• 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.

• Journal of Animal Science and Technology
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• v.61 no.3
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• pp.147-153
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• 2019

A goal for swine farming is the improvement in the number of live-born and weaned piglets per sow. Hence, the effect of parities should consider the correlation between the component traits of reproductive performance, weaning, and duration. Sows were housed in farrowing pens (W 2.2 ${\times}$ D 1.8 ${\times}$ H 1.2 m) on a partially slatted plastic floor. Twenty sows used in this study were between the first and sixth parity in gilts (P1), parity 2-5 (P3), and parity 6-9 (P6). Data collection by parity was classified into three categories: (1) reproduction performance (gestation length, total number of piglets born, number of piglets live born, number of piglets stillborn, total piglet birth weight; (2) weaning traits (weaning period, number of piglets weaning, total piglets weaning weight); (3) duration traits (farrowing duration, placenta expulsion duration, time from last piglet to first placenta, average birth interval, and tail wagging behavior). Gestation length was higher in P6 than P1 and P3 of different parity sows. The maximum value in P1 and P3 was 117 days, but the median value in P6 was 117 days (p < 0.05). The total number of piglets born (p = 0.113), number of piglets live born (p = 0.118), number of still piglets born (p = 0.151), and total piglet birth weight (p = 0.117) were not affected by parity. The number of live piglets was higher than the other parities by an average of $15.6{\pm}2.1$ in P1. The duration of farrowing was the lowest at 22.2 min in P6, but the maximum value was 42.2 min more than other parities (p = 0.355). Weaning traits of sows also did not differ significantly (p > 0.05), but the weaning period from P1 was lower than that of the other parities (p = 0.170). The number of piglets weaned was 10 heads on average in P1, P3, and P6 (p < 0.05). However, the mean values of the total piglet weaning weight (p = 0.377) of P6 (62.0 10.4 kg) were higher than those of P1 (54.9 10.2 kg) and P3 (58.4 13.6 kg). The placenta expulsion duration was higher in P6 than that in P1 and P3 (p = 0.447). The time from the last piglet to first placenta was be lower in P3 than that of the other parities (p = 0.206). The average birth interval was higher in P3 than that of the other parities (p = 0.156). Tail wagging (count) behavior was higher in P6 than in the other parities (p = 0.065). The data showed that the reproduction performance, total piglets born, and weight were higher in the gilts group, and higher in the weaning trait than that in the P6 group. This study examined the relationship between reproductive performance, birth interval and tail motion according to sow parity. Regarding duration, farrowing duration was lower in P6 than that in the other parities, but placenta expulsion and tail wagging were higher in P6 than in the other parities. Therefore, it is possible that the results from these sows could be used as basic data for effective farm management.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.247-250
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• 2011

The objective of this study was to find out candidate genes associated with litter size trait in pigs of inbred Large Yorkshire and Landrace populations. 86 sows were screened for candidate genotypes along with litter size data recordings. Association of litter size with genotypes of candidate genes were investigated to verify the usefulness of each gene's genotypes as markers for the trait. For the lines of Large Yorkshire, PRLR3 and RBP4 genes were genotyped. Frequency distribution of PRLR3 with genotypes AA, AB and BB were each 0.14, 0.44 and 0.42. And the average litter size by PRLR3 genotypes were 8.83, 10.81 and 10.70 piglets per litter, the average estimated breeding values of which were 0.243, 0.332, 0.365, respectively for AA, AB and BB genotypes. Genotypic frequencies of RBP4 by AA, AB and BB genotypes were 0.10, 0.44 and 0.46. The average litter size by genotypes of RBP4 were 10.40, 10.57 and 10.35 piglets per litter and their corresponding average estimated breeding values were 0.451, 0.353 and 0.261, respectively for genotypes AA, AB and BB. Significance in differences among genotypes were not observed, but B allele of RBP4 seems to be associated with litter size. In Landrace lines, frequencies of RBP4 genotypes, AA, AB and BB were 0.29, 0.55 and 0.16. And the average litter size of these genotypes were 10.50, 11.08 and 11.00 piglets per litter. The corresponding averages of estimated breeding values of each genotypes were 0.172, 0.135 and 0.104. In Landrace lines, allele A was more likely to be associated with litter size, even if differences among average litter size were not significant. We conclude that genotyping of two candidate genes is a helpful tool to identify genetic potentials of litter size in pigs.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.263-270
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• 2013

