Comparison of five types of pig crosses. I. growth and carcass traits

E L S E V I E R Livestock Production Science 40 (1994) 171-178

LIVESTOCK PRODUCTION

SCIENCE

Comparison of five types of pig crosses. I. growth and carcass traits

A. Blasco a'*, P. Gou b, M. Gispert b, J. Estany c, Q. Soler d, A. Diestre b, J. Tibau d aDepartamento de Ciencia Animal, Universidad Politdcnica de Valencia, P.O. Box 22012, Valencia 46071, Spain

blnstitut de Recerca i Tecnologia Agroalimentdries, Centre de Tecnologia de la Cam (CTC-IRTA), Granja Camps i Armet, Monells 17121, Spain

CCentre R + D, Universitat de Lleida, Institut de Recerca i Tecnologia Agroalimentgtries (UdL-IRTA), Alcalde Rovira Route, 177, Lleida 25001, Spain

Olnstitut de Recerca i Tecnologia Agroalimentgzries, Centre de Control Porc# (CCP-1RTA), Veinat de Sies, Monells 17121, Spain

Received I April 1993; accepted 11 January 1994

Abstract

109 gilts and 119 barrows from five crosses: Landrace (LR) x Large White (LW) females crossed with either Duroc (DU), LW or Belgian Landrace (BL) terminal simms, and DU × LW females crossed with either LW or BL sires, were used in the experiment. The animals were grouped and fed ad libitum from 23 to 97 kg. Growth rate and food consumption were measured. The animals were then slaughtered and standard carcass measurements were made. 55 left side carcasses were fully dissected, 84 were partially dissected and 82 hams of the remaining left side carcasses were also dissected. The cross with DU terminal sire grew fastest and showed a better food conversion ratio. There were no significant differences in killing-out and carcass length. The BL progeny had the highest carcass lean content, the best conformation and the highest proportion of ham and loin.

Keywords: Pig; Crossbreeding; Growth; Carcass

1. Introduct ion

Current pig production schemes in Europe are based on a three or four way cross. In Spain the most common cross is the one which uses F1 Landrace × Large White sows crossed with a terminal sire which gives a good conformation to the final product. Carcasses with good conformation are well valued in some markets because they are associated with a higher kil l ing out percentage, higher ham percentage and also with a higher carcass lean content. Halothane posit ive pigs, like Pietrain or Belgian Landrace, are commonly used as terminal sires

*Corresponding author.

0301-6226/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDIO301-6226(94)OOOO3-P

because they give a good conformation to the carcass, although some difficulties have been detected in the process of dry-curing in well conformed hams (Arnau et al., 1992).

The Duroc breed was introduced into Spain by national breeders to be crossed with the Iberian breed, which is considered to produce the highest quality for meat processing - particularly dry cured ham - in order to obtain a product with better growth characteristics. In other European countries different crosses of white breeds with the Duroc were introduced to improve meat quality due to its higher level of intramuscular fat (Steane, 1986). The Duroc breed has also shown some advantages in growth rate when used as a terminal sire

172 A. Blasco et al. / Livestock Production Science 40 (1994) 171-178

( Simpson et al., 1987). The interest in the Duroc breed has been orientated also on the possibility that the sows with a Duroc component could benefit from more heterosis and be more resistant - i.e. have more parities - than the normal Landrace ×Large White sows (Bras- camp et al., 1979; Kuhlers et al., 1989).

The advantages of a crossbreed including Duroc - higher meat quality - may be matched by the disad- vantages of a carcass with less meat content. However, the advantages of a leaner carcass of crossbreeds that include Belgian Landrace, could be machted by a poorer ham quality or a lower growth. In a series of two papers the products of three terminal sires (Duroc, Large White and Belgian Landrace) mated with two types of sow (Landrace×Large White and Duroc×Large White) are compared. In this paper growth and carcass quality of the products are studied, and in the next paper it is studied the fresh and cured meat quality of the same crosses.

