Genetic parameters for meat and fat quality and carcass composition traits in Iberian pigs

Carcass composition and quality traits were measured in heavy Iberian pigs after extensive handling. The weights of trimmed hams, forelegs and loins were recorded on 2170–2553 pigs, intramuscular fat content in M. longissimus (IMF) on 1489 and percentages of palmitic, stearic, oleic and linoleic acids in the subcutaneous fat on 1495 pigs, slaughtered at about 160 kg live weight. For carcass traits the heritability estimates ranged from 0.28 to 0.41. Heritability estimate for IMF was 0.25 and estimates of heritability for the measured fatty acids ranged from 0.29 to 0.41. The estimated genetic correlations (rg) suggest antagonism between IMF and weights of hams (rg=−0.30) and loins (rg=−0.33) and an unfavourable positive association of premium cuts with linoleic acid content (rg: 0.31–0.57). The incorporation of meat and fat quality traits to the selection aims of the breeding scheme for Iberian pigs seems advisable.     

Influence of sex and terminal sire line on performance and carcass and meat quality of Iberian pigs reared under intensive production systems

A trial was conducted to study the effects of sex (castrated males; females) and terminal sire line (DD, Danish Duroc; SD, Spanish Duroc; RIB, Retinto Iberian) on performance and carcass and meat quality of pigs slaughtered at 145 kg body weight. The female line was pure Iberian in all cases. Each treatment was replicated five times (six pigs). Females were more efficient, had less carcass and inter- and intramuscular fat and more trimmed primal cuts yield than castrated males. Duroc sired pigs grew faster and had better feed conversion and carcass quality than RIB sired pigs. Crossbreeds from SD had less carcass yield than crossbreeds from DD or RIB. We conclude that productive performance and primal cuts yield were higher for females than for castrated males. Danish Duroc sires are an alternative to Spanish Duroc and Retinto Iberian sires for production of heavy pigs destined for the dry cured industry.     

Development of meat and carcass quality characteristics in Iberian pigs reared outdoors

A study of age-related changes in carcass traits and meat quality characteristics of Longissimus dorsi (LD) and Biceps femoris (BF) of free-ranged Iberian pigs was carried out to check whether the slaughter age used in the traditional management system of Iberian pigs is adequate. There was a great increase in live and carcass weight during fattening, principally due to an increase in fat deposition, as could be deduced from the percentage of dissectible fat and the backfat thickness. However, intramuscular fat in LD and BF showed only slight changes during the fattening. Myoglobin content tended to increase throughout lifetime in both muscles, whereas water-holding capacity decreased in intermediate ages and showed the highest values in the oldest animals. Total collagen content did not vary during lifetime; on the other hand, insoluble collagen increased from 7 to 77% of total collagen. It can be concluded that the traditional management system of Iberian pigs can be improved by fattening the pigs at a younger age, without negative consequences on the meat quality.     

Oxidative and lipolytic deterioration of different muscles from free-range reared Iberian pigs under refrigerated storage

Three different type of muscles, two glicolytic (Serratus ventralis and Longissimus dorsi) and one oxidative (Masseter) were displayed under refrigeration at +4?°C during 10 days to evaluate differences in lipolytic and oxidative changes of different muscles with different metabolic pattern. Thiobarbituric acid reactive substances (TBARS), phospholipid content, hexanal content and fatty acid profiles of neutral and polar lipid fractions were analysed at day 0 and day 10. Phospholipid content (g phospholipids/g intramuscular fat) significantly (P<0.035) decreased from day 0 to day 10 in m. Masseter (0.33 vs. 0.25, respectively), but not in m. L. dorsi (0.12 vs. 0.09, respectively) and m. S. ventralis (0.19 vs. 0.14, respectively). Changes in fatty acid profiles of neutral and polar lipids significantly differed among muscles after storage. Slight differences were found in neutral lipids from m. L. dorsi and m. S. ventralis, while neutral lipids from m. Masseter were highly altered. Great changes affected fatty acid profiles from polar lipids in the three muscles. m. Masseter muscle showed significantly higher (P<0.000) TBARS values (1.13, 0.65 and 0.60 mg MDA/kg meat, respectively) and hexanal content (689.2, 241.2 and 355.8 μg/g meat, respectively) than m. L. dorsi and m. S. ventralis. In conclusion, oxidative meat is more prone to oxidative and lipolytic deterioration than glycolytic muscles during refrigerated storage and as a consequence of that a lower shelf-life.     

