Genetic analysis for sow stayability at different parities in purebred Landrace and Large White pigs

Genetic parameters for sow stayability were estimated from farrowing records of 10,295 Landrace sows and 8192 Large White sows. The record for sow stayability from parity k to parity k + 1 (k = 1, …, 6) was 0 when a sow had a farrowing record at parity k but not at parity k + 1, and 1 when a sow had both records. Heritability was estimated by using single-trait linear and threshold animal models. Genetic correlations among parities were estimated by using two-trait linear–linear and single-trait random regression linear animal models. Genetic correlations with litter traits at birth were estimated by using a two-trait linear–linear animal model. Heritability estimates by linear model analysis were low (0.065–0.119 in Landrace & 0.061–0.157 in Large White); those by threshold model analysis were higher (0.136–0.200 & 0.110–0.283). Genetic correlations among parities differed between breeds and models. Genetic correlation between sow stayability and number born alive was positive in many cases, implying that selection for number born alive does not reduce sow stayability. The results seem to be affected by decisions on culling made by farmers.     

Accuracy of imputation of single nucleotide polymorphism marker genotypes from low‐density panels in Japanese Black cattle

Using target and reference fattened steer populations, the performance of genotype imputation using lower‐density marker panels in Japanese Black cattle was evaluated. Population imputation was performed using BEAGLE software. Genotype information for approximately 40 000 single nucleotide polymorphism (SNP) markers by Illumina BovineSNP50 BeadChip was available, and imputation accuracy was assessed based on the average concordance rates of the genotypes, varying equally spaced SNP densities, and the number of individuals in the reference population. Two additional statistics were also calculated as indicators of imputation performance. The concordance rates tended to be lower for SNPs with greater minor allele frequencies, or those located near the ends of the chromosomes. Longer autosomes yielded greater imputation accuracies than shorter ones. When SNPs were selected based on linkage disequilibrium information, relative imputation accuracy was slightly improved. When 3000 and 10 000 equally spaced SNPs were used, the imputation accuracies were greater than 90% and approximately 97%, respectively. These results indicate that combining genotyping using a lower‐density SNP chip with genotype imputation based on a population of individuals genotyped using a higher‐density SNP chip is a cost‐effective and valid approach for genomic prediction.     

不同添加剂对苜蓿青贮饲料品质的影响

利用糖蜜、甲酸、乳酸菌制剂和酶制剂分别或共同对 2种不同含水率的苜蓿进行了青贮调制试验 ,结果表明 :不同添加剂处理的苜蓿 1(含水率 71%～ 73% )和苜蓿 2 (含水率 6 2 %～ 6 4 % )青贮饲料的等级均为良好 ,且发酵品质均比对照组有所提高。糖蜜使苜蓿 1和苜蓿 2青贮饲料乳酸与总酸质量比分别提高 4 7%和 32 % ,NDF降解率分别提高 10 %和 2 2 % ;乳酸菌制剂降低了青贮饲料中乳酸含量 ,提高了乙酸含量 ,使NDF降解率分别比对照组提高 2 6 %和 18% ;酶制剂提高了动物的消化率 ;乳酸菌制剂和酶制剂共同作用使乳酸与总酸质量比分别降低了37%和 39% ,同时提高了动物消化率和青贮饲料的营养价值 ;甲酸处理使饲料中乙酸与总酸质量比分别降低了31%和 2 5 % ,NDF降解率分别提高了 19%和 14 % ,并在一定程度上抑制了蛋白质和氨基酸的分解。糖蜜有效抑制了苜蓿 1青贮饲料的二次发酵 ,但苜蓿 2青贮饲料的发酵品质显著优于苜蓿 1(P <0 0 5 )。     

Heritability and genetic correlation estimates of semen production traits with litter traits and pork production traits in purebred Duroc pigs