2. Material and methods

2.1. Animals

17 Landrace (LR) × Large White (LW) sows were inseminated with semen of Duroc (DU), Belgian Lan- drace (BL) and LW breeds, and 11 D U X L W sows were inseminated with LW and BL semen. 9 Large White sires from four leading International Breeding Companies, 8 Duroc sires from the Danish National Program and 11 Belgian Landrace sires from a Spanish Breeding Company - which regularly imports sires from the Belgian National Program, provided the semen used in the experiment.

Sows were mated in three successive parities, ran- domizing the effect of parity (i.e., all types of terminal sires were used in each parity). Sows were divided into two reproductive groups, the second group being inseminated 12 weeks later, which led to six farrowing batch (six blocks of data). Farrowing period was from November 1989 to November 1990.

Piglets were weaned at four weeks of age and the boars were castrated before weaning. The proportion of females and castrated males from each litter were similar. After weaning, they were kept in boxes in the same building, where they remained until they were transferred to the IRTA test station. Animals were

grouped in pens, each pen having only one type of cross, and fed ad lib. All the pens were in the same building. The average initial weight was 23 kg and the average final weight 97 kg. Food composition was the same in the first five batches, but it was changed for technical reasons in the last batch, although both foods shared the same nutritional value: 176 and 175 g/kg of crude protein, 9.3 and 9.9 g/kg of Lysine, 2.9 and 3.3 g/kg of Methionine and 13.07 and 13.04 MJ/kg of digestible energy content, respectively.

Animals were weighed at the beginning and at the end of the test, and total food intake of each pen was measured. If a pig was excluded from the pen before the end it was assumed to have eaten as much as the others until the day before exclusion.

2.2. Slaughter and dissection methods

A total of 109 gilts and 119 barrows were slaughtered in the Carcass Evaluation Unit (IRTA-CTC), after a standardized pre-slaughter treatment ( 12 hours in lair- age, electrically stunned with 350 V at 50 Hz). The following predictor variables of the carcass lean content were recorded on the left side of hot carcasses:

• Leg conformation: a visual assessment of the shape of the hind leg was made from 1 = very good conformation to 5 = very poor conformation.

• Carcass length (mm): measured from the anterior edge of the symphysis pubis to the recess of the first rib.

The following automatic probe measurements (mm) were taken using a Fat-O-Meater (SKG Denmark) over M. longissimus dorsi at 60 mm from the mid-line:

• Last rib backfat: Subcutaneous fat thickness measured at the head of the last rib.

• 3/4 backfat: Subcutaneous fat thickness measured between the 3rd and 4th last ribs.

• 3/4 muscle depth: loin muscle thickness measured between the 3rd and 4th last ribs.

Eye muscle area (cm 2) was also taken on the trans- verse cut of the M. longissimus dorsi between the 3rd and 4th last ribs at 24 h p.m.

After removal of flare fat and kidneys, the left side of each carcass was divided into 17 joints according to the EC-reference method for the full dissection (Sche- per and Scholz, 1985). Two different systems of carcass dissection were used:

• Full reference method, where all joints were dis-

A. Blasco et al. / Livestock Production Science 40 (1994) 171-178 173

sected into their constituent parts (subcutaneous fat, lean, intermuscular fat, bone and waste) .

• Simplified reference method, based on the dissection of the main parts of the carcass: leg, loin, shoulder, belly, tender loin, neckfat and backfat (Branscheid et al., 1990).

All the left hams were dissected. The distribution of carcasses by crosses and methods of dissection is shown in Table 1. The carcass weight distribution was calculated as weight of individual jo int (g ) / ca rcas s weight (kg) . The distribution of full carcass lean content in the main joints was calculated as weight of the individual actual lean in the jo int ( g ) / e s t ima ted weight of full carcass lean content (kg) . The composit ion of the main joints was calculated as weight (g) of the individual const i tuents /sum of constituents dissected in the joint (kg) .

