the measurement points used in live evaluation. On the next day, animals were slaughtered according to the Pig Testing Station method. Next, m. longissimus dorsi and the surrounding tissues were measured and dissection measurements were made. Based on all (live and postmortem) measurements taken in this study, it was found that gilts of all breeds had thicker fat on the back and thinner fat on the flank as measured behind the last rib. This was true for all measurement techniques. The meat content of these animals ranged from 58.6% in the Polish Large White breed to 66.9% in the Pietrain breed. The test animals were found to be a representative and uniform sample of the current population of pigs raised in Poland. They provide excellent material to validate the possibility of using ultrasonography for fatness and meatiness evaluation in pigs. Key words: pig, ultrasonographic measurements, ALOKA, PIGLOG The main objective of pig breeding is to improve the population for economically important traits. The level of these traits should reflect the needs of the meat industry and consumer preferences as well as making fattening profitable. The genetic improvement of meatiness in animals requires appropriate breeding and selection

2 28 M. Tyra et al. work in which animal evaluation plays a pivotal role (Różycki and Tyra, 2009). Recent years have seen a remarkable development of ultrasonography a diagnostic technique used in human and veterinary medicine as well as animal breeding. It is the only widely available method other than X-ray analysis which allows viewing the inside of the body without having to open it up. Furthermore, it has the advantage of being safe for both the investigator and the animal when compared to X-ray technique. The progress that has been achieved in recent years and the relatively low cost and ease of portability of ultrasound equipment made this technique fairly popular in animal breeding (Mörlein et al., 2005; Wall et al., 2004). However, high-quality images were not recorded and losslessly fed into the computer until the advent of digital video, digital photography and computer-assisted digital image processing. In the latest devices, appropriate graphics cards allow ultrasonographic equipment to be connected to a computer and the images obtained to be archived on electronic data carriers. Moreover, ultrasonographic measurement software allows the thickness of backfat and the height, width, cross-sectional area and circumference of m. longissimus dorsi to be dimensioned. It also enables dimensioning with simultaneous calculation of the area of any shape on the image. The measuring devices have also become more sensitive. Current ultrasonographic equipment offers 6- or even 8-bit resolution, which allows 64 and 128 grey levels, respectively, in the images obtained. These technical solutions ensure good reproduction of detail in the images, thus making image measurements more accurate. It is believed that the results obtained using this method will be more accurate than those obtained in the current station and live animal testing system. The benefit of increased accuracy of measurement should translate into greater breeding progress concerning the traits being improved. The aim of the study was to determine the usefulness of ultrasonographic measurement technique for breeding work with pigs. The possibility of using ultrasonographic devices for both live and postmortem evaluation of animals was investigated. The results obtained will be presented in a series of three papers: Part I characterization of test material and analysis of measurements obtained by different techniques; Part II estimation of relationships (correlations) between the measurements obtained using these techniques; and Part III development of regression equations to estimate carcass meat percentage using measurements taken from ultrasound images. In this first paper in a series, we characterized the test animals and analysed the results obtained using different measurement techniques. Material and methods Experimental material Subjects were gilts (100 kg b.w.) tested in Polish Pig Performance Testing Stations (SKURTCh). Animals having different meat contents were chosen from among the most numerous breeds in the Polish pig population. A total of 476 animals rep-

