The effects of gender and castration of females on performance and carcass and meat quality of heavy pigs destined to the dry-cured industry

The effects of gender and castration of females (IF, intact females; CF, castrated females; CM, castrated males) on performance and carcass and meat quality were studied in crossbred pigs (Landrace × Large White dams × Duroc sires) slaughtered at 119.2 (experiment 1) or 131.6 (experiment 2) kg body weight. Intact females had better feed conversion and less carcass fat than CF and CM. Trimmed shoulder yield was higher for CM than for CF with IF being intermediate. Primal cut yield and meat quality were similar for all treatments. Proportion of linoleic acid in backfat was lower in CF than in IF or CM and the differences were significant when pigs were slaughtered at 131.6 kg. The higher fat content and the fatty acid profile favor the use of castrated females and males over intact females for the production of heavy pigs destined to the dry-cured industry.     

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.     

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.     

The effect of food deprivation prior to slaughter on performance, behaviour and meat quality

The effects of repeated food deprivation, prior to slaughter, on performance, feeding behaviour and meat quality of pigs was examined. Three experimental treatments were compared. In treatment 1 pigs had ad libitum access to feed up to the point of loading on the day of slaughter. Treatment 2 involved a 12-h fast prior to slaughter and treatment 3 involved a 20-h fast prior to slaughter. Pigs were slaughtered on a weight basis therefore each pen was emptied over a period of weeks. This meant some pigs experienced repeated food deprivation. The feeding pattern of pigs which were deprived of food for 12 h was very similar to that observed before feed restriction. Pigs which were deprived of food for 20 h spent significantly more time at the feeder post fasting. This was particularly marked during the first 2–3 h when access to feed was restored. Feed deprivation for 12 h prior to slaughter did not adversely affect performance, carcass weight, meat quality or welfare in the present study. Fasting for 20 h reduced carcass weight by 1 kg, which was not statistically significant but could result in financial losses related to carcass weight. The negative effects on meat quality, of repeated feed deprivation, resulted from slower growth rates rather than feed deprivation per se.     

Impact of increasing dietary energy level during the finishing period on growth performance,pork quality and fatty acid profile in heavy pigs

Sixty Duroc × (Landrace × Large White) gilts of 93.5 of body weight (BW) were used to investigate the effect of increasing dietary net energy content (2280, 2350, and 2420 kcal/kg) on growth performance and carcass, meat, and fat characteristics. Animals were intended for dry-cured ham production. Therefore, pigs were slaughtered at 130 kg BW and a minimum fat thickness at Gluteus medius muscle (m. GM) was required. No effect was detected on daily gain or energy intake but feed intake decreased and feed conversion ratio tended to improve as energy increased. Fat depth at m. GM was wider and the proportion of suitable carcasses tended to be greater when energy increased. The treatment had scarce effect on meat and fatty acids. We conclude that 2350 kcal of net energy per kg of feed would optimize the productive and quality responses in gilts when are intended for dry-cured ham production.     

Effect of housing system, slaughter weight and slaughter strategy on carcass and meat quality, sex organ development and androstenone and skatole levels in Duroc finished entire male pigs

This study aimed at evaluating the effect of housing system (HS), slaughter weight (SW) and strategy (SS) on carcass a nd meat quality, sexual organ development and boar taint in entire males. Twelve pens of 10 pigs were used (two trials). Half of male pens were allowed visual contact with females (MF) and half with males (MM). Half MM or MF were slaughtered at 105 or 130 kg in trial 1, or penwise or by split marketing in trial 2 at 120 kg. Housing system showed no significant effect on carcass or meat quality. MF presented significantly longer testicles and heavier bulbourethral glands compared to MM. The distribution of androstenone and skatole levels was affected by SW but not by HS or SS, samples with androstenone >1 μg/g of the different groups falling within the range of 16 to 22%. All correlations between androstenone and sex organs were significant. Housing system and slaughter strategy did not reduce the risk of boar tainted carcasses.     

Effect of concentrate level and slaughter body weight on growth performances,carcass traits and meat quality of Barbarine lambs fed oat hay based diet

This study was conducted to evaluate concentrate level (CL) and slaughter body weight (SW) effects on growth performances, carcass traits and meat quality of Barbarine lambs. Twenty-four weaned male lambs (23.1 kg), receiving an oat-hay based diet, were allotted into two groups. The LCL group received low concentrate level (300 g) and the HCL group received high concentrate level (600 g). Lambs were slaughtered at two prefixed weights (35 and 42 kg). For each group and each weight, six lambs were slaughtered. Lambs from HCL group had higher ADG, carcass yields, carcass compactness and subcutaneous fat thickness, and lower carcass meat proportion. CL increase did not affect meat pH, meat and fat color, chemical and fatty acid composition. Late slaughtering improved carcass yields and increased carcass adiposity. However, it did not affect carcass meat proportion and shoulder tissue composition. SW had effect on meat color and fatty acid composition.     