2.3. S ta t i s t i ca l a n a l y s e s

Least-squares analyses of variance with covariates was used (SAS Institute Inc., 1987). Fixed effects of type of cross, sex and block were included in all the analyses with individual data. Final weight was a covariate in the analyses of daily gain and age at the end of the test. Initial weight was a covariate in the analyses of daily gain. The analyses of food conversion rate and food intake did not include sex effect but the proportion of gilts of the pen, and the covariates used were initial and final average weight of the pen. The covariate carcass weight, including flare fat and kidneys, was used in the analyses o f carcass traits.

Double sampling scheme with regression (Conniffe and Moran, 1972) was adopted to analyze the full car-

cass lean content. Carcass lean content was estimated by stepwise regression of the lean of the fully dissected carcasses on the predictor variables defined above.

To calculate individual daily lean tissue gain and lean tissue food conversion rate of the pen the estimated lean content was used. As initial lean content has little influence on the comparisons in estimated lean tissue growth rate and lean tissue food conversion rate (Fowler et al., 1976), it was considered to be the same for all the crosses (600 g /kg ) .

3. Results

Ham lean content (HLC) , 3 /4 backfat (BF) and eye muscle area ( E M A ) were used to fit the individual lean content (LC) . The equation was the following:

LC = 173.76 + 0.57 × HLC - 3.40

X B F + 0 . 9 9 X E M A

The R 2 was 0.96 and the residual standard deviation was 9.0 g /kg . There were no different coefficients of regression between crosses. Biases within crosses between estimated lean content and actual lean content were calculated in the fully dissected carcasses. These biases ranked from 0 to 2 g / k g showing that the esti- mation of lean content was practically unbiased.

Table 2 Least squares means ( LSM ) and standard errors (SE) of growth and carcass quality traits at constant final liveweight (97 kg) and at constant carcass weight (78 kg), respectively, by sexes

Gilts Barrows Sig.

LSM SE LSM SE

Table 1 Distribution of carcasses by crosses and methods of dissection

Crosses Reference-method of dissection Total

Simplified Full Ham dissected

DU× (LR×LW) 20 LWX (DU × LW) 18 LW× (LR×LW) 12 BL× (DUX LW) 19 BL× (LR× LW) 15 Total 84

10 14 44 10 17 45 13 19 44 11 17 47 11 15 41 55 82 221

Growth traits Daily liveweight gain (g/d) 791 8 886 8 ** Age at the end of the test (d) 170 1.3 161 1.3 ** Daily lean tissue gain (g/d) 317 4 316 4 NS

Carcas traits Killing out (g/kg) 830 1.8 831 1.7 NS Carcass length (mm) 809 2.4 800 2.3 ** Lefconformation 2.20 0.05 2.23 0.05 NS Eye muscle area (cm z) 41.3 0 .64 37.8 0.60 ** Last rib backfat (mm) 14.4 0.3 17.4 0.3 ** 3/4 backfat 15.4 0.3 18.7 0.3 ** 3/4 muscle depth 51.5 0.4 49.6 0.4 ** Carcass lean content (g/kg) t 558 3 524 3 **

tpredicted carcass lean content.


Table 3 Least squares means (LSM) and standard error (SE) of growth and carcass quality traits at constant final liveweight (97 kg) and at constant carcass weight (78 kg), respectively, by crosses

DUX ( L R × L W ) LWX ( D U × L W ) LWX (LRXLW) B L × ( D U × L W ) BL× ( L R × L W )

LSM SE LSM SE LSM SE LSM SE LSM SE

Growth traits Daily liveweight gain (g /d) 888a 14 809b 13 843b 15 825b 13 828b 14 Daily lean tissue gain (g /d) 340ab 7 279c 7 294c 8 326b 7 343a 8 Age at the end of the test (days) 158c 2.3 168ab 2.2 163bc 2.5 170a 2.1 169ab 2.4 Daily food intake (kg/d) 2.05 0.08 1.95 0.06 1.99 0.08 2.01 0.08 2.02 0.07 Food conversion rate 2.31 0.09 2.47 0.07 2.48 0.09 2.45 0.08 2.48 0.08

