肉牛改良蒙古牛效果分析

上世纪70年代以来锡林郭勒盟先后引进安格斯、利木赞、夏洛来、西门塔尔等肉牛品种改良蒙古牛.分析测定了不同品种杂交一代公母牛及蒙古牛6月龄、18月龄和30月龄体重的变化规律.结果安蒙、利蒙、夏蒙、西蒙杂一代6月龄公母犊平均体重分别比同龄蒙古牛增加37.87 kg、40.60 kg、66.35 kg和43.71 kg,分别提高32.75%、35.11%、57.37%和38.0%.18月龄公母牛平均体重分别比同龄蒙古牛增加78.75 kg、96.73 kg、107.72 kg和100.59 kg,分别提高35.84%、44.02%、49.03%和45.78%.30月龄公母牛平均体重分别比同龄蒙古牛增加67.07 kg、84.86 kg、110.18 kg和116.26 kg,分别提高19.86%、25.13%、32.62%和34.42%.     

Crossbreeding parameters of general immune response traits in White Leghorn chickens

Crossbreeding parameters of immune response traits were estimated from a set of well characterized crossbred populations derived from three chicken lines selected over 12 generations for three different general immune response traits and their F1, F2 and backcrosses. The three traits investigated were the selection criteria from each of the lines, i.e. antibody response to the Newcastle disease virus vaccine 3 weeks after vaccination (ND3), cell-mediated immune response (response to phytohemagglutinin, PHA) and phagocytic activity measured as carbon clearance (CC). Crossbreeding parameters included direct and maternal additive line effects, direct and maternal heterosis as well as direct epistatic recombination loss. They were estimated as linear combinations of genetic group effects estimated using animal model methodology. Significant line differences were obtained for ND3 and, to a lesser extent, CC. They were mainly due to direct effects, maternal effects being significant for none of the 3 traits. Significantly negative direct heterosis effects were also observed for ND3 and CC, but not for PHA. Maternal heterosis effects were not estimated for CC. They were non significant for PHA, and negative and significant (− 0.78 ± 0.24) for ND3. The significant favourable recombination gain estimated for ND3 (3.21 ± 0.88) indicates that epistatic interactions could be important for this trait.The present work shows that it was worthwhile to complete second generation crosses to be able to assess to what extent immunity gained by selection is maintained in advanced crossbred generations, and to compare the transmission of immune traits implicated in different aspects of immunity.     

Crossbreeding effects for litter and lactation traits in a Saudi project to develop new lines of rabbits suitable for hot climates

A five-years crossing scheme involving the Spanish V line (V) and Saudi Gabali (S) rabbits was practiced to produce 14 genetic groups: V, S, 1/2V1/2S, 1/2S1/2V, 3/4V1/4S, 3/4S1/4V, (1/2V1/2S)², (1/2S1/2V)², (3/4V1/4S)², (3/4S1/4V)², ((3/4V1/4S)²)², ((3/4S1/4V)²)², Saudi 2 (a new synthetic line) and Saudi 3 (another new synthetic line). A total of 3496 litters from 1022 dams were used to evaluate litter size at birth (LSB) and weaning (LSW), litter weight at birth (LWB), litter weight at 21 d (LW21) and litter weight at weaning (LWW), pre-weaning litter mortality (PLM), milk yield at lactation intervals of 0–7 d (MY07), 0–21 d (MY021), 0–28 d (TMY) and milk conversion ratio as g of litter gain per g of milk suckled during 21 d of lactation (MCR021). A generalized least squares procedure was used to estimate additive and heterotic effects (direct, maternal, and grand-maternal).The comparison among V, S, Saudi 2 and Saudi 3 showed a complementarity between V and S. Line V was superior for LSB, LSW, LWB, PLM, MY07, MY021 and TMY, while line S was superior for the other traits (LW21, LWW and MCR021). Saudi 2 and Saudi 3 had the means equal to or higher than the founder lines (V or S) for all traits. Saudi 2 showed better values in litter size and pre-weaning litter mortality compared to Saudi 3 with no significant differences for the other traits. Concerning crossbreeding parameters, direct additive effects were significant for all traits, ranging between 12.3% and 31.8% relative to the average of the means of V and S. All estimates for direct heterosis except LWB and MCR021 were significant and ranged from 5.3% to 27.5%. No estimates for maternal additive effects and grand-maternal additive and heterotic effects were significant. Only estimates for maternal heterotic effects of LSB and LSW were significant (8.6% and 10.6%, respectively).     

紫色大白菜育种思路初探

应用大白菜与紫色小白菜亚种间杂交转育紫色性状,获得2份紫色大白菜中间材料。比较了转育获得的紫色大白菜与普通大白菜的外叶颜色、球内叶颜色以及包球的球色等。结果表明,转育紫色小白菜获得的紫色大白菜材料只在叶片的正面表现紫色,而叶片的反面依然表现绿色;剖开后的剖面表现为紫色、白色和黄色相间排列的几种颜色。研究认为,该类型的紫色材料可以在小白菜、半包球大白菜,如快菜类型和娃娃菜等紫色品种中应用,所育成的大白菜品种可以作为拼盘搭色时凉拌或做汤食用,效果会更佳。桔红心品种的VC含量在4种球色大白菜品种中最高。初步探讨了国内外紫色大白菜研究的育种思路和应用进展。     

引入皖西鹅的适应性及改良本地鹅的效果研究

本文阐述了引入皖西白鹅的适应性及杂交改良本地鹅的效果。结果表明,由安徽省引入吉林省的皖西白鹅能够适应引入地的饲养管理条件,与本地鹅杂交,改良的Ｆ１代增重比本地鹅提高３４．４％,毛重提高３２．６％,绒重提高２５．７％,受精率达８６％。     