We estimated heritabilities of semen production traits and their genetic correlations with litter traits and pork production traits in purebred Duroc pigs. Semen production traits were semen volume, sperm concentration, proportion of morphologically normal sperms, total number of sperm, and total number of morphologically normal sperm. Litter traits at farrowing were total number born, number born alive, number stillborn, total litter weight at birth, mean litter weight at birth, and piglet survival rate at birth. Litter traits at weaning were litter size at weaning, total litter weight at weaning, mean litter weight at weaning, and piglet survival rate from birth to weaning. Pork production traits were average daily gain, backfat thickness, and loin muscle area. We analyzed 45,913 semen collection records of 896 boars, 6,950 farrowing performance records of 1,400 sows, 2,237 weaning performance records of 586 sows, and individual growth performance records of 9,550 animals measured at approximately 5 mo of age. Heritabilities were estimated using a single-trait animal model. Genetic correlations were estimated using a 2-trait animal model. Estimated heritabilities of semen production traits ranged from 0.20 for sperm concentration to 0.29 for semen volume and were equal to or higher than those of litter traits, ranging from 0.06 for number stillborn and piglet survival rate at birth to 0.25 for mean litter weight at birth, but lower than those of pork production traits, ranging from 0.50 for average daily gain to 0.63 for backfat thickness. In many cases, the absolute values of estimated genetic correlations between semen production traits and other traits were smaller than 0.3. These estimated genetic parameters provide useful information for establishing a comprehensive pig breeding scheme.     

Performance of using opposing homozygotes for paternity testing in Japanese Black cattle

Genome-wide single nucleotide polymorphism (SNP) markers in Japanese Black cattle enable genomic prediction and verifying parent–offspring relationships. We assessed the performance of opposing homozygotes (OH) for paternity testing in Japanese Black cattle, using SNP genotype information of 50 sires and 3,420 fattened animals, 1,945 of which were fathered by the 50 genotyped sires. The number of OH was counted for each sire–progeny pair in 28,764 SNPs with minor allele frequencies of ≥0.05 in this population. Across all pairs of animals, the number of OH tended to increase as the pedigree-based coefficient of relationship decreased. With a threshold of 288 (1% of SNPs) for paternity testing, most sire–progeny pairs were detected as true relationships. The frequency of Mendelian inconsistencies was 2.4%, reflecting the high accuracy of pedigree information in Japanese Black cattle population. The results indicate the utility of OH for paternity testing in Japanese Black cattle.     

Chemerin analog regulates energy metabolism in sheep

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500 µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high‐density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20 min but then increased gradually from 60 to 180 min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep.     

Effects of GH gene polymorphism and sex on carcass traits and fatty acid compositions in Japanese Black cattle

To investigate the effects of bovine growth hormone (bGH) gene polymorphism on carcass traits and fatty acid compositions in Japanese Black cattle caused by nucleotide substitution of CTG (allele A)/GTG (allele B) at codon 127 and of ACG (allele A and B)/ATG (allele C) at codon 172 of bGH, GH genotypes of 135 cattle were determined using allele specific-multiplex polymerase chain reaction (PCR). Allele A gave greater rib thickness and lower melting point of fat (MP) while allele B gave higher C18:1% ( P  < 0.05). Allele C gave higher C18:1, monounsaturated fatty acid (MUFA), unsaturated fatty acid (USFA) percentages ( P  < 0.05). It also gave lower saturated fatty acid (SFA) percentages, higher MUFA/SFA and USFA/SFA ratios, and lower MP ( P  < 0.05). Interactions of sex and GH alleles were analyzed. In heifers, allele A gave higher carcass weight, daily carcass gain, rib eye area, rib thickness, subcutaneous fat thickness, and BMS while allele B gave greater rib eye area and rib thickness ( P  < 0.05). Allele C gave higher C18:1 ( P  < 0.01), MUFA ( P  < 0.01), USFA percentages ( P  < 0.05) and MUFA/SFA and USFA/SFA ratios ( P  < 0.01), and lower C16:0 and SFA percentages ( P  < 0.05) and MP ( P  < 0.01). GH gene polymorphism affected carcass traits and fatty acid compositions although the effects were more pronounced in heifers.     