3 Using ultrasonography in breeding work with pigs 29 resenting Polish Large White (n = 151), Polish Landrace (n = 149), Pietrain (n = 84) and Duroc (n =92) breeds were studied. Animals were housed in individual pens and fed ad libitum on fine pelleted diet supplied from automatic feeders. The ingredient composition of the diets is detailed in Pig Testing Station methodology (Różycki and Tyra, 2010). Live measurements On the day before slaughter, backfat and muscle thickness was measured using a PIGLOG 105 device according to the performance test procedures (Eckert and Szyndler-Nędza, 2009), and m. longissimus dorsi and backfat thickness were measured ultrasonographically with an ALOKA unit at locations corresponding to the measurement points used in live evaluation. The following live measurements were made: 1. A PIGLOG 105 ultrasound device was used to measure backfat thickness and loin eye height on the right side of the body at three locations: P2 backfat thickness behind the last rib (at the junction of the thoracic and lumbar vertebrae), 3 cm off the midline, P4 backfat thickness behind the last rib (at the junction of the thoracic and lumbar vertebrae), 8 cm off the midline, P4M loin eye height at P4. 2. An ALOKA SSD 500 device with the model UST-5011U 3.5 MHz, 12.5 cm linear transducer was used to record ultrasonographic images on the right side of the body, at the junction of the thoracic and lumbar vertebrae (behind the last rib). After saving the images on a computer disk, they were dimensioned using Multiscan software. The results were obtained for (Figure 1): Figure 1. A dimensioned image of m. longissimus dorsi

4 30 M. Tyra et al. height of m. longissimus dorsi (UWP) at P4 (equivalent to P4M measurement taken using a PIGLOG 105 device), width of m. longissimus dorsi (USP), backfat thickness (U2P) at P2 (equivalent to measurement of P2 backfat thickness taken using a PIGLOG 105 device), backfat thickness (U4P) at P4 (equivalent to measurement of P4 backfat thickness taken using a PIGLOG 105 device), cross-sectional area of m. longissimus dorsi (UOP) (red area), cross-sectional area of fat over loin eye area of m. longissimus dorsi (UTP) (blue area). The measurement location of the ALOKA device was determined on the skin of the animal to perform postmortem (dissection) measurements. The live ultrasonographic measurement was repeated three times to check repeatability of the result. Postmortem measurements On the next day, animals were slaughtered at 100 kg b.w. according to the Pig Testing Station method. Next, m. longissimus dorsi and the surrounding tissues were measured ultrasonographically using an ALOKA SSD 500 device at the location marked during the live measurement. As with live animals, the measurement was repeated three times and the results were averaged after dimensioning. As in the case of live measurements obtained ultrasonographically, the archived images were dimensioned and the following data were obtained: height of m. longissimus dorsi (UWD), equivalent to live measurement of UWP and P4M and dissection measurement of DW, width of m. longissimus dorsi (USD), equivalent to live measurement point USP and dissection point DS, backfat thickness (U2D), equivalent to live backfat thickness measurement point U2P and P2, and dissection measurement of D2, backfat thickness (U4D), equivalent to live backfat thickness measurement point U4P and P4, and dissection measurement of D4, cross-sectional area of m. longissimus dorsi (UOD), equivalent to UOP, cross-sectional area of fat over loin eye area of m. longissimus dorsi (UTD), the area between dissection measurement points D2, D4, and D6. After 24-h chilling, the right half-carcasses were weighed and cut into ham, neck, shoulder, belly, loin, knuckle, feet and head (according to the Pig Testing Station method). The contour of the longissimus muscle section was traced on wax paper on a line between the juncture of the last thoracic vertebra and the first lumbar vertebra. The following dissection measurements were taken at this juncture with a caliper and planimeter: height of m. longissimus dorsi (DW) (line b on Figure 2), equivalent to measurement points P4M (PIGLOG) and UWD and UWP (ALOKA), width of m. longissimus dorsi DS (line a on the diagram), equivalent to USP and USD, backfat thickness at D2, equivalent to measurement points P2, U2D and U2P,

5 Using ultrasonography in breeding work with pigs 31 backfat thickness at D4, equivalent to measurement points P4, U4D and U4P, planimetered loin eye area DPO, equivalent to measurement points UOD and UOP. Figure 2. Dissection measurements of muscle and backfat The cuts from half-carcasses were weighed and subjected to detailed dissection into meat, bone and fatty tissue. Half-carcass meat content was calculated from dissection results and based on the equation: % MD actual meat content calculated based on dissection Statistical analysis The measurements obtained were used to estimate basic statistical parameters of the measurement points taken using different techniques (ultrasonographic, live and dissection measurements). Statistical analysis was performed by analysis of variance using the GLM procedure of the SAS statistical package (1989). The calculations were made using the following statistical model: Y ijkl = µ + d i + f j + α(x ijk ) + e ijkl where: y ijkl ijkl th observation, µ overall mean, d i effect of i th breed, f j effect of j th sire, α(x ijk ) covariance on right half-carcass weight, e ijkl random error. Differences between the means for individual breeds were tested at the level of 5% and 1% using Duncan s multiple range test.

