亲本连续五代人工饲料选育对两广二号F1代杂交种的影响

为探讨两广二号人工饲料选育品系的选育效果,使用人工饲料连续选育了5代的932、芙蓉、7532和湘晖组配成9·芙×7·湘（两广二号）,以普通杂交种两广二号为对照,开展颗粒饲料育调查和桑叶育调查。结果表明：人工饲料选育品系2、3龄起蚕率达88％和89％,比对照有较大幅度提高,24h疏毛率和1、2龄眠蚕体重与对照相近;桑叶育时,人工饲料选育品系的茧质、结茧率和全龄经过没有明显变化,但蛹期抗性降低。试验表明：亲本的连续5代人工饲料选育,明显提高了两广二号F1代对人工饲料的适应性,且对原有优良性状影响不大,但选育品系人工饲料育时的发育整齐度仍需提高。     

秋丰×白玉人工饲料适应性品系小蚕人工饲料育效果试验

人工饲料育相对于桑叶育有蚕体发育不齐等方面的不足,人工饲料适应性品系的应用能提高人工饲料育的发育整齐度。为深入了解经人工饲料摄食选育的秋丰×白玉人工饲料适应性品系[以下称秋丰×白玉(人)]在生产上的表现,于2018年春蚕期和晚秋蚕期进行了秋丰×白玉(人)小蚕人工饲料育试验。试验结果表明,与未经人工饲料摄食选育的常规品种秋丰×白玉相比,秋丰×白玉(人)的发育整齐度明显提高,蚕茧产质量有明显优势,其中盒种产茧量、全茧量和茧层量分别提高12.23%、7.19%和15.34%,茧丝长、茧丝量分别提高12.13%和20.27%。小蚕人工饲料育应优先选用人工饲料适应性品系。     

家蚕多代食性歧化选择对后代摄食性和经济性状的影响

利用桑叶粉含量不同的人工饲料饲养及全龄桑叶饲养2种方式,调查由菁松A、菁松B、皓月A、皓月B等4个家蚕品系定向选出的高食性和低食性新品系及高食性品系杂交组合的主要实用性状,以探讨连续多代食性选择对后代摄食性和经济性状的影响。用桑叶粉质量分数为10%~40%的平板饲料饲育,高食性品系的疏毛率达92%~100%,其中菁松A和菁松B的高食性品系与低食性品系相比,疏毛率最大相差分别达到100%和94%;用不含桑叶粉的人工饲料饲养皓月B的高食性品系,其疏毛率达93.3%,而菁松A低食性品系对所有配方的饲料几乎都不取食。用含10%桑叶粉的颗粒饲料饲养高食性品系杂交组合R菁松×R皓月,其摄食性和适应性显著优于对照菁松×皓月。不同食性品系全龄桑叶育试验结果表明:蚕体质量总体上是高食性品系大于低食性品系和对照品系;全龄发育经过高食性品系有不同程度缩短,而低食性品系延长;全茧量和茧层量多数是高食性品系高于低食性品系和对照品系,但茧层率大多是高食性品系低于低食性品系和对照品系;不同食性品系之间生命率的差异不明显。对F1代的产茧量和茧丝品质鉴定表明:在全龄桑叶育条件下,高食性R菁松×R皓月的产茧量和茧丝长、出丝率、洁净、纤度等指标与对照菁松×皓月比较均不存在显著差异,而解舒率和解舒丝长极显著高于对照;在1~2龄人工饲料育、3~5龄桑叶育的条件下,R菁松×R皓月的上述各项指标均不同程度优于对照菁松×皓月。试验结果说明,食性选择不仅能显著改变家蚕对人工饲料的摄食性,而且对家蚕的生长发育、产茧量和茧丝品质也有不同程度影响,向高食性方向选育不会导致产茧量、茧丝品质和生命率的下降,但有可能引起茧层率降低。因此,在通过食性系统选择培育人工饲料适应性家蚕品种的过程中,应同时注重茧层率的选择。     

