Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: II. Commercial applications.

The objectives of this study were to determine the value of supplementing creatine monohydrate (CMH) in a complete swine finishing ration and determining its effects on meat quality. Crossbred barrows (n = 59) were allotted five pens per treatment with three pigs per pen. Dietary treatments, including 20 g CMH x pig(-1) x d(-1) fed for 5, 10, or 15 d before slaughter, were compared to control pigs that received no CMH. The basal diet was a corn-soybean meal finishing diet. At 123.5 kg, pigs were delivered to a commercial packing plant (80 km) and slaughtered according to industry practices. After a 24-h chill at 4 degrees C, right-side loins were collected from the fabrication line and vacuum-packaged for delivery to the University of Missouri Meat Lab. Hams were scanned for lean content by a primal cut electromagnetic scanner. After scanning, ham pH and light reflectance (L*, a*, b*) were obtained on the gluteus medius muscle. Loin pH and light reflectance were obtained at the 10/11th-rib juncture. The posterior section of the boneless loin was weighed, vacuum-packaged, and stored for 7 d at 1 degree C. After aging, light reflectance, weights, and Warner/Bratzler shear force measurements were taken. A linear trend (P = 0.071) was observed for ham 24-h L* values, and a cubic trend was observed for ultimate loin pH (P = 0.102). Hunter L* values of the longissimus possessed a negative linear contrast (P = 0.009) after aging, revealing that the loins of those animals treated for 10 and 15 d exhibit higher L* values. A cubic trend (P = 0.057) was shown for percentage of moisture lost as purge; 5- and 10-d treatments were intermediate to control and 15-d treatments. Warner/Bratzler shear force measurements for chops aged 7 d increased in a linear fashion (P = 0.024). This data suggests that 5-d supplementation of CMH before slaughter improves several pork quality attributes. However, it seems that supplementing CMH in swine diets for 10 or 15 d could reduce the quality of fresh pork.     

Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: III. Evaluating the cumulative effect of creatine monohydrate and alpha-lipoic acid

The objective of this study was to evaluate short-duration supplementation of alpha-lipoic acid (ALA) and creatine monohydrate (CMH) to improve fresh pork quality. Forty-eight commercial hybrid barrows were blocked by BW and randomly allotted to one of four treatments: 1) no CMH or ALA; 2) supplementation of 24 g of CMH(-1) x pig(-1) x d(-1); 3) supplementation of 600 mg ALA(-1) x pig(-1) x d(-1); or 4) combined CMH and ALA supplements. Twelve pigs per treatment were individually penned with ad libitum access to water and a finishing diet. Treatments were hand-fed to individual pigs daily (divided into three equal doses) for 5 d before slaughter at 113 kg BW in two separate groups of 24 pigs each. Intramuscular pH was recorded at 45 min postmortem and again at 24 h in the ham semimembranosus (SM) and the longissimus muscle (LM) between the 10th and 11th rib. A Meatcheck (SFK Technology, Peosta, IA) conductivity probe was inserted in the same anatomical locations as pH measurement, providing an index value (PY) from 0 to 100 (a higher index value indicates more intact muscle cells and higher water-holding capacity). Color (L, a, b values) measurements were obtained at 24 h postmortem on the ham gluteus medius (GM), SM, and LM. Two 2.54-cm-thick loin chops were removed from the loin for determination of Warner-Bratzler shear force and glycolytic potential. The intact SM and the posterior portion of the boneless loin were vacuum-packaged and stored for 7 d to determine purge loss. Creatine-supplemented pigs had a higher (P = 0.03) PY value in the SM (66.67) at 45 min postmortem than either ALA, singularly (63.50), or in the combined CMH/ALA (62.27) treatments. (A higher PY index indicates superior water-holding capacity.) Lipoic acid supplementation resulted in the highest pH at 45 min (P = 0.029). These results justify further evaluation of the potential positive influence of supplementing alpha-lipoic acid to improve pork quality.     

Creatine monohydrate supplemented in swine finishing diets and fresh pork quality: I. A controlled laboratory experiment.