Lineage relationship analysis of RORgammat+ innate lymphoid cells

Lymphoid tissue-inducer (LTi) cells initiate the development of lymphoid tissues through the activation of local stromal cells in a process similar to inflammation. LTi cells express the nuclear hormone receptor RORγt, which also directs the expression of the proinflammatory cytokine interleukin-17 in T cells. We show here that LTi cells are part of a larger family of proinflammatory RORγt(+) innate lymphoid cells (ILCs) that differentiate from distinct fetal liver RORγt(+) precursors. The fate of RORγt(+) ILCs is determined by mouse age, and after birth, favors the generation of cells involved in intestinal homeostasis and defense. Contrary to RORγt(+) T cells, however, RORγt(+) ILCs develop in the absence of microbiota. Our study indicates that RORγt(+) ILCs evolve to preempt intestinal colonization by microbial symbionts.     

Competence of <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> and <Emphasis Type="Italic">Frankliniella intonsa</Emphasis> strains as vectors for <Emphasis Type="Italic">Chrysanthemum stem necrosis virus</Emphasis>

The vector competence of Frankliniella occidentalis for Chrysanthemum stem necrosis virus (CSNV) was evaluated. Three vector strains with distinct competences for Tomato spotted wilt virus (TSWV) transmission were investigated, including an artificially selected strain (TsH) that has a particularly high competence (>90 %). Newly hatched larvae of F. occidentalis were given an acquisition access period of 5 days on CSNV-infected D. stramonium leaves, and reared to maturity. Their transmission efficiencies were examined using a leaf disk assay using Petunia x hybrida leaves. Following the leaf disk assay, the virus accumulation in the vectors was examined via a double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) of their bodies. The results showed that the CSNV acquisition and transmission efficiency of the TsH strain did not differ from those of the others, indicating that the competence of F. occidentalis as a vector for CSNV is not related to that for TSWV. The CSNV transmission and acquisition efficiencies of two F. intonsa strains (Hiroshima and Fukuoka) were also evaluated. In Hiroshima strain, 35 % of adults were viruliferous, but only two transmitters (3 %) were observed. In Fukuoka strain, 6 % were viruliferous, and no transmitters were observed. These results indicate that F. intonsa cannot be a major vector for CSNV. The accumulation of CSNV in the adults of F. occidentalis and F. intonsa evaluated using DAS-ELISA showed a significant difference in ELISA values among transmitter, viruliferous non-transmitter, and non-viruliferous individuals. These results clearly demonstrated that only transmitters that accumulated a threshold quantity of virus can transmit CSNV to plants.     

Footpad dermatitis in broiler chickens in Japan

The prevalence of footpad dermatitis (FPD) in broiler chickens in Japan was investigated. In the first examination at slaughterhouses, lesions were commonly observed on the footpads of a total of 8,985 broiler chickens from 45 flocks on 36 farms. In 3 flocks, all the birds examined had lesions. In the other 42 flocks, the incidence of FPD ranged from 31.9% (81/254) to 99.5% (1/222). The footpad lesions were classified into 4 categories according to the severity of dermatitis as follows; score 0, 1,181 birds (13.1%); score 1, 2,992 birds (33.3%); score 2, 3,000 birds (33.4%); and score 3, 1,812 birds (20.2%). The mean scores of the flocks varied widely from 0.31 to 2.69. Males had higher mean scores than females. No significant differences were found between the mean scores of birds reared in windowless houses and those in open-sided houses. On 4 farms, the investigation was carried out in different seasons, and 3 of them showed higher mean scores in winter than in summer. Next, observation of 2,255 birds from 15 flocks on 5 farms during a 4-week rearing period revealed that FPD was already produced at 7 days of age and worsened with age.