Methyl donors dietary supplementation to gestating sows diet improves the growth rate of offspring and is associating with changes in expression and DNA methylation of insulin‐like growth factor‐1 gene

The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB₁₂, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.     

发酵酸羊乳冻干粉的生产方法

介绍了发酵酸羊乳冻干粉的生产方法,主要有羊乳预处理、羊乳发酵、冻干制粉和包装质检四个生产工序。应用此法生产的酸羊乳冻干粉保留了酸羊乳原有的色、香、味和营养物质,还具有较高的乳酸菌生物活性。     

抗青枯病番茄砧木品种宝砧6号的选育

宝砧6号是以自交系Y0609-4-6为母本,自交系T0802-7-4为父本配置而成的番茄砧木一代杂交种。该品种为无限生长型,生长旺盛,茎秆粗壮,株型紧凑,高抗青枯病;与生产上主栽品种嫁接亲和性好,对果实品质、商品性无不良影响,作砧木嫁接栽培抗青枯病和抗早衰能力效果明显,嫁接种植田后期可延长采收15~20 d,增产幅度超过15%。目前该品种已成为资源车田、永福三皇等番茄产业基地嫁接砧木的主要应用品种,推广应用面积达400 hm~2。     

Design method and homogeneity control of bridge fair-faced concrete

According to the structural characteristics of bridge engineering, the mix optimization design method of bridge fair-faced concrete was presented, and C30~C50 concrete with high cohesion and package, outstanding fluidity and excellent mechanical properties were prepared. Through the test of air content of fresh concrete, micro hardness and micro structure in different parts of hardened concrete specimens, effects of viscosity-modifying admixtures on homogeneity of concrete were discussed. The results showed that the composition of bridge fair-faced concrete were relatively homogeneous, and the microstructure were relatively dense. When C30 concrete mixed with 5 × 10 -5 cellulose ether or 6% silica fume (mass fraction of cementitious material), air content of fresh concrete were less than 2%, and slurry viscosity values were between 1 900 and 2 000 MPa·s. Also, the micro hardness values in different parts of hardened concrete specimens were closed. The results were applied in practical bridge engineering, which generally meets the apparent quality requirements of bridge fair faced concrete.     

早籼型水稻温敏核不育系M103S的选育与光温反应特性

以温敏核不育水稻安农S—1为母本，以常规高产早籼稻品系92153为父本进行杂交，通过低温选择和人工气候箱鉴定，育成了育性转换临界温度23—24℃的早籼型温敏核不育系M103S。光周期长于12．5h，日平均温度高于24℃，可以用于制种，日平均温度低于23℃，可以用于繁殖。光周期长于13．5h，日平均温度高于23℃，可以用于制种。自然条件下不育起点温度为日均温23—24℃，耐低温期为3—4d。敏感期为抽穗前的7—14d。播始历期为53—79d，主茎叶片数10．0—12．6片。从播种到始穗的活动积温和有效积温，分别为1493．8—1766．3℃和733．4—1058．3℃。不育期的株高63．6—77．5cm，平均72．0cm，单株有效穗6．4—12．0个，平均9．3个，穗长20．9—22．7cm，平均21．2cm，每穗颖花数112．1—137．3朵，平均122．3朵。可育期株高65．7cm，单株有效穗7．2个，穗长17．2cm，每穗总粒数114．1粒，结实率47．23％，千粒重31．34g。以M103S为母本，与100多个早籼品种进行测配，杂种表现生育期早、穗大、粒多、千粒重高。     

速生人工林桉树木材材色处理初步研究

试验用漂白剂、酸性染料和其他化学药剂,采用单纯漂白、单纯染色、先漂白再染色和化学着色等4种不同的方案对人工林桉树木材进行材色改良处理研究.结果发现:单纯漂白可获得一定的材色改良效果;硫化物类、过硫酸铵类的药剂配方漂白效果不明显;硼氢化钠类的药剂配方可得到一定的漂白效果;双氧水类、次氯酸钠类的药剂配方可得到很好的漂白效果.单纯染色比较难获得好的材色处理效果.采用先漂白后染色的方法,获得的材色过于鲜艳.采用化学着色的方法,可获得较理想的材色改良效果;草酸类药剂配方着色效果明显,可消除材色缺陷,根据不同的配方和处理工艺可获得从浅粉红色到红棕色的色调;用双氧水做活性剂,引入带发色团的化学药剂,材色改良效果明显,通过调整配方药品的浓度和处理工艺可获得从浅黄色到橙黄色的不同色调和较佳的材质.     

