• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.192-200
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• 2019

Objective: Leukemia inhibitory factor (LIF) binds to a heterodimeric receptor composed of LIF receptor (LIFR) and glycoprotein 130 (GP130) to transmit signals into the cell. LIF plays an important role in reproduction by regulating immune response, decidualization, and implantation in several species. However, the expression of LIF and LIFR in the endometrium throughout the estrous cycle and pregnancy in pigs is not fully understood. Methods: We analyzed the expression of LIF and LIFR in the endometrium on days 0 (estrus), 3, 6, 9, 12, 15, and 18 of the estrous cycle, and days 12, 15, 30, 60, 90, and 114 of pregnancy, in conceptuses on days 12 and 15, and in chorioallantoic tissues on days 30, 60, 90, and 114 of pregnancy in pigs. We also determined the effects of estrogen and progesterone on the expression of LIF and LIFR in endometrial tissues. Results: The expression of LIF increased in the endometrium during the late diestrus phase of the estrous cycle and during mid- to late- pregnancy, while the expression of LIFR increased during early pregnancy. The expression of LIF was induced by increasing doses of estrogen, whereas the expression of LIFR was induced by increasing doses of progesterone. Conclusion: These results indicate that the expression of LIF and its receptor LIFR in the endometrium is regulated in a stage-specific manner during the estrous cycle and pregnancy, suggesting that LIF and its receptor signaling system may play critical roles in regulating endometrial function in pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1355-1362
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• 2019

Objective: S100A7A, a member of the S100 protein family, is involved in various biological processes, including innate immunity, antimicrobial function, and epithelial tumorigenesis. However, the expression and function of S100A7A in the endometrium during the estrous cycle and pregnancy are not well understood in pigs. Therefore, this study determined the expression and regulation of S100A7A at the maternal-conceptus interface in pigs. Methods: We obtained endometrial tissues from pigs throughout the estrous cycle and pregnancy, conceptus tissues during early pregnancy, and chorioallantoic tissues during midto late pregnancy and analyzed the expression of S100A7A in these tissues. We also determined the effects of steroid hormones, estradiol-$17{\beta}$ ($E_2$) and progesterone, and interleukin-$1{\beta}$ (IL1B) on S100A7A expression in endometrial tissues. Results: We found that S100A7A was expressed in the endometrium during the estrous cycle and pregnancy in a pregnancy status- and stage-dependent manner and was localized to endometrial luminal epithelial (LE) and superficial glandular epithelial cells with strong intensity in LE cells on day 12 of pregnancy. Early stage conceptuses and chorioallantoic tissues from day 30 to term pregnancy also expressed S100A7A. The expression of S100A7A was increased by $E_2$ and IL1B in endometrial tissues. Conclusion: S100A7A was expressed at the maternal-conceptus interface at the initiation of implantation in response to conceptus-derived estrogen and IL1B and could be a unique endometrial epithelial marker for conceptus implantation in pigs. These findings provide an important insight into the understanding of conceptus-endometrial interactions for the successful establishment of pregnancy in pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.452-458
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• 2019

Objective: The study was carried to determine the interaction effects of pen enrichment and sex on behavioral activities, skin lesions and physiology of Windsnyer pigs. Methods: Forty-eight growing Windsnyer pigs of both sex, with an average initial body weight of 21.6 (${\pm}9.01$) kg were used. Four pigs were randomly assigned to either enriched or barren pens at a stocking density of $0.35m^2/pig$. Enriched pens contained 2 L bottles filled with stones and suspended at head level on ropes stretching across the pens. In addition, two plastic balls (90 mm in diameter) and 500 mL bottles (235 mm long) were placed on the floor of each enriched pen. Results: Pigs in barren environments had higher heart rates (p<0.001) than those in enriched pens. There was an interaction of pen environment and sex on rectal temperature (p<0.001). Females in enriched pens had higher rectal temperatures (p<0.05) than females in barren pens. There was no interaction of pen environment and sex on time spent eating and drinking (p>0.05). Time spent bullying was influenced (p<0.05) by pen environment and sex. Female pigs in barren environment spent more time on bullying than females in enriched pens. There was an interaction of pen environment and sex on time spent lying down and walking (p<0.05). Female pigs in enriched pens spent more time lying down than females in barren pens. Males in barren pens spent more time walking than males in enriched pens while no effect of pen environment was observed in females. There was an interaction of pen environment and sex on the number of skin lesions in the head, neck and shoulder region and other parts of the body (p<0.05). Conclusion: It was concluded that pen enrichment reduced the number of skin lesions and anti-social behaviors, especially for female pigs. There is a need, therefore of housing indigenous pigs under confinement.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1077-1083
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• 2019