6 32 M. Tyra et al. Results Tables 1 to 4 present basic statistical characteristics (means, standard deviations, minima and maxima) and coefficients of variation for PIGLOG 105 live measurements (Table 1), ultrasonographic images of live animals (Table 2), their equivalents measured ultrasonographically on half-carcass image (Table 3), and dissection measurement points (Table 4). In addition, Table 4 shows the actual meat content of different breeds determined based on detailed dissection. Our study included animals of the most numerous breeds raised in Poland that show considerable differences in the level of subcutaneous fat and carcass meatiness. The best meatiness in this breed group was characteristic of Pietrain animals (66.9%) followed by Duroc pigs (59.6%). In the two most common breeds raised in Poland, i.e. Polish Landrace and Polish Large White, this parameter was 1% lower (58.8% and 58.6%, respectively). Live measurements of backfat thickness taken with a PIGLOG 105 device (Table 1) and values of backfat thickness measurements at both points (P2 and P4) were similar among the same breeds. Thickest backfat was found in Polish Landrace gilts at P2 (1.09 cm) and thinnest in Pietrain gilts at P2 (0.91 cm). The differences in backfat thickness at this point were statistically significant between the Pietrain and other breeds (P 0.01). Backfat thickness measurements at P4 were slightly lower compared to P2 in most of the breeds, and Pietrain animals were also the dominant breed. Likewise, post-slaughter dissection measurements (taken with a caliper, Table 4) showed slightly lower backfat thickness in gilts of all breeds on the flank at D4 (equivalent to P4, U4P, U4D) compared to the D2 midback site (equivalent to P2, U2P and U2D). Thinnest backfat at both measurement points was found in Pietrain gilts and thickest in the Duroc breed. Table 1. Basic statistical characteristics of measurement points for the live evaluation method Measurements Breeds x δ min max v P2 (cm) PLW 1.06 B PL 1.09 A Pietrain 0.91 ABC Duroc 0.98 C P4 (cm) PLW 1.05 B PL 1.07 A Pietrain 0.94 AB Duroc P4M (cm) PLW 4.98A PL 5.15 B Pietrain 5.53 ABc Duroc 5.23 c Values with the same letters indicate significant differences between the breeds (A, B P 0.01, a, b P 0.05), P2 backfat thickness behind the last rib (at the junction of thoracic and lumbar vertebrae), 3 cm off the midline, P4 backfat thickness behind the last rib (at the junction of thoracic and lumbar vertebrae), 8 cm off the midline, P4M loin eye height at P4.

