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To clarify the genetic influence of mycoplasmal pneumonia of swine (MPS) lesion-selected Landrace (La) on MPS resistance and immune characteristics in three-way crossbred pigs (LaWaDa), the LaWaDa pigs were compared with the non-selected crossbred (LbWbDb) and purebred (La) pigs. The MPS lesion score in the three lines was as follows: La lineLaWaDa lineLbWbDb line, with significant differences among the lines. The proportions of myeloid cells and T cells were lower and higher, respectively, in the LaWaDa pigs compared with those in the other two lines. Messenger RNA (mRNA) expression of interleukin (IL)-6, IL-10, transforming growth factor-β, and interferon-γ in peripheral blood was significantly increased after vaccination in the La and LaWaDa lines. IL-4 mRNA expression in the LaWaDa line was intermediate to the La and LbWbDb lines. Furthermore, principal component analysis for immune traits and MPS lesions was executed to clarify the characteristics of each pig line. These findings suggest that the immune responses in the three pig lines are genetically distinct and that MPS resistance and some immunity characteristics from the La line were transmitted to the three-way crossbred pigs.

To search for an index for chemical composition related to superior taste in Japanese Black beef, we conducted panel tests and analyzed the chemical composition of seven beef brands. Thirty-five sirloin beefs from five heifers were used in this study, sold under seven beef brands graded as more than A4 on the Japanese Meat Grade scale. The chemical composition analyses assessed both raw and roasted meat, the latter of which was roasted under the same conditions as those used for the panel test. Results of the panel test and chemical composition analyses revealed that fatty acid composition, sugar content, adenosine triphosphage (ATP)-related compounds, amino acid composition and odor composition in the sirloin meat differed among beef brands. Furthermore, the correlations of chemical compositions between roasted and raw meat were significantly high. Sugar content and ATP-related compounds in roasted meat were significantly correlated with the item 'overall evaluation' of the panel test. ATP-related compounds, such as inosinic acid, carnosine and taurine, in roasted and raw meat were correlated significantly with the item 'umami intensity' of the panel test. These results suggest that the composition of these components is important for an index related to the overall evaluation of beef.

Maintenance energy requirements (MER) of mice selected for high (H) or low (L) oxygen consumption (OC) were compared. Forty-four mice from H and L OC lines were weaned at 3 weeks and divided into four experimental groups: group A were sacrificed at 4 weeks; group B were fed ad libitum, and groups C and D were fed 2.8 and 2.4 g/day, respectively, from 4 to 8 weeks of age. Groups B-D were sacrificed at 8 weeks. Chemical components were estimated for all groups. MER was estimated using a model that partitioned metabolizable energy intake into that used for maintenance, and protein and fat deposition. The feed conversion ratio for the B group was significantly higher in the H than in the L line. Feed intake for metabolic energy content per metabolic body size was significantly also higher in the H line, whereas accumulated energy content per metabolic body size was significantly higher in the L line. MER of the H line was greater than that of the L line (P 0.10). These results suggest that selection for H or L OC produced differences in chemical components, feed efficiency, and MER between the H and L lines.

The objective of this study was to test for association of candidate single nucleotide polymorphisms (SNPs) with sow prolificacy reproductive traits, such as litter size, ovulation rate and lifetime performance, in gilts of a Large White pig population. Preliminary research on 25 animals selected from the high- and low-performance groups of 347 animals with case-control studies indicated that seven genes were associated with total number of piglets born (TNB). Six of the seven genes were associated with reproductive traits, including TNB, number of piglets born alive (NBA) and average weight of piglet weaning (AWW). A MBL2 SNP was significantly associated with TNB and NBA in first parity. A CFB SNP was associated with TNB in first parity. An ACE SNP was associated with TNB in first and second parities. An EGF polymorphism was associated with TNB, NBA and AWW in second parity. A KCNC2 polymorphism was significantly associated with TNB and NBA in second parity. A SLC22A5 SNP was associated with TNB and NBA in second parity. Six candidate SNPs were associated with TNB; the only exception was a PRKAG3 polymorphism. A candidate gene approach enables some of these polymorphisms to be used in genetic improvement programs based on marker-assisted selection.