The relationship between the chemical composition of the carcass and the fatty acid composition of intramuscular fat and backfat of several pig breeds slaughtered at different weights

Pigs of Belgian Landrace (B), Duroc (D), Hampshire (H), and Pietrain (P) breeds were slaughtered at 90, 110 and 130 kg body weight (BW) and the carcass chemical composition and fatty acid profiles of intramuscular fat of loin and backfat were determined. The carcass of Pietrain pigs had a higher concentration of protein and less fat than of B, D and H breeds. In tissues, the PUFA:SFA ratio was lower in the heavier (130 kg BW) than in lighter pigs (90 and 110 kg BW). This feature was higher in P pigs compared with the other breeds. The backfat had a higher concentration of PUFA:SFA ratio than intramuscular fat. The PUFA n− 6:n− 3 ratio was not affected by the breed and weight of pigs, but it was lower in backfat than in longissimus muscle fat. The protein concentration in the carcass was positively related to PUFA and negatively to SFA concentration in tissues.     

Carcass and meat quality characteristics of immunocastrated male,surgically castrated male,entire male and female pigs

The aim of the study was to evaluate the effect of immunocastration on meat and carcass quality compared with meat from females, entire and surgically castrated males. One hundred and eighteen (Landrace × Duroc) × Pietrain crossbred pigs were assigned to four experimental groups: entire males (EM), females (FE), surgically castrated males (CM) and vaccinated males (IM). Pigs were reared in two pens per sex and slaughtered at an average of 180 days of age. Carcass and meat quality characteristics such as testis size and length, fat depth, lean content, proportion of the carcass represented by each joint, pH, colour and intramuscular fat were evaluated. There was a significant reduction in the size of these sexual organs in IM compared with EM. CM and IM were fatter than FE and EM in the loin area but, in the ham area, CM was the fattest and EM the leanest, while IM and FE were in between. Intramuscular fat of IM (2.1%) was no different from the other sexes evaluated, although it was higher in CM (2.5%) with respect to FE (1.7%) and EM (1.8%). There was no difference between the IM and other treatment groups in meat quality. Regarding ours results we can conclude that from the point of view of meat and carcass quality the immunocastration could be a good alternative to the surgical castration.     

Optimizing colour quality of modified atmosphere packed sliced meat products by control of critical packaging parameters

Distribution of fat, muscle and bone tissues was studied in bucks, wethers and doe Jebel Akhdar (JA) Omani goats raised under intensive management and slaughtered at 11, 18 or 28 kg body weight (BW). Weight of individual tissues was expressed as percentage of total respective tissue weight in the half carcass. Weight of total body fat in the empty body weight (EBW) ranged between 7.6% in bucks at 11 kg BW and 23.5% in does at 28 kg BW. At 18 kg BW, JA goats had higher TBF, carcass and non-carcass fat than those slaughtered at 12 kg BW (P<0.001). Does and wethers had a faster rate of deposition of carcass and non-carcass fat relative to EBW. Therefore, they had higher fat content (P<0.001) than bucks at 28 kg BW. The highest proportion of fat in the body was deposited intermusculary whereas the omentum constituted the highest non-carcass fat proportion. About 55% of the musculature in JA goat carcasses was found in muscle groups of the proximal hind leg, around the vertebral column and in the proximal forelimb (expensive muscle groups). Bucks had higher proportions of musculature in the forequarter (P<0.001) and intrinsic muscles of the neck but lower proportions of muscles at the proximal hind limb (P<0.001) than does and wethers. About 51% of the total skeleton was found in the axial skeleton, 22–23% in the forelimb and 22–23% in the hind limb of JA goats. There were few sex or slaughter weight effects on proportions of bone weight in the skeleton. In general, slaughter weight and sex effects on tissue distribution were more pronounced in the fat tissue. The magnitude of these effects on muscle and bone tissues was small and is unlikely to have economic impact on meat production from goats.     

Carcass quality,physico-chemical parameters,muscle fibre traits and myosin heavy chain composition of m. longissimus lumborum from Puławska and Polish Large White pigs

In 54 Puławska pigs and 60 Polish Large White pigs (PLW), slaughtered at 30 and 100 kg body weight, carcass and meat quality of m. longissimus lumborum were studied. Analysis revealed that in both examined body weight groups, hot carcass weight, carcass yield percentage, meat content, and weight of ham and carcass ham percentage were significantly lower and backfat thickness higher for Puławska pigs compared to PLW pigs, while PLW pigs exhibited significantly longer carcasses, greater loin eye area, and, in the case of lighter pigs, smaller proportion of loin in the carcass. Muscles of Puławska pigs, in the lighter group, had higher IMF content and a* value, while in the heavier group they exhibited higher pH₄₅, pH₂₄ and a* values, lower L*, drip loss, WHC, and thermal loss compared with PLW pigs. PLW pigs had higher WB and hardness values and more glycolytic muscles characterised by higher TNF.     