Effect of gender and castration of females and slaughter weight on performance and carcass and meat quality of Iberian pigs reared under intensive management systems

A total of 360 Iberian dam × Duroc sire pigs was used to study the influence of gender and castration of females (CM, castrated males; CF, castrated females; IF, intact females) and slaughter weight (SW; 145 and 156 kg body weight, BW) on performance and carcass and meat quality. Each treatment was replicated four times (15 pigs). Intact females ate less, tended to have better feed conversion and had less carcass fat and more primal cuts yield than CM and CF. Pigs slaughtered at 156 kg BW ate more feed and had worse feed conversion than pigs slaughtered at 145 BW. An increase in SW improved carcass yield, but tended to decrease trimmed ham yield. Intact females are an alternative to castrated females for intensive production of Iberian pigs. Also, the reduction in slaughter weight from 156 to 145 kg BW is recommended for this type of production.     

Effect of housing conditions on production,carcass and meat quality traits of growing rabbits

Production, carcass traits and meat quality of rabbits housed in cages or in different pens were compared. Rabbits (n = 579) were sorted into 5 groups: C = cage (2 rabbits/cage); pen without platform: P11 = 9 rabbits/pen; P16 = 14 rabbits/pen; pen with platform: PW = wire net platform, 14 rabbits/pen; PD = platform with straw-litter, 14 rabbits/pen. Feed intake and average daily gain between 5 and 11 weeks, and body weight at 11 weeks were significantly higher in C rabbits than that of the mean of pen-housed groups, while the PD group had the lowest growth performance. C rabbits had the smallest hind part to reference carcass (P < 0.001) and the largest percentage of perirenal and scapular fat (P < 0.001). The meat/bone ratio was the largest in group C (P < 0.05). Differences were recorded in a* value and lipid content of m. Longissimus dorsi. Rabbits housed in cages generally had the best performance whereas those housed in pens with platform exhibited the worst.     

Effect of vaccination against gonadotrophin-releasing factor on growth performance, carcass, meat and fat quality of male Duroc pigs for dry-cured ham production

The aim of this study was to compare production, carcass and meat quality parameters, boar taint compounds and fat composition of green and dry-cured hams, between immunocastrated (IM), surgically castrated (CM) and female (FE) Duroc purebred pigs (n=75, 138.7±8.27kg). Liveweight and fat and muscle thicknesses were measured and average daily gain was calculated during growth. Carcass, meat and fat quality parameters were measured. Immunocastrated grew faster than CM or FE after the second dose of vaccine. IM had the lowest dressing percentage but similar % of ham and carcass lean to FE and CM. The effect of the immunocastration on carcass fatness depended on the location, did not affect fat and meat quality and reduced skatole and androstenone levels. Both in green and dry-cured ham, immunocastration slightly altered FA composition. Thus, Duroc pigs vaccinated with Improvac are suitable for the production of high quality dry-cured ham.     

Effect of feeding system on the growth and carcass characteristics of Iberian pigs, and the use of ultrasound to estimate yields of joints

Forty three-castrated male Iberian pigs of the Torbiscal line with an average initial weight of 102.27kg were used. A group of 22 pigs was fed according to the traditional way in free-range conditions with acorn and grass from November to January. Another group of 21 animals was fed 3.72kg/day of a conventional feed that contained 12.53MJME/kg, 16.21% crude protein, 4.94% fat and 6.64% of crude fiber, during the same period. Measurements of backfat thickness and Longissimus dorsi muscle area at the last rib were taken by means of a real-time ultrasound device (Kretz Technick Inc., 600 V-V2.32, Sonovet, Austria) in all pigs before slaughter. After slaughter, carcass, ham and foreleg weights and backfat and muscle area measurement from the last rib chop were recorded. The average daily gain, carcass yield, fat thickness, loin area, ham weight and proportion of hams were significantly higher (P<0.05) in the pigs fed in confinement than in those fed extensively (653.36g, 77.97%, 56.46mm, 3031mm(2), 22.26kg and 14.32% vs 501.48g, 76.94%, 51.74mm, 2673mm(2), 21.52kg and 13.79%, respectively). This paper shows the prediction equations for hams, forelegs and total hams and forelegs weights and proportions with respect to slaughter weight and live ultrasound measurements in pigs fed either extensively or in confinement. The ultrasound measurements better predicted the carcass cuts absolute amounts (R(2)=0.591-0.875) than the carcass cuts proportions (R(2)=0.23-0.40). The use of real-time ultrasound should be used with caution to predict the absolute quantities of hams and forelegs from Iberian pigs since the ultrasound measurements are only moderately accurate.     