To understand the influence of crossbreeding on Mycoplasma pneumonia of swine (MPS) resistance and immune characteristics, two crossbred lines were characterized. One crossbred line, LaWa, was generated by crossing the MPS pulmonary lesion selected Landrace line (La) and the highly immune-selected Large White line (Wa). The second crossbred line, LaWb, was generated by crossing the La line and the nonselected Large White line (Wb). The crossbred LbWb line (nonselected Landrace line × nonselected Large White line) and the La line were used as controls. The LaWa and LaWb lines had an intermediate level of MPS lung lesions between La and LbWb lines, although the difference was not statistically significant. After stimulation with sheep red blood cells (SRBCs), the LaWb and LaWa lines showed immune characteristics similar to that of the La line; the number of monocytes in peripheral blood increased, while B cells, T cells, secretion of SRBC-specific immunoglobulin G, and interleukin (IL)-13 decreased. Additionally, the number of natural killer (NK) cells and the expression of IL-4 and IL-17 were significantly higher in the LaWb and LaWa lines, respectively. These data suggested that crossbreeding of La and Wa lines resulted in the inheritance of some of the selected immune responses.

Five generations of Landrace pigs selected for average daily gain, backfat thickness, Mycoplasmal pneumonia of swine (MPS) lesion score, and plasma cortisol levels, was executed to decrease the MPS lesion score. Genetic parameters and correlated genetic responses for respiratory disease and peripheral blood immune traits were estimated in 1395 Landrace pigs. We estimated the negative genetic correlation of MPS lesion score with phagocytic activity (PA) at 7 weeks of age (-0.67). The breeding values of PA at 7 weeks of age and 105 kg body weight and the correlated selection response of the ratio of granular leukocytes to lymphocytes at 105 kg body weight were significantly increased, and sheep red blood cell-specific antibody production (AP) was significantly decreased in a selection-dependent manner. Increasing of natural immunological indicators (e.g. PA) and decreasing of humoral immunological indicator (e.g. AP) were observed due to genetically decreasing MPS lesion score.

Mycoplasma pneumonia of swine (MPS) is responsible for significant economic losses in the swine industry. We selected Landrace pigs for reduced MPS pulmonary lesions over five generations, and measured concentrations of the following cytokines: interleukin (IL)-10, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-γ to estimate their correlation with MPS lesions. Sheep red blood cells (SRBC) were injected twice intramuscularly at 70 and 95 kg body weight. Blood serum samples were collected after 1 week of secondary SRBC inoculation and cytokine concentrations were analyzed by ELISA. Genetic parameters and breeding values were estimated. The heritability estimates of IL-10, IL-13, IL-17, TNF-α and IFN-γ were 0.20 ± 0.06, 0.12 ± 0.06, 0.27 ± 0.07, 0.20 ± 0.10 and 0.05 ± 0.03, respectively. Genetic correlations of IL-17 and TNF-α with pulmonary MPS lesions were high (-0.86 ± 0.13 and 0.69 ± 0.29, respectively) and those of IFN-γ and IL-13 with MPS lesions were moderately negative (-0.45). Through selection, the breeding values of IL-17 and IFN-γ increased substantially and those of TNF-α decreased. These results suggest that innate and cellular immunity are more important for the suppression of pulmonary lesions in MPS than humoral-mediated immunity, such as antibody response.

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions were compared between the immunity-selected Large White line and the non-selected Large White line. The selected Large White line showed a higher level of pulmonary MPS lesions compared with the non-selected Large White line. Subsequent to vaccination, the percentage of natural killer cells and T cells (CD3(+) CD4(+) CD8(-) and CD3(+) CD4(-) CD8(+) T cells) were significantly increased in the non-selected line but remained unchanged in the immunity-selected Large White line. Secretion of Mycoplasma hyopneumoniae vaccine-specific immunoblogulin G and phagocyte activity in peripheral blood were significantly higher in the immunity-selected Large White line than in the non-selected line. Expression of interleukin (IL)-4 and IL-6 messenger RNA in hilar lymph nodes was significantly lower in the immunity-selected Large White line than in the non-selected line. However, expression of IL-10 in all immune tissues was significantly higher in the immunity-selected Large White line. These results suggest that the selection for high immunity was not effective in increasing resistance to MPS lung lesions.

