家鸡羽色性状遗传调控机制研究进展

自然界中鸟类呈现出丰富的羽毛颜色,羽色性状在躲避天敌、捕食、求偶及抵御紫外线等方面都具有重要作用。对鸡羽毛颜色性状的研究有助于加强品种区分、识别,在育种工作中建立品种间的显著标识和保障同一品种外观整齐尤为重要。羽毛颜色是禽类表型遗传研究的重要组成部分,它主要由黑色素和类胡萝卜素所决定。目前鸡羽毛颜色性状遗传调控机制的研究大多集中在黑色素相关通路,其中,Wnt、KIT/KITL和EDN3/EDNRB等信号通路对黑素细胞的生长发育、迁移和分化具有重要的调控作用,α-MSH/ASIP-MC1R信号通路负责调控黑色素的合成。已有研究显示,通过全基因组范围内的遗传变异检测技术挖掘与羽色性状相关的基因和变异位点,可以揭示黑羽、麻羽、显性白羽、隐形白羽、常染色体白化、银羽、性连锁不完全白化、深棕色羽、淡紫色羽(灰羽)、非依赖酪氨酸酶的隐性白羽、斑点羽和性连锁横斑羽(芦花羽)等多种羽色性状的遗传调控机制。此外,以图灵模型为理论基础可以解释复杂羽色图案的形成机制。作者通过总结黑色素相关调控通路与图灵模型对家鸡羽毛颜色性状的遗传调控机制,对近年来已经确定基因座的家鸡羽毛颜色性状相关研究展开综述,以期为鸡羽色分子机制研究以及在育种过程中开展鸡羽色性状标记辅助选择提供参考。     

黑色素皮质素受体1(MC1R)基因与鸟类羽色

鸟类羽色的表型跟黑色素皮质素受体1位点有很大关系,即MCIR(Melanocortin Receptor1,MC1R)。其位点基因不同,羽色也有一定的差异。本文将对MCIR基因的定位、突变、作用机理等做出相关内容阐述,并对其研究方向提出相关意见。     

固始鸡快羽系胫色、羽色与羽毛生长变化规律的研究

本实验对固始鸡快羽系胫色、羽色的变化规律及羽毛生长情况进行了观测。结果表明 :随着周龄的增加 ,胫色的变化是由浅色向深色转变 ;而羽毛则是由深色向浅色转变。固始鸡快羽系部分公鸡 6周龄已有明显的性征表现 ,此时羽色鲜艳、亮丽、鸡冠发育清楚可辨 ,公鸡羽色多为红棕黄羽。羽毛脱换情况为 :从 5日龄开始长尾羽 ,9日龄快羽鸡部分个体的颈部开始换羽 ,到 13日龄全部开始换羽 ,换羽顺序依次为尾、颈、胸、体干 (沿翅膀边缘两侧 )至背部。     

影响番鸭羽色性状的候选基因研究现状

番鸭羽色性状作为品种的特征备受育种者关注。了解番鸭羽色性状的遗传方式可以指导现场育种,而了解控制羽色性状的候选基因,可以为番鸭羽色性状的分子遗传学研究提供指导。番鸭羽色性状的分子遗传学研究结果又可以用于番鸭羽色的分子标记辅助选择。文章综述了可能与番鸭不同羽色性状相关的基因研究现状,可为番鸭羽色研究提供指导。     

黑羽灵山土鸡与黄脚麻鸡及广西三黄鸡杂交后代的羽色、胫色遗传规律研究

采用黑羽灵山土鸡分别与黄脚麻鸡、广西三黄鸡进行正反交交配,观察F1代羽色、胫色的表现。试验结果表明,黑羽灵山土鸡与麻鸡杂交的后代羽色以黑羽为主,同时存在一定比例的麻羽个体;与广西三黄鸡杂交的后代羽色较为杂乱,同时出现黑羽、黄羽和麻羽。胫色方面,黑羽灵山土鸡的黑色素只沉着于表皮,真皮层为黄色,与黄脚麻鸡、广西三黄鸡杂交后代的黑羽个体情况类似,证明控制黑羽灵山土鸡胫色性状的基因型可能为ZidZId、ZIdZId或ZIdW。     

黑化雉鸡羽色遗传的研究

通过黑化雉鸡 (Melanisticmuckedpheasant)和大型环颈雉鸡 (Jumboringneckedpheas ant)的正交和反交 ,以及F1 中进行自交 ,观察F1 和F2 中羽色性状的表现和分离比例。试验结果表明 ,黑化雉鸡羽色性状对于环颈雉鸡羽色的遗传方式是显性遗传 ,而且显性是完全的 ;黑化雉鸡羽色性状也由常染色体上一对等位基因M来控制的 ,并不存在显性致死现象     

番鸭的羽色突变及变异

到目前为止,番鸭羽色遗传变异已发现了10种.作者综述羽色突变与变异及其具体表现型,并对各种羽色的遗传方式加以分析.     