The vent sexing and the auto-sexing by using sex-linked traits are general sexing methods of day-old chicks. Currently, the feather sexing which is based on the differences in the feather characteristics at hatching is the representative sexing method of chicken, because the late-feathering is sex-linked trait. The feather sexing can be used if the breed has dominant feathering gene (K) in maternal and recessive gene ($k^+$) in paternal. Therefore it is necessary to identify the association of feathering genes and quantitative traits in chickens. In this study, we investigated the influence of the rate of feathering on productive traits in Korean Native Chicken. In results, there was no significant difference between early-feathering chickens and late-feathering chickens in reproductive performance such as fertility and hatchability. Livability, body weights, egg production, egg weight and egg quality also did not significantly differ between early- and late-feathering chickens. Age at first egg was the only trait of those tested in which significant difference was observed. The early-feathering chickens laid eggs 3 days earlier than late-feathering chicken. As a result, there is no influence of feathering phenotypes on productive performance in Korean Native Chickens. Consequentially, establishing the feather sexing strain is available using the Korean Native Chicken breed without considering of the effect of feathering genes on productive traits.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1225-1233
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• 2017

Objective: Calving ease (CE) is a complex reproductive trait of economic importance in dairy cattle. This study was aimed to investigate the genetic merits of CE for Holsteins in Korea. Methods: A total of 297,614 field records of CE, from 2000 to 2015, from first parity Holstein heifers were recorded initially. After necessary data pruning such as age at first calving (18 to 42 mo), gestation length, and presence of sire information, final datasets for CE consisted of 147,526 and 132,080 records for service sire calving ease (SCE) and daughter calving ease (DCE) evaluations, respectively. The CE categories were ordered and scores ranged from CE1 to CE5 (CE1, easy; CE2, slight assistance; CE3, moderate assistance; CE4, difficult calving; CE5, extreme difficulty calving). A linear transformation of CE score was obtained on each category using Snell procedure, and a scaling factor was applied to attain the spread between 0 (CE5) and 100% (CE1). A sire-maternal grandsire model analysis was performed using ASREML 3.0 software package. Results: The estimated direct heritability ($h^2$) from SCE and DCE evaluations were $0.11{\pm}0.01$ and $0.08{\pm}0.01$, respectively. Maternal $h^2$ estimates were $0.05{\pm}0.02$ and $0.04{\pm}0.01$ from SCE and DCE approaches, respectively. Estimates of genetic correlations between direct and maternal genetic components were $-0.68{\pm}0.09$ (SCE) and $-0.71{\pm}0.09$ (DCE). The average direct genetic effect increased over time, whereas average maternal effect was low and consistent. The estimated direct predicted transmitting ability (PTA) was desirable and increasing over time, but the maternal PTA was undesirable and decreasing. Conclusion: The evidence on sufficient genetic variances in this study could reflect a possible selection improvement over time regarding ease of calving. It is expected that the estimated genetic parameters could be a valuable resource to formulate sire selection and breeding plans which would be directed towards the reduction of calving difficulty in Korean Holsteins.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.598-602
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• 2004

The Tongcheng pig breed is a famous Chinese indigenous breed. The Ministry of Agriculture of China has filed it as 1 of 19 national key conservation breeds selected from more than 100 Chinese indigenous pig breeds in 2000. In order to improve the reproductive performance, it has been intensively selected to increase the litter size for about 10 years. The population randomly sampled from conservation nucleus of eight families in the Tongcheng pigs was genotyped for identification of their estrogen receptor locus polymorphisms with the PCR-RFLPs method. Only AB heterozygotes and BB homozygotes were detected, and $X^2$ test demonstrated that the locus was in disequilibrium at a significant level (p<0.05). In the present paper, the litter sizes in different parities were regarded as different traits. Holistic status of other unspecific and unidentified genes was estimated by using the statistical methods. Coefficients of kurtosis and skewness showed that the litter size still presented segregating characteristic in the 2nd, 5th, 7th, 8th and 9th parities. Analysis of homogeneity of variance between families confirmed the results for the 5th, 7th and 8th parities. The heritability of litter size for the 1st to 10th parities was estimated with paternal half-sib model and individual estimated breeding values (EBVs) were evaluated by a single trait animal model as well. We found that the averages of EBVs for litter size in each parity did not differ significantly between genotypes, despite the significant difference for original phenotype records in the 3rd, 4th and 5th parities (p<0.05 or p<0.01). The results may be explained by the deduction that the polymorphisms of ESR locus are no longer the important genetic base of litter size variation when the frequency of allele B accumulated in the experience of selection procedure, and further conferring that there exist special genes associated with litter size in the recent Tongcheng pigs population can be made.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.320-327
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• 2017

Objective: The objective of this research was to estimate genetic correlations between number of piglets born alive in the first parity (NBA1), litter birth weight in the first parity (LTBW1), number of piglets weaned in the first parity (NPW1), litter weaning weight in the first parity (LTWW1), number of piglets born alive from second to last parity (NBA2+), litter birth weight from second to last parity (LTBW2+), number of piglets weaned from second to last parity (NPW2+) and litter weaning weight from second to last parity (LTWW2+), and to identify the percentages of animals (the top 10%, 25%, and 50%) for first parity and sums of second and later parity traits. Methods: The 9,830 records consisted of 2,124 Landrace (L), 724 Yorkshire (Y), 2,650 LY, and 4,332 YL that had their first farrowing between July 1989 and December 2013. The 8-trait animal model included the fixed effects of first farrowing year-season, additive genetic group, heterosis of the sow and the litter, age at first farrowing, and days to weaning (NPW1, LTWW1, NPW2+, and LTWW2+). Random effects were animal and residual. Results: Heritability estimates ranged from $0.08{\pm}0.02$ (NBA1 and NPW1) to $0.29{\pm}0.02$ (NPW2+). Genetic correlations between reproduction traits in the first parity and from second to last parity ranged from $0.17{\pm}0.08$ (LTBW1 and LTBW2+) to $0.67{\pm}0.06$ (LTWW1 and LTWW2+). Phenotypic correlations between reproduction traits in the first parity and from second to last parity were close to zero. Rank correlations between LTWW1 and LTWW2+ estimated breeding value tended to be higher than for other pairs of traits across all replacement percentages. Conclusion: These rank correlations indicated that selecting boars and sows using genetic predictions for first parity reproduction traits would help improve reproduction traits in the second and later parities as well as lifetime productivity in this swine population.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.111-119
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• 2020

Objective: This study was conducted to examine the effects of a mixture of pinecone oil, garlic, and brown seaweed extracts (PGBE) on milk production traits as well as physiological and ethological parameters in Holstein cows during the summer season (24 May to 03 July 2015, Korea). Methods: Among the extract combinations tested, we found that the level of 2,2'-azino-bis (3-ethylberzothiazoline-6-sulphonic acid) cation radical scavenging activity of the 0.16% PBGE complex at ratio of 1:1:1 (vol/vol) was comparable to that of the control (ascorbic acid; 1 mg/mL). Additionally, the PBGE complex reduced lipopolysaccharide-induced COX-2 expression in bovine mammary epithelial cells. Based on these findings, 40 lactating Holstein cows were used to measure the effects of PBGE complex at ratio of 1:1:1 (vol/vol) on milk production, immune response, metabolites, and behavior patterns by dividing the cows into two groups fed diets containing PGBE complex (n = 20; 0.016%/kg feed dry matter basis) or not containing PGBE complex (control, n = 20) for 40 d. Results: Results showed that PGBE complex did not influence milk composition, eating and ear surface temperature patterns, immune response, or metabolic parameters but promoted average milk yield throughout the experimental period. Additionally, a tendency of higher total antioxidant capacity and glutathione in the PGBE group was observed compared to the those in the control. When the temperature-humidity index (THI) exceeded 72 (average THI = 73.8), PGBE complex-fed cows experiencing heat stress showed increased milk yield and a tendency of increased rumination compared to the control. Conclusion: We suggest that incorporation of a combined mixture of 0.016% PGBE (1:1:1 ratio, vol/vol) to diet has the potential to improve milk yield and health status of cows under mild to moderate heat stress, denoting that it might be useful as an alternative anti-stressor in the diet of dairy cows under hot conditions.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.272-280
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• 2016

Chrysanthemum is one of the top floriculture species with ornamental and medicinal value. Although chrysanthemum breeding program has contributed to the development of various cultivars so far, it needs to be advanced from the traditional phenotype-based selection to marker-assisted selection (molecular breeding) as shown in major cereal and vegetable crops. Molecular breeding relies on trait-linked molecular markers identified from genetic, molecular, and genomic studies. However, these studies in chrysanthemum are significantly hampered by the reproductive, genetic, and genomic properties of chrysanthemum such as self-incompatibility, inbreeding depression, allohexaploid, heterozygosity, and gigantic genome size. Nevertheless, several genetic studies have constructed genetic linkage maps and identified molecular markers linked to important traits of flower, leaf, and plant architecture. With progress in sequencing technology, chrysanthemum transcriptome has been sequenced to construct reference gene set and identify genes responsible for developments or induced by biotic or abiotic stresses. Recently, a genome sequencing project has been launched on a diploid wild Chrysanthemum species. The massive sequencing information would serve as fundamental resources for molecular breeding of chrysanthemum. In this review, we summarized the current status of molecular genetics and genomics in chrysanthemum and briefly discussed future prospects.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.320-333
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• 2019

Objective: The Shanghai Holstein cattle breed is susceptible to severe mastitis and other diseases due to the hot weather and long-term humidity in Shanghai, which is the main distribution centre for providing Holstein semen to various farms throughout China. Our objective was to determine the genetic mechanisms influencing economically important traits, especially diseases that have huge impact on the yield and quality of milk as well as reproduction. Methods: In our study, we detected the structural variations of 1,092 Shanghai Holstein cows by using next-generation sequencing. We used the DELLY software to identify deletions and insertions, cn.MOPS to identify copy-number variants (CNVs). Furthermore, we annotated these structural variations using different bioinformatics tools, such as gene ontology, cattle quantitative trait locus (QTL) database and ingenuity pathway analysis (IPA). Results: The average number of high-quality reads was 3,046,279. After filtering, a total of 16,831 deletions, 12,735 insertions and 490 CNVs were identified. The annotation results showed that these mapped genes were significantly enriched for specific biological functions, such as disease and reproduction. In addition, the enrichment results based on the cattle QTL database showed that the number of variants related to milk and reproduction was higher than the number of variants related to other traits. IPA core analysis found that the structural variations were related to reproduction, lipid metabolism, and inflammation. According to the functional analysis, structural variations were important factors affecting the variation of different traits in Shanghai Holstein cattle. Our results provide meaningful information about structural variations, which may be useful in future assessments of the associations between variations and important phenotypes in Shanghai Holstein cattle. Conclusion: Structural variations identified in this study were extremely different from those of previous studies. Many structural variations were found to be associated with mastitis and reproductive system diseases; these results are in accordance with the characteristics of the environment that Shanghai Holstein cattle experience.