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In sorghum [Sorghum bicolor (L.) Moench], hybrid cultivars for the biofuel industry are desired. Along with selection based on testcross performance, evaluation of the breeding population per se is also important for the success of hybrid breeding. In addition to additive genetic effects, non-additive (i.e., dominance and epistatic) effects are expected to contribute to the performance of early generations. Unfortunately, studies on early generations in sorghum breeding programs are limited. In this study, we analyzed a breeding population for bioenergy sorghum, which was previously developed based on testcross performance, to compare genomic selection models both trained on and evaluated for the per se performance of the 3rd generation S0 individuals. Of over 200 ancestral inbred accessions in the base population, only 13 founders contributed to the 3rd generation as progenitors. Compared to the founders, the performances of the population per se were improved for target traits. The total genetic variance within the S0 generation progenies themselves for all traits was mainly additive, although non-additive variances contributed to each trait to some extent. For genomic selection, linear regression models explicitly considering all genetic components showed a higher predictive ability than other linear and non-linear models. Although the number and effect distribution of underlying loci was different among the traits, the influence of priors for marker effects was relatively small. These results indicate the importance of considering non-additive effects for dissecting the genetic architecture of early breeding generations and predicting the performance per se.

application/pdf, We used daily records from provincial Japanese weather stations and monthly test-day records of milk production to investigate the length of the lags in the responses of cows’ milk yield and somatic cell score (SCS) to heat stress (HS). We also investigated the HS thresholds in milk yield and SCS. Data were a total of 17,245,709 test-day records for milk and SCS in Holstein cows that had calved for the first time between 2000 and 2015, along with weather records from 60 weather stations. Temperature–humidity index (THI) values were estimated by using average daily temperature and average daily relative humidity. Adjusted THI values were calculated by using temperature, relative humidity, wind speed, and solar radiation. The model contained herd, calving year, month of test day, age group, days in milk, and THI as a fixed effect. THIs for each day from 14days before the test day until the test day were used to represent the HS effects. The HS occurring 3days, and between 8 and 10days, before the test day had the greatest effect on the milk yield and SCS, respectively. The threshold THI values for the HS effect were about 60–65 for both traits. © 2019 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science

We used test‐day records and daily records from provincial weather stations in Japan to evaluate heat tolerance (HT) in Holstein cows according to a random regression test‐day model. Data were a total of 1,641,952 test‐day records for heritability estimates and 17,245,694 test‐day records for genetic evaluation of HT by using milk yield and somatic cell score (SCS) in Holstein cows that had calved for the first time in 2000 through 2015. Temperature–humidity index (THI) values were estimated by using average daily temperature and average daily relative humidity records from 60 provincial Japanese weather stations. The model contained herd–test‐day, with lactation curves on days in milk within month–age group as a fixed effect. General additive genetic effect and HT of additive genetic effect were included as random effects. The threshold value of THI was set to 60. For milk yield, estimated mean heritabilities were lower during heat stress (THI = 78; 0.20 and 0.28) than when below the heat stress threshold (THI ≤ 60; 0.26 and 0.31). For SCS, heritability estimates (range 0.08–0.10) were similar under all heat stress conditions. Genetic trends of HT indicated that EBVs of HT are changing in an undesirable direction.

During fiscal years 2014-2018, a total of 254 internship programs were held by local government organizations under the VPcamp project, a project sponsored by the Japanese Ministry of Education, Science and Technology. We conducted a Poisson regression analysis using the number of applicants for each program as dependent variable and potential factors as independent variables that might affect the number of applicants. The factors that were found to significantly affect the number of applicants were: the program opening date; the type of venue where the program took place; the target grades of veterinary students; the regional location of the local government that organized the program; and the proximity of the local government from a veterinary school.