7 Using ultrasonography in breeding work with pigs 33 Table 2. Basic statistical characteristics of measurement points evaluated ultrasonographically on live animals Measurements Breeds x δ min max v U2P (cm) PLW 2.27 Cd PL 2.38 Bd Pietrain 2.25 AB Duroc 2.55 AC U4P (cm) PLW 1.45 C PL 1.49 B Pietrain 1.19 ABC Duroc 1.56 A UWP (cm) PLW 5.52 Ac PL 5.60 Bd Pietrain 7.08 ABC Duroc 5.72 Cde USP (cm) PLW 9.17 C PL 9.11 B Pietrain ABC Duroc 8.98 A UOP (cm 2 ) PLW 50.2 C PL 49.6 B Pietrain 64.6 ABC Duroc 48.6 A UTP (cm 2 ) PLW 19.4 Cd PL 20.6 Be Pietrain 14.1 ABC Duroc 21.3 Ade Values with the same letters indicate significant differences between the breeds (A, B P 0.01, a, b P 0.05), UWP height of m. longissimus dorsi at P4, USP width of m. longissimus dorsi, U2P backfat thickness at P2, U4P backfat thickness at P4, UOP cross-sectional area of m. longissimus dorsi, UTP cross-sectional area of fat over loin eye area of m. longissimus dorsi. The mean values of backfat thickness measurements taken with an ALOKA ultrasound device on live animals at U2P and U4P (Table 2) and postmortem at U2D and U4D (Table 3) were very similar in all the pig breeds investigated. Analysis of the between-breed differences showed that as with PIGLOG 105 measurements, the live measurement of U2P revealed that Duroc gilts had thickest backfat (2.55 cm) and Pietrain gilts thinnest (2.25 cm). Meanwhile, postmortem measurements taken with the same device at the same point showed thinnest backfat in Polish Landrace

8 34 M. Tyra et al. (U2D = 2.18 cm) and thickest backfat in Pietrain animals (U2D = 2.51 cm). For backfat thickness measured with this device on the flank, Pietrain gilts had the lowest value and Duroc gilts the highest value when measured on both live animals and postmortem. The values of these measurements ranged from U4P = 1.19 cm (Pietrain) to U4P = 1.56 cm (Duroc) for live measurements, and from U4D = 1.21 cm (Pietrain) to U4D = 1.46 cm (Duroc) for postmortem measurements. Table 3. Basic statistical characteristics of measurement points evaluated ultrasonographically on half-carcass images Measurements Breeds x δ min max v U2D (cm) PLW 2.23 B PL 2.18 A Pietrain 2.51 ABC Duroc 2.35 C U4D (cm) PLW 1.31 BD PL 1.24 CD Pietrain 1.21 AB Duroc 1.46 AC UWD (cm) PLW 5.48 C PL 5.36 B Pietrain 7.02 ABC Duroc 5.33 A USD (cm) PLW 9.35 Cd PL 9.21 Be Pietrain ABC Duroc 8.57 Ade UOD (cm 2 ) PLW 51.1 C PL 49.9 B Pietrain 64.3 ABC Duroc 48.2 A UTD (cm 2 ) PLW 18.1 Cd PL 19.2 B Pietrain 13.2 ABC Duroc 20.1 Ad Values with the same letters indicate significant differences between the breeds (A, B P 0.01, a, b P 0.05), UWD height of m. longissimus dorsi, USD width of m. longissimus dorsi, U2D backfat thickness at P2, U4D backfat thickness at P4, UOD cross-sectional area of m. longissimus dorsi, UTD cross-sectional area of fat over loin eye area of m. longissimus dorsi.

9 Using ultrasonography in breeding work with pigs 35 Table 4. Basic statistical characteristics of measurement points for the dissection method Measurements Breeds x δ min max v D2 (cm) PLW 1.60 Cd PL 1.64 Be Pietrain 1.20 ABC Duroc 1.77 Ade D4 (cm) PLW 1.58 Cd PL 1.65 Be Pietrain 1.17 ABC Duroc 1.72 Ade DW (cm) PLW 6.79 A PL 6.78 B Pietrain 7.94 ABC Duroc 6.82 C DS (cm) PLW C PL 9.97 B Pietrain ABC Duroc 9.85 A DPO (cm 2 ) PLW 52.7 C PL 52.2 B Pietrain 66.6 ABC Duroc 51.4 A %MD (%) PLW 58.6 Ad PL 58.8 Be Pietrain 66.9 ABC Duroc 59.6 Cde Values with the same letters indicate significant differences between the breeds (A, B P 0.01, a, b P 0.05), DW height of m. longissimus dorsi, DS width of m. longissimus dorsi, D2 backfat thickness at P2, D4 backfat thickness at P4, DPO planimetered loin eye area, %MD actual meat content calculated based on detailed dissection. In the case of the measurements of m. longissimus dorsi height and width, it was found that compared to the other breeds, Pietrain gilts were characterized by the greatest height and width of loin eye measured on live animals with ALOKA (UWP, USP; Table 2) and PIGLOG devices (P4M; Table 1) as well as, postmortem using an ALOKA device (UWD, USD; Table 3) and based on dissection measurements (DW, DS; Table 4). For live animal measurements, the smallest loin eye height was

