• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.9-14
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• 2012

The purpose of this study was to estimate heritabilities and genetic correlations for reproductive and productive traits and to apply their estimates to selection strategies in a swine population. Reproductive and productive traits considered in this study were number of born alive piglet (NBA), number of weaned piglet (NW), loin eye area (LEA), days to 90 kg (D90KG), back fat thickness (BF), and lean meat content (LEAN). Data were collected from 9,886 litters on 2,447 sows for reproductive traits and 10,181 gilts and boars for productive traits from Jan. 2000 to Dec. 2008 in a swine GGP farm. The statistical model to estimate genetic parameters for considering traits was a multiple traits animal model with including animal and maternal additive effects and litter effects on reproductive traits and animal additive effects on productive traits as random as well as some of fixed effects. For estimating (co) variance components of several random effects, restricted maximum likelihood methodology was used on this assumed model. The estimated heritabilities by animal additive effects and maternal effects were 0.07 and 0.02 for NBA and 0.03 and 0.02 for NW, respectively. Genetic correlation estimate for direct genetic effects between NBA and NW was 0.14. Heritability estimates for direct genetic effects were 0.19, 0.39, 0.36, and 0.43 for LEA, D90KG, BF and LEAN, respectively. The genetic correlation of LEA with LEAN was 0.35. Productive traits were antagonistically correlated with reproductive traits. From these results it is concluded that, if selection is done for strong positive effects of reproductive traits, then this would decline productive performance.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.725-732
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• 2012

This study was carried out to investigate the effects of hydrated potato starch on the quality of low-fat ttoekgalbi (Korean traditional patty) packaged in modified atmosphere conditions during storage. The ttoekgalbi was prepared from 53.2% lean beef, 13.9% lean pork, 9.3% pork fat, and 23.6% other ingredients. Two low-fat ttoekgalbi treatments were prepared by substituting pork fat with hydrated potato starch; either by 50% fat replacement (50% FR) or 100% fat replacement (100% FR). Both 50% and 100% FR increased the moisture, crude protein, and decreased fat content, cooking loss, and hardness. For MAP studies, 200 g of ttoekgalbi were placed on the tray and filled with gas composed of 70% $O_2$: 30% $CO_2$ (70% $O_2$-MAP) and 30% $CO_2$: 70% $N_2$ (70% $N_2$-MAP), and were stored at $5^{\circ}C$ for 12 d. During the storage time, both 50% and 100% FR showed higher protein deterioration, while no differences were found in CIE $a^*$, CIE $L^*$, lipid oxidation, and bacterial counts in comparison to control. The ttoekgalbi with 70% $O_2$-MAP was more red, lighter in color, and showed higher TBARS values compared with 70% $N_2$-MAP. The meat with 70% $N_2$-MAP showed lower aerobic bacterial counts in control than those with 70% $O_2$-MAP. The lower anaerobic bacterial counts were observed only in 50% FR and 100% FR packed with 70% $N_2$-MAP in comparison with 70% $O_2$-MAP. In conclusion, the fat replacement with hydrated potato starch showed no negative effects on the quality of low fat ttoekgalbi during storage and 70% $N_2$-MAP was better than 70% $O_2$-MAP for low-fat ttoekgalbi packaging.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.206-215
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• 2010

A total of 582 gilts and barrows were analyzed to investigate the regressive relationships to slaughter weight (SW) of variables related to production efficiency and pork quality. Average initial weights and SW were 88.6 and 122.5 kg, respectively, for gilts and 88.7 and 121.4 kg, respectively, for barrows. Average daily gain and gain:feed ratio were not affected by SW. Backfat thickness, which was significantly greater (p<0.01) in barrows (23.3 mm) than in gilts (20.7 mm), increased with increasing SW (0.21 mm/kg; p<0.001). When the 4-notch carcass yield and quality grades were quantified according to an arbitrary 1 point-per-1 notch scale, the former, but not the latter, regressed on SW (-0.64/10 kg; p<0.01). The percent yield of the belly per total lean (overall mean=20.7%) increased with increasing SW (0.37%/10 kg; p<0.001), whereas in other cuts, the SW effect was negligible. The redness of the loin also increased with increasing SW (p<0.05), but other physicochemical characteristics were minimally influenced by SW. In sensory evaluation, effects of SW for fresh and cooked loin, ham, and belly were mostly considered insignificant in terms of quality, albeit statistically significant in several cases. However, positive regressions on SW (p<0.01) of the marbling and acceptability scores of fresh loin as well as the fat:lean ratio of fresh belly were noteworthy. Collectively, SW of approximately 125 kg was maximal for both sexes under the current carcass yield grading, in which 94 kg is the upper weight limit for grade A carcass. However, if the carcass weight limit of the grading was to be removed or broadened, the SW for gilts (but not that for barrows because of their excessive fat content at above 125-kg SW) could be increased to 135 kg or greater without compromising carcass quality.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.687-694
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• 2008