广西现行家蚕品种人工饲料累代定向系统选育

为提高广西现行家蚕品种两广二号对人工饲料的摄食性和适应性,以24h疏毛率、各龄起蚕率及存活率等为选育指标,用饲料、实用型颗粒饲料及桑叶多种饲料结合,以个体选育和蛾区选育为重点对其原原种932、芙蓉、7532、湘晖进行累代定向系统选育。以未经人工饲料选育的932、芙蓉、7532、湘晖为对照,以各品种进行1~2龄饲料育,3~5龄桑叶育及全龄桑叶育,调查累代人工饲料选育对参选品种人工饲料摄食性和适应性的影响。试验结果表明：累代选育明显提高了品种对人工饲料的摄食性;选育在一定程度上提高了品种对人工饲料的适应性。中系品种经过多代选育后对人工饲料的摄食性和适应性均达到较好水平,日系品种对人工饲料的摄食适应性虽有提高,但对人工饲料的适应性仍然一般。多数选育品种死笼率有下降的趋势,表明选育在一定程度上提高了蛹期的抗性;累代选育对品种的茧质（全茧量和茧层率）影响不明显;累代选育没有降低饲料育对蚕发育延缓的影响。综合各方面结果来看,人工饲料累代定向系统选育可明显提高家蚕对人工饲料的适应性,有望选出适宜人工饲料育的新品系。     

家蚕原种人工饲料适应性品系的选拔

研究了家蚕中、日系原种与杂交种对人工饲料适应性的差异；经累代定向选择，建立了苏５、青松人工饲料适应性品系，该品系对人工饲料适应性比非选拔系有明显提高，配以优良的原种饲料，进行原种稚蚕人工饲料育，综合成绩基本达到桑叶育水平。     

华康2号亲本品系人工饲料摄食性选育效果初报

为培育适应人工饲料育的BmNPV抗性品种,促进人工饲料省力化养蚕,2017年以蚁蚕24 h疏毛率为主要选育指标,用桑叶粉含量30%的家蚕实用性颗粒人工饲料进行了华康2号4个亲本品系秋丰N(中系)、白玉NA系(日系)、白玉NB系(日系)和白玉NC系(日系)的4代摄食性选育,调查了华康2号亲本品系对人工饲料的摄食性和选育效果。试验结果表明:通过累代人工饲料选育,明显提高了华康2号中系亲本和日系亲本对颗粒人工饲料的摄食性,而颗粒人工饲料对华康2号中系亲本和日系亲本的茧质成绩和眠蚕体质量影响不大。     

鲁17和92原蚕全龄人工饲料育研究

研究了家蚕新品种鲁17、92原蚕的全龄人工饲料育,结果表明,该品种具有较好的人工饲料适应性,其全龄人工饲料育的各龄眠重、5龄逐日蚕体重与茧质成绩明显优于对照品种菁松、皓月。使用本实验所用配方的人工饲料饲养该品种,其全龄人工饲料育茧质成绩可达到桑叶育水平,中、日系茧层率分别为23.41%、24.28%,日系品种的人工饲料适应性明显优于中系品种。     

Z18等14份家蚕品系资源稚蚕颗粒人工饲料适应性及饲育成绩调查

为探究安徽省农业科学院蚕桑研究所保育的部分家蚕品系对人工饲料育的适应性,从而为选育适宜安徽省地理气候条件的人工饲料育适应性蚕品种奠定基础,挑选了 Z18等14份家蚕品系资源进行1～2龄颗粒人工饲料育3～5龄桑叶育(以下简称稚蚕饲料育)适应性及饲育成绩调查,以优食一号、菁松x皓月作为品种对照,以全龄桑叶育作为饲育方式对照...     

两广二号亲本累代人工饲料选育对一代杂交种饲养成绩的影响

以广西现行品种两广二号的4个亲本932、芙蓉、7532、湘晖为对象,探索累代人工饲料选育效果,经9代连续选育后重新组配成四元杂交组合,命名为GS9,并以两广二号为对照品种,调查1～2龄颗粒人工饲料育3～5龄桑叶育对一代杂交种饲养成绩的影响,结果表明：1～2龄颗粒人工饲料育3～5龄桑叶育时,亲本经连续9代选育后提高了一代杂交种饲料育的发育整齐度和存活率,促进了幼虫后期的蚕体生长;且对5龄经过、全龄经过和茧质影响不明显.对两广二号的亲本进行多代人工饲料选育,提高了一代杂交种对人工饲料的适应性,表明这种选育方法是有效的;但GS9尚未达到实用化程度,应继续选育提高,以期育成适宜人工饲料育的家蚕品种.     

