Earticle

In this study, 844 Hanwoo proven bulls in South Korea (called KPN) were classified into 8 groups based on their birth year. Microsatellite (MS) marker information for paternity identification of each individual is pr ovided at the homepage of the National Agricultural Cooperation Federation, Korea (NACF) and is mainly fo r the analysis of genetic diversity and structural changes. The polymorphism analysis of KPN whole groups revealed the average number of alleles in each marker (number of alleles), the expected heterozygosity (Hex), the observed heterozygosity (Hob), the polymorphism information content (PIC) and the Fis mean as 10.54, 0.76 4, 0.773, 0.727 and -0.014, respectively. For group D, with the birth year 2004-2005, the Hex and Hob were 0.777 and 0.792 respectively and the PIC was 0.740. The Hex of group C and D, with birth years 2003-2004 and 2007 -2008, respectively, were greater than Hob. In all the other groups, Hob was greater than Hex. Genetic compositi on and structure were analyzed using STRUCTURE software. According to the analyzed results, the generatio n of Hanwoo groups showed changes in specific genetic components according to the flow. It was confirmed that the continuous improvement in the Hanwoo affects the genetic structure of the proven bulls group. The results of this study are expected to be used for enhancing the efficiency of Hanwoo improvement project.

The Zygote arrest 1 (ZAR1) gene is known to affect early embryonic development in various vertebrates. In this study, we performed the association analysis to check whether there is any significant relationship bet ween semen kinematic characteristics and the ZAR1 gene. To determine semen kinematic characteristics, we measured motility (MOT), straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR), amplitude of lateral head displacement (ALH), and beat cross frequency (B CF) of spermatozoa in boars. In order to detect single nucleotide polymorphisms (SNPs), we extracted genomi c DNA from multiple Duroc boars, and then subsequently used them in sequencing reactions. As a result, thr ee SNPs were detected in the intronic region of ZAR1 gene (g.2435T>C in intron 2, g.2605G>A and g.4633A> C in intron 3 ). SNPs g.2435T>C and g.2605G>A were significantly associated with MOT (p<0.01) and VSL (p <0.05), and g.4633A<C SNP was significantly associated with MOT, VCL, VSL, VAP, and ALH (p<0.01). The results obtained from this study suggest that the SNPs in the ZAR1 gene might be potential molecular marker s for selecting high-quality semen.

The present study was undertaken to investigate the reproductive performance of the female breeding pigs after artificial insemination (AI) using the frozen boar semen imported from Canada, thereby finding insights into improving the efficiency of AI using the frozen semen (FSAI). Analyzed in the present study were the records of a total of 626 FSAI in a great grandparent (GGP) farm beginning from May through November of the year of 2016 (Farm A) and 2,024 FSAI beginning from 2015 through 2017 from a second GGP farm (Farm B). Both the total number of piglets born (TNB) and the number born alive (NBA) were greater during May than during September within FSAI (p<0.05) in Farm A (p<0.01 for the effect of the month). In Farm B, no difference was detected between the years in any of the farrowing rate, TNB, and NBA. When the records from Farm A and Farm B were pooled, the farrowing rate was greater for Farm A vs. Farm B (p<0.01), with no difference between the two farms in TNB and NBA. Moreover, TNB and NBA were less for FSAI than for AI using the liquid semen (LSAI; 10.9±0.3 vs. 13.4±0.1 and 10.0±0.3 vs. 12.0±0.1 piglets, respectively, for FSAI vs. LSAI in TNB and NBA, respectively; p<0.01). In conclusion, these results suggest that the reproduction efficiency for FSAI, which is lower than that for LSAI, could be improved by selecting an optimal period of the year for the use of the former.

The effect of bisphenol S (BPS) on the viability and production of reactive oxygen species (ROS) was studied in boar sperm and ovarian granulosa cells. Boar semen was incubated in Beltsville thawing solution with either 0 or 5 μM BPS for 3 and 6 h. The viability of sperm was analyzed by SYBR14/PI doubling staining, and production of ROS was detected. Ovarian granulosa cells were also treated with BPS for 24, 48, and 72 h. Then, cell viability (0, 5, 10, and 20 μM) and ROS production (only 0 and 5 μM BPS) were assessed. The results showed that, BPS decreased sperm viability at 3 and 6 h, and that BPS increased ROS production (p<0.05). Also, BPS reduced the viability of ovarian granulosa cells (p<0.05), and stimulated ROS production (p<0.05). These results suggest that BPS damages sperm activation and ovarian granulosa cells in the reproductive system.

The present study was undertaken to examine if the carcass and pork quality of finishing pigs reared on a low plane of nutrition (LPN) could be improved compared with that of the pigs finished on a high plane of nutrition (HPN). Sixty-eight crossbred (LYD) barrows and 68 LYD gilts weighing approximately 50 kg were fed a diet containing 3.54 Mcal DE/kg with 1.00% lysine (HPN) or 3.02 Mcal DE/kg with 0.68% lysine (LPN) in eight pens up to approximately 120 kg and slaughtered. The belly, loin, ham, and Boston butt were cut out from a total of 20 carcasses, after which physicochemical and sensory quality attributes of the belly and the representative muscle of each of the loin, ham, and Boston butt were evaluated. The ADG, gain:feed ratio, and backfat thickness were less for LPN than for HPN (p<0.05). The cooking loss, hardness, and chewiness values for the Boston butt were less for LPN vs. HPN. In sensory evaluation for fresh meat (muscle), the subjective quality scores were greater for LPN vs. HPN in color, marbling, and acceptability for the loin, the muscle:fat balance score for the belly tending to be greater for LPN (p<0.10). In addition, LPN was superior to HPN in the flavor and juiciness in sensory evaluation for cooked ham. In conclusion, the present results suggest that the carcass and pork quality of finishing pigs could be improved with reduced growth performance by using LPN.

This study was conducted to evaluate the acceptability of cured cooked boneless chicken drumettes as a raw material for Chuncheon Dakgalbi and to observe its effect on pH, lipid oxidation, volatile basic nitrogen (VBN) content and total viable count (TVC) during refrigerated storage under vacuum. Boneless chicken drumettes were dry cured with a mixed curing agent (0.20% w/w) consisting of sodium chloride (93.1%), sodium nitrite (5.9%) and sodium bicarbonate (1.0%) for 24 h at 2±2℃. Cured samples were cooked using an oven at 150℃ for 20 min and stored at 5.5±0.5℃ for 60 days under vacuum. Non-cured cooked sample was used as a control. Sensory evaluation was performed on day 2 of storage using 22 untrained panelists and samples were mixed with Dakgalbi sauce and reheated using a microwave for 2 min. There were no significant differences between control and treatment group on appearance, flavor, texture, juiciness and overall acceptability. Cured cooked boneless chicken drumettes had significantly (p<0.05) higher pH, lower lipid oxidation, VBN and TVC consistently during storage in comparison with control. These results suggest that dry curing could be applied to boneless chicken drumettes as raw material for Chuncheon Dakgalbi and could extend its shelf life during refrigerated storage under vacuum.