OBJECTIVE In practical breeding, selection is often performed by ignoring the accuracy of evaluations and applying economic weights directly to the selection index coefficients of genetically standardized traits. The denominator of the standardized component trait of estimated genetic evaluations in practical selection varies with its reliability. Whereas theoretical methods for calculating the selection index coefficients of genetically standardized traits account for this variation, practical selection ignores reliability and assumes that it is equal to unity for each trait. The purpose of this study was to clarify the effects of ignoring the accuracy of the standardized component trait in selection criteria on selection responses and economic weights in retrospect. METHODS Theoretical methods were presented accounting for reliability of estimated genetic evaluations for the selection index composed of genetically standardized traits. RESULTS Selection responses and economic weights in retrospect resulting from practical selection were greater than those resulting from theoretical selection accounting for reliability when the accuracy of the estimated breeding value (EBV) or genomically enhanced breeding value (GEBV) was lower than those of the other traits in the index, but the opposite occurred when the accuracy of the EBV or GEBV was greater than those of the other traits. This trend was more conspicuous for traits with low economic weights than for those with high weights. CONCLUSION Failure of the practical index to account for reliability yielded economic weights in retrospect that differed from those obtained with the theoretical index. Our results indicated that practical indices that ignore reliability delay genetic improvement. Therefore, selection practices need to account for reliability, especially when the reliabilities of the traits included in the index vary widely.

The semen production traits of bulls from 2 major cattle breeds in Japan, Holstein and Japanese Black, were analyzed comprehensively using genome-wide markers. Weaker genetic correlations were observed between the 2 age groups (1 to 3 yr old and 4 to 6 yr old) regarding semen volume and sperm motility compared with those observed for sperm number and motility after freeze-thawing. The preselection of collected semen for freezing had a limited effect. Given the increasing importance of bull proofs at a young age because of genomic selection and the results from preliminary studies, we used a multiple-trait model that included motility after freeze-thawing with records collected at young ages. Based on variations in contemporary group effects, accounting for both seasonal and management factors, Holstein bulls may be more sensitive than Japanese Black bulls to seasonal environmental variations; however, the seasonal variations of contemporary group effects were smaller than those of overall contemporary group effects. The improvement of motilities, recorded immediately after collection and freeze-thawing, was observed in recent years; thus, good management and better freeze-thawing protocol may alleviate seasonal phenotypic differences. The detrimental effects of inbreeding were observed in all traits of both breeds; accordingly, the selection of candidate bulls with high inbreeding coefficients should be avoided per general recommendations. Semen production traits have never been considered for bull selection. However, negative genetic trends were observed. The magnitudes of the estimated h were comparable to those of other economically important traits. A single-step genomic BLUP will provide more accurate predictions of breeding values compared with BLUP; thus, marker genotype information is useful for estimating the genetic merits of bulls for semen production traits. The selection of these traits would improve sperm viability, a component related to breeding success, and alleviate negative genetic trends.

With the aim of obtaining information to establish an import risk assessment on African swine fever (ASF) and other transboundary animal diseases (TADs) into Japan, a questionnaire survey was conducted between 1 August and 20 September 2019 on air travellers arriving into Japan from China. There were 248 responses with 2.8 % of respondents illegally importing pork products. The quantity imported per traveller varied between 250 g and 2 kg. Concerning the travellers' perception in regard to the difficulty of importing a pork product in their luggage, 32 respondents (12.9 %) considered it very easy or rather easy and 216 (87.1 %) very difficult or rather difficult. In regard to the recognition of respondents of the illegality of importing pork products into Japan, seven respondents (2.8 %) did not consider this practice to be illegal whilst 241 (97.2 %) had some idea of the illegal nature of this behaviour. The regression analysis revealed that the practice of illegal importation of pork products was significantly affected by the level of difficulty perception held by the traveller (P0.001) and that the difficulty perception is significantly affected by the level of recognition of illegality by the traveller (P0.001). The result of this study will not only provide useful data in developing a model to assess the probability of introduction of ASF and other TADs into Japan and other countries, but also in monitoring the effect of measures taken by the government to reduce the illegal importation of meat and meat products.