Selection for high (H) and low (L) oxygen consumption (OC) as an indirect estimation of maintenance energy requirement was determined. Feed intake and body weight were measured and feed conversion ratio (FCR) of 4-8-week-old mice was calculated. Respiratory activity of hepatic mitochondria was measured at 12 weeks. Total feed intake (H: 103.74 g, L: 97.92 g, P 0.01), daily feed intake (H: 3.70 g/day, L: 3.50 g/day, P 0.01) and FCR (H: 18.79, L: 15.50, P 0.01) were significantly different between lines. The line by sex interaction was significant for FCR. No line differences were observed in males; and the FCR of the H line was greater than in the L line in females. H line mice had the highest hepatic mitochondrial respiratory activity in state 2 (P 0.01), the highest uncoupled respiratory rate of mitochondria in the presence of an uncoupling agent (P 0.001), and the mitochondrial proton leak. The adenosine diphosphate/ O ratio was highest in the L line (P 0.05). This suggests that the selection for high and low OC induced differences in basal mitochondrial respiration and basal metabolism, resulting in difference in FCR between H and L lines.

The thoracic vertebral number is associated with body length and carcass traits, and represents one of the most important traits in the pig industry. Recent studies have shown that vertnin (VRTN) gene is associated with variations in the vertebral number in commercial European pigs. However, the genetic relationships and effect of this VRTN gene in pig production and carcass traits remain uncertain. Therefore, we investigated the genetic relationships among traits such as vertebral numbers, carcass weight and length-related traits, and meat production traits, and the effect of VRTN gene polymorphisms on these traits in a Duroc purebred population selected for its meat production traits. Highly positive genetic correlations were obtained between the thoracic vertebral numbers and length-related traits (0.56 to 0.84), whereas low correlations were obtained with production traits and carcass weight (-0.16 to 0.05). VRTN gene polymorphisms indicated that the number of thoracic vertebrae and length-related traits were significantly associated with the VRTN genotype, but had no significant effect on production traits and carcass weight. The results indicate that VRTN gene may be used as an effective selection marker to obtain pigs with high thoracic vertebral numbers and length-related traits, without adversely affecting meat production traits.

Monosaccharides such as glucose contribute to the development of meat flavor upon heating via the Maillard reaction; therefore, monosaccharide content is related to beef palatability. Here, we analyzed the effects of genetic and environmental factors on the content of glycogen, one of the precursors of monosaccharides, in the muscles of 958 fattened Japanese Black cattle from Yamagata Prefecture. Analysis of variance showed that muscle glycogen content was affected by the farm and postmortem periods, but not by sex, slaughter age, slaughter month or number of days detained at the slaughter yard. Additionally, consumption of digestible brown rice feed elevated muscle glycogen levels. Glycogen heritability was estimated to be 0.34, and genetic correlations between glycogen and carcass weight (CW) or beef marbling standard (BMS) were weak. The predicted breeding values varied among paternal lines. These results demonstrated that genetic factors might improve muscle glycogen content and therefore beef palatability, but do not influence CW or BMS.

From a series of studies on single nucleotide polymorphisms (SNPs) in the bovine growth hormone (GH) gene of Japanese Black cattle, the type-C (127(Val) and 172(Met) ) that is specific for this breed has been intensively focused upon because of the economic importance for carcass traits, such as intramuscular oleic acid contents. In the present study, we intended to analyze the 3-D structure of GH of haplotype C, and developed a novel method to detect the type C gene. Three-D analysis of the type C protein showed that the amino acid residues (127(Val) and 172(Met) ), which are present in the third and fourth helixes, respectively, and are important for binding with GH receptors, are shifted to deeper positions in the molecule compared with that for type A (127(Leu) and 172(Thr) ), implying the alteration of binding interaction with receptors. A novel, efficient and cost-effective method (Dot-blot-SNP technique) for type C genotyping was successfully established, of which the basal method was a reported genotyping of SNPs for a large number of plants, reducing the cost to 10% or less of direct sequencing.