Influence of alfalfa grazing-based feeding systems on carcass fat colour and meat quality of light lambs

One hundred and twenty-seven lambs were fed as follows: lambs and dams grazing alfalfa (Gr); the same as Gr but lambs had access to concentrate (Gr + S); ewes grazed and lambs received milk and concentrate until weaning and thereafter concentrate and straw (Rat-Gr); ewes and lambs were stall-fed (Ind). Lambs were slaughtered at 22-24 kg live weight and fat and M. rectus abdominis colour was measured instrumentally and subjectively. The evolution of the instrumental colour and texture of M. longissimus lumborum was also recorded.There were significant differences in the instrumental colour of subcutaneous fat amongst feeding systems, but no differences were observed upon visual appraisal. On average, M. rectus abdominis colour in the four feeding systems was classed as pink. Differences in longissimus thoracis colour at 0 h disappeared at 24 h of air exposure and there were no differences in pH or cooking losses. At no time were any differences in instrumental texture found.     

Ultrasonic and sensory characterization of dry-cured ham fat from Iberian pigs with different genetics and feeding backgrounds

The textural and ultrasonic properties of the subcutaneous fat from five batches of dry-cured hams from animals with different genetics (Iberian, Iberian×Duroc) and type of feeding ("montanera", concentrate feeds with different oleic acid content) were studied and related to the sensory traits (oiliness and brightness) of their biceps femoris muscle. The different genetics and feeding backgrounds found in the batches brought about differences in their ultrasonic velocities (average velocity from 4 to 20°C ranged from 1608 to 1650m/s) and textural parameters (maximum force at 8°C ranged from 11 to 21N). On average, batches with lower textural parameters had lower velocities and higher sensory scores. Ultrasonic measurements were used to carry out a discriminant analysis which allowed 78.3% of the samples to be correctly classified in the batches considered. Therefore, ultrasonic and sensory techniques could be useful in the characterization and differentiation of dry-cured hams from Iberian pigs.     

Effect of grass or concentrate feeding systems on lamb carcass and meat quality

Thirty-two male Ile de France lambs were divided into four equal groups at age 37 days. Two groups were allowed to graze a natural pasture in France each at a different growth rate (grass high and grass low groups). The other two groups were raised in stalls and fed concentrates to achieve the same growth rates (stall high and stall low groups, respectively) as from the grass groups. The animals were slaughtered when they attained 35 kg and their carcass and meat quality were evaluated. Animals from the two high growth rate groups were slaughtered at an average age of 129 days while those from the low growth rate groups were slaughtered at 163 days. Carcasses from stall-fed lambs were heavier than those from grass-fed lambs as the digestive tract percentage was higher in the grass lambs. Carcasses from stall lambs had better muscular conformation score (P <0.05) and were fattier than those from grass-fed animals. Subcutaneous fat was more yellow and harder in grass-fed lambs (P <0.05). Meat from grass-fed lambs was darker (P <0.05) in colour (lower L*) than meat from stall animals up to 24 h of display. Meat from stall fed animals was more tender and juicier than meat from grass-fed animals (P <0.01), as judged by a trained panel of assessors. Typical lamb flavour was higher in stall-fed lambs (P <0.01). Meat from grass-fed animals had more pronounced liver flavour (P <0.05) and less fatty flavour (P <0.01) than stall-fed lambs. Overall the difference in meat quality between the two different growth rates was minimal.     

Effect of organic production system on broiler carcass and meat quality

The effect of organic production on broiler carcass and meat quality was assessed. Two hundred and fifty Ross male chickens were assigned to two different systems of production: conventional, housing in an indoor pen (0.12 m(2)/bird); organic, housing in an indoor pen (0.12 m(2)/bird) with access to a grass paddock (4 m(2)/bird). At 56 and 81 days of age, 20 chickens per group were slaughtered to evaluate carcass traits and the characteristics of breast and drumstick muscles (m. pectoralis major and m. peroneus longus). The organic chickens had carcasses with a higher breast and drumstick percentages and lower levels of abdominal fat. The muscles had lower pHu and water holding capacity. Instead cooking loss, lightness values, shear values, Fe, polyunsaturated fatty acids of n-3 series and TBA-RS were higher. The sensory quality of the breast muscle was better. Organic production system seems to be a good alternative method, due to better welfare conditions and good quality of the carcass and meat. A negative aspect was the higher level of TBA-RS in the muscles, probably due to greater physical activity.     