Carcass traits Killing out (g /kg) 827 3.0 827 3.1 828 3.5 837 2.9 834 3.2 Carcass length (ram) 804 4.1 810 4.1 808 4.7 797 3.9 805 4.5 Leg conformation 2.55a 0.09 2.55a 0.09 2.47a 0.10 1.81b 0.08 1.70b 0.10 Eye muscle area (cm 2) 39.8ab 1.07 37.8bc 1.08 36.6c 1.22 41.0ab 1.02 42.6a 1.22 Last rib backfat (mm) 15.3b 0.5 17.7a 0.5 17.1a 0.6 14.7b 0.5 14.7b 0.6 3/4 backfat 16.6b 0.5 18.9a 0.5 18.3a 0.6 16.1b 0.5 15.6b 0.6 3/4 muscle depth 50.1b 0.7 47.7c 0.7 47.8c 0.9 52.8a 0.7 54.2a 0.8

Carcass lean content (g /kg) l 543b 5 518c 6 523c 6 556ab 5 565a 7

Means with different letters significantly ( P < 0.05 ). mEstimated lean content.

Table 4 Least squares means (LSM) and standard errors (SE) of the distri- butions (g /kg) of the carcass weight and carcass lean among the main joints at constant carcass weight (78 kg) by sexes

Gilts Barrows Sig.

LSM SE LSM SE

Distribution of the main cuts in the carcass (g /kg) Ham 246 1.0 242 ! .0 ** Hind shank 37 0.3 37 0.3 NS Loin 127 0.7 120 0.7 ** Backfat + neckfat 62 1.2 72 1.1 ** Shoulder 141 0.7 141 0.6 NS Belly 93 0.8 95 0.7 *

Distribution of the lean in the carcass (g /kg) Ham 306 1.3 306 1.3 NS Loin 165 1.3 161 1.4 * Shoulder 162 1.2 165 1.2 NS Belly 90 1.1 89 1.2 NS

Table 2 shows the least square means of gilts and barrows for daily gaia, and carcass quality. As it was expected, barrows grew faster and finished the test ear- lier than gilts. However, no significant differences were found between sexes in daily lean tissue gain because

gilt carcasses had more estimated carcass lean content. Gilts carcasses had significatively less backfat thickness and more eye muscle area and 3/4 muscle depth. No significative differences were detected between sexes in subjective ham conformation scores.

Table 3 shows the effect of cross on daily gain, food conversion rate, and carcass quality. The cross with Duroc as terminal sire grew faster and finished the trial at younger age than the others, but for the predicted daily lean tissue gain it was not different from the BL sired crosses, due to a higher lean content and killing out of the BL sired pigs. The cross BL X (DU × LW), which has a DU component in the sow, did not show any significant difference with the DU sired cross in lean content. The best leg conformation scores were obtained in BL-sired pigs as expected. An interesting result was that the lean content of the DU X (LR × LW) cross was better than the lean content of the crosses sired by LW. The carcasses from LW sired pigs were the fattest and consequently had the lowest daily lean tissue gain.

No significant differences were found in daily food intake and in food conversion rate, although it seems that the terminal product sired with Duroc - which had

A. Blasco et aL / Livestock Production Science 40 (1994) 171-178 175

Table 5 Least squares means (LSM) and standard errors (SE) of the distribution (g/kg) of the carcass weight and the carcass lean among the main joints at constant carcass weight (78 kg) by crosses

DUX (LR×LW) LW× (DU×LW) LW× (LR×LW) BL× (DU×LW) BL× (LR×LW)


Distribution of the main cuts in the carcass (g/kg) Ham 245b 1.7 236c 1.7 238c 2.0 252a 1.6 25 la 1.9 Hind shank 39a 0.5 36c 0.5 37bc 0.6 38ab 0.5 37abc 0.5 Loin 124ab 1.3 120c 1.3 122bc 1.5 126ab 1.2 127a 1.4 Bakcfat + neckfat 65b 2.1 74a 2.1 74a 2.4 60b 2.0 61 b 2.3 Shoulder 142a 1.2 141a 1.2 137b 1.3 143a 1.1 14lab 1.3 Belly 92c 1.3 96b 1.3 100a 1.5 90c 1.2 91 c 1.4

Distribution of the lean in the carcass (g/kg) Ham 307b 2.2 297c 2.2 300c 2.5 317a 2.2 312ab 2.7 Loin 164 2.0 159 2.0 164 2.3 163 2.1 164 2.7 Shoulder 164 1.8 164 1.8 161 2.1 166 1.9 161 2.5 Belly 89b 1.7 93ab 1.7 98a 2.0 85c 1.8 83c 2.3

Means with different letters differ significantly (P < 0.05).