Creatine monohydrate (CMH) was fed during the final stage of growth to determine its effects on fresh pork quality. Twenty-four Duroc-sired market hogs (107 kg) were individually penned and fed a corn-soybean finishing diet containing 0.55% lysine with 2% added choice white grease. Treatments consisted of a control diet (control) tested against two durations of CMH-supplemented diets (25 g CMH x pig(-1) x d(-1)) fed for 5 (5 d) or 10 (10 d) d before slaughter. Eight pigs were used per treatment. Pigs were slaughtered on day 11 of treatment (118 kg). Postmortem pH was measured in the loin (10th rib) and ham semimembranosus at 45 min (pH1) and 24 h (pH2). At 24 h, Hunter L* values were taken at the 10th rib and the ham semimembranosus. At 48 h, drip loss was determined from the loin (8th rib) and semimembranosus. Percentage of moisture, crude fat, and crude protein were determined for loin (9th rib) and semimembranosus. Treatment 2 semimembranosus tended to have a higher pH1 (P = 0.083) and pH2 (P = 0.05) than controls. Although not statistically different, 10 d semimembranosus had the highest proportion of moisture and lowest CP:moisture ratio, suggesting greater myofiber hydration. No statistical differences were detected across treatments for loin pH1, pH2, CP:moisture, or drip loss. Loins and semimembranosus from 5 d pigs had a numerically higher proportion of chemically determined i.m. fat, suggesting optimal intramuscular creatine phosphate saturation may allow for more energy to be stored as i.m. fat. Standard deviations of ham L* value means for 5 d (SD = 2.53) and 10 d (SD = 2.05) were 26 and 48% lower than controls (SD = 3.95). Standard deviations of loin L* value for 5 d (SD = 2.53) and 10 d (SD = 2.53) were 51 and 64% lower than controls (SD = 1.86). These results suggest that CMH supplementation buffers early postmortem and ultimate pH decline in the semimembranosus, which may reduce 48-h moisture loss.     

Vitamin-mineral supplementation and accelerated chilling effects on quality of pork from pigs that are monomutant or noncarriers of the halothane gene

We examined the effects of vitamin and mineral supplementation of the finishing diet on growth and accelerated chilling of carcasses on carcass and muscle traits of halothane gene carrier and noncarrier pigs. Barrows and gilts that were either monomutants (MON, n = 49) or noncarriers (NON, n = 28) of the halothane gene were fed a standard finishing diet until they reached 86 kg. They then were randomly assigned to one of four finishing diets formulated to contain 11 IU/kg vitamin E (0), 311 IU/kg vitamin E plus additional vitamins and minerals (300), 611 IU/kg vitamin E plus additional vitamins and minerals (600), or 911 IU/kg vitamin E plus additional vitamins and minerals (900) until they were slaughtered (118 kg). Alternating carcass sides were assigned either a normal chilling procedure (NC, 4 degrees C for 24 h) or an accelerated chilling procedure (AC, -20 degrees C for 1.5 h and then 4 degrees C for 22.5 h). Supplementing vitamin E in the finishing diet increased (P < 0.05) the concentration of vitamin E in the longissimus muscle. Supplementing vitamin E in the diets of MON pigs did not affect color, firmness, or cooking losses of loins or color and firmness of hams. For the NON genotype, increasing the level of vitamin E in the diet decreased (P < 0.05) the percentage of PSE loins and hams. Color and firmness scores of the gluteus medius and longissimus muscles were improved 0.4 unit (P < 0.005) by AC compared with NC of carcasses. Loin chop juiciness and flavor were improved (P < 0.05) in the MON genotype for AC compared to NC. Accelerated chilling reduced (P < 0.05) the percentage of PSE loins from 38 to 17% and PSE hams from 32 to 10% for the MON genotype, but percentage of PSE was not affected (P > 0.05) by chilling treatment for the NON genotype. No interaction between diet and chill treatments existed for muscle quality traits (P > 0.05). Supplementing finishing diets of NON pigs with at least 600 IU/kg vitamin E, in addition to other vitamins and minerals, or accelerated chilling of MON carcasses can reduce the incidence of PSE pork.     