Feeding Iberian pigs with acorns and grass in either free-range or confinement affects the carcass characteristics and fatty acids and tocopherols accumulation in Longissimus dorsi muscle and backfat

The experiment was undertaken to provide information on the influence of grass intake in a high fat diet based on acorns, in either free-range or confinement, on the carcass yield and characteristics, and on the accumulation of fatty acids and tocopherols. Groups raised free-range or with acorns and grass in confinement had the highest total backfat. Grass addition to the feed did not significantly modify the carcass weight and cut yield. However, outdoor raising produced lower carcass weights and yield, Longissimus dorsi muscle and ham weights than those fed the formulated diet or acorns and grass in confinement. Neither grass intake nor outdoor rearing did modify significantly the proportion of saturated fatty acids of the backfat. However, a lower proportion of saturated fatty acids was found in the intramuscular neutral lipids from pigs fed outdoors. Pigs reared free-range had significantly (P=0.0001) higher proportions of C18:1n-9 in the inner layer and in the intramuscular neutral lipids than the other groups. The grass intake significantly (P=0.0001) increased the proportion of C18:3n-3 in the inner and outer fat layers and intramuscular neutral lipids, while the outdoor rearing system not only affected on the proportion of linolenic acid but also C22:5 and C22:6 of the inner backfat layer and intramuscular polar lipids. These results suggest that the outdoor rearing allows a higher accumulation of n-3 fatty acids maybe due to an increased activity of the desaturase and elongase enzymes. On the other hand, the accumulation of tocopherols was not significantly modified neither by the grass intake nor the outdoor rearing, while differences were detected by the type of feeding (diet vs. acorns/acorns and grass). It is concluded, that the outdoor rearing system affects the nutritional value of meat, mainly by improving the fatty acid composition.     

Influence of a severe reduction of the feeding level during the period immediately prior to free‐range fattening on performance and fat quality in Iberian pigs

BACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free‐range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free‐range fattening. RESULTS: Animals from the M group showed longer and higher‐perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected. CONCLUSION: A severe reduction of the feeding level previous to free‐range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry     

Effect of breed type,housing and feeding system on performance of growing pigs managed under organic conditions

BACKGROUND: There is a need for information on the performance and carcass quality of pigs under different organic management systems. This study compared Duroc‐sired progeny from three maternal breed types when kept either at pasture or in housing with an outdoor run and offered ad libitum concentrate either alone or with fodder beet or grass/clover silage as additional forage. RESULTS: Liveweight gain, feed intake and the proportion of forages consumed did not differ between genotypes. Carcass fatness of progeny was lowest for a ‘modern’ genotype (Camborough 12) and highest for a ‘traditional’ purebred genotype (Saddleback), with a ‘crossbred traditional’ genotype (Saddleback × Duroc) being intermediate (11.4, 14.3 and 13.4 mm P₂ respectively, standard error of mean (SEM) 0.27, P < 0.001). With a cereal‐based concentrate available ad libitum, intake of forages was low (<2% of dry matter intake). Although growth rate did not differ between housing systems, daily feed intake was greater at pasture (2.47 vs 2.22 kg meal equivalent, SEM 0.05, P < 0.001), giving poorer feed efficiency (P < 0.01). Pastured animals consumed less additional forage and had a higher killing‐out % but similar carcass fatness. CONCLUSION: For organic pig production to be financially sustainable, disadvantages arising from the genotype and/or rearing system chosen need to be offset by a market premium for the pigs produced. Copyright © 2007 Society of Chemical Industry     

Effect of exercise on skeletal muscle proteolytic enzyme activity and meat quality characteristics in Iberian pigs

The effects of physical activity on performance, carcass traits, Psoas major lysosomal and exoprotease acitivies and meat quality were studied in 24 castrated male Iberian pigs during the last fattening period (from 111.1±SD: 5.2kg). Pigs were randomly distributed in three groups. Two groups receiving the same diet were reared in confinement, one housed in individual pens of 8m(2) (sedentary group) and the other was housed outdoor with daily (up to 2km) forced walking (exercise group). And one group was reared under the traditional production system walking daily several km and fed mostly with acorn from Quercus ilex and Quercus rotundifolia and grass (free-range group). No differences were found in performance and carcass traits. In exercised pigs a lower activity of cathepsin B+L and total cathepsins (P<0.05) was observed. Exercise induced the inhibition of dipeptidyl peptidases II and III and arginyl aminopeptidase and the activation of dipeptidyl peptidases IV and leucyl aminopeptidase (P<0.05). Although no effects on total free amino acids in Psoas major muscle were observed the concentration of branched chain amino acids decreased in the free-range pig group probably related to an increase in physical activity. Exercise had no effects in Psoas major postmortem tenderness and water holding capacity.     