Table 6 Least squares means (LSM) and standard errors (SE) of joint composition of the main cuts (g/kg) at constant carcass weight (78 kg) by sexes

Gilts Barrows Sig.

LSM SE LSM SE

HAITI lean 697 3.4 665 3.3 ** fat 164 3.5 196 3.4 ** bone 85 0.7 85 0.7 NS lean/bone 8.24 0.08 7.91 0.08 **

Loin lean 729 2.8 707 2.9 ** fat 49 1.9 62 2.0 ** bone 200 2.5 207 2.6 *

Shoulder lean 652 3.8 619 3.9 ** fat 174 4.1 212 4.2 ** bone 100 1.0 96 1.0 **

Belly lean 559 6.4 508 6.6 ** fat 275 7.7 332 7.9 ** bone 93 1.6 86 1.6 **

a h igher dai ly gain at an in termedia te level o f fatness - was the mos t efficient.

S o m e di f ferences in the distr ibution o f carcass

weight among the main cuts at constant carcass we igh t

(78 kg) be tween sexes were found (Tab le 4) . Gi l t

carcasses y ie lded more ham and loin - 304 g and 532

g in the whole carcass - and less backfa t -neckfa t and

belly - 760 g and 152 g - than barrows. H o w e v e r the

differences in the distribution o f carcass lean in the

main joints were not important , a l though gilts carcasses

had a s ignif icat ively higher lean content in the loin than

boars (4 g / k g ) (Tab le 4 ) .

Carcass weight distribution and carcass lean t issue

distribution among main cuts at constant carcass weight

by crosses are shown in Table 5. B L sired carcasses

showed the mos t valuable carcass weight distribution.

They had higher ham and loin contents ( 1.140 and 532

g per carcass) and less backfat + neckfat and belly (988

and 684 g) than L W sired pigs. D U sired carcasses

were not significantly different in the y ie ld o f the fatty

jo ints but they had a lower ham yield than B L sired

carcasses. BL sired carcasses also showed a h igher

proport ion o f carcass lean in the ham and a lower pro-

port ion o f carcass lean in the bel ly in compar i son with

the other crosses. The cross sired by Duroc occupied

an intermediate position.

The jo in t composi t ion o f the main cuts is presented

in Tables 6 and 7. Bone content was lower in gil ts for

the high pr iced cuts ( h a m and lo in) . L e a n / b o n e ratio

o f the ham was also h igher in gilts (Tab le 6) . BL sired

pigs showed the best l e a n / b o n e ratio o f the ham (Tab le

7) and, in general, a lower bone content and higher


Table 7

Least squares means (LSM) and standard errors (SE) of joint composition of the main cuts (g /Kg) at constant carcass weight (78 kg) by cFogses

D U x ( L R × L W ) L W × (DU × L W ) L W × (LR × LW) BL× ( D U × L W ) BL× (LR × LW)


Ham lean 682b 5.8 655c 5.8 662c 6,7 698a 5.6 708a 6.6 fat 177b 6.1 202a 6.0 199a 6.9 165b 5.9 159b 6.9 bone 87 1.3 87 1.3 85 1.4 84 1.2 82 1.4 lean/bone 7.91b 0.14 7.57b 0.14 7.86b 0,16 8.39a 0.14 8.66a 0.16

Loin lean 720a 4.7 702b 4.6 714ab 5,5 723a 4.8 729a 5.3 fat 54 3.1 61 3.1 55 3,7 54 3.2 52 3.6 bone 202 4.1 213 4.1 207 4.8 198 4.2 196 4.7