Objective: Sow longevity is important for efficient and profitable pig farming. Recently, there has been an increasing interest in social genetic effect (SGE) of pigs on stress-tolerance and behavior. The present study aimed to estimate genetic correlations among average daily gain (ADG), stayability (STAY), and number of piglets born alive at the first parity (NBA1) in Korean Yorkshire pigs, using a model including SGE. Methods: The phenotypic records of ADG and reproductive traits of 33,120 and 11,654 pigs, respectively, were evaluated. The variances and (co) variances of the studied traits were estimated by a multi-trait animal model applying the Bayesian with linear-threshold models using Gibbs sampling. Results: The direct and SGEs on ADG had a significantly negative (-0.30) and neutral (0.04) genetic relationship with STAY, respectively. In addition, the genetic correlation between the social effects on ADG and NBA1 tended to be positive (0.27), unlike the direct effects (-0.04). The genetic correlation of the total effect on ADG with that of STAY was negative (-0.23) but non-significant, owing to the social effect. Conclusion: These results suggested that total genetic effect on growth in the SGE model might reduce the negative effect on sow longevity because of the growth potential of pigs. We recommend including social effects as selection criteria in breeding programs to obtain satisfactory genetic changes in both growth and longevity.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.757-766
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• 2019

Objective: MicroRNAs are a class of endogenous small regulatory RNAs that regulate cell proliferation, differentiation and apoptosis. Recent studies on miRNAs are mainly focused on mice, human and pig. However, the studies on miRNAs in skeletal muscle of sheep are not comprehensive. Methods: RNA-seq technology was used to perform genomic analysis of miRNAs in prenatal and postnatal skeletal muscle of sheep. Targeted genes were predicted using miRanda software and miRNA-mRNA interactions were verified by quantitative real-time polymerase chain reaction. To further investigate the function of miRNAs, candidate targeted genes were enriched for analysis using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment. Results: The results showed total of 1,086 known miRNAs and 40 new candidate miRNAs were detected in prenatal and postnatal skeletal muscle of sheep. In addition, 345 miRNAs (151 up-regulated, 94 down-regulated) were differentially expressed. Moreover, miRanda software was performed to predict targeted genes of miRNAs, resulting in a total of 2,833 predicted targets, especially miR-381 which targeted multiple muscle-related mRNAs. Furthermore, GO and KEGG pathway analysis confirmed that targeted genes of miRNAs were involved in development of skeletal muscles. Conclusion: This study supplements the miRNA database of sheep, which provides valuable information for further study of the biological function of miRNAs in sheep skeletal muscle.

• Animal Bioscience
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• v.34 no.12
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• pp.2012-2022
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• 2021

Objective: In most retail centers, primal pork cuts for sale are usually prepared into retail-ready slices and overwrapped with air-permeable plastic film. Also, meat of Korean native black pig (KNP) is reputed for its superior quality, however, its shelf life during retail display has not been studied. Thus, the objective of this study was to evaluate shelf life of prepackaged retail-ready KNP belly and shoulder butt slices during refrigerated display. Methods: Bellies and shoulder butt obtained at 24 h post-mortem from finishing KNP were used. Each belly or shoulder butt was manually cut into 1.5 cm-thick slices. The slices in each cut type were randomly taken and placed on white foam tray (2 slices/tray) overwrapped with polyvinyl chloride film. The retail-ready packages were then placed in a retail display cabinet at 4℃. Shelf life and sensory quality of the samples were evaluated on day 1, 3, 6, 9, 12, and 15 of display. Results: The shoulder butt reached the upper limit (20 mg/100 g) of volatile basic nitrogen for fresh meat after 9 days while, the belly remained within this limit throughout the display time (15 days). Both the cuts reached a thiobarbituric acid reactive substances level of above 0.5 mg malondialdehyde/kg after 9 days. The a^* (redness) values remained unchanged during first 9 days in both cuts (p>0.05). After 9 days, off-flavor was not found in either cut, but higher off-flavor intensity was found in shoulder butt after 12 days. The shoulder butt was unacceptable for overall eating quality after 12 days while, belly still was acceptable after 12 days. Conclusion: The belly showed a longer shelf life compared to the shoulder butt, and a shelf life of 9 and 12 days is recommended for the prepackaged retail-ready KNP shoulder butt and belly slices, respectively.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.405-416
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• 2021

Objective: This study evaluated the effects of feeding diets naturally contaminated with deoxynivalenol (supplemental 2 mg/kg) on health, growth, and the effects of a mycotoxin-detoxifying additive in newly-weaned pigs. Methods: Thirty-six pigs (27 day-old) were housed individually and assigned to 3 treatments for 5 weeks: CON (diet containing minimal deoxynivalenol), MT (diet with supplemental 1.9 mg/kg of deoxynivalenol), and MT+D (MT + mycotoxin-detoxifying additive, 0.2%, MegaFix, ICC, São Paulo, Brazil). The mycotoxin-detoxifying additive included bentonite, algae, enzymes, and yeast. Blood was taken at week 2 and 5. Jejunal tissue were taken at week 5. Data were analyzed using the MIXED procedure of SAS. Results: Pigs fed MT+D tended to have decreased (p = 0.056) averaged daily feed intake during week 1 than MT. At week 2, serum aspartate aminotransferase/alanine aminotransferase in MT tended to be lower (p = 0.059) than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating hepatic damages in MT and recovery in MT+D. Pigs fed MT had lower (p<0.05) blood urea nitrogen/creatinine than CON, supporting hepatic damage. At week 5, pigs fed MT tended to have reduced (p = 0.079) glucose than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating impaired intestinal glucose absorption in MT, which was improved in MT+D. Pigs fed CON tended to have increased (p = 0.057) total glutathione in jejunum than MT, indicating oxidative stress in MT. Pigs fed MT+D had a reduced (p<0.05) proportion of Ki-67-positive cells in jejunum than MT, indicating lower enterocyte proliferation in MT+D. Conclusion: Feeding supplemental 1.9 mg/kg of deoxynivalenol reduced growth and debilitated hepatic health of pigs, as seen in leakage of hepatic enzymes, impaired nitrogen metabolism, and increase in oxidative stress. The mycotoxin-detoxifying enhanced hepatic health and glucose levels, and attenuated gut damage in pigs fed deoxynivalenol contaminated diets.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.261-269
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• 2021