Effects of L-carnitine supplementation on quality characteristics of fresh pork bellies from pigs fed 3 levels of corn oil

Crossbred pigs (n = 216) were used to test the effect of supplemental L-carnitine (CARN) on the fatty acid composition and quality characteristics of fresh pork bellies from pigs fed diets formulated with different inclusion levels of corn oil. Pigs were blocked by BW (43.6 ± 1.0 kg) and allotted randomly to pens of 6 pigs within blocks. Then, within blocks, pens were assigned randomly to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement, with either 0 or 100 mg/kg of supplemental CARN and 3 dietary inclusion levels (0, 2, or 4%) of corn oil (CO). When the lightest block weighed 125.0 kg, all pigs were slaughtered, and left-side bellies were captured during carcass fabrication for quality data collection. Fresh pork bellies were evaluated for length, width, thickness, and firmness (bar-suspension and Instron-compression methods) before a 2.5-cm-wide strip of belly was removed and subsequently dissected into subcutaneous fat, primary lean (latissimus dorsi), secondary lean (cutaneous trunci), and intermuscular fat for fatty acid composition determination. Although belly length, width, and thickness of fresh pork bellies were not affected by CARN (P ≥ 0.128) or CO (P ≥ 0.073), belly firmness decreased linearly (P < 0.001) with increasing dietary CO, but there was no (P ≥ 0.137) effect of CARN on any belly firmness measure. Dietary CARN increased (P < 0.05) the proportion of total SFA in the intermuscular fat layer, increased (P < 0.05) the proportion of total MUFA in the primary and secondary lean layers, and decreased (P < 0.05) the proportion of total PUFA in the intermuscular fat and secondary lean layers of pork bellies. Moreover, the SFA and MUFA compositions decreased linearly (P < 0.001) with increasing dietary CO, and the rate of the decrease in SFA composition was greater (P < 0.001) in the fat layers than the lean layers. Conversely, the PUFA content increased linearly (P < 0.001) with increasing dietary CO, and the rate of the increase in PUFA was greater (P < 0.001) in the fat than the lean layers, and greater (P = 0.022) in the primary than secondary lean layer. Results from this study would indicate that differences in the amount and rate of fatty acid deposition associated with feeding increased amounts of CO, along with moisture differences among the belly layers, combine to negatively affect fresh pork belly firmness.     

Effect of vitamin E on improving fresh pork quality in Berkshire- and Hampshire-sired pigs

This study was designed to evaluate the effects of vitamin E supplementation on pork quality of two genotypes with distinct differences in pork quality traits. Pigs (n = 240; BW = 87 +/- 0.35 kg) were allotted by weight to one of 20 treatments (4 pens/treatment, 3 pigs/pen) in a 2 x 2 x 5 factorial randomized complete block design. Factors included 1) genotype (Berkshire or Hampshire sired), 2) sex (gilts or barrows), and 3) vitamin E level (12.1, 54.7, 98.8, 174.0, and 350.6 IU of vitamin E/kg diet). Hampshire-sired pigs had greater average daily gain (1.05 vs 0.98 kg) and gain:feed (0.30 vs 0.27) and less average daily feed intake (ADFI) (3.46 vs 3.62 kg) than Berkshire-sired pigs (P < 0.001) for the 6-wk study. Hampshire-sired barrows consumed more feed (3.54 vs 3.38 kg/d) and were less efficient (0.29 vs 0.31) than Hampshire-sired gilts (P < 0.05), but this sex difference was not observed in Berkshire-sired pigs (interaction, P < 0.05). Berkshire-sired pigs had greater backfat (34.1 vs 21.1 mm; P < 0.001), reduced longissimus muscle area (37.6 vs 46.3 cm2; P < 0.001), reduced lean percentage (53.0 vs 55.8; P < 0.001), and a greater head-on yield (79.8 vs 79.2; P < 0.05). Vitamin E increased (P < 0.05) ADFI linearly (P < 0.05), but had no effects on carcass composition. Loin chops from Hampshire-sired pigs had reduced ultimate pH (5.64 vs 5.91), greater drip loss (92.2 vs 66.3 mg), and increased Minolta L* (52.6 vs 48.6), a* (8.9 vs 7.5), and b* (6.9 vs 5.2) values compared to Berkshire-sired pigs (P < 0.001). Vitamin E had no effect on pH, temperature, drip loss, and L* or a* values, but tended (P < 0.07) to increase b* values linearly (P < 0.06). Oxidation as indicated by thiobarbituric acid reactive substances (TBARS) was greatest in Hampshire-sired gilts at the lowest level of vitamin E, and decreased linearly (P < 0.001) with additional vitamin E. However, TBARS responded in a cubic fashion (P < 0.05) to vitamin E in Hampshire-sired barrows and were not affected in Berkshire-sired gilts or barrows (three-way interaction, P < 0.02). Hampshire-sired pigs had greater TBARS than Berkshire-sired pigs (0.053 vs 0.047 mg malondialdehyde equivalents/kg). Vitamin E supplementation increased serum concentrations of vitamin E on d 21 (1.06 to 4.79 microg/mL) and d 42 (1.02 to 2.82 microg/mL) and increased tissue concentrations of vitamin E (1.99 to 4.83 microg/g) linearly (P < 0.001). Vitamin E supplementation was not effective in improving fresh meat quality in genotypes with poor or superior meat quality traits.     

