Pre‐pubertal growth,muscle and fat accumulation in male and female sheep—Relationships with metabolic hormone concentrations,timing of puberty and reproductive outcomes

Metabolic homeostasis is aligned with changes in growth and body composition, through processes mediated by circulating metabolites and metabolic hormones, and is eventually linked to reproductive success. In the present study with sheep, we determined the relationships among phenotypic and genotypic rates of growth, muscle and fat accumulation, and the circulating concentrations of metabolic and tested for relationships with the timing of puberty and subsequent reproductive outcomes. We used 64 females and 62 males with known phenotypic values for depth of eye muscle (EMD) and fat (FAT) and known Australian Sheep Breeding Values at post‐weaning age for live weight (PWT), depth of eye muscle (PEMD) and depth of fat (PFAT). Blood plasma sampled every 20 min for 8 hr via was assayed for growth hormone (GH), insulin‐like growth factor I (IGF‐I), insulin, leptin, ghrelin, follistatin, glucose and non‐esterified fatty acids (NEFA). In males, PWT was positively related to the concentrations of GH, follistatin and glucose, whereas FAT and PFAT were positively related to IGF‐I concentrations (p < .01). Testosterone concentration was negatively related to muscle variables (p < .001) and to PFAT (p < .05). In females, the only significant relationship detected was the positive link between EMD and insulin concentrations (p < .05). Reproductive variables were only measured in females. Live weight at first oestrus was related positively to insulin concentration and negatively to GH concentration (p < .05). No other relationships with reproductive variables were significant. The relationships that were detected suggest subtle differences between the sexes in the way their metabolic homeostasis responds to changes in the rates of growth, and muscle and fat accumulation, perhaps due to interference by testosterone in the males.     

种公猪精液伪狂犬病野毒的筛查

本文基于1 100头基础母猪的规模化场进行公猪精液伪狂犬病病毒筛查,农业部规定伪狂犬病病原学检测方法是通过ELSIA方法检测猪伪狂犬病gE野毒抗体。由于抗体检测具有滞后性,导致正在发生感染的猪群g E抗体检测往往呈阴性,但此时通过病原学检测精液已经正在排毒。本文互补了ELSIA抗体检测方法与荧光定性PCR检测病原的优劣,成功实现种公猪精液伪狂犬病病毒的筛查。     

不同犊牛培育方法对育成母牦牛生长发育的影响

采用不同犊牛培育方法,分别考察对传统饲养条件和高效繁育技术条件下对后代公犊牛及育成母牛生长发育的影响。研究结果表明:与传统对照组相比,犊牛培育组犊牛成活率达到97.23%,犊牛培育组的成活率、初选合格率、复选合格率和定选合格率分别为91.67%、80.56%和77.78%,分别比传统对照组提高12.90%、13.79%、11.54%和27.26%,差异显著(P<0.05)。犊牛体高、体斜长、胸围、管围及体重显著提高,差异显著(P<0.05)。采用犊牛培育技术,后代犊牛及育成牛生长发育各项指标较对照组明显增加,有效提高牦牛种母牛培育合格率,从而为建立优良种母牛核心群提供一条切实有效的生产途径。     

Use of field records and competition results in genetic evaluation of station performance tested Swedish Warmblood stallions

The main objective of this study was to investigate possibilities to increase accuracy in the selection and test of Swedish warmblood stallions by combining information from stallion performance tests (SPT) with information from competitions and riding horse quality tests (RHQT). Data on 801 stallions judged at the SPT 1979–2005 were used for the analyses, which also included about 14 900 horses from the RHQT, 26 800 horses with results in show jumping and 14 200 horses with results in dressage competitions.Heritability coefficients were on average 0.41 for individual gaits under rider and 0.36–0.65 for jumping traits in SPT. Heritabilities for competition traits were 0.17 for dressage and 0.27 for show jumping. The heritability for overall conformation in SPT was 0.25. Genetic correlations between stallion performance test traits and competition results were 0.44–0.77 for gaits and dressage, and 0.78–0.96 for jumping traits in SPT and show jumping. The genetic correlation between conformation and results in dressage competitions was 0.22.For stallions participating in SPT in 2004 and 2005 accuracy increased when evaluating stallions by adding information from relatives that have taken part in RHQT and competitions. For show jumping accuracy changed from 0.60 to 0.68 for stallions born in Sweden, an increase with 13%, when information from RHQT and competitions in show jumping were used. For stallions born in a foreign country, the corresponding figure was, 5%, lower. For dressage the information from RHQT and competition results in dressage changed the accuracy from 0.41 to 0.55, an increase with 34%, for stallions born in Sweden. The improvement in accuracy for imported stallions was 11%.     