不同羽色鸽种MC1R基因的扩增与序列分析

黑素皮质素受体1(Melanocortin-1 Receptor,MC1R)是一种7跨膜结构G蛋白耦联受体,在鸟类羽色形成中起着重要作用。为探讨MC1R对太湖鸽特殊羽色形成的影响,本实验利用PCR和直接测序法对太湖鸽、乌鸽和白卡奴鸽MC1R基因编码区进行扩增,并对不同鸽种MC1R基因序列进行差异性分析。结果表明:鸽MC1R基因编码区全长942 bp,共编码313个氨基酸,存在7个跨膜结构;白卡奴鸽与乌鸽的MC1R基因编码区核酸序列基本一致,黑羽和棕羽太湖鸽的MC1R基因序列没有差异,而太湖鸽与其他2个鸽种分别于279bp(A>G)和520bp(G>A)处存在碱基差异,其中G520A造成了氨基酸(Ser174Gly)的改变,推测该位点突变与太湖鸽特殊羽色形成有关。     

罗斯商品代鸡初生雏的公母比例

罗斯鸡是由英国引进的蛋用型种鸡之一。四系杂交的罗斯棕壳商品鸡,其初生雏可观察背部和头部的羽色以鉴别公母(母雏为金黄色或棕色,公雏为银色或白色)。我们于1986年2月5日至7月6日在松江县种禽场采用羽色鉴别方法共测定了21批雏鸡,查明在172550羽出壳苗鸡中,有公雏96606羽,占55.98％;母雏75944羽,占44.02％。通过肛门鉴别检验,白色羽公雏中有2～3％左右实际是母雏,其羽色呈微淡黄     

优质肉鸡羽色遗传及选择

优质肉鸡羽色遗传及选择张细权，包世增（华南农业大学动物科学系广州５１０６４２）广东省优质肉鸡羽色基本上不是黄色就是麻色，其他羽色肉鸡通常都不被认为是优质肉鸡。对麻色或黄色的喜爱，各地有所不同。优质肉鸡强调的是肉质鲜美、有鸡味，它跟羽色没有多大关系。但...     

Plumage colour and feather pecking in laying hens,a chicken perspective?

1. This study investigated whether feather damage due to feather pecking and bird behaviour were influenced by plumage colour in Oakham Blue laying hens (black, white, grey colour variants). The reflectance properties of feathers and spectral composition of light environments experienced by the hens were also examined. 2. Nine hundred and seventy-nine birds were inspected and scored for feather damage; 10.5 h of video recordings were examined to record feather pecking and bird behaviour. Feathers and light environments were measured using a USB-2000 spectrometer and DH-2000-CAL-DTH lamp. 3. Oakham Blue birds with white plumage had less feather damage due to feather pecking than black or grey birds. There was more severe feather pecking in the mornings than in the afternoon. White birds feather pecked severely more than black or grey birds, although there were no other behavioural differences between plumage colours. 4. White feathers reflected at a higher intensity than black or grey feathers. However, black and grey feather spectra were relatively flat and the contribution of UV wavelengths to plumage reflection was proportionally greater than that for white feathers. 5. Light intensity inside a poultry house was 100 x (UW/cm2/nm) less than on the range and there was low or no UV reflectance. Under the dim, artificial lights inside a poultry house, Oakham Blue hens with black and grey feathers may be less visible to conspecifics than white birds because their plumage reflects at a lower intensity. Furthermore, the lack of available UV light inside vs. outside and the higher contribution of UV reflectance to black and grey plumage may make black and grey birds appear more different inside the house than white birds. It is possible that this novel/unusual appearance may make black or grey Oakham Blue hens more susceptible to feather pecking.     

Group size and plumage damage in laying hens

1. Ninety‐one Shaver 288 laying hens were kept in groups of 1, 2, 4 or 6 birds per cage and were provided with a floor space of 1300 cm² for the single birds and 650 cm²/bird for the groups. The overall damage to the plumage of each bird was assessed at monthly intervals from 18 to 72 weeks of age.