10 36 M. Tyra et al. obtained for Polish Large White gilts (UWP = 5.52 cm, P4M = 4.98 cm), and the smallest loin eye width for Duroc gilts (USP = 8.98 cm). Also for postmortem measurements taken with an ALOKA device and calipers, Duroc gilts were characterized by the smallest loin eye height and width. Tables 2, 3 and 4 also provide data on live and postmortem measurements of loin eye area and fat area over loin eye. Analysis of the results demonstrated that for both live and postmortem measurements, Duroc gilts were characterized by the smallest loin eye area and Pietrain gilts by the highest. A reverse pattern was true for fat area over loin eye within particular breeds (Tables 2 and 3). The largest fat area was characteristic of Duroc animals (UTP = 21.3 cm 2, UTD = 20.1 cm 2 ), and the lowest of Pietrain animals (UTP = 14.1 cm 2, UTD = 13.2 cm 2 ). On the whole, Pietrain animals had considerable advantage for most of the analysed traits, and the differences observed in relation to the other breeds were highly significant (P 0.01) or significant (P 0.05). The standard deviations, shown in the tables for ultrasonographic (live and postmortem) measurements of backfat and muscle thickness were comparable for all the breeds. When analysing variation of traits given in the tables, it is generally concluded that the highest coefficients of variation occurred for ultrasonographic measurements with PIGLOG and ALOKA devices on live animals, and the lowest for dissection measurements. These values were in the 19 25% range for the former measurements and ranged from 5.8% to 19% for dissection measurements. Analysis of the coefficients of variation for individual measurement points revealed that for ultrasonographic measurements, the highest variation occurred for loin eye width (V = 26%) and the lowest for loin eye height (V = 19.7%). Variation of traits for the dissection measurements of m. longissimus dorsi was lower compared to the measurements of backfat thickness. There was no such relationship for ultrasonographic measurements with an ALOKA unit, but for live measurement with a PIGLOG device, this pattern was found in the white breeds (Polish Large White and Polish Landrace). Discussion The data presented above on meat content and backfat thickness show that the material studied can be considered representative for the Polish pig population, because the results concerning backfat thickness and meat content in pigs conform with the live and station test results of Polish Large White, Polish Landrace, Pietrain and Duroc gilts reported in the recent papers by Eckert and Żak (2009) and Różycki and Tyra (2009). The differences observed in our study between the breeds in backfat thickness are expected and in agreement with the results reported by Tyra and Żak (2010), who obtained the lowest values for backfat thickness also for the Pietrain breed (1.23 cm) and the highest for the Duroc breed (1.67 cm), based on dissection measurements. The uniformity of test material was also indicated by the value of standard deviations and coefficients of variation for individual traits presented in our study. These

11 Using ultrasonography in breeding work with pigs 37 parameters are consistent with the findings of Terry et al. (1989), who also observed higher variation of traits measured ultrasonographically (variation coefficients of 16 50%) compared to dissection measurements (variation of 10%). This high variation of traits obtained by the authors cited above was probably due to the use of the older A-mode instruments compared to the B-mode device (ALOKA 500 SSD) used in our study. Greater accuracy of measurements obtained with B-mode compared to A-mode devices was reported by See (1998), for whom ALOKA 500V was a reference instrument to other ultrasonographic instruments, including PIGLOG 105 (A-mode). Based on all live and postmortem measurements performed in our study, it is concluded that gilts of all breeds had thicker fat on the back and thinner fat on the flank, measured behind the last rib. This is consistent with the findings of Szyndler- Nędza and Mucha (2004) and Vaclavovsky