蚕品种“秋丰×白玉”人工饲料适应性再选育生产试验初报

随着农村小蚕人工饲料育技术的兴起,适于人工饲料育的蚕品种日益成为生产需求。"秋丰×白玉"是浙江蚕区主要推广应用的蚕品种,我们前期对其相应的母种进行了人工饲料适应性再选育。为调查人工饲料适应性再选育蚕品种"秋丰×白玉"的生产实用性状,对其进行了农村生产试验。结果表明,小蚕1～2龄人工饲料育,24h疏毛率、72h就眠率、2龄起蚕率、3龄起蚕率分别较对照提高了3.13%、11.76%、15.29%、486.67%,死笼率降低了41.60%,张种产量与对照相仿;小蚕1～3龄人工饲料育产量较对照降低10%左右。     

适合人工饲料育家蚕品种“R9501×RB”的育成初报

R9501是由日系品种9202经14代人工饲料摄食性系统选择培育而成,RB是由中系品种苏春经16代人工饲料摄食性系统选择培育而成。家蚕品种R9501×RB人工饲料育2龄发育整齐度达80％以上,疏毛率达到95％以上,4龄起蚕结茧率、死笼率、全茧量、茧层量、茧层率、解舒率等6项性状均略高于对照种春蕾X镇珠;5龄经过、茧丝长、解舒丝长、纤度、净度5项性状基本与对照种春蕾×镇珠持平;张种产量、张种产值分别比对照高2．3kg和92元。实验室与农村生产鉴定R9501×RB是一对综合经济性状优良的人工饲料摄食性家蚕品种。     

浙江现行蚕品种对小蚕人工饲料适应性的比较试验

用山东省蚕业研究所研制的粉状人工饲料,对我省现行推广的6对家蚕品种和2个雄蚕品种进行1-2龄人工饲料育的适应性比较试验。结果表明：各蚕品种喂饲人工饲料24 h后,疏毛率达95%以上的蚕品种有华东x春晨（99.80%）、菁松x皓月（98.69%）、明丰x春玉（96.15%）、秋丰x白玉（96.04%）、春华x秋实（95.45%）和华菁x平72（95.41%）;从各品种的生长情况和茧质来看,1-2龄人工饲料育的除全龄经过延长两天左右外,其虫蛹率、万蚕产茧量、全茧量、茧层量和茧层率均与全龄桑叶育基本接近。     

原蚕稚蚕颗粒人工饲料育的研究

调查了6个家蚕原种、2个杂交种对颗粒人工饲料的摄食性,重点探讨了4个原种1~2龄颗粒饲料育对其生长发育、产卵性能和叶卵转效率的影响。结果表明,不同蚕品种对颗粒人工饲料的摄食性存在极大差异,从24 h疏毛率来看,杂交种高于原种,日系品种高于中系品种。原蚕稚蚕颗粒人工饲料育的1~3龄发育经过比全龄桑叶育对照显著延长,但5龄期发育加快,差距缩小。小蚕颗粒人工饲料育对原蚕虫蛹生命率无明显影响,全茧量高于全龄桑叶育,但茧层率低于对照组。造卵数1~2龄颗粒饲料育略少于全龄桑叶育,但残留卵率显著降低,平均产卵量与全龄桑叶育基本相同,良卵率也无明显差异。小蚕颗粒饲料育的5龄食下量均低于全龄桑叶育,4个品种平均减少11.0%,叶卵转化率比全龄桑叶育平均提高15.6%。     

