种“鸡蛋”

记得小时候我可喜欢吃鸡蛋了。什么煮鸡蛋，炒鸡蛋，炖鸡蛋，百吃不厌，一天没蛋吃，我就吵得鸡犬不宁，爸爸妈妈也拿我没办法。

Research on the Behavior and Egg Fertilization Rate of Dwarf Layers and White Leghorn Chickens Fed in Floor-Rearing System

Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.

Evaluation of Immunomodulatory Activity of the Herbals Formula Viranur, Turmeric （Curcuma heyneana Val.） and Phyllanthus （Phyllanthus niruri L.） in Layer Chicken Vaccinated with Avian Influenza

The aim of this research was to know the effect of herbal as immunomodulator on chicken layer vaccinated with avian influenza. A total of 60 chickens were alloted into three treatment groups： control group （KA）, group KB and group KC, with 20 chicken each group. All the chickens were vaccinated with Newcastle disease （ND） in the age of one week, and a week later they were vaccinated with avian influenza （AI）. The chickens in group KB were drunken with herbal solution containing of 5 g turmeric （Curcuma heyneana Val.） and 25 g phyllanthus （Phyllanthus niruri L.） and group KC were drunken with herbal solution containing of 36 g the herbals formula Viranur and 25 g phyllanthus （Phyllanthus niruri L.）, respectively for four weeks. Thirty days after AI vaccinated, all of chicken were weighed and necropsied. Samples from bursa of Fabricius, tymus and spleen were taken for weighing and histopathological examination. The weight indexs of bursa of Fabricius, tymus and spleen were not significantly different between control group and treatment group in the considered statistically significance （P 〉 0.05）, but the treatment groups （KB and KC） had higher weight index. The histopathologically changes of spleen in both control group and treatment groups were not different, although in the group KC, in bursa of Fabricius, there was lymphocyte increase in its lymphoid follicles; and in the group KB and KC, the tymus were more widening in the cortex than medulla. The conclusion of this study showed that the herbals can stimulate lymphocyte activity.

Sexual size dimorphism and female reproduction in the white-striped grass lizard Takydromus wolteri

Sexual size dimorphism （SSD） has long attracted the attention of biologists, and life-history variation is thought to play an important role in the evolution of SSD. Here we quantified SSD and female reproductive traits to identify potential asso- ciations between SSD and female reproduction in the white-striped grass lizard Takydromus wolteri. In a population from Chuzhou, China, the largest male and female were 53.0 mm and 57.5 mm in snout-vent length （SVL）, respectively. Females were larger in SVL and abdomen length, whereas males were larger in head size and tail length. Females produced up to five clutches of eggs during the breeding season, with large females producing more clutches and more eggs per clutch than small ones. As a result, large females had a higher annual fecundity and reproductive output. Egg size was positively correlated with matemal SVL in the first clutch, but not in subsequent clutches. These results suggest that T. wolteri is a species with female-biased SSD, and that fectmdity selection, in which large females have higher fecundity due to their higher capacity for laying eggs, is likely correlated with the evolution of SSD in this species

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity （clutch size）, greater reproductive output （clutch mass） and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.

Recombinant canarypox virus expressing the VP2 protein of infectious bursal disease virus induces protection in vaccinated SPF chickens

Dear Editor,Infectious bursal disease virus（IBDV）causes infectious bursal disease,a highly contagious immunosuppressive disease that affects young chickens and causes economic losses in the poultry industry worldwide.IBDV replicates mainly in actively dividing B lymphocytes within the bursa of Fabricius（BF）,leading to immunosuppression in affected flocks（Mahgoub et al.,2012）.Viral protein 2（VP2）,