2. Most of the plumage damage occurred during the first 24 weeks after caging and was attributed mainly to mechanical abrasion between the birds’ bodies and their cages. Little additional deterioration in feather cover occurred between 45 and 72 weeks of age.

3. The plumage damage of single birds was always less than that of birds kept in groups.     

Feather pecking in groups of growing bantams in relation to floor litter substrate and plumage colour

1. As part of a programme investigating the causation of pecking damage in fowls, this experiment tested a proposal that birds may receive more feather pecks when their plumage colour contrasts with floor litter colour, because litter particles on plumage (as a consequence of dustbathing) may then have greater stimulus value. 2. Groups consisting of 7 light- and 7 dark-coloured bantams were reared from 1 to 11 weeks of age in pens with either wood shavings (light coloured, n=6) or peat (dark coloured, n=6) floor litter. 3. Feather loss from pecking commenced in the 3rd week of life and increased thereafter, but observed pecking damage scores were not consistent with the hypothesis being tested. 4. Despite many more pecks at birds being seen (over 10 weeks) in the wood shavings groups' (661 at particles on plumage, 1795 not at particles) than in peat groups (205, 787), there was no effect of litter substrate on pecking damage. The only evidence supporting the proposal was the finding that, in groups on wood shavings, significantly more pecks at particles on plumage were directed from light coloured birds towards dark ones, than from light to light, dark to light, or dark to dark. 5. Feather eating was confirmed from the presence of feather material in 2% to 15% of faecal droppings collected from each group at 11 weeks, but these proportions were not correlated with pecking damage scores. 6. The results imply that only some feather pecks/pulls were damaging and only some eaten feathers were pulled from other birds.     

Preen gland function in layer fowls: factors affecting preen oil fatty acid composition

1. Preen oil derived from the preen gland has previously been shown to differ in its composition between birds of different ages, sex and diet. As a part of a larger study on preening behaviour and its components, the relative percentages of fatty acids in preen oil were examined in laying hens that differed in age, beak trimmed status, feather pecking status (pecker and pecked) and method of sampling (either direct from the preen gland or from lipid extracted from feathers). 2. Five experiments are described. Fatty acids extracted from lipid were analysed by gas chromatography (GC). Fatty acid composition was affected by age, by whether or not a bird was feather pecked (but not if it was a feather pecker) and by lipid source. 3. Changes in preen oil composition with age (shown here) may be due to changes in circulating concentrations of hormones. Differences in preen oil composition between feather pecked and non-pecked birds may influence plumage odour and therefore taste, making the plumage of some birds more attractive to pecking than others. 4. The proportions of some fatty acids derived from feathers differed to those extracted from the preen gland. Lipid found on feathers is most likely a combination of that from the preen gland and from sebaceous secretions from the skin.     

贵州省鸟类新纪录——栗树鸭

2020年4月14日,在贵州省贵阳阿哈湖国家湿地公园保育区内(106°39′0.13″E,26°30′28.46″N,1107 m)开展鸟类监测,于浅水沼泽区拍摄到2只雁鸭类,经鉴定为栗树鸭(Dendrocygna javanica)。通过查阅相关文献,该种在贵州省的分布尚未记录过,属贵州省鸟类新纪录。本文对发现地概况、形态特征、生境特征和分布现状以及对该物种的保护进行了简要讨论。     

Thermal resistance of chicken (Gallus domesticus) plumage: a comparison between broiler and free-range birds.

1. We compared Ross chickens reared under broiler and free-range conditions to see whether there was a difference in thermal resistance of the plumage. 2. There was no difference in resistance to heat loss attributable to rearing environment for plumage from the back and leg but there was a significant difference in the pectoral region. 3. Free-range birds had a thicker plumage and a higher total resistance to heat transfer in the pectoral region, despite showing a lower resistance per unit depth than broiler birds. The pectoral plumage was more heavily soiled in broiler birds, which is the most likely explanation for the higher resistance per unit depth. 4. We suggest that behavioural selection of microclimate is likely to be a more important determinant of heat balance in free-range birds than intrinsic plumage adaptations.     

Effects of stocking density, flock size and management on the welfare of laying hens in single-tier aviaries

Management practices, stocking rate and flock size may affect laying hen welfare but there have been few replicated studies in commercial non-cage systems that investigate this. This study used a broad range of physical and physiological indicators to assess the welfare of hens in 36 commercial flocks. Six laying period treatments were examined with each treatment replicated 6 times. It was not possible to randomly allocate treatments to houses, so treatment and house were largely confounded. Three stocking rates were compared: 7 birds/m(2) (n = 2450), 9 birds/m(2) (n = 3150) and 12 birds/m(2) in either small (n = 2450) or large (n = 4200) flocks. In addition, at 12 birds/m(2), in both small and large flocks, birds were subjected to either standard (SM) or modified (MM) management. MM flocks had nipple drinkers and no nest-box lights. Bone strength, fracture incidence, heterophil:lymphocyte (H:L) ratio, live weight, organ weights, serum creatine, serum osmolality, muscle pH and faecal corticosterone were measured on samples of birds at the end of the rearing period and at the end of lay. During the laying period, mortality, production and integument condition were recorded at regular intervals. Birds housed at 9 birds/m(2) had higher mortality than birds housed at 12 birds/m(2) by the end of lay, but not higher than birds housed at 7 birds/m(2). Birds housed at 7 and 9 birds/m(2) had lower percent liver weight, and worse plumage condition than most of the 12 bird/m(2) treatments. Modified management tended to improve plumage condition. There were no clear effects of flock size on the welfare indicators recorded. At the end of the rearing period fracture incidence was almost negligible and H:L ratio was within a normal range. By the end of lay fracture incidence was 60% and H:L ratio was high, with no treatment effect for either measure. This, together with information on faecal corticosterone, feather loss and mortality, suggests that the welfare of birds in all treatments was relatively poor by the end of lay.     

Aviary Systems and Conventional Cages for Laying Hens: Effects on Production,Egg Quality,Health and Bird Location in Three Hybrids

Abstract

In two experiments, a total of 4346 laying hens housed in battery cages, with three hens per cage (C), and in two aviary systems, both with tiered wire floors and litter (Lövsta with two tiers (L) and Marielund with three tiers (M)), were used for studies on production, egg quality, health, plumage and foot condition, bone strength and bird location. Three hybrids were used: Lohmann Selected Leghorn (LSL) were kept in all three systems, Dekalb XL (DK) were kept in both aviaries and Lohmann Brown (LB) in M only. Production and feed conversion in M were inferior but not significantly different from C but significantly better than in L. Proportions of dirty eggs were significantly higher in the avaries. No significant differences were found in interior egg quality traits between keeping systems. LSL showed higher production and better feed conversion than the other hybrids and a tendency for a lower proportion of mislaid eggs. Mortality varied considerably between the aviary pens, reaching 35% in LB mainly owing to cannibalism and salpingitis. Keel bone lesions and bumble foot appeared in the aviaries, while toe pad hyperkeratosis was observed in C. Hens in aviaries had significantly stronger bones (tibia and humerus) and showed more wounds from pecks, inferior plumage condition and dirtier feet than in C. LSL had more bumble foot injuries than LB but better plumage condition than DK. The birds used the different parts in the aviaries well, especially the perches on the resting top tier during the night.     

Evaluation of a breast support conveyor to improve poultry welfare on the shackle line

A breast support conveyor has the potential to improve bird welfare by avoiding the need to invert and suspend broilers by their legs as they move from the point of shackling to entry into the electric waterbath. To evaluate its effect on welfare under commercial conditions, a breast support conveyor was installed under the conventional shackle line of a small poultry processing plant. A structured assessment of the behaviour of the birds indicated a significant decrease in struggling and wing flapping at the point of shackling, on the straight conveyor and at entry into the waterbath. This resulted in a lower prevalence of red wing tips and bruising in the first wing joint. The shackle line and conveyor in this installation, however, passed around a 90° corner, which appeared to cause more disturbance to the birds on the conveyor than to comparable birds suspended from shackles in the traditional manner. The results indicate that a breast support conveyor has the potential to improve bird welfare on straight shackle lines and that, because struggling activity and duration following shackling are reduced, the time between shackling and stunning could also be reduced using this method, further improving bird welfare. Breast support conveyors should not be used when the shackle lines have sharp bends.     

The genetic relationship of the dark, jubilee and white plumage colorations of the Indian Game bantam

The evidence derived from a genetical study of the plumage coloration of a stock of Indian Game bantams indicates that the three varieties differ one from the other in respect of the autosomal dominant gene 1. The Dark lacks the gene altogether, being ii in constitution, the Jubilee is heterozygous for it (Ii) and the White is homozygous (II). This gene is an incomplete dominant and affects the production of both black and red pigments, the black far more than the red. The degree of the density of the chestnut ground colour in the Dark and Jubilee varieties is determined by a number of modifying genes. It is possible by continued selection against this ground‐colour in the birds homozygous for the gene I to obtain a pure white bird, the white variety of the Indian (Cornish) Game.