This study was conducted to investigate effects of dietary supplementation of lysine and leucine on growth performance and meat quality parameters in finishing pigs. The experiment was designed using lysine levels(0.45%, 0.75%) and leucine levels(1.0%, 2.0%, 3.0%) according to 2×3 factorial design. A total of thirty-six pigs[(Landrace×Yorkshire)×Duroc] with an average initial weight of 75.5±2kg were allotted to one of the six dietary treatments. Each treatment had three replications of two pigs per replicate. No difference was found in average daily gain(P>0.05), while feed intake and feed/gain were higher in 0.45% of lysine treatments than in 0.75% of lysine treatments(P<0.05). Retail lean meat percentage was lower in 0.45% of lysine treatments than in 0.75% of lysine treatments(P<0.05), but there were no differences in other carcass characteristics(P>0.05). Marbling score was significantly increased(P<0.05) in 0.45% of lysine treatments compared to 0.75% of lysine treatments, while other meat quality parameters were not affected by lysine levels(P>0.05). Supplemental dietary leucine had no effect on growth performance, carcass characteristics, and meat quality parameters(P>0.05) except that Hunter b* value were increased with added levels of leucine(P<0.05). In conclusion, feeding of lysine-deficient diets in finishing pigs improved marbling scores of pork. Feeding diets high in leucine, however, did not increase intramuscular fat or marbling scores.

• Journal of Animal Science and Technology
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• v.57 no.3
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• pp.8.1-8.8
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• 2015

Background: The demand for healthy, lean and consistent meat products containing low saturated fatty acid content and high quality polyunsaturated fatty acids (PUFA), especially long-chain (${\geq}C_{20}$) omega-3 PUFA, has increased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, and this study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patterns of genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle of Australian crossbred sheep. Methods: Twenty-four weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms of nutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins and minerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that infer health benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNA extraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNA expression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism. Results: Both low and high Spirulina supplementation levels strongly up-regulated the transcription of all the selected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did not influence the gene expression patterns in these tissues. Conclusions: The evidence indicates that high Spirulina supplementation level resulted in a decrease in intramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production of melatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negatively affected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASN genes responsible for fat production. These findings are consistent with the observed phenotypic data suggesting that low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.161-166
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• 2008

To determine if body weight change is directly related to altered leptin and neuropeptide Y (NPY) gene expression, we assessed adipose tissue weight, percent body fat, leptin and NPY mRNA levels and serum leptin concentration in pigs at weights of 1, 20, 40, 60, and 90 kg. The results indicated that the weight of adipose tissues and the percent body fat of pigs significantly increased and correlated with body weight (BW) from 1 to 90 kg (p<0.01). Serum leptin concentrations and leptin mRNA levels in omental adipose tissue (OAT) increased from 1 to 60 kg, and then decreased from 60 to 90 kg. At 60 kg, the serum leptin concentration and leptin mRNA level significantly increased by 33.5% (p<0.01) and 98.2% (p<0.01), respectively, as compared with the levels at 1 kg. At 60 kg, the amount of leptin mRNA in subcutaneous adipose tissue (SAT) was significantly higher than that of 1 and 40 kg animals (p<0.05). NPY gene expression in the hypothalamus also changed with BW and at 60 kg the NPY mRNA level significantly decreased by 54.0% (p< 0.05) as compared with that in 1 kg. Leptin mRNA in OAT was correlated with serum leptin concentrations (r = 0.98, p<0.01), body weight (r = 0.82, p<0.05) and percent body fat (r = 0.81, p<0.05). This is the first report of the developmental expression of leptin in porcine OAT, peritoneal adipose tissue (PAT) and SAT, and proves that the expression of leptin in OAT could reflect the levels of circulating leptin. These results provide some information for nutritional manipulation of leptin secretion which could lead to practical methods of controlling appetite and growth in farm animals, thereby regulating and improving efficiency of lean meat production and meat production quality.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.39-44
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• 2008

This study was conducted to evaluate the effects of nutritional levels on the growth and pork quality of Korean native black pigs (54 pigs from 35-75kg). Three nutritional levels (high, medium and low in ME and lysine) were tested. As nutritional levels increased, the average daily gain improved, and the days to market weight were reduced. There were no significant differences in dressing percentage, backfat thickness, loin eye area and % lean among the dietary treatments. However, barrows showed thicker (p<0.05) for backfat than gilt. The analysis of Korean native black pig carcass traits indicated that the fatty acid composition of loin-eye muscle, intra-muscular fat content, sarcomere length, and muscle ratio between red- and white-muscles did not show any statistically significant variation. However, regarding intra-muscular fat, H carcasses (high energy diet) contained higher levels of saturated fatty acids with lower levels of unsaturated fatty acids compared to the carcasses from the other two energy groups (M and L). In addition, the levels of n-3 tended to be lower as the energy/lysine level in the diet increased, while the ratio of n-6/n-3 tended to decrease as the energy/lysine level increased, even though the differences were not statistically significant. Even with no statistically significant differences, it was interesting to observe that the sarcomere length tended to increase as the energy level of the diet increased, and with muscle ratio analysis, the red muscle ratio from the L-group, and the white muscle ratio from the M-group were higher than the other energy groups.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.164-169
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• 1997