Timing of magnesium supplementation administered through drinking water to improve fresh and stored pork quality

Thirty-two pigs were used to determine the timing effect of magnesium (Mg) supplementation given through drinking water on pork quality. Pigs (16 barrows and 16 gilts) were individually penned, provided 2.7 kg of feed (0.12% Mg) daily (as-fed basis), and allowed free access to water via a nipple waterer for the duration of the study. After 5 d of adjustment, pigs (120 +/- 0.8 kg BW) were allotted randomly by weight and sex to 900 mg/L of supplemental Mg from magnesium sulfate heptahydrate in drinking water for -6, -4, -2, or 0 d relative to slaughter. The LM and semimembranosus (SM) muscles were removed 24 h postmortem. Retail display storage was simulated for 8 d, and the LM was vacuum-packaged for 25 or 50 d at 4 degrees C. Magnesium did not affect the pH of the LM at either 45 min (P = 0.15) or 24 h postmortem (P = 0.23). However, the pH of the SM at 24 h postmortem tended to be greater (P = 0.08) for pigs consuming Mg for 2 d than for those not supplemented. Fluid loss after 8 d of storage was less (P < 0.05) in the LM of pigs supplemented with Mg for 6 d than in those without supplementation. Furthermore, fluid loss from the SM of pigs provided supplemental Mg for 2 d, but not for 4 or 6 d, was lower (P < 0.05) on each day of retail display than the SM of unsupplemented pigs. Minolta L*, a*, and b* color measurements of the LM during display storage were not (P > 0.10) affected by Mg supplementation. However, Mg supplementation for 2 or 4 d decreased paleness (lower L* value) after 25 d (P < 0.05), but not 50 d (P > 0.10) of vacuum-packaged storage. Magnesium addition for 2 d decreased the extent of oxidation (thiobarbituric acid-reactive substances) of the LM after 4 d of display storage compared with 0 d of Mg (P < 0.05). Oxidation of the SM during 8 d of display storage increased linearly (P < 0.05) as duration of supplementation increased from 2 to 6 d but did not differ (P = 0.22) from 0 d of Mg supplementation. Although the response to Mg supplementation was variable, supplementation for 2 d before slaughter was considered most efficacious because of the following: decreased fluid loss from the SM, and lower lipid oxidation formation in the LM during retail storage; a darker, more desirable LM color after 25 d of vacuum-packaged storage; and cost reductions compared with longer durations.     

Dietary supplementation with Moringa oleifera and mulberry leaf affects pork quality from finishing pigs

Moringa oleifera and Morus alba leaves are nutritious non-traditional feed ingredients containing bioactive substances. This study was to evaluate the potential application of dietary Moringa and Morus leaf powder on the growth traits, carcass characteristics and meat quality of finishing pigs. Moringa did not alter growth performance or carcass characteristics, but it decreased meat b* value, increased MyHCIIa and decreased MyHCIIx mRNA levels, and increased CP and concentrations of Ala, Thr, Ile, Lys and Pro in longissimus thoracis. Morus increased final BW, ADFI and ADG, decreased F/G ratio, improved slaughter weight, carcass weight, carcass yield and meat a* value, and decreased shear force, drip loss, MyHCIIx and MyHCIIb mRNA levels, and increased MyHCI and MyHCIIa mRNA levels. Morus also increased CP, Glu, Gly, Ala, Arg, Ile, Phe, Pro, Ser, Tyr and Asp, and C16:1, C18:1n9c, C20:4n6, C18:3n3, C20:3n3, C22:1n9 and n-3 PUFA, but decreased C12:0 and C16:0. In summary, Morus improved the parameters and held great potential as an unconventional feed crop.     