et al. (2002). Based on live measurements taken with a PIGLOG 105 device, the authors of these papers showed that fat thickness on the back (P2) is slightly greater than on the flank (P4). Newcom et al. (2005), Cisneros et al. (1996), Moeller and Christian (1998) and Vilchez and Chavez (1998), who used an ALOKA instrument to measure backfat thickness on live animals, obtained similar values of backfat thickness as in our study. They ranged from mm (Vilchez and Chavez, 1998) to 26.1 mm (Moeller and Christian, 1998). The authors quoted above also measured backfat thickness postmortem during the dissection of pig half-carcasses. Backfat thickness was 22.9 mm (Cisneros et al., 1996) and 23.4 mm (Newcom et al., 2005) when measured behind the last rib, and 27.2 mm (Moeller and Christian, 1998) and 25.0 mm (Vilchez and Chavez, 1998) when measured behind the 10th rib. Our results concerning loin eye area show that breed has a marked effect on this parameter because the largest loin eye area was found in Pietrain gilts and the smallest in Duroc gilts. These results agree with the findings of Tyra and Żak (2010), who showed on the basis of postmortem measurements at performance station that the largest loin eye area was characteristic of Pietrain gilts (62.5 cm 2 ) and the smallest of Duroc gilts (50.5 cm 2 ) out of all breeds analysed. Edwards et al. (2003) obtained a similar value for Duroc animals (50.2 cm 2 ) and a slightly lower value of this parameter for the Pietrain breed (53.2 cm 2 ). Based on ultrasound measurements of live Duroc animals, Chen et al. (2002) showed loin eye area to be slightly lower (43.1 cm 2 ). In studies designed to adapt equipment to other than intended purposes, attention should be given to the technical aspects of the measurements, especially where the results obtained may raise some doubt or additional questions, such as the differences in backfat thickness observed during ultrasonographic measurements between measurement points equivalent to measurement points of live animal evaluation. U2P, U2D and U4P, U4D measurements show considerably greater differences than corresponding dissection (D2, D4) or even live measurements (P2, P4). Our study justified a conclusion that larger differences in ultrasonographic measurements are mainly due to technical limitations of the measuring equipment, in particular to the specific nature of the measuring probe. The UST-5011U probe used in our study has the widest available area of linear measurement (12.5 cm), but despite such

12 38 M. Tyra et al. a broad measurement area the measurements were rejected for high-lean (Pietrain and Duroc) pigs because the measuring probe did not visualize the whole m. longisimus dorsi. Another limitation of this probe type is that its measuring surface is flat. As far as animal measurements are concerned, this is a drawback because it is not immediately adjacent to the arched back of pigs over the whole measuring length. For this reason, the measurements obtained on the basis of such images can be afflicted with an error. This inaccuracy is mainly evident in the case of backfat thickness measurements at UP2 and UD2. These measurements may be associated with greater error despite using a thick gel layer and attempts to fit the probe to the measuring surface by placing minimum pressure on the back. And in the case of ultrasonographic measurements performed during dissection, the error may be even greater because rigor mortis prevented all attempts to adjust the probe to make proper contact with the skin. This is why the highest values for U2D measurement locations were obtained for Pietrain and Duroc animals. Where ultrasonographic devices are used to measure large-sized animals (cattle, pigs), this problem can be solved by fitting curved gel pads to the measuring probes (Greiner et al., 2003). These pads are already used for live testing of fatness and muscling in cattle. They ensure proper fit of the probe to the back surface, but considerably attenuate ultrasonic waves, which reduces image resolution (quality) when measurements involve in-depth tissue penetration. Because of these limitations, many authors use longitudinal