Avian and Poultry Biology Reviews 16 (2), 2005

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Advances in DNA Analysis by RAPD Methodology in An Avian Species with Little Available Sequence Information: the Red-Legged Partridge (Alectoris rufa)

Cristina B. GarcõÂa and Maria Victoria Arruga*

Laboratorio de CitogeneÂtica y GeneÂtica Molecular, Facultad de Veterinaria, Miguel Servet, 177. 50013. Zaragoza, Spain

ABSTRACT

Although there have been many recent advances in chicken genomics there are still many avian species with little available sequence information. RAPDs are generated by applying the polymerase chain reaction (PCR) to genomic DNA samples using randomly constructed oligonucleotides as primers. In the present study, RAPDs has been used to gain a better understanding of the genomic DNA of the red-legged partridge. Multiple bands per reaction are generated and band patterns of the different species were compared using a software for image analysis.The similarity between these species was estimated by calculating the band sharing index. We conclude that this methodology can successfully be used to differentiate red-legged partridges, other partridges of the same genus Alectoris, and even their hybrids

Keywords: red-legged partridge, DNA analysis, RAPD

The Chicken Electroretinogram with Special Reference to

Spreading Depression

T. Ookawa

Formerly: Department of Physiology, Gifu University School of Medicine, Gifu, Japan

ABSTRACT

A phenomenon of spreading depression (SD)was first defined by Lea¬ o (in1944) in the exposed cortex of the dorsal surface of the rabbit's cerebral hemisphere.The retinal SD resembles electrophysiologically Leao's SD in many respects. However, there is noticeable difference between the cerebral and retinal SD. Namely, the retinal SDis characterised by a ``milky wave'' that moves across the surface of the isolated retina in toads. Furthermore, the optical changes (milky waves) accompanying SD appear to the naked eye after stimulation of the isolated chick retina.

Recent studies on the electroretinopram (ERG) of the chicken have demonstrated that they are essentially similar to those of mammals, including man. Moreover, SD in the isolated chicken retina has been extensively studied and has provided much information into the nature of the retina. On the other hand, investigations into the ERG and isolated retina of the chicken have been limited. More detailed study on the correlation between the ERG of the isolated chicken retina and SD is needed.

Keywords: chicken, electroretinogram, isolated retina, cerebral and retinal spreading depression

Interactions Among Endocrine, Nutritional and Genetic Factors
Controlling Metabolism in the Broiler

R.W. Rosebrough*, J.P. McMurtry, M.P. Richards, A.D. Mitchell, T.G. Ramsay, and C.M. Ashwell

Growth Biology Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture-Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA

Mention of a trade name, proprietary product or vendor does not constitute a guarantee or warranty of the product by USDA or imply its approval to the exclusion of other suitable products or vendors.

ABSTRACT

Birds have the ability to store large quantities of excess energy in liver, adipose tissue and in the yolk of developing oocytes. Lipogenesis takes place primarily in the liver of birds and involves a series of linked, enzyme-catalyzed reactions comprising glycolysis, the citric acid cycle and fatty acid synthesis. Hepatic lipogenesis is subject to both nutritional and hormonal control. Adipose tissue serves primarily as a storage site for lipid, especially in the form of triglycerides with little lipogenesis occurring in this tissue Lipid accumulation by adipose tissue and the developing oocyte depends on a plasma lipid supply derived from hepatic lipogenesis as well as lipid absorbed from the diet. Hepatic lipogenesis and the export of lipid are crucial steps linked to fat accretion and oocyte growth and maturation (yolk formation) in egg-laying hens. The nutritional state of the bird, as determined by the amount and composition of feed consumed, dramatically affects heptic lipid metabolism. Variations in nutrient intake are communicated to the liver and other internal organs by alterations in the levels of hormones that respond to dietary changes.

The present studies of changes in the levels of key metabolic hormones and hepatic expression of genes that code for selected lipogenic enzymes, lipid transport proteins, and uncoupling protein are important because they add to our understanding of the relationship between nutritional state and lipid metabolism, specifically as it relates to growth, body composition and reproductive performance in broiler chickens.

Keywords: hepatic lipogenesis, metabolic hormones, endocrine system, nutrition, broiler

Day-old Chick Quality: Relationship to Hatching Egg Quality, Adequate Incubation Practice and Prediction of Broiler Performance

K. Tonaa, V. Bruggemana, O. Onagbesana*, F. Bamelisa, M. Gbeassorb, K. Mertensa and E. Decuyperea

aLaboratory for Physiology and Immunology of Domestic Animals, Department of Animal Production, Faculty of Agricultural and Applied Biological Sciences, Catholic University of Leuven, Belgium; bUniversite de LomeÂ, Faculte des Sciences, LomeÂ, Togo

ABSTRACT

The weight and quality of the broiler chicks that emerges fromthe egg depend on several factors, whichmay include the broiler breeder age, egg storage conditions before incubation, and the incubation conditions. Several studies have determined the effect of some of these influencing factors on broiler chick hatching weight with little attention to post-hatch broiler performance. Chick physical quality had received little attention but recently, it has become apparent that the quality of broiler chicks may be linked to the history of the hatching eggs as well as the potential post-hatch performance of the broiler to slaughter age. It has therefore become important to develop universally accepted methods for measuring chick quality. Previous methods for evaluating chick quality relied heavily on hatching weight. Recently, methods for determining and quantifying chick quality based on physical appearance were reported. Physical parameters for determining chick quality were defined and scored according to the level of anomaly in the parameters. Also, the potential influence of these parameters on post-hatch performance was reported. This paper reviews the different methods available for measuring chick quality. The different methods are discussed in the context of the parameters for determining chick quality and the factors that may affect it. These include pre-incubation and incubation factors such as age of breeders, egg storage, temperature, relative humidity, and turning requirements. All these factors have implications on chick embryo physiology and development and consequently on the quality of the hatched chick. The potential application of chick quality measurement for predicting performance to slaughter is also discussed.

Keywords: chick quality, chick weight, egg quality, pre-incubation factors, incubation factors, growth potential