地方品种猪肉品质及其膳食营养论述

随着社会经济的快速发展与人民生活水平的不断提高,消费者对肉制品的食品安全、风味与口感、营养与健康有了更高的要求.大量试验研究表明,我国地方猪种的肉品质相比长白猪、大约克猪、杜洛克猪、杜长大猪等国外品种品系,有着明显优势.文章对我国地方品种猪肉品质的优势特点及其膳食营养和对人体健康的影响进行综述.     

Pancreatic enzyme supplementation in normal and exocrine pancreatic insufficient pigs

The effect of pancreatic enzyme preparation (Combizyme Forte granulate) on the growth rate of normal, sham-operated and pancreatic duct ligated growing pigs was studied in 2 trials. In the first trial 6 normal Yorkshire pigs were fed a pancreatic enzyme supplement and 6 other pigs from the same litter were fed without supplementation. The growth rate over a period of 4 weeks was not significantly greater in the supplemented group. In a second trial exocrine pancreatic insufficiency, without diabetic symptoms, was produced in 12 pigs (aged 1.5 months and weighing 14 kgs) by ligation of the main pancreatic duct. The growth rates over a period of 20 days after surgery were 240 g, 454 g and 483 g/day in ligated pigs, in ligated pigs supplemented with pancreatic enzyme and in sham-operated control pigs, respectively. The difference between the ligated groups was significant (p less than 0.01) indicating the efficiency of the pancreatic enzyme therapy.     

Effects of dietary vitamin E and fat supplementation on pork quality

The effects of dietary vitamin E (VE, alpha-tocopherol acetate) and fat supplementation on growth and carcass quality characteristics, oxidative stability of fresh and cooked pork patty in storage, fatty acid profiles of muscle and adipose tissue, and VE concentrations of plasma, muscle, and adipose tissue were studied. Six hundred pigs were allocated to 1 of 6 diets and fed for 63 d in a 3 x 2 factorial design. The dietary treatments included 3 fat levels (normal corn, high oil corn, high oil corn plus added beef tallow) and 2 levels of VE supplementation (40 IU/kg, normal VE supplementation; and 200 IU/kg, high VE supplementation). At 113 kg of BW, 54 pigs were slaughtered as a subsample to evaluate dietary effects on pork quality. Growth performance and meat quality characteristics did not differ (P > 0.05) among treatment groups. The high level of VE supplementation had a beneficial effect on the oxidative stability of pork as indicated by thiobarbituric acid reactive substance (TBARS) values. Lean tissue had lower (P < 0.05) TBARS in the group fed the high VE than in those fed the normal VE level. The TBARS values differed among storage periods (0 to 6 d) and also between fresh and cooked ground ham. Fat type did not significantly affect total saturated and unsaturated fatty acids proportions in the neutral and polar fraction of muscle. Adding VE acetate led to greater (P < 0.05) monounsaturated and total unsaturated fatty acid proportions in neutral lipids of muscle and adipose tissues. Increasing dietary levels of VE acetate increased the concentration of VE in plasma and muscle. These results indicate that dietary VE acetate supplementation increased (P < 0.05) lipid stability and the VE concentration of muscle.     

Effect of dietary vitamin E supplementation and feeding period on pork quality

Feeding increased levels of dietary vitamin E can inhibit lipid oxidation. The aim of this study was to investigate the effect of levels of dietary alpha-tocopherol acetate (VE) and feeding duration on meat quality and lipid oxidation. Eighty-one pigs were allocated to 1 of 3 diets containing 40, 200, or 400 IU of VE/kg of feed, and each diet group was divided into 3 feeding periods (3, 6, or 9 wk). Carcass characteristics and meat quality were evaluated. Oxidative stability of fresh and cooked pork patties and pork chops was determined after chilled or frozen storage. Increasing dietary concentrations of VE did not affect any growth performance parameter. Drip loss, however, decreased (P < 0.05) with increased dietary VE levels. Moreover, an increased duration of VE feeding improved (P < 0.05) pH and drip loss. Less lipid oxidation (P < 0.05) was detected in fresh ground pork from pigs fed greater concentrations of VE after 4 d of storage. A greater (P < 0.05) resistance to oxidation in cooked ground pork was observed in pigs fed 200 or 400 IU of VE/kg at 2 and 6 d of storage. Fresh and cooked pork patty oxidation decreased (P < 0.05) linearly as feeding duration increased from 3 to 9 wk. After 6 mo of freezer storage, lipid oxidation of pork chops from pigs fed 200 or 400 IU of VE/kg was lower (P < 0.05) than for pigs fed 40 IU of VE/kg. Likewise, lipid oxidation of pork chops of pigs fed VE for an extended period of time (6 wk) was lower (P < 0.05) after 9 mo of storage. Fatty acid profiles of neutral lipid fraction of the LM became more unsaturated (P < 0.05) with added VE to the feed. These results indicate an increased intake of dietary VE concentration, and prolonged feeding of VE can improve drip loss and reduce lipid oxidation in ground pork and pork chops. This study suggests that supplementation with 200 IU of VE/kg of feed for 6 wk before market is beneficial in improving lipid stability and pork quality.     