贵州省退耕还林工程社会经济效益阶段评价研究

通过对水城、黎平、望谟、关岭、麻江、黔西、龙里、习水、开阳、铜仁10个退耕还林工程综合效益监测重点县107个固定样地户主共91户退耕农户进行连续4年的跟踪调查，同时结合10个县面上统计数的分析及其典型县204户退耕农户的典型调查，对监测区退耕还林的经济、社会效益进行了评价：退耕还林工程区环境效益经济值明显提高，水土流失得到有效控制；工程区退耕农户收入增加，粮食总产量稳定；退耕还林促进了农村劳动力的转移。     

Salix tetradenia Hand.‐Mazz: a new natural plant host of ‘Candidatus phytoplasma’

This article reports Salix tetradenia Hand.‐Mazz as a new host of Candidatus phytoplasma and demonstrates its association with witches' broom disease on S. tetradenia plants. Plants exhibited typical visual symptoms of phytoplasma with virescence, abnormality of flowers and witches' broom, and phytoplasma bodies were observed by transmission electron microscopy. Products of 1.2 kb were amplified by nested PCR using phytoplasma universal primer pairs R16F2n/R16R2, but no amplification products were obtained from symptomless plants. The sequence analysis of three 16S rDNA isolates showed 99.84%, 99.68% and 99.76% identify, respectively, with the homologous gene (nc_005303) of member of ‘Candidatus phytoplasma asteris’ (16SrI) group. Phylogenetic and virtual computer‐simulated restriction fragment length polymorphism analysis of the 16S rRNA, tuf and rp gene sequences confirmed that this phytoplasma clustered in the 16SrI‐B subgroup. These results indicated that the diseased S. tetradenia plants were infected by a phytoplasma of the 16SrI group. This is the first report on the occurrence of phytoplasma disease on S. tetradenia worldwide.     

Effects of different dietary energy and protein levels and sex on growth performance,carcass characteristics and meat quality of F1 Angus x Chinese Xiangxi yellow cattle

Background：The experiment evaluated the effect of nutrition levels and sex on the growth performance,carcass characteristics and meat quality of F1 Angus × Chinese Xiangxi yellow cattle.Methods：During the background period of 184 d,23 steers and 24 heifers were fed the same ration,then put into a2×2×2 factorial arrangement under two levels of- dietary energy（TON：70/80%DM）,protein（CP：11.9/14.3%DM）and sex（S：male/female） during the finishing phase of 146 d.The treatments were-（1） high energy/low protein（HELP）,（2） high energy/high protein（HEHP）,（3） low energy/low protein（LELP） and（4） low energy/high protein（LEHP）.Each treatment used 6 steers and 6 heifers,except for HELP- 5 steers and 6 heifers.Results：Growth rate and final carcass weight were unaffected by dietary energy and protein levels or by sex.Compared with the LE diet group,the HE group had significantly lower dry matter intake（DMI,6.76 vs.7.48 kg DM/d）,greater chest girth increments（46.1 vs.36.8 cm）,higher carcass fat（19.9 vs.16.3%） and intramuscular fat content（29.9 vs.22.8%DM）.The HE group also had improved yields of top and medium top grade commercial meat cuts（39.9 vs.36.5%）.The dressing percentage was higher for the HP group than the LP group（53.4 vs.54.9%）.Steers had a greater length increment（9.0 vs.8.3 cm）,but lower carcass fat content（16.8 vs.19.4%） than heifers.The meat quality traits（shear force value,drip loss,cooking loss and water holding capacity） were not affected by treatments or sex,averaging 3.14 kg,2.5,31.5 and 52.9%,respectively.The nutritive profiles（both fatty and amino acid composition） were not influenced by the energy or protein levels or by sex.Conclusions：The dietary energy and protein levels and sex significantly influenced the carcass characteristics and chemical composition of meat but not thegrowth performance,meat quality traits and nutritive profiles.     

甘蔗叶鞘剥离过程弹性齿运动分析与试验

通过对弹性齿运动状态的分析阐述了弹性齿在叶鞘撕裂和剥离过程中的作用机理,采用ADAMS软件对弹性齿与甘蔗茎秆的接触过程进行仿真分析,确定剥叶滚筒中心距及弹性齿与甘蔗茎秆之间的相对速度变化对叶鞘撕裂和剥离产生的影响。利用物理样机进行剥叶滚筒中心距单因素试验和剥叶滚筒转速单因素试验对运动分析结果进行验证,并通过高速摄影对仿真的结果进行验证。结果表明,剥叶滚筒中心距为310 mm,弹性齿与甘蔗茎秆接触时刻,y轴方向的线速度差为3.91~5.87 m/s时,弹性齿可沿茎秆表面向下滑动,有利于叶鞘沿着纤维方向撕裂,x轴方向的线速度差为4.61~7.54 m/s时,弹性齿在甘蔗轴线方向可以持续滑动,有利于对叶鞘造成刮擦脱离,综合剥叶效果为含杂率低于7%、茎秆折断率低于15%。弹性齿与茎秆分离时刻,由于弹性恢复产生线速度突变,相对速度差增大4~5倍,有利于将叶鞘从茎秆上撕扯脱落。