引进肉用绵羊品种的杂交利用研究进展

文章综述了从国外引进优良肉用绵羊品种对国内不同地方绵羊品种杂交改良方面的研究应用情况,重点介绍了萨福克羊、杜泊羊、无角陶赛特羊、美利奴羊、特克塞尔羊等优良绵羊品种与我国不同地方绵羊品种杂交,其杂交后代在生长发育性能、产肉性能、胴体品质等方面的表现,旨在总结中国肉用绵羊的杂交改良工作,为推动中国肉用绵羊杂交改良,提高地方绵羊的生长性能和肉用性能,扩大我国肉羊的生产规模,促进我国畜牧业的健康发展和动物性肉食结构平衡提供借鉴。     

Assessment of potential trade‐off between maternal colouration and offspring quality in the ornamental “red cherry” shrimp Neocaridina davidi (Bouvier)

Maternal colouration based on carotenoids has been proposed to negatively affect offspring quality in several taxa, since females might trade off their limited carotenoid resources between body colouration and eggs. This study investigated in the ornamental “red cherry” shrimp (Neocaridina davidi) the relationship between maternal colouration and female reproductive performance, as well as offspring quality. Females selected displayed a broad array of body colour, from less coloured to intensely red coloured and were paired with transparent males. The first two spawning events of each female were studied and compared. The number of newly hatched juveniles was associated to maternal weight, but not to maternal colouration. Offspring quality was measured in terms of survival at the end of the 90‐day growth period, weight and length increment for 0–30 days and 30–60 days periods, and protein, lipid and glycogen contents in 30‐day‐old offspring. Yet, neither of these variables was associated to maternal colouration. These results indicate that there is no trade‐off between maternal colouration and offspring quality in this species. Furthermore, no association was found between maternal and offspring colouration, evaluated at a similar age. However, body colouration in 180‐day old females was significantly higher than in 90‐day‐old females, indicating that female colouration is strongly influenced by age.     

硒对母猪氧化应激及其后代抗氧化能力的营养调控研究

硒作为的重要微量元素之一,可以通过胎盘和乳组织进行转移。仔猪可以从乳汁中获取硒源,提高硒含量,进而提高仔猪的初生重。同时,硒也能够调节母猪妊娠期间代谢速度,控制妊娠期自由基产生,进而提高胎盘输送营养功能。文章从母猪氧化应激体系角度来解析硒对母猪妊娠期氧化应激的调控机制、硒对哺乳母猪生产性能的调控作用。     

The interaction between maternal and post‐hatch n‐3 fatty acid supplementation in broiler diets

This study investigated whether offspring from n‐3‐supplemented breeders have an enhanced performance and immune organ weight when fed a post‐hatch n‐3‐enriched diet in comparison with their control‐fed counterparts and the importance of timing of omega‐3 supplementation. Therefore, 480 Ross‐308 broiler breeder hens were fed one of four different diets (120/treatment). The control diet (CON) was a basal diet, rich in n‐6 fatty acids (FA). The three other diets were enriched in n‐3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA) or 2/1 (EPA). At 33 weeks of age, eggs were incubated to obtain 1440 offspring. They were set up according to their maternal diet and sex in 48 pens of 30 chicks each (12 pens per maternal treatment: six male and six female). Half of the offspring were given a post‐hatch control diet, whereas to other half received an n‐3‐supplemented diet. Zootechnical performance was followed for starter, grower and finisher phase, and at the end of each phase two, chicks per pen were sacrificed to determine the weight of the immune organs. No interaction was found between maternal and post‐hatch n‐3 treatment for zootechnical performance. An interaction arose between the maternal and post‐hatch n‐3 supplementation for proportional bursa weight at day 1 and day 14 and proportional liver weight at day 14, but effects on immune organ weight were rather limited. Offspring post‐hatch n‐3 supplementation did not enhance maternal n‐3 supplementation.     

苹果属无融合生殖SERKs基因家族的克隆和表达分析

本研究利用同源克隆法以苹果属平邑甜茶和杂种后代叶片为试验材料,克隆得到4个SERK基因家族片段,并分析了SERKs家族基因在平邑甜茶和杂种后代不同器官和组织中的表达情况。研究结果表明:分离获得的4个SERK基因家族片段的氨基酸序列与模式植物拟南芥、烟草等植物的同源性均在84%以上,同时与其他物种的氨基酸序列进行Blast比对都具有较高的同源性;RT-PCR定量分析结果表明SERK1、SERK2、SERK3、SERK4基因主要在生殖器官中表达。因此,推测SERKs基因在平邑甜茶和杂种后代生殖发育过程中起着重要的调控作用。本研究结果为进一步揭示无融合生殖的发生机理奠定了基础。     