Because sows are industrially vital for swine production, monitoring for their health or disorder status is important to ensure high reproductive performance. Especially, ambient temperature changes in different season, especially during summer, are directly influenced to the reproductive performance of sows. Although the serum biochemical parameters are widely applied in the veterinary medicine with wide ranges for the physiological process, the values are also influenced by several factors such as age, breed, gender, and stress. In addition, domestic sows in Korea-specific reference interval (RI) for serum biochemistry has not been established yet. Therefore, the present study was aimed to evaluate seasonal variation of RIs in the serum biochemistry in domestic sows in Korea at different seasons and to establish normal RIs using a RI finding program (Reference Value Advisor). Significant difference (p < 0.05) on the different seasons were identified in several serum biochemical parameters including BUN, CRE, GGT, GLU, ALB, TP, LDH and Na in sows. Therefore, we further established RIs, specific in domestic sows in Korea regardless of season. The established RIs based on the serum biochemical values provide a baseline for interpreting biochemical results in the domestic sows in Korea, regardless of seasonal effect. It may contribute to develop a strategy for better reproductive performance by improving breeding management practice and evaluating health of pig herds, which facilitate to avert the economic loss in summer infertility in sows.

• Animal Bioscience
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• v.35 no.11
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• pp.1649-1655
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• 2022

Objective: The primary objective of this study was to determine the genetic parameters for reproductive traits among Large White pigs, including the following traits: total number born (TNB), number born alive (NBA), litter birth weight (LBW), average birth weight (ABW), gestation length (GL), age at first service (AFS) and age at first farrowing (AFF). Methods: The dataset consisted of 19,036 reproductive records from 4,986 sows, and a multi-trait animal model was used to estimate genetic variance components of seven reproductive traits. Results: The heritability estimates for these reproductive traits ranged from 0.09 to 0.26, with the highest heritability for GL and AFF, and the lowest heritability for NBA. The repeatabilities for TNB, NBA, LWB, ABW, and GL were ranged from 0.16 to 0.34. Genetic and phenotypic correlations ranged from -0.41 to 0.99, and -0.34 to 0.98, respectively. In particular, the correlations between TNB, NBA and LBW, between AFS and AFF, exhibited a strong positive correlation. Furthermore, for TNB, NBA, LBW, ABW, and GL, genetic correlations of the same trait between different parities were moderately to strongly correlated (0.32 to 0.97), and the correlations of adjacent parities were higher than those of nonadjacent parities. Conclusion: All the results in the present study can be used as a basis for the genetic assessment of the target population. In the formulation of dam line selection index, AFS or AFF can be considered to combine with TNB in a multiple trait swine breeding value estimation system. Moreover, breeders are encouraged to increase the proportion of sows at parity 3-5 and reinforce the management of sows at parity 1 and parity ≥8.

• Animal Bioscience
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• v.34 no.9
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• pp.1491-1498
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• 2021

Objective: This research was carried out to investigate the effects of corn particle size on the apparent total tract digestibility (ATTD) of energy and nutrients fed to pigs at four different growth stages and therefore to provide basis for better application of corn in pig feeds. Methods: Eighteen weanling piglets, 18 growing barrows, 24 gestating sows and 24 lactating sows were used in this study. Within each stage, pigs were allotted to 1 of 3 or 4 corn-soybean meal diets which were formulated with different corn particle size in a completely randomized design with 6 replicate pigs per diet. Each stage lasted for 19 days, including 7 days for cages adaptation, 7 days for adaptation to diets and followed by 5 days for total collection of feces and urine. Results: For nursery and growing stages, the results showed that digestible energy content and ATTD of gross energy (GE), dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) was increased (p<0.05) as the corn particle size reduced. Meanwhile, the metabolizable energy content and ATTD of crude protein (CP) tended to increase. For gestating sows, no differences were found in the ATTD of nutrients among dietary treatments. As for lactating sows, there were linear and quadratic increases (p<0.05) in the ATTD of DM, GE, NDF as the corn being finer milled. Quadratic response in ATTD of ADF and CP (p<0.05) were observed as sows fed with four different diets. Conclusion: Reducing corn particle size can increase digestibility of nutrients fed to young pigs and lactating sows. No effects were observed in present experiment when gestating sows were fed with different particle sized corn.