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1

Laying characteristics of one- and twoyear old pheasants (Phasianus colchicus, L.)

100%
Krystianiak S., Kontecka H., Nowaczewski S., Rosinski A.
|
2007
|
vol. 55
|
issue 1-2
65-72
EN
The aim of the study was to assess laying traits, the weight of eggs and characters of the laying rhythm of pheasants in the first and second years of reproduction. Pheasants (10 cockerels and 50 hens) were kept in aviaries. Daily, individual control of laying was performed beginning with the day of the first laying and ending with the last egg. The following parameters were evaluated: age at first laying, length of the laying period, number of laid eggs and the average weight of the egg in the 8th week of laying. The laying rhythm was also assessed and comprised: the number of egg clutches, the number of eggs in a clutch, the number of eggs in the longest clutch, the number of intervals, the length of intervals and the longest interval between clutches. During the first period of reproduction, in comparison with the second, pheasants laid slightly more eggs of similar average weight. The first laying period was longer than the second and was characterised by a greater number of egg clutches and greater number of intervals between clutches. The greatest number of eggs was laid in 10-egg and longer clutches, although the 1-egg clutches were the most numerous. A positive correlation was found between the number of eggs and the number of clutches, the greatest number of eggs in a clutch and the number of intervals between clutches. The similar values of the reproductive characters of one- and two-year old pheasants point to the possibility of longer utilization of these birds than only for one laying period. On the other hand, the considerable variability between the experimental hens with regard to the number and the length of egg clutches, as well as the intervals between them, indicate the possibility to carry out selection taking into account traits characterising the laying rhythm.
2
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Effects of growth hormone on neuroendocrine function

100%
Bartke A., Chandrashekar V., Steger R. W.
Acta Neurobiologiae Experimentalis
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1996
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vol. 56
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issue 3
833-842
EN
Although the role og growth hormone (GH) in the control of reproductive functions is not well understood, there is considerable evidence that the states of both GH deficiency and GH excess are typically associated with reproductive deficits.To identify the possible involvement of functinal alternations in the hypothalmic-pituitary system in producing these deficits, we are studying neuroendocrine function related to reproduction in transgenic animals overexpressing GH, in animals with congenital GH deficiency, and in animals with selective immunonoutralization of GH.The results indicate that GH acts on the hypothalmus to alter dopaminergic and noradrenergic control of prolactin and gonadotrophin release.Life-long elevation of GH levels outside the physiological range disrupts feedback control of luteininzing hormone (LH) relaese by gonadal steroids.Plasma LH and follicle-stimulating hormone (FSH) levels and feedback control of LH release are also abnormal in GH-deficient animals indicating that physiologival levels of endogenous GH are normally involved in the control of gonadotropin release.Differences between the effects of bovine vs.human GH in transgenic moce and differential effects of GH mechanisms involved in the actions of HG on the hypothalmic-pituitary system.
3

Associations between the prolactin receptor gene polymorphism and reproductive traits of boars

100%
Kmiec M., Terman A.
Journal of Applied Genetics
|
2006
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vol. 47
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issue 2
139-141
EN
The prolactin receptor gene (PRLR), located on chromosome 16 in pigs, is a candidate gene for reproductive traits. The experiment was aimed to detect the DNA mutations in this gene and to find probable relations between the genotype and some reproductive traits in boars. The polymorphism in the PRLR gene was identified by PCR-RFLP method using specific primers and the restriction enzