Pakchong 5 purebred has good carcass and lean percentages. Compared to Duroc crossbred pigs, Pakchong 5 crossbreds have similar carcass and lean percentages, larger LEA, and slightly more carcass fat, with comparable meat quality and chemical composition. Pakchong 5 boars are more affordable for very small- to medium-scale pig producers.

ABSTRACT. Mutations in melanocortin 1 receptor (MC1R) gene and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) gene have been shown to affect coat color patterns in pigs. Additional functional marker genes, such as insulin like growth factor-2 (IGF2) and orphan nuclear receptor, germ cell nuclear factor (NR6A1), have been described for variations in factors such as fat deposition, litter size, and vertebra number in pigs. In this study, we investigated 129 pigs representing 4 breeds: Thai indigenous, classified into black (similar to Raad or Ka done pig) and black and white (similar to the Hailum and Kwai pig) coat color types; wild boar; Duroc; and Chinese Meishan. Mutations of MC1R, KIT, IGF2, and NR6A1 were detected using polymerase chain reaction-restriction fragment length polymorphism. The genotypes variation in MC1R and KIT genes could be used to differentiate four groups of coat color: solid black, black and white, red, and wild type. For IGF2, the GG genotype was present in wild boar only; for NR6A1 the TT genotype was found only in Duroc pigs. We identified novel 14-bp deletions in KIT that were associated with black and white coat color in 12724 P. Klomtong et al.

Thai indigenous pigs (TIPs) are important genetic resources. Crosses with exotic pig breeds and wild boars may cause genetic losses. To date, the physical characteristics of TIPs have been inconsistent. The classification of TIPs by genetic information is needed to pursue an appropriate conservation program. In this study, the genetic diversity, cluster analysis, and phylogenetic relationship of TIPs were investigated using twenty-nine pig microsatellite markers. Blood samples were collected from TIPs from three regions of Thailand: north (NT, n = 118), northeast (NE, n = 61), and south (ST, n = 75). The mean total number of distinct alleles and the effective number of alleles per locus were 11.851 and 5.497, respectively. The mean observed heterozygosity (Ho) and mean expected heterozygosity (He) were 0.562 and 0.837, respectively. The F values of the microsatellite loci were positive under Hardy–Weinberg Equilibrium at p < 0.001, with overall mean values of Fis, Fit, and Fst of 0.247, 0.281, and 0.046, respectively. A total of 5, 5, and 17 private alleles were found at frequencies greater than 0.050 in the NT, NE, and ST pigs, respectively. Three optimal clusters (K = 3) were proposed within the TIP populations. Pigs from the NT and NE regions were mixed in two clusters, while members of the ST region were clearly separated. The phylogenetic tree confirmed that the pigs from NT and NE were each divided into two subgroups, while the pigs from ST were clustered into one group. A microsatellite analysis revealed the high genetic diversity of the TIP populations and confirmed the genetic divergence of the TIPs from the European and Chinese breeds. A genetic admixture of the TIP with the local wild boars was detected.

The present study was performed to compare the expression of sperm proteins, i.e. triosephosphate isomerase (TPI) and acrosin binding protein (ACRBP) and seminal plasma proteins, i.e. glutathione peroxidase 5 (GPX5) and fibronectin 1 (FN1), in boar semen with good, moderate and poor freezability. The study was conducted by determining the protein contents in 32 sperm samples and 38 seminal plasma samples of semen. The ejaculated semen was divided into two portions: the first portion was centrifuged to separate the pellet of sperm from the seminal plasma and the second portion was cryopreserved. After thawing, the ejaculates were classified into three groups according to their post-thawed sperm motility: good (60.2 ± 1.7%), moderate (29.3 ± 2.0%) and poor (16.6 ± 2.2%) freezabilities. The expressions of GPX5 and FN1 in seminal plasma and TPI and ACRBP in sperm were determined using Western blot analysis. It was found that, for sperm proteins, the level of TPI was negatively correlated with the post-thawed total sperm motility (r = -0.38, P = 0.029). For seminal plasma proteins, the level of FN1 in the seminal plasma was positively correlated with the post-thawed total sperm motility (r = 0.37, P = 0.021) and progressive motility (r = 0.39, P = 0.016). The expression of GPX5 was not correlated with any of the frozen–thawed sperm qualities (P &gt; 0.05). In conclusions, boar semen containing a high level of FN1 in seminal plasma has better freezability. Frozen–thawed sperm motility was positively correlated with the level of FN1 in boar seminal plasma and negatively correlated with TPI in boar spermatozoa.