We recently developed a Landrace line that is resistant to mycoplasmal pneumonia of swine (MPS) infection by genetic selection for five generations, and we reported that the immunophenotype of this line is different from that of the non-selected line in terms of changes in peripheral blood leukocyte population after MPS vaccination. This study followed up previous findings demonstrating changes in soluble factors in blood, namely, hormones, Mycoplasma hyopneumoniae-specific immunoglobulin G (IgG), and cytokines. These two lines were injected with MPS vaccine on days -7 and 0 after blood sampling on those days, and blood samples were collected on days -14, -7, 0, 2, 7 and 14. We found changes in the levels of many hormones and cytokines in both lines. However, we found that only growth hormone (GH) and interferon (IFN)-γ levels were statistically different between these two lines. GH concentration was reduced (day 0) and IFN-γ concentration was increased (day 14) in the MPS-selected line compared with the non-selected line, despite unchanged IFN-γ messenger RNA expression in blood cells. Although detailed mechanisms underlying these phenotypes remain unsolved, these traits would be useful to improve MPS resistance in pig production and provide an insight into MPS infection.

Although our previous report demonstrated that adiponectin and AdipoR1 gene expressions changed among different lactation stages in the bovine mammary gland, its in vivo kinetics remain unclear in ruminant animals. In this study, we investigated the changes in circulating concentrations of adiponectin, as well as other metabolic hormones and metabolites, (i) during the periparturient period and (ii) among different lactation stages, in Holstein dairy cows. In experiment 1, serum adiponectin concentrations increased after parturition. Serum insulin concentrations were lower in the postpartum than prepartum period, whereas serum growth hormone (GH) concentrations increased in the postpartum period. Serum nonesterified fatty acids (NEFA) levels were increased during the postpartum period and were dependent on the parity. In experiment 2, there was no significant difference in plasma adiponectin concentrations among lactational stages. Plasma insulin concentrations tended to be lower in early lactation while plasma GH levels tended to be higher. Plasma NEFA concentrations were significantly lower in mid- and late-lactation stages than non-lactation stages. These findings indicate that elevation of serum adiponectin might be involved in energy metabolism just around parturition, and might exert its action through regulation of receptor expression levels in target tissues in each lactational stage in Holstein dairy cows.

This study was conducted to evaluate immunological changes in peripheral blood leukocytes in pigs that were genetically selected for their improved resistance to mycoplasmal pneumonia of swine (MPS), using MPS vaccine as an antigen. Twelve castrated MPS-selected Landrace pigs were compared with the same number of pigs from a nonselected line by using a time-course analysis at the hematological level. After the second sensitization with MPS vaccine, the percentages of B cells, CD4(+) T cells, and natural killer (NK) cells in total leukocytes were lower in the selected line than in the nonselected line, whereas the percentage of granulocytes in total leukocytes increased in the MPS-selected line. We also assessed the proliferative ability of peripheral blood mononuclear cells (PBMCs) stimulated with Mycoplasma hyopneumoniae, lipopolysaccharide or concanavalin A, and found that although the proliferative ability of the PBMC was not different between the two lines at a steady state, the nonselected line showed a significantly higher proliferative ability after sensitization with MPS vaccine than the selected line regardless of antigens used. These results thus indicate that the selection of pigs on the basis of MPS resistance changes their immunophenotype, and would give us beneficial information for the prevention of MPS infection.