Influence of dietary conjugated linoleic acid (CLA) and age at slaughtering on performance, slaughter- and meat quality, lipoproteins, and tissue deposition of CLA in barrows

To assess the effects of dietary conjugated linoleic acid (CLA) on performance, slaughter and meat quality, 100 Danish barrows were fed diets containing 0.5% sunflower oil (control) and 0.5% CLA from 40 kg live weight until slaughter at either 100 or 130 kg live weight. Plasma total cholesterol (P=0.006) and HDL-cholesterol (P=0.021) was reduced, and plasma FFA-concentration increased (P=0.06) in pigs fed CLA. CLA supplementation improved (P=0.01) the feed utilisation by 4.7% and 4.3% for pigs slaughtered at 100 and 130 kg, respectively. Daily gain tended (P=0.06) to increase with the CLA-treatment (1.236 versus 1.194 kg for CLA- and control, respectively). Dietary treatments had no effects on slaughter- (meat percentage and backfat thickness) and meat quality responses (pH, temperature and water holding capacity). CLA tended (P=0.09) to reduce the intramuscular cholesterol, but had no influence on the total content of intramuscular fat.     

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.     

Studies on the Criollo goat of Northern Mexico: Part 1 - The effects of body weight on body components and carcass development

Male Criollo castrate goats were reared on natural rangeland and also given some concentrate supplementation. They were slaughtered in groups of ten at 8, 12, 16 and 24 kg live weight. At slaughter the weights of body components were recorded and also carcass measurements and joint weights on the chilled left half of each carcass, which was then completely dissected into lean, fat and bone tissues. With increasing slaughter weight the proportion of internal body components minus gut contents, increased relative to the external components. In some of the goats from the higher slaughter weight groups the gut contents formed up to 26% of the total live weight. The dressing percentage based on empty body weight did not show an appreciable increase with increasing slaughter weight. The lean proportion in the carcass rose from 56% of the carcass weight in the 8 kg group to about 68% in the 24 kg group. The proportion of fat in the carcasses did not show any increase with increasing slaughter weight. The results indicate that, in terms of yield of lean meat and also edible offal, it is better not to slaughter castrate male Criollo goats before 24 kg live weight.     

Effect of sex and terminal sire genotype on performance, carcass characteristics, and meat quality of pigs slaughtered at 117 kg body weight

The effects of gender (barrows; gilts) and terminal sire genotype (DD, Danish Duroc; PxLW, Pietrain×Large White) on performance and carcass and meat quality of pigs sacrificed at a fixed weight of 117 kg were studied. Barrows ate more feed, grew faster, and had poorer feed conversion and less yield of trimmed lean cuts than gilts. Castrates were fatter and had more intramuscular fat and more intense colour of the meat than females. Crossbreds from DD boars grew faster and had better feed conversion than crossbred from P×LW boars. Also, DD sired-pigs had smaller dressing percentages but more trimmed lean cuts proportion than P×LW sired-pigs. Meat from DD pigs was more tender, had more intramuscular fat, and presented lower a* value than meat from P×LW pigs. We conclude that DD boars are a good alternative to P×LW boars for production of heavy pigs destined for the dry-cured industry.     

Effects of porcine somatotropin (PST) administration on the fat/lean content and processing properties of pork bellies

Porcine somatotropin (PST)-supplemented pigs were slaughtered at 109 or 131·8 kg; bellies were analyzed for compositional and bacon processing characteristics and compared with bellies from controls (slaughtered at 109 kg). Bellies from control and 109 kg, PST-treated pigs were significantly lighter (P < 0·01) in weight whereas the PST-treated bellies were significantly (P < 0·01) leaner than controls regardless of slaughter weight. The leaner bellies resulted in greater (P < 0·01) brine pickup, reduced smokehouse yields and bacon with less fat regardless of slaughter weight. Frying yield for the bacon from PST-treated pigs was significantly (P < 0·01) higher than that of the controls probably because of the fat/lean difference. The changes observed in bacon from PST-supplemented pigs appear to be due to the compositional change induced by PST administration.     