rather than transverse scans for live ultrasound measurements (as in the present study). Although the longitudinal placement of the probe limits the amount of information available for measurement of backfat thickness and loin eye height (inability to make loin eye, fat area and other measurements), the accuracy of the results obtained with this method increases (Witczak et al., 2005; Thériault et al., 2009). Increased image resolution, which is so important when dimensioning loin eye area or loin eye fat, can be obtained by using the latest generation of devices and measuring probes with double sampling frequency (McEvoy et al., 2007). The images generated are clearer while showing more detail. However, one limitation is the lack of specialist probes with such large measuring surfaces as that used in our study. The measuring surface of other probes available on the market usually does not exceed 8 cm in length. As a result, muscle images have to be reconstructed from two halves, which will always be associated with an error (working muscles, moving animals) resulting from misalignment of the two image halves. Thus, the benefit of increased probe resolution may ultimately be negated by misalignment of the measurements, especially when live animals are measured. These technical obstacles largely prevent the use of the latest ultrasonographic units for performance testing of cattle and pigs. In conclusion, the test animals are a representative and uniform sample of the current population of pigs raised in Poland. They provide excellent material to validate the possibility of using ultrasonography for fatness and meatiness evaluation in pigs. The mean values obtained for measurement points using ultrasonography are consistent with the analogous measurements obtained using ultrasonic and dissection technique and with literature data. The only exception were U2D backfat

13 Using ultrasonography in breeding work with pigs 39 measurements (mainly in high-lean animals) resulting from the technical limitations of the measuring equipment (construction of the measuring probe). However, the practical usefulness of the measurement technique (ultrasonography) for breeding work will be determined by the relationships (correlations) between ultrasound image measurements and actual results obtained from dissection of half-carcasses, as well as by the accuracy of the proposed regression equations for estimating meat content, which will be the subject of further analysis. References C h e n P., B a a s T.J., M a b r y J.W., D e k k e r s J.C.M., K o e h l e r K.J. (2002). Genetic parameters and trends for lean growth rate and its components in U.S. Yorkshire, Duroc, Hampshire, and Landrace pigs. J. Anim. Sci., 80: C i s n e r o s F., E l l i s M., M i l l e r K.D., N o v a k o f s k i J., W i l s o n E.R., M c K e i t h F.K. (1996). Comparison of transverse and longitudinal real-time ultrasound scans for prediction of lean cut yields and fat-free lean content in live pigs. J. Anim. Sci., 74: E d w a r d s D.B., B a t e s R.O., O s b u r n W.N. (2003). Evaluation of Duroc- vs. Pietrain-sired pigs for carcass and meat quality measures. J. Anim. Sci., 81: G r e i n e r S.P., R o u s e G.H., W i l s o n D.E., C u n d i f f L.V., W h e e l e r T.L. (2003). Prediction of retail product weight and percentage using ultrasound and carcass measurements in beef cattle. J. Anim. Sci., 81: M c E v o y F.J., S t r a t h e A.B., M a d s e n M.T., S v a l a s t o g a E. (2007). Changes in the relative thickness of individual subcutaneous adipose tissue layers in growing pigs. Acta Vet. Scand., 7, 49, p. 32. M o e l l e r S.J., C h r i s t i a n L.L. (1998). Evaluation of the accuracy of real-time ultrasonic measurements of backfat and loin muscle area in swine using multiple statistical analysis procedures. J. Anim. Sci., 76: M ö r l e i n D., R o s n e r F., B r a n d S., J e n d e r k a K.