Shoulder lean 636b 6.4 605c 6.3 625b 7,5 653a 6.5 658a 7.3 fat 184b 6.9 220a 6.8 203a 8.0 179b 7.0 179b 7.9 bone 105a 1.6 98b 1.6 98b 1.9 95b 1.7 93b 1.9

Belly lean 543 10.6 508 10.5 533 12.4 544 10.8 539 12.1 fat 282 12.8 328 12.6 310 15.0 290 13.0 306 14.6 bone 98a 2.6 86b 2.6 84b 3, I 94a 2.7 85b 3.0

Means with different letters differ significantly (P < 0.05 ).

lean content in all the joints. Duroc sired pigs had an intermediate position.

4. Discussion

A main problem in crossbred comparisons is the genetic origin of the breeds, because there is a consid- erable variation within breed in productive traits. More- over, the results of pure breed trials should be considered with caution in crossbreeding studies because some maternal effects could be important in crossbreeding experiments (Bereskin and Steele, 1986, McLaren et al., 1987).

As an example of this problem, final products with Duroc as a terminal sire have been found to be leaner than the sired with Large White (Smith et al., 1988; McGloughin et al., 1988; Langlois and Minvielle, 1989a), fatter (Edwards et al., 1992) or not different (Simpson et al., 1987).

This can invalidate crossbreed comparisons unless the origins of the breeds are well defined together with the reasons for choosing a particular origin. In our experiment we deliberately chose what we considered

to be highly productive animals within the breed. Thus, we chose the Duroc breed from the Danish National Program because it has been successfully selected on carcass lean content (Barton-Gade, 1990). The Bel- gian Landrace breed comes from a Spanish company which has large imports from the Belgian National Program and carries out his own selection program with great emphasis on conformation. The sources of Lan- drace and Large White have been four leading international breeding companies because they have preferentially selected these breeds during the last few decades.

Although a high selection pressure has been made to increase lean content of LW (see, for example, Meat and Livestock Commission, 1992) and in some cases in DU breeds (Barton-Gade 1990), BL sired pigs still appears to have the highest carcass lean content. The results of the 1st Stotfold Trial carried out by the Meat and Livestock Commission (1989) to compare Meat Type sires and White type sires from four breeding companies showed that carcass lean content was, in general, slightly higher in the Meat Type carcasses (5 g/kg) at 65 kg carcass weight (although the progeny of the Meat Type sires from one of the four participant

A. Blasco et al. / Livestock Production Science 40 (1994) 171-178 177

Companies had 22 g/kg more lean in the carcass than the progeny from their White Type sires). This difference is very small compared with the difference we obtained between BL sired pig and LW sired pigs (47 g/kg at 78 kg carcass weight), but Meat-Type sires usually contain less than a 50% of halothane positive breeds, to avoid Porcine Stress Syndrome.

McLaren et al. (1987) found breed-of-dam effects on carcass traits. However, when DU and LR dam effects were compared, they were similar for carcass traits with the exception that DU presented a higher belly weight. We also have not found differences on carcass traits when LR is replaced by DU in the dam line, with the sole exception that the latter had the highest proportion of the shoulder and the lowest proportion of the belly.

The Spanish meat industry generally gives a consid- erable importance to the proportion of higher priced joints and the distribution of lean in the carcass, and visual assessment of shape or conformation is still used as an indirect measurement of these characteristics. BL sired pigs have shown advantages in the proportion of higher-priced cuts and better ham lean/bone ratio, which justifies the demand for well conformed sire lines.

Sex differences in lean content of the cuts were similar to those found by other authors (Scott et al., 1984; Kanis et al., 1986; Langlois and Minvielle, 1989b). Kempster and Evans (1979) and Martel et al. (1988) also found that gilts have a higher percentage of lean than barrows in the more expensive cuts.