Feedlot performance and carcass evaluation of heifers fed finishing diets as weanling calves or as yearlings

Twenty commercial Herefored, Angus and Hereford × Angus, weanling and yearling heifers from the same herd were compared for feedlot performance and certain carcass characteristics. Yearlings tended to gain weight more rapidly than did weanlings. Since the cattle were group-fed, no analyses of feed efficiency could be performed. Yearlings appeared, however, to require less feed per unit of gain. The cattle were slaughtered when live weight approached 443 kg. Weanlings were fatter; had more kidney, pelvic and heart fat; merited higher (less desirable) USDA yield grades; had more desirable USDA quality grades and higher dressing percentage (P<0·05) than did yearlings. Ribeye area was not different between treatments. Yearlings yielded a higher percentage of closely trimmed retail lean cuts than did weanlings (P < 0·05). Sensory panel scores were higher (more desirable) for weanlings than for yearlings for both ribeye and inside round steaks (P < 0·05), while no differences were identified for flavor, juiciness or overall palatability of steaks. Warner-Bratzler shear force data generally supported taste panel evaluations for tenderness. These data suggest that carcass composition is impacted by the way cattle are managed and refute the idea that cattle have the same body composition at a given weight regardless of age at slaughter or nutrient density of the diet during finishing.     

Reduction of carcass yield in transported pigs

Pigs (53-70 kg) in a non-fasted state were either not transported or subjected to a journey lasting for 1 h or 6 h prior to slaughter. Pigs given the short transport lost 0.6% and pigs given the long transport 2.3% of their initial live weight. After lairage for 1 h with access to water, all pigs were killed 8 h after their last feed. Compared with pigs not transported before slaughter, killing out percentage was slightly, but not significantly, lowered in the short transport group and significantly (P<0.05) reduced in the long transport group. The loss in carcass weight of the latter group amounted to 2.1% of the carcass weight of the untransported control pigs. Overall, killing out percentage and liver weight expressed as a percentage of liveweight were negatively correlated with the percentage loss of live weight in transport (P<0.02). The carcass weight loss on chilling was not influenced by treatment. Measurements of adrenal ascorbic acid suggested that most of the stress of transport occurred during the loading and first hour of the journey. Transported pigs drank more water in lairage, particularly those transported for 6 h which also had a higher total protein concentration in their plasma (P<0.05). Plasma creatine phosphokinase activity was not influenced by transport. It is suggested that enforced deprivation of water is an important contributing factor to the weight loss of pigs during transport but that physical activity is not.     

Effects of finishing period length with vitamin E supplementation and alfalfa grazing on carcass color and the evolution of meat color and the lipid oxidation of light lambs

Indoor-kept concentrate-fed light lambs (n = 54) were supplemented with 500 mg of dl-α-tocopheryl acetate/kg concentrate for 0, 10, 20 and 30 d before slaughtering at 22–24 kg BW. Simultaneously, 8 lambs with their dams were alfalfa-grazed and the lambs were slaughtered at the same weight. The age at slaughter and carcass characteristics were more affected by grazing than by supplementation with α-tocopherol. The grazing lambs had similar α-tocopherol levels to the lambs fed concentrate with dl-α-tocopheryl acetate for 10 days before slaughter. The length of the feeding period affected the evolution of the color, delaying the blooming and discoloration of the meat. Feeding lambs α-tocopherol enriched concentrate during the last 10 days of life or grazing them on alfalfa drastically diminished the lipid oxidation of the meat. Alfalfa grazing is a feasible alternative to increase light lamb meat shelf life without using additives.     

Compared development of intermuscular and subcutaneous fat in carcass and primal cuts of growing pigs from 30 to 140kg body weight

A total of twenty two Large White X Landrace castrated males were slaughtered at 30, 70, 110 or 140kg BW. Carcasses were weighed and cut into four primal cuts (belly, ham, loin, and shoulder). Each cut was weighed and dissected into bone, muscle, skin, and intermuscular and subcutaneous adipose tissues. Kidney fat was also taken and weighed. Kidney fat grew more rapidly than subcutaneous or intermuscular fat averaged over all four cuts. In the shoulder and loin, about one third of total adipose tissue was in the intermuscular fraction. In the belly, there was as much (in 30-110kg BW pigs) or more (in 140kg BW pigs) intermuscular than subcutaneous adipose tissue. In the ham, the intermuscular fraction of adipose tissue grew more slowly than the subcutaneous one, so that it represented less than one fourth of total ham adipose tissue in 140kg BW pigs. Intermuscular adipose tissue exhibited a lower lipid content than subcutaneous adipose tissue, whatever the body weight, but the differences in lipid content between the adipose tissues decreased with increasing weight. These results show that the relative development of intermuscular and subcutaneous adipose tissues differs according to anatomical location.