-V., W i c k e M. (2005). Non-destructive estimation of the intramuscular fat content of the longissimus muscle of pigs by means of spectral analysis of ultrasound echo signals. Meat Sci., 69: N e w c o m D.W., B a a s T.J., S c h w a b C.R., S t a l d e r K.J. (2005). Genetic and phenotypic relationships between individual subcutaneous backfat layers and percentage of longissimus intramuscular fat in Duroc swine. J. Anim. Sci., 83: S e e M.T. (1998). Heterogeneity of (co)variance among herds for backfat measures of swine. J. Anim. Sci., 76: S z y n d l e r - N ę d z a M., M u c h a A. (2004). Comparison of fatness between boars and gilts based on live measurement. Scientific Messenger of Lviv National Academy of Veterinary Medicine, 6 (No. 2), 5: T e r r y C.A., S a v e l l J.W., R e c i o H.A., C r o s s H.R. (1989). Using ultrasound technology to predict pork carcass composition. J. Anim. Sci., 67: T h é r i a u l t M., P o m a r C., C a s t o n g u a y F.W. (2009). Accuracy of real-time ultrasound measurements of total tissue, fat, and muscle depths at different measuring sites in lamb. J Anim Sci., 87 (5): T y r a M., Ż a k M. (2010). Characteristics of the Polish breeding population of pigs in terms of intramuscular fat (IMF) content of m. longissimus dorsi. Ann. Anim. Sci., 10, 3: V a c l a v o v s k i J., M a t o u s e k V., K e r n e r o v a N., K o u g l o v a P., N y d l V., N o v o t n y F. (2002). Prediction of lean content in breeding pigs by in vivo and post mortem methods. Czech. J. Anim. Sci., 47, (11): V i l c h e z C., C h a v e z E.R. (1998). Correlations Between Ultrasonic Measurements on Live Crossbred Gilts and Carcass Characteristics. Agricultural and Environmental Sciences. Research Report, pp

14 40 M. Tyra et al. W a l l P.B., R o u s e G.H., W i l s o n D.E., T a i t R.G. Jr, B u s b y W.D. (2004). Use of ultrasound to predict body composition changes in steers at 100 and 65 days before slaughter. J. Anim. Sci., 82 (6): W i t c z a k C.A., M o k e l k e E.A., B o u l l i o n R., W e n z e l J., K e i s l e r D.H., S t u r e k M. (2005). Noninvasive measures of body fat percentage in male Yucatan swine. Comp. Med., 55 (5): Accepted for printing 15 II 2011 Mirosław Tyra, Magdalena Szyndler-Nędza, Robert Eckert Możliwości zastosowania techniki ultrasonograficznej (USG) w pracy hodowlanej nad trzodą chlewną. Cz. I Analiza pomiarów ultradźwiękowych, ultrasonograficznych oraz dysekcyjnych ras świń najliczniej hodowanych w kraju Streszczenie Celem podjętych badań było określenie przydatności ultrasonograficznej techniki pomiarowej (USG) do jej zastosowania w praktyce hodowlanej ukierunkowanej na ocenę otłuszczenia i umięśnienia świn. Badania dotyczyły zarówno możliwości zastosowania tego typu urządzeń w ocenie przyżyciowej, jak i poubojowej. Niniejsza praca jako pierwsza z cyklu dotyczy charakterystyki materiału badawczego oraz wyników pomiarowania, jakie na tym materiale uzyskano z wykorzystaniem różnych technik pomiarowych. Materiał do badań stanowiły loszki o masie ciała 100 kg oceniane w Stacji Kontroli Użytkowości Rzeźnej Trzody Chlewnej (SKURTCh). Ogółem w badaniach uwzględniono 476 zwierząt ras wbp (151 szt.), pbz (149 szt.), Pietrain (84 szt.) i Duroc (92 szt.). W dniu poprzedzającym ubój dokonywane były pomiary grubości słoniny i mięśnia najdłuższego grzbietu (m. longissimus dorsi) aparatem ultradźwiękowym PIGLOG 105 oraz aparatem ultrasonograficznym ALOKA SDD 500 w miejscach będących odpowiednikami punktów pomiarowych stosowanych w ocenie przyżyciowej. Następnego dnia zwierzęta poddane zostały ubojowi zgodnie z metodyką SKURTCh. Następnie dokonany był pomiar USG mięśnia najdłuższego grzbietu i otaczających go tkanek oraz wykonano pomiary dysekcyjne. Na podstawie wszystkich przeprowadzonych w niniejszej pracy pomiarów (przyżyciowych i poubojowych) stwierdzono, że loszki wszystkich ras charakteryzowały się grubszą słoniną na grzbiecie i cieńszą na boku tuszy mierzoną za ostatnim żebrem. Dotyczy to wszystkich technik pomiarowych. Mięsność tych zwierząt wahała się od 58,6% w rasie wbp do 66,9% w rasie Pietrain. Stwierdzono, że objęte badaniami zwierzęta stanowią reprezentatywną i wyrównana próbę, odzwierciedlającą aktualną populację zwierząt hodowanych w kraju. Jest to doskonały materiał do przeprowadzenia badań mających na celu zweryfikowanie możliwości zastosowania techniki ultrasonograficznej do oceny otłuszczenia i umięśnienia świń.