The present experiment was conducted to evaluate the effects of feed processing and feeding methods on growth performance and carcass characteristics of growing-finishing pigs. A total of 72 pigs (LYD, 22.24 kg BW) were employed for a 90-d feeding trial. Treatments were 1) mash dry feeding (MD), 2) mash wet feeding (MW), 3) pellet dry feeding (PD), and 4) extruded pellet dry feeding (EPD). Corn, soybean meal and wheat bran in the basal diets were extruded before mixing and pelleting for EPD diet production. Ileal or fecal digestibility and carcass traits including lean meat percentage and weights of stomach ulcer were also examined. During the growing period, pigs fed PD showed improved (p < 0.05) average daily gain (ADG) and feed conversion (F/G) over those fed MD, whereas no significant differences in average daily feed intake (ADFI) were found among dietary treatments. Finisher pigs fed MD showed lover, but not significant, ADG and F/G than those fed MW, PD or EPD. For the overall period, pigs fed PD grew faster (p < 0.05) than those fed MD or EPD. Feed intake was different between the two feeding methods (MD vs MW), and between the two processed feeds (PD vs EPD). The digestibility of crude fat was higher (p < 0.05) in pigs fed EPD than in pigs fed mash feeds. NFE digestibility of EPD treatment was also higher (p < 0.05) than that of PD. Back fat (10th rib area) was thicker (p < 0.05) tn pigs fed MD than in pigs fed EPD. other carcass traits including incidence of esophagogastric ulcers were not different among treatments. In conclusion, pelleting appeared to bo the desirable processing methods and wet feeding could also be recommended for growing-finishing pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.5
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• pp.712-720
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• 2018

Objective: The aim of this experiment was to evaluate the effect of dietary supplementation with the docosahexaenoic acid (DHA)-rich microalgae, Aurantiochytrium limacinum (AURA) on pig performance, carcass traits, and the fatty acid composition of pork Longissimus lumborum (LL) and backfat. Methods: A total of 144 Pig Improvement Company (PIC)${\times}$Goland finishing pigs (72 females and 72 castrated males) of mean weight 117.1 (${\pm}13.1$) kg were blocked by sex and body weight and provided with 0% or 1% AURA in isonutritive and isocaloric diets. A total of 24 pens provided 12 replicates per treatment. Animals were weighed on day 0 and 28 with feed and water intake recorded per pen. After 31 days supplementation (28 days of study and 3 days until the slaughtering date) three animals per pen (n = 72) were slaughtered and the LL and backfat thickness, lean meat content and dressing percentage were recorded for the carcasses. The fatty acid (FA) profile of the LL and backfat was established by direct FA methyl ester synthesis. Results: No differences were observed for any performance parameters or carcass traits. Supplementation with AURA resulted in significant changes to the FA profiles of both the LL and backfat with male and female pigs responding differently to supplementation in terms of particular FAs. Overall, pork LL samples had significantly higher eicosapentaenoic acid (p<0.001) and DHA concentrations (p<0.001), and higher omega-3 (n-3) FAs (p<0.001), as well as an increased omega3:omega6 (n-3:n-6) ratio (p = 0.001). For backfat, supplementation resulted in significantly higher amounts of DHA (p<0.001) and n-3 FAs (p<0.001). Conclusion: These results indicate that dietary supplementation with 1% AURA over a 31 day period can increase the FA composition of pork LL and backfat, specifically the DHA, with no major impact on growth performance and carcass traits.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1074-1080
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• 2017

Objective: The growth, carcass and retail cut yield records on 1,428 Hanwoo steers obtained through progeny testing were analyzed in this study, and their heritability and genetic relationships among the traits were estimated using animal models. Methods: Two different models were compared in this study. Each model was fitted for different fixed class effects, date of slaughter for carcass traits and batch of progeny test live measurement traits, and a choice of covariates (carcass weight in Model 1 or backfat thickness in Model 2) for carcass traits. Results: The differences in body composition among individuals were deemed being unaffected by their age at slaughter, except for carcass weight and backfat thickness. Heritability estimates of body size measurements were 0.21 to 0.36. Heritability estimates of retail cut percentage were high (0.56 from Model 1 and 0.47 from Model 2). And the heritability estimates for loin muscle percentage were 0.36 from Model 1 and 0.42 from Model 2, which were high enough to consider direct selection on carcass cutability traits as effective. The genetic correlations between body size measurements and retail cut ratio (RCR) were close to zero. But, some negative genetic correlations were found with chest girths measured at yearling (Model 1) or at 24 months of age or with chest widths. Loin muscle ratio (LMR) was genetically negatively correlated with body weights or body size measurements, in general in Model 1. These relationships were low close to zero but positive in Model 2. Phenotypic correlation between cutability traits (RCR, LMR) and live body size measurements were moderate and negative in Model 1 while those in Model 2 were all close to zero. Conclusion: Therefore, the body weights or linear body measurements at an earlier age may not be the most desirable selection traits for exploitation of correlated responses to improve loin muscle or lean meat yield.