日本盘鲍与皱纹盘鲍杂交育种技术研究

１９９８年于山东省蓬莱市用１０只日本盘鲍与３００只皱纹盘鲍,在２２０ｍ＾２的育苗水体中培育出平均壳长１４．７ｍｍ的杂交鲍苗１４３．８万只,６５００只／ｍ＾２,;在５８０ｍ＾２的育苗水体中培育出平均壳长１１．９ｍｍ的皱纹盘鲍自交鲍苗１７７．９万只,３１００只／ｍ＾２。杂交鲍苗的壳和存活率明显大于我国的皱纹盘鲍自交鲍苗。     

蓝身大斑石斑鱼冷冻精子(♂)与棕点石斑鱼(♀)杂交后代发育及生长特征分析

蓝身大斑石斑鱼(Epinephelus tukula)和棕点石斑鱼(Epinephelus fuscoguttatus)在自然环境中存在地理分布、繁殖时间和温度等方面的生殖隔离。本研究利用蓝身大斑石斑鱼冷冻精子与棕点石斑鱼卵人工授精,在水温为30℃、盐度为20的条件下培育,对其胚胎发育、胚后变态发育进行了详细的观察,利用显微镜和解剖镜拍摄、记录胚胎发育和变态发育的形态特征和发育时序,统计了杂交受精率、孵化率和畸形率,并对鱼苗生长进行了测量。结果显示,杂交受精卵经过1037 min完成胚胎发育。原肠早期,在胚层一侧就形成了胚盾,神经管在胚孔封闭时也开始出现,在视泡和耳囊发育的同时,克氏囊(末球)也开始形成。在心脏跳动之前,胚体先开始抽动,当977 min肌节发育到23对时,心脏开始间歇性的跳动,间歇时间24~40 s,心率98次/min;发育到1018 min时,间歇时间变短,心率约为93次/min;之后间歇性现象消失,心跳频率达到93次/min,这些现象在以往鱼类胚胎发育资料中均无记载。变态发育的典型特征是三叉棘的生长和退化,杂交幼鱼3 mm (10 d)时,形成背鳍棘和腹鳍棘;全长21.5 mm (35 d)时,三叉棘退化,完成变态发育;55.3 mm (45 d)时,表型特征与成体相似。冷冻精子的受精率、孵化率和畸形率分别为(76.67±5.77)%、(85.67±5.13)%和(6.33±1.54)%,与新鲜精子无显著差异(P<0.05)。鱼苗65 d时,体长达到8.89 cm,杂交后代体色趋于一致,且生长速度快;1龄时,平均全长和体重分别达(32.58±1.60) cm和(559.76±80.85) g。对比养殖实验显示,1龄棕点石斑鱼(♀)´蓝身大斑石斑鱼(♂)杂交后代体重是棕点石斑鱼(♀)´鞍带石斑鱼(♂)杂交后代的1.63倍,全长为1.24倍;这一时期的生长方程为W=0.0311L2.8079,R²=0.9886。研究结果表明,蓝身大斑石斑鱼和棕点石斑鱼杂交胚胎和胚后发育不存在遗传障碍,后代受精率和孵化率高、畸形率低,具有生长快杂交优势,为2种石斑鱼杂交育种和苗种大量培育提供了一定的遗传基础。     

Comparison of the performance of Holstein-Friesian and Jersey×Holstein-Friesian crossbred dairy cows within three contrasting grassland-based systems of milk production

The performance of spring calving Holstein-Friesian (HF) and Jersey×Holstein-Friesian (J×HF) dairy cows was examined during three successive years (mean of 35 HF cows and 31 J×HF cows per year). Throughout the experiment cows were managed on one of three grassland-based systems of milk production, namely low concentrate (LC), medium concentrate (MC) or high concentrate (HC). Post-calving, cows were housed and offered grass silage, supplemented with 6.0, 8.0 and 10.0 kg concentrate/cow/d in systems LC, MC and HC, respectively (mean period from calving to start of full time grazing, 69 days). During the grazing period target concentrate feed levels were 0, 2.5 and 5.0 kg/cow/d for systems LC, MC and HC, respectively (mean period from start of full time grazing to start full time re-housing, 206 days). Full lactation concentrate inputs were 530, 1092 and 1667 kg/cow, in systems LC, MC and HC, respectively. There were no significant genotype×system interactions for any of the milk production parameters examined. Food intake during the confinement and grazing periods was unaffected by genotype. Milk yield was highest with HF cows while milk fat and milk protein content were highest with the J×HF cows (P<0.001). Genotype had no effect on fat plus protein yield. Milk yield and fat plus protein yield were higher with systems MC and HC than with LC (P<0.001). HF cows were on average 44 kg heavier than J×HF cows, while the mean condition score of the J×HF cows was approximately 0.2 units higher than that of the HF cows (P<0.001). Live weight and condition score changes during the lactation followed similar trends with both genotypes. The J×HF cows had fewer days to first observed heat (P<0.05), a higher conception rate to first service (P<0.01), first plus second service (P<0.001), and a higher pregnancy rate at the end of the breeding season (P<0.05). Although mean somatic cell score was unaffected by genotype, the proportion of cows with one or more cases of mastitis was lower with the J×HF cows (P<0.05). In summary, while the J×HF cows had improved fertility performance compared to the HF cows, both genotypes exhibited similar levels of tissue mobilisation and deposition throughout the lactation, while there was no evidence of a genotype×grassland system interaction for any of the milk production parameters examined.     

杏鲍菇14号杂交菌株选育研究

用杏鲍菇9号菌株和11号菌株通过单孢杂交育种技术选育出杏鲍菇14号杂交新茵株。杏鲍菇14号杂交新菌株的子实体呈棍棒形，生物学效率达到84．64％。