Selection for lean growth efficiency in Duroc pigs influences pork quality

A unique line of Duroc pigs was established by intensive selection for increased lean growth efficiency. The objective of this study was to determine the influence of this selection strategy on fresh pork quality traits. Two lines of Duroc pigs originating from the same foundation herd were evaluated. One line was selected for lean growth efficiency over five generations (Select line), and the other was a contemporary line maintained from the foundation herd (Control line). All pigs in the trial tested negative for the halothane gene. Selection for lean growth efficiency resulted in improved lean gain, carcass lean, increased loin eye area, and less overall carcass fat. The Select line had significantly lower subjective firmness scores in longissimus and significantly greater amounts of moisture and protein lost as measurable drip in longissimus, semimembranosus, and semitendinosus. There were no differences in subjective color scores or in Hunter L, a, and b values between lines. No selection line differences were observed in glycolytic potential or ultimate pH. The longissimus and the semitendinosus exhibited significantly lower early postmortem pH values in Select line pigs. Warner-Bratzler shear values were higher for Select line longissimus chops. Degradation of troponin-T was decreased in the Select line longissimus samples. This result suggests that reduced degradation of myofibrillar proteins may be associated with increased moisture and protein lost during storage. This research points out that elimination of the halothane gene will solve some but not all of the genetically influenced pork quality problems faced by the industry. The Select line of pigs appears to be more prone to producing pork that is soft and exudative, indicating a link between soft and exudative pork and some genetic selection strategies may exist. Therefore, it appears that selection for some economically important traits, such as feed efficiency or increased lean growth in the absence of the halothane gene, may compromise pork quality.     

Interactive effect of ractopamine and dietary fat source on pork quality characteristics of fresh pork chops during simulated retail display

Crossbred pigs (n = 216) were used to test the interactive effect, if any, of ractopamine (RAC) and dietary fat source on the performance of finishing pigs, pork carcass characteristics, and quality of LM chops during 5 d of simulated retail display (2.6 degrees C and 1,600 lx warm-white fluorescent lighting). Pigs were blocked by BW and allotted randomly to pens (6 pigs/pen), and, after receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 diets in a 2 x 2 factorial arrangement, with 5% fat [beef tallow (BT) vs. soybean oil (SBO)] and RAC (0 vs. 10 mg/kg). Diets were formulated to contain 3.1 g of lysine/Mcal of ME and 3.48 Mcal/kg of ME. Across the entire 35-d trial, pigs fed RAC had greater (P < 0.01) ADG and G:F, but RAC did not affect (P = 0.09) ADFI; however, performance was not affected (P >or= 0.07) by dietary fat source. Carcass weight, LM depth, and lean muscle yield were increased (P < 0.01), whereas fat depth was decreased (P = 0.01), in carcasses from RAC-fed pigs; however, carcass composition measures were similar (P >or= 0.27) between fat sources. Feeding 10 mg/kg of RAC reduced (P 相似文献   

Effect of dietary kapok oil supplementation on growth performance,carcass traits,meat quality and sensory traits of pork in finishing‐pigs

Kapok seed and oil from the tropical zone are widely used as pig feed to harden porcine fat in Japan. This study evaluated the effect of dietary kapok oil supplementation on pork quality and sensory traits. Five Duroc pigs each were assigned to an experimental group supplemented with kapok oil and a control group. Dietary kapok oil supplementation had no effect on growth performance and intramuscular fat content in the Longissimus dorsi muscle (LM). Supplemental kapok oil increased saturated fatty acid contents in subcutaneous and intramuscular fat and decreased monounsaturated fatty acid levels (P < 0.05). Off‐flavor detection by a trained panel was higher in the experimental than the control group (P < 0.05), but tenderness, juiciness, texture and flavor intensity of LM chops were similar in both groups. The overall palatability of pork as judged by a consumer panel decreased with kapok oil supplementation (P < 0.01). These results indicate that while growth performance, intramuscular fat contents and carcass characteristics were unchanged, while dietary kapok oil supplementation makes firm fat to prevent inferior soft fat in pork, it can lower the palatability of pork due to a decrease in monounsaturated fatty acids.     