Study of long-distance movement of Plum pox virus (Sharka) as an alternative resistance-evaluation method in Prunus

During the breeding programs for Plum pox virus (PPV, Sharka) resistance in Prunus, the evaluation of the new releases through symptoms observation on leaves has been contradictory and represents one of the main handicaps in these programs. In order to increase the accuracy of this traditional evaluation method, we here analyze an alternative method based on the study of the ability of a genotype to allow the long-distance movement of the virus through its vascular vessels. Two different plant models have been assayed: (a) in Model I, the inoculation was performed in the ‘GF305’ rootstock with a later grafting of the genotype under evaluation and a scion of healthy control ‘GF305’, to evaluate the long-distance movement through the studied genotype from the rootstock to the scion (xylem transport), and (b) in Model II, the inoculation with ‘GF305’ diseased scions was performed by grafting these diseased scions onto the studied genotypes, which were grafted onto healthy ‘GF305’ peach seedlings, to evaluate the long-distance movement through the studied genotype from the scion to the rootstock (phloem transport). The results show that, regardless of the presence of symptoms, susceptible genotypes allowed the movement of the virus through their vascular vessels in both directions studied. However, the resistant apricot ‘Stark Early Orange’ did not allow this movement. We propose the study of the ability of a genotype to allow the long-distance movement of the virus as an alternative and more accurate method for the evaluation of PPV resistance. However, this protocol is much more tedious than the traditional one and could be used mainly in the evaluation of a reduced number of more interesting genotypes.     

DNA and morphological diversity of selected Greek tomato (Solanum lycopersicum L.) landraces

Utilizing inter-simple sequence repeats (ISSRs), the genetic diversity of 33 Greek tomato (Solanum lycopersicum L.) landraces and three cultivars, three cherry tomato (S. lycopersicum var.cerasiforme) cultivars and two accessions of Solanum pimpinellifolium L. was studied. Furthermore, 12 ISSR primers were also used to identify 27 morphotypes derived from 7 landraces. Based on Jaccard's coefficient, an average genetic similarity of 0.797 (ranged from 0.56 to 0.95) was found among the accessions. Cluster analysis using the UPGMA method placed all tomato landraces and cultivars into a single group, while the cherry hybrids and the S. pimpinellifolium accessions were placed in a second group. The ISSR data distinguished all the 27 morphotypes from each other and grouped the morphotypes derived from the same landrace together. The ISSR technology proved useful in describing genetic diversity among Greek tomato landraces and was capable of distinguishing the closely related morphotypes.     

上海动物园斑嘴环企鹅繁殖数据相关性分析

根据2008～2018年上海动物园斑嘴环企鹅种群的繁殖数据,运用双变量相关性分析的方法,分析入孵数、受精数和出雏数的相关性。研究结果显示:入孵数与受精数相关系数为0. 432(P <0. 05);入孵数与出雏数相关系数为0. 447(P <0. 05);受精数与出雏数相关系数为0. 895(P <0. 01),呈现显著正相关性。其中入孵数与受精数以及入孵数与出雏数在0. 05水平(双侧)上显著相关,相关程度为中等相关;受精数与出雏数在0. 01水平(双侧)上极显著相关,相关程度为强相关。分析得出:入孵数与受精数以及入孵数与出雏数在变化趋势上有同步性,但是并没有必然因果关系,而出雏数主要取决于受精数,受精数直接影响出雏数,根据分析结果对上海动物园圈养斑嘴环企鹅种群发展制定相应措施。     

案例教学法在家畜育种学教学中的应用

分析了家畜育种学教学过程中存在的问题和案例教学法在教学中的作用。采用最新研究成果,精心挑选科研团队培育的新品种作为教学案例,讨论了案例教学法在家畜育种学课程中的实施过程和应用效果。     

小麦新品种洛麦22的选育及对育种启示

小麦新品种洛麦22由洛阳农林科学院选育,具有高产、广适、品质优良、商品性好等特点,2008年通过河南省农作物品种审定委员会审定,得到河南省科技成果转化资金项目资助,并已成为河南省主推小麦品种。介绍了其选育经过、主要特点及对小麦育种的启示。