Assuming a normal distribution for lean content, the percentage of carcasses in each grade of the EC Pig Grading Scheme was calculated for each cross. The difference between the LW sired pig carcasses and the LB sired pig carcasses, using current market prices, was 3.4 pts (0.025 ECUs) per kg of carcass weight. An economic advantage of 4.8 pts. (0.035 ECUs) per kg was obtained when the proportion of ham and loin in the carcass was considered. This advantage of LB sired pig carcasses was approximately halved when compared with DU sired pig carcasses. However, the better growth characteristics of DU sired pigs should compensate this advantages. For example, taking the estimates of food conversion rate of Table 3, DU sired pigs show an advantage in food savings of 5.3 (0.039 ECUs) per kg of carcass at current market prices when compared with BL × (LR × LW).

The main inconveniences of using BL sires are due to the Porcine Stress Syndrome (PSS), which is often present in well conformed breeds. This factors and other factors related to meat quality could be taken into account for carcass evaluation in the near future. In the next paper of this series we study the meat quality of all of these crosses.

Acknowledgements

We are very grateful to the S.A.T. Bergantes for supporting a part of this work, and to Dr. John Webb for his useful advice in designing the experiment. This study has been supported with funds from the Spanish Ministry of Education and Science, (CICYT-GAN89- 0440-C02).

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R~sum~

Blasco, A., Gou, P., Gispett, M., Estany, J., Soler, Q., Diestre, A. et Tibau, J., 1994. Comparaison de cinq types de porcs crois6s. I. Croissance et caract~res de carcasse. Livest. Prod. Sci., 40:171-178 (en anglais).

Cent-neuf pores femelles et 119 m~es castr6s issus de cinq croisements: femelles Landrace (LR) xLarge White (LW) crois6es avec des verrats terminaux Duroc (DU), LW ou Landrace Beige (BL), ont 6t6 utilis6s dans l'exp6rience. Les animanx 6taient 61ev6s en groupes et aliment~s ad libitum entre 23 et 97 kg. La vitesse de croissance et la consommation d'aliment 6taient mesur6es. Les animaux 6talent ensuite abattus et les mesares standard 6taient effectu6es sur la carcasse. Cinquante-cinq demi-carcasses gauches 6taient totalement diss&lu6es, 84 l'6taient partieilement, et 82 jambons des demi-carcasses gauches restantes 6taient 6gaiement diss&lu6s. Le croisement avec le verrat terminal DU pr6sentait la croissance la plus rapide et ia meilleure efficacit6 aiimentaire. I1 n'y avait pas de diff6rences significatives de rendement ni de longueur de carcasse. Les descendants des BL avaient la plus forte teneur en maigre darts la carcasse, la meilleure conformation et les proportions de jambon et de longe les plus 61ev6es.

Kurzfassung

Blasco, A., Gnu, P., Gispert, M., Estany, J., Soler, Q., Diestre, A. und Tibau, J., 1994. Vergleich von ftinf Typen yon Schweinekreuzungen. I. Wachstums- und Schlaehtk6rpermerkmale. Livest. Prod. Sci., 40:171-178 (auf englisch).

109 Jungsauen und 119 Kastraten von folgenden ftinf Kreuzungen: Landrasse (LR) X Large White (LW)-Sauen, angepaart mit Duroc (DU), LW oder Belgischer Landrasse (BL)-Ebem und (DU × LW )-Sauen, angepaart mit LW oder BL-Ebern wurden untersucht. Die Tiere wurden in Gruppen ad libitum geflittert im Mastabschnitt yon 23-97 kg. Zunabme and Futterverbranch wurden gemessen and nach der Schlachtung die Standard-Schlachtk6rperma[~. 55 linke Hiilften wurden vollst/indig, 84 teilweise zerlegt und von den restlichen 82 Hitlften die Schinkea. Die Kreuzungen mit dem Du-Vater wuehsen am schnellsten und zeigten eine bessere Futterverwertung. In der Sehlaehtk6rperlgtnge und in der Schlachtausbeute gab es keine signifikanten Untersehiede. Die BL-Nachkommen hatten den h6chstea Fleischanteil, die beste Konfurmation und den h6ehsten Anteil yon Schinken und Kotelett.

Documents

Comparison of five types of pig crosses. I. growth and carcass traits