Hydrogenated dietary fat improves pork quality of pigs from two lean genotypes

Pork quality is influenced by nutrition, genetics, management, and pork-processing procedures. Pigs of lean genotype fed diets high in unsaturated fat may have thinner, lower-quality bellies with a soft fat composition. Therefore, we investigated the effects of supplementing 5% choice white grease that had been chemically hydrogenated to iodine values of 80, 60, 40, or 20 on pork quality. Diets were fed to barrows and gilts of two genotypes (NPD [Ham-line x Manor hybrid] and PIC [406, 419, or 420 x C22]; n = 240) in a 4 x 2 x 2 factorial design. Pigs (76.8 kg of mean initial weight) were placed on test at a common age and were fed dietary treatments for 52 d. Pigs of PIC genotype were heavier at trial initiation, had higher feed intake and feed conversion ratio (F/G; P < 0.05), and greater backfat (26.3 vs. 24.0 mm; P < 0.001) and loin depth (59.0 vs. 55.3 mm; P < 0.001) compared with the NPD genotype pigs. As the iodine value of dietary fat was reduced, belly thickness increased (P < 0.05) and length decreased linearly (P < 0.05). Congruently, belly fat iodine value decreased from 73.9 to 67.4 (linear effect; P < 0.001) and belly fat C18:2 concentration declined from 20.6 to 16.3% (linear and quadratic effect; P < 0.001). The belly mono- and polyunsaturated fat ratio increased 29% as diet iodine value declined from 80 to 20 (linear and quadratic effect; P < 0.001). Further, there was a linear increase (P < 0.001) in saturated fatty acid concentration of belly fat (C14:0, C16:0, and C18:0) as dietary fat iodine value declined. Quadratic (P < 0.005) effects were detected in the level of C18:1trans as iodine value decreased from 80 to 20, paralleling dietary content. Dietary fat iodine value did not affect fat digestibility, ADFI, or F/G. Pork belly quality was improved as defined by reduced iodine value, C18:2 content, increased saturated fatty acid content, increased thickness, and decreased length as dietary iodine value decreased. Results indicate that reduction of dietary fat iodine value by chemical hydrogenation has the desirable effect of improving pork quality and does not alter growth performance.     

Interactive effect of ractopamine and dietary fat source on quality characteristics of fresh pork bellies

Crossbred pigs (n = 216) were used to test the interaction, if any, of ractopamine (RAC) and dietary fat source on the characteristics of fresh pork bellies. Pigs were blocked by BW (77.6 +/- 6.5 kg) and allotted randomly to pens (6 pigs/pen). After receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 treatments arranged in a 2 x 2 factorial design, with 5% fat (beef tallow vs. soybean oil) and RAC (0 vs. 10 mg/kg). At the conclusion of the 35-d feeding period, pigs were slaughtered at a commercial pork packing plant (average BW of 108.8 +/- 0.6 kg), and fresh bellies were captured during carcass fabrication. Neither RAC (P = 0.362) nor fat source (P = 0.247) affected belly thickness. Subjective (bar-suspension) or objective (compression test) measures of belly firmness were not (P > or = 0.148) affected by the inclusion of RAC in the diet; however, bellies from pigs fed soybean oil (SBO) were softer than those from pigs fed beef tallow (BT), as indicated by perpendicular (P < or = 0.005) and parallel (P < 0.001) suspensions. Moreover, bellies from BT-fed pigs required more (P = 0.096) force to compress 50% of their thickness than bellies from SBO-fed pigs (52.29 vs. 43.51 kg). Color (L*, a*, and b* values) of the belly lean and fat was not (P > or = 0.131) affected by RAC, and lean color was similar (P > or = 0.262) between fat sources; however, belly fat from BT-fed pigs was lighter (P = 0.030) and redder (P = 0.013) in color than belly fat from SBO-fed pigs. Bellies of SBO-fed pigs had greater (P < 0.001) proportions of PUFA and lower (P < 0.001) proportions of SFA and MUFA than belly fat from pigs fed BT. Regardless of the RAC inclusion level, PUFA:SFA and iodine values were lower in belly fat from pigs fed BT than SBO; however, within SBO-fed pigs, PUFA:SFA and iodine values were further increased by feeding RAC (RAC x fat source, P < 0.001). As expected, dietary fat source altered the fatty acid composition of fresh pork bellies, which subsequently impacted fresh belly firmness. Interestingly, including RAC in swine finishing diets exacerbated the effect of feeding SBO on pork fat polyunsaturation.     