The leptin receptor (LEPR) gene is considered a candidate gene for fatness traits. It is located on SSC 6 in a region in which quantitative trait loci (QTLs) for backfat thickness (BF), fat area ratios, and serum leptin concentration (LEPC) have previously been detected in a Duroc purebred population. The objectives of the present study were to identify porcine LEPR polymorphisms and examine the effects of LEPR polymorphisms on fatness traits in this same population. The Duroc pigs (226 to 953 pigs) were evaluated for BF, fat area ratios using image analysis, and LEPC. A total of seven single nucleotide polymorphisms (SNPs) in the full-length LEPR coding region were identified in pigs from the base population. Four non-synonymous SNPs of the LEPR gene and 15 microsatellite markers on SSC 6 were then genotyped in all pigs. During candidate gene analysis, we detected significant effects of the non-synonymous SNP c.2002CT in exon 14 on all traits. In fine mapping analysis, significant QTLs for BF, fat area ratios, and LEPC were detected near the LEPR gene in the same region. These results indicated that the c.2002CT SNP of LEPR has a strong effect on BF, fat area ratios and LEPC.

The reduction of extra subcutaneous, intermuscular and abdominal fat is important to increase the carcass lean percentage of pigs. Image analyses of fat area ratios were effective for estimation of separated fat in pig carcasses. Serum concentrations of leptin are useful as physiological predictors of fat accumulation in pigs. The objectives of the present study were to perform a quantitative trait locus (QTL) analysis for fat area ratios and serum leptin concentrations in a Duroc purebred population. Pigs (n = 226 to 538) were measured for fat area ratios of carcass cross-sections at the fifth to sixth thoracic vertebrae, half body length and last thoracic vertebra using an image analysis system, and serum leptin concentration. In total, animals were genotyped for 129 markers and used for QTL analysis. For fat area ratios, four significant and 12 suggestive QTLs were detected on chromosomes 1, 6, 7, 8, 9, 12 and 13. Significant QTLs were detected on the same region of chromosome 6, which was located near a leptin receptor gene. For serum leptin concentrations, two significant and two suggestive QTLs were detected on chromosomes 6, 9, and 16, and the QTLs on chromosome 6 were also in the same region for fat area ratios.

Genetic improvement of the reproductive performance of pigs is important for pig breeding despite their low heritabilities. The objectives of this study were to investigate the effectiveness of selection concerning reproductive traits and to determine the optimal number of parity records required for accurate estimation of breeding values (BVs) in the open population of a commercial pig breeding company. The study used records of 2220 purebred Large White pigs (9845 litters) farrowed between 1998 and 2009 in the two herds of the Pacific Ocean Breeding Co. Ltd. The traits studied included farrowing interval (FI), total number of piglets at birth (TNB), average weaning weight per litter (AWW), and raising rate (RR). A statistical model was applied to the 4-trait repeatability animal model. The heritabilities of FI, TNB, AWW and RR were low. The genetic trends in TNB (h(2) = 0.09) showed approximately 1.0 increase in 6 years from 2003 to 2008. The predicted error variances indicated that up to fourth parity records are necessary for accurate genetic evaluation. The present study results indicated that even reproductive traits with low heritability can be improved.

In pig production, dietary additive antibiotics are usually used for growth stimulation and disease prevention, although there is public concern about the increased incidence of resistant antibiotics and food safety. It is possible that such antibiotics might be replaced by naturally derived products such as seaweed and licorice. In this study, we evaluated the effect of dietary addition of seaweed and licorice on enhancing the immune function in swine. The animals of each group (eight animals per group) were sensitized at day 42 and 49, and the immunoglobulin production and the expression of cytokines were detected by the ELISA and real-time PCR. As the results, saliva IgA production of the seaweed-treated group increased around five times compared to that of control (day 56). Delayed hypersensitivity reaction and IgG production of the seaweed-treated group increased around 1.8-2.0 times. In addition, enhanced saliva IgA production was detected at day 50 (around two times) and day 51 (around five times) by the licorice treatment, and lower expression level of tumor necrosis factor-α messenger RNA at day 51 (around 1/25) was observed in the licorice treatment. We conclude that the replacement of antibiotics by naturally derived dietary additives might be feasible for immune system enhancement.