稚蚕人工饲料中桑绿枝粉的添加效果及加工特点

在家蚕稚蚕人工饲料中分别添加 15 %的桑绿枝粉、冬桑条粉、桑皮粉等 ,并与豆腐渣、市售纤维素粉末等进行了对照试验 ,结果以添加桑绿枝粉的稚蚕人工饲料各项成绩最为理想 ,稚蚕对其有良好的摄食性 ,从而为研制稚蚕低成本人工饲料开辟了新的原料来源     

Effect of selection for growth on normal and reduced protein diets on weight gain, feed intake, feed efficiency and body composition in mice

Mice selected for weight gain from 3 to 9 weeks of age on a normal (N) protein diet containing 19.3% protein and a reduced (R) protein diet with 5.1% protein were reared on both diets in generations 7 and 9. The lines NH, NC, NL, RH, RC and RL (H, high; C, control; L, low) were tested for weight gain on diet N and R and for feed intake and feed efficiency on diet N in generation 7. In generation 9, the lines were tested for body composition traits (fat, protein and water percentage) at 3, 6, 9 and 12 weeks of age on both diets. A significant (p < 0.0001) genotype × environment interaction for growth rate was observed in generation 7. Weight gain at both the protein levels was best improved by selection at the protein level itself. Furthermore, the ranking of the lines on diet N was similar for weight gain, feed intake and feed efficiency. In generation 9 at 9 weeks of age, the ranking of the lines for fat percentage was equal to the ranking for weight gain in generation 7 on both test‐diets. The association between weight gain and protein or water percentage was less pronounced, particularly on diet R. These results suggest that the largest genetic improvement in growth rate is obtained when the protein content of the feed is the same in selection and production. However, when selection is carried out in one environment while the animals have to perform under conditions with varying nutrient protein contents, selection in an inferior environment may be advantageous.     

Perinatal maternal feeding with an energy dense diet and/or micronutrient mixture drives offspring fat distribution depending on the sex and growth stage

Maternal nutrition during pregnancy and lactation influences offspring development and health. Novel studies have described the effects on next generation obesity‐related features depending on maternal macro‐ and micro‐nutrient perinatal feeding. We hypothesized that the maternal obesogenic diet during pregnancy and lactation programs an obese phenotype, while maternal micronutrient supplementation at these stages could partially prevent these features. Thus, the aim was to assess the influence of a perinatal maternal feeding with an obesogenic diet enriched in fat and sucrose and a micronutrient supplementation during pregnancy and lactation on offspring growth and obese phenotypical features during life course. Female Wistar rats were assigned to four dietary groups during pregnancy and lactation: control, control supplemented with micronutrients (choline, betaine, folic acid and vitamin B₁₂), high‐fat sucrose (HFS) and HFS supplemented. At weaning, the offspring were transferred to a chow diet, and weight and fat mass were measured at weeks 3, 12 and 20. At birth, both male and female offspring from mothers fed the obesogenic diet showed lower body weight (?5 and ?6%, respectively), while only female offspring weight decreased by maternal micronutrient supplementation (?5%). During lactation, maternal HFS diet was associated with increased body weight, while micronutrient supplementation protected against body weight gain. Whole body fat mass content increased at weeks 3, 12 and 20 (from 16 to 65%) due to maternal HFS diet. Maternal micronutrient supplementation decreased offspring fat mass content at week 3 (?8%). Male offspring showed higher adiposity than females at weeks 12 and 20. In conclusion, maternal HFS feeding during pregnancy and lactation was associated with a low offspring weight at birth and obese phenotypical features during adult life in a sex‐ and time‐dependent manner. Furthermore, maternal methyl donor supplementation protected against body weight gain in male offspring during lactation and in female offspring also during juvenile period.     