建鲤自交及与黄河鲤正反杂交子代的生长比较和通径分析

以建鲤、黄河鲤为亲本,建立了建鲤自交JL(建鲤♀×建鲤♂)、正交JH(建鲤♀×黄河鲤♂)、反交HJ(黄河鲤♀×建鲤♂)3个试验组合,PIT标记后在养殖157、398、598 d时测定生长参数.结果表明:(1)157、398 d时增重率均为HJ>JH>JL,HJ与JL差异显著(P<0.05);598 d时JL>JH>HJ,子代差异不显著(P>0.05).(2)体长、体重的变异系数在157、398 d 时HJ>JH>JL,598 d 时JL>HJ>JH.体长的变异系数小于体重的变异系数.(3)肥满度随养殖时间增加而增长,JL的肥满度最高并与JH、HJ差异显著;(4)雌、雄鱼生长差异显著,雌鱼生长始终快于JL;雄鱼仅在157 d时有优势,398、598 d时杂种优势衰退.(5)在对体重的决定系数上,398 d时子代均以体长的决定系数占主导;598 d时HJ(♀)、JL(♀)中体高的决定系数占主导,JL(♂)、HJ(♂)、JH(♀)中体长的决定系数占主导,JH(♂)中体长、体高对体重的决定系数差异很小.(6)养殖时间对体重的差异显著性、绝对增重率无显著影响(P>0.05),对体长、绝对增长率、特定生长率、体重变异系数、生长指标及肥满度有极显著影响(P<0.01);鱼的不同交配组合和不同性别对上述生长参数均有极显著影响.     

Reproductive performance and offspring quality of Chinese mitten crab Eriocheir sinensis (H. Milne-Edwards) females fed an optimized formulated diet and the razor clam Sinonovacula constricta

After feeding female Eriocheir sinensis on an optimized formulated diet or fresh razor clam Sinonovacula constricta for 7 months, their reproductive performance and offspring quality were compared. To evaluate diet nutrient contents, the proximate, fatty acid and amino acid compositions of the formulated diet and the razor clam were analysed. The nutritional value of the diets was determined by assessing survival, gonadosomatic index (GSI) and hepatosomatic index (HSI) of female crabs from both diet treatments, together with the percentage of females that spawned, total egg production per female and fecundity (number of eggs g^?1 female wet weight). Furthermore, the quality of eggs and newly hatched larvae from the two dietary treatments were determined using the following parameters: egg diameter, wet weight and dry weight, hatchability, proximate and fatty acid profile of eggs, larval carapace length, resistant to starvation and osmotic shock, larval survival and development to the zoea II stage. Higher protein, phospholipids (PL) and amino acids (AA) contents were found in the razor clam while the formulated diet contains higher levels of ash, total lipid (TL) and 18:1n‐9, 18:2n‐6 and 22:6n‐3 fatty acids. Although female crabs fed the two different diets showed similar reproductive performances, newly hatched zoea I larvae produced by the crabs fed the formulated diet had significantly longer mean carapace length and shorter development time to the zoea II stage under identical culture condition (P<0.05). Moreover, dietary fatty acid appeared to have more significant effects on the fatty acid composition of the hepatopancreas than it did on mature ovaries or eggs. This suggests that the fatty acid profile of mature ovaries is indicative of the specific fatty acid required for ovarian development in E. sinensis. In conclusion, our results show that the optimized formulated diet developed in this laboratory can totally replace the razor clam, a broodstock food widely used in E. sinensis hatcheries in China. This encouraging result should facilitate more reliable hatchery production of this important aquaculture species.     

普通野生稻杂交后代抗白叶枯病鉴定筛选

为了从野生稻中发掘优异的水稻白叶枯病抗性材料,拓宽栽培稻抗白叶枯病遗传基础,达到控制水稻白叶枯病的目的,对合系35与元江普通野生稻远缘杂交后代不同世代的不同株系材料分年度进行了抗白叶枯病能力的鉴定和分析,并调查了后代材料对水稻白叶枯病的抗病能力,获得了一批高抗和中抗材料,为今后定位高抗白叶枯病基因以及水稻抗病育种提供了依据。     

Analysis of the Offspring Sex Ratio of Chicken by Using Molecular Sexing

The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.     

Effects of Maternal Dietary Energy Restriction on Fat Deposition of Offspring

The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breeders were studied. These female birds involved three experimental treatments and a control group with normal dietary energy diets （ND, 11.7 MJ of ME. kgt during the laying）. In treatments 2, 3 and 4, the energies of diets were 20%, 30% and 50% （LD20, LD30 and LD50） lower than those of the control, respectively. The study commenced at the beginning of the laying period when the total egg production reached 5% of the flock. All the broiler offspring were fed the same diets. The results showed that in low energy diets, offspring showed decreased 1-day-old weight, but 49-day-old weight was higher in LD20 diet （P〈0.05）. For offspring during days 1-49, the average daily gain （ADG） in LD20 group and the feed conversion ratio in LD50 group were improved as compared with those of the control （P〈0.05）. Compared with the control, abdominal fat percentage increased in 49-day-old offspring from LD30 diet （P〈0.05）; the fat content of breast muscle in offspring increased in broilers fed low energy diets （P〈0.05）. In 28-day-old offspring from breeders given LD20 and LD50 diets, liver fat percentages were higher compared with ND （P〈0.05）. The subcutaneous fat thickness in 28-day-old offspring from LD50 group and 49-day-old offspring from LD30 group was higher （P〈0.05）. On day 49, the serum cholesterol （CHO） of offspring from breeders fed LD20 diet and serum high-density lipoprotein （HDL） of offspring from breeders fed LD50 diet reduced compared with those of the control （P〈0.05）. In addition, a higher triiodothyronine （T3） content in serum was found in offspring from broiler breeders given LD20 and LD30 diets （P〈0.05）. Serum thyroxine （T4） in offspring significantly decreased with the decrease of diet energy （P〈0.05）. In conclusion, to a certain extent, dietary energy restriction in breeders could improve growth performance and promote lipid metabolism of offspring.