Effect of production system on carcass measurements and meat quality of Kivircik lambs

Effect of production system on carcass and meat quality was investigated in four groups of lambs: i. W-C lambs were weaned between 45 and 60 days of age and then were fattened with concentrate feed until slaughter; ii. W-G-S lambs were weaned and then taken to pasture and wheat stubble; iii. UW-C lambs were fattened with concentrate feed and they suckled their dams until slaughter; iv. UW-G lambs were kept with their dams and were taken to pasture in the day-time. Hot carcass weight was 13.62, 12.52, 14.37 and 13.88 kg (P < 0.001), and dressing percentage was 55.24, 51.77, 57.83 and 55.38% (P < 0.001), for W-C, W-G-S, UW-C and UW-G lambs, respectively. Ultimate meat pH was higher in W-G-S lambs than lambs from W-C and UW-C systems (P < 0.05). W-G-S lambs had higher shear force value in longissimus dorsi muscle (P < 0.05) and lower meat lightness (P < 0.001) than those of other systems. Panellists gave the lowest sensory scores, except juiciness, to meat of W-G-S lambs.     

Meat quality characteristics in different lines of Iberian pigs

Physico-chemical parameters involved in technological meat quality for dry cured processing of four different lines (Entrepelado, Lampi?o, Retinto and Torbiscal) of Iberian pigs were studied in the Masseter (MS) and Longissimus dorsi (LD) muscles. The line of Iberian pig significantly affected intramuscular fat content of MS muscle, animals from the Torbiscal line showing lower values. Proportions of several fatty acids of total lipids and polar lipids from the MS muscle were also affected. However, fatty acid composition and total lipids, neutral lipids and polar lipids of LD muscle and neutral lipids of MS muscle were scarcely affected. Lipid oxidation was also unaffected by Iberian pig line, but instrumental colour parameters of MS muscle showed significant variations.     

Prediction of the feeding background of Iberian pigs using the fatty acid profile of subcutaneous, muscle and hepatic fat

Thirty Iberian pigs weighing 95 kg were randomly distributed into three groups of 10 animals each and fattened in three traditional management systems ['montanera' (MO), fed extensively on acorns, 'cebo' (CE) fed on a commercial diet and 'recebo' (RE), fed on acorns and a commercial diet]. Fatty acids from the Masseter muscle, lard and liver were analysed. In the lard, fatty acid profiles from MO and RE pigs presented minor differences; however, in the liver, RE pigs showed differences to MO pigs in most of the fatty acids studied. This suggests that the muscle and especially the liver fatty acid profile reflects the feeding regime during the last phase of feeding, while the lard reflects longer term differences.     

Comparison of some components of pigs kept in natural (free-range) and large-scale conditions

A new pig genotype of Hungarian Large White (75%) × Mangalica (pig with curly bristles, 25%) was used in the experiments. The experimental group was kept in a farming system under strictly natural circumstances until a body weight of 120 kg was attained. Neither antibiotics nor yield-increasing hormones were given to this group. The control group was kept in the usual large-scale farming conditions until body weight of 120 kg was attained. In most cases, protein, zinc, and copper levels and, in some cases, iron levels were significantly higher in some major cuts (neck-end (Boston-butt), loin, ham) of the 'free-range' pigs (n = 12) in comparison with the control animals kept in large-scale farming conditions. There was, on average, 15% less cholesterol in the muscles and 30% less cholesterol in the liver and less linoleic acid in all tissues of 'free-range' pigs than in the control group. There was less fat, but the amount of thiamin and riboflavin in the liver of the naturally kept pigs was twice that in the controls. In respect of TBA-reactive compounds, there were no significant differences between the two groups, but superoxide dismutase (SOD) showed significantly higher activities in all cuts from pigs kept in a large-scale farming system. This may be the effect of a higher level of linoleic acid in the fat.