人工饲料对草地螟消化酶活性及羧酸酯酶mRNA表达量的影响

通过对经验型筛选和正交试验优化出的饲料配方饲养的草地螟(Loxostege sticticalis)5龄幼虫中肠淀粉酶、蛋白酶、酯酶和脂肪酶4种消化酶进行活性测定。结果表明:饲料HG在蔗糖的添加量稍做改动后,其饲养效果更接近于草地螟天然食料灰菜(Chenopodium album);饲料12的淀粉酶、蛋白酶、酯酶和脂肪酶都与对照组相差较多,蛋白含量、脂类含量与糖类含量需做进一步的修正与试验。另外利用RT-PCR方法,通过研究人工饲料HG, 12及对照组H对草地螟羧酸酯酶基因转录水平的影响,从分子水平快速评价出饲料HG优于饲料12。研究结果为今后的草地螟人工饲养及饲料配方进一步改进提供了理论依据。     

稚蚕人工饲料中几种微量元素的添加效果

测定桑叶粉及基础饲料中钛、铁、硒、稀土元素的含量，分别为６１～９２、５２０～１０００、０．３８４、５．５ｍｇ／ｋｇ和３７、６５０～７１０、０．４１４、５．４ｍｇ／ｋｇ。在基础饲料中以６．７～５２．２ｍｇ钛／ｋｇ饲料剂量添加柠檬酸钛，对１～２龄蚕的生长发育未见有促进作用；以柠檬酸混合稀土、柠檬酸钟、柠檬酸镧形式向基础饲料中加入１７．４～１４１．６ｍｇ／ｋｇ饲料的混合稀土或其单体元素铈和镧，其生长发育没有促进而略受抑制。稚蚕饲料中添加１％磷酸高铁（相当于２４００ｍｇ／ｋｇ饲料），稚蚕期的生长发育有明显促进，促进程度随添加时间的延长而进一步加大，这种促进作用不是通过改变饲料适口性来实现的。     

人工饲料组成对BmNPV-Bm表达系统外源基因表达活性的影响

为进一步提高家蚕杆状病毒—家蚕 (BmNPV Bm)表达系统的表达活性 ,通过改变人工饲料中桑叶粉、大豆粉、玉米粉和水分的添加量 ,探讨了人工饲料的营养组成对BmNPV Bm表达系统外源植酸酶基因表达活性的影响。在大豆粉含量相同的条件下 ,植酸酶基因表达活性随桑叶粉含量的增加而降低 ,桑叶粉含量为 10 %时表达量最高 ;在桑叶粉含量相同的情况下 ,大豆粉含量为 35 %时表达量最高 ;饲料含水量以添加干物重的 1 9倍时表达量最高。外源基因的表达活性与蚕体重的生长表现出一致的趋势。     

Urea cycle metabolism: effects of supplemental ornithine or citrulline on performance, tissue amino acid concentrations and enzymatic activity in young pigs fed arginine-deficient diets

Two experiments were conducted with young pigs to determine the efficacy of ornithine (Orn) or citrulline (Cit) as precursors of arginine (Arg). In Exp. 1, pigs were individually fed an Arg-deficient, semipurified diet (.18% Arg) supplemented with .3% Arg or an equimolar quantity of Orn or Cit. Supplemental Arg or Cit increased rate and efficiency of weight gain, but Orn addition was without effect. Free Arg in plasma 3 h post-prandial was increased by addition of either Arg or Cit to the basal diet. Liver Arg was elevated by dietary addition of Arg, Orn or Cit; kidney Arg and Orn were elevated only in pigs receiving supplemental Cit. Arginine or Cit addition to the diet increased Arg concentration in muscle tissue, but muscle Orn was unresponsive to any of the supplements fed. In Exp. 2, pigs were again fed the Arg-deficient, semipurified diet supplemented with .3% Arg or four times an isomolar quantity of ornithine. Arginine addition to the diet increased weight gain and feed efficiency, while Orn supplementation was without effect. Plasma Orn was increased by excess Orn, while plasma Cit was unaffected by supplemental Arg or Orn. Moreover, excess Orn increased free Orn and proline (Pro) in liver, kidney and muscle. Free Cit, however, increased only in liver from feeding excess Orn. In addition, excess Orn decreased both plasma ammonia and free glutamine (Gln) concentration in brain. Arginase activity was roughly 10, 40 and 100 times greater in hepatic tissue than in renal cortex, renal medulla or intestinal mucosa, respectively, while hepatic ornithine transcarbamoylase (OTC) activity was about 15 times greater than the activity present in mucosa tissue. Renal OTC activity was too low to be accurately measured.