ホルスタイン種における在群期間に関する直接および間接遺伝評価値から遺伝的趨勢を予測した．データは，1985年から1995年までに初産分娩した雌牛からの838，232の長命性記録，1997年から2003年までに体型審査を受審した165，715の体型審査記録である．在群期間に関する遺伝的趨勢は，在群期間に関する記録をもつ個体およびそれらの父牛について遺伝評価（以下，直接評価）値から推定した．在群期間の記録が得られていない雌牛およびそれらの父の在群性に関する遺伝評価値は，体型形質に関する遺伝評価に対して最良予測法を応用して間接的（以下，間接評価）に推定した．間接評価のためのモデルは，14の体型形質を採用したモデルを最大モデル，相関の高い複数の体型形質から選択的に8形質を採用したモデルを縮小モデルとし，それら2種類のモデルによる推定値を比較した．間接評価値を推定した個体の両親のいずれか，または両方が直接評価値をもつ場合，それらの評価値と間接評価値を結合した．在群性について推定された遺伝率は，0.08であった．直接評価値および間接評価値間の相関係数は，最大モデルおよび縮小モデルに関して各々0.52および0.66であった．このことより，間接評価値の推定には，最大モデルよりもむしろ縮小モデルが適すると判断した．直接評価および縮小モデルを採用した間接評価による遺伝的趨勢の予測より，わが国では，在群性の直接選抜を行っていないにもかかわらず，雌牛の在群期間の向上が示唆された．

熊本県,長崎県および秋田県において1993年12月までに出荷された褐毛和種の枝肉データを用いて日齢枝肉重量(枝肉重量/出荷時日齢),ロ-ス芯面積,皮下脂肪厚,歩留基準値,BMSナンバー,BCSナンバー,しまりおよびきめの8形質について,遺伝的趨勢を明らかにした.分析には,10,471頭の枝肉データを用い,個体モデルのBLUP法により種雄牛および雌牛の育種価の推定を行った.数学モデルには,要因として農協•出荷年次,出荷月,性,個体および出荷月齢の一次,二次回帰を取り上げた.この分析に必要な遺伝的パラメーターはHendersonの方法IIIにより推定した.その遺伝率推定値は,日齢枝肉重量,ロース芯面積,皮下脂肪厚,歩留基準値,BMSナンバー,BCSナンバー,しまりおよびきめでそれぞれ,0.225,0.313,0.297,0.397,0.271,0.218,0.247および0.195であった.遺伝的趨勢をみるため1975年から1989年までの生年に対する雌牛の標準化推定育種価平均値の直線回帰係数を求めたところ,日齢枝肉重量,ロース芯面積,BMSナンバー,BCSナンバー,しまりおよびきめでそれぞれ,0.665,0.051,0.030,-0.016,0.015および0.011となり,すべて1%水準で有意であった.また,種雄牛についてはどの形質についても,一定の趨勢は見られなかった.しかし,肉量および肉質に関する形質について,高い育種価推定値を示す種雄牛が,より多くの後代を持つことが明らかになった.

The morphology of the testis of the mutant As (aspermia) strain rat with severely interrupted spermatogenesis was investigated in the present study. The most advanced development in spermatogenesis was observed at the step 8 at which spermatids had basally-oriented acrosomes. Multinucleate giant cells derived from round spermatids were frequently encountered within the seminiferous tubules. The functionally normal status of the blood-testis barrier between adjacent Sertoli cells was confirmed by morphological and lanthanum tracer studies. By light microscopy, a peculiar structure was found within the pachytene spermatocyte, consisting of numerous particles of approximately 25 nm in diameter. By histochemical and electron microscopic studies, this structure was identified as an aggregate of ribosomes. Neither immature spermatogenic cells up to the pachytene phase, nor Sertoli cells nor interstitial regions showed a recognizable abnormality. It seems that the testicular disruption in the As mutant rat is due to the abnormality in the protein synthetic pathway in pachytene spermatocytes.