Intramuscular fat content has little influence on the eating quality of fresh pork loin chops

Fresh pork loins (n = 290) were selected from a commercial packing facility based on subjective marbling of the intact loin and 24-h pH to determine the influence of marbling on sensory attributes. The study was designed using pigs from a similar genetic background, raised in similar production facilities, and slaughtered on a single kill day to minimize the effects of genetics, management, environment, and slaughter day. Loins were vacuum-packaged, transported to the University of Illinois Meat Science Laboratory, and aged for 7 d, after which a chop was removed from the area of the tenth rib for proximate analysis. Quality measurements, including National Pork Producers Council color, marbling, and firmness, ultimate pH, Minolta L*, a*, and b*, and drip loss, were determined after aging. After the proximate composition was completed, 150 loins were selected to provide a continuous and uniform distribution of extractable lipid, ranging from 1 to 8%, and a pH range from 5.5 to 5.8. Trained sensory panel analyses (end point cooking temperatures of 62, 71, or 80 degrees C) as well as measurement of Warner-Bratzler shear force (cooked to 71 degrees C) were performed on chops from the 150 loins. Consumer evaluation was also conducted on a subset (n = 40) of these loins, which were broken down into 5 discrete levels of intramuscular lipid, with averages of 1.6, 2.5, 3.6, 4.5, and 5.7% extractable lipid. Consumers were also asked to select the chops they would most prefer from a retail display case based on the amount of marbling present. Results from the consumer portion of the study indicated that intramuscular fat content had limited effects on perceived tenderness, juiciness, pork flavor, and oiliness; some significant differences (P < 0.05) were detectable, but they were numerically small. Most consumers also selected lean chops from the retail case, with nearly 50% selecting chops with less than 1.7% extractable lipid. Warner-Bratzler shear force was negatively related (P < 0.0001) to extractable lipid, with an R(2) value of 0.10. Results from the trained panel sensory analysis indicate that the percentage of extractable lipid did not correlate strongly with perceived tenderness, juiciness, or pork flavor for this group of pork loins that was controlled for genetics, pH, management, and day of slaughter.     

Effects of the halothane genotype and slaughter weight on texture of pork

The objective of this study was to investigate the effects of the halothane (HAL) genotype, slaughter weight (SW), and the HAL x SW interaction on compositional and textural traits of raw and cooked pork. Pigs were bred to exhibit one of the three HAL genotypes (NN, Nn, and nn) with otherwise equivalent genomes. The nn halothane reactors are known to typically produce PSE pork, whereas NN pigs do not typically produce PSE pork. Pietrain x Large White gilts and boars, all with verified Nn genotype (by DNA test), were mated to obtain F2 littermates of the three HAL genotypes. These pigs were slaughtered at either 101 +/- 3 ("light") or 127 +/- 3 ("heavy") kg BW and were evaluated for longissimus muscle traits. The pH at .5 h after death (pH1) was 6.35, 6.13, and 5.68 in NN, Nn, and nn pigs, respectively. Sarcomere length was greater in nn than in NN and Nn pigs (1.94 vs 1.83 and 1.85 microm, respectively). Mechanical resistance was higher in nn than in NN pigs for both raw and cooked meat. Meat from nn pigs was judged by a trained panel to be less rough, more cohesive, harder, more fibrous, less granular, more elastic, and less easy to swallow than meat from NN pigs. For most traits under study, the heterozygotes were intermediate between the homozygotes but closer to NN than to nn pigs. Muscle from heavy pigs had longer sarcomeres and less moisture than muscle from light pigs. The n allele of the HAL gene unfavorably affects pork texture, and this effect is maintained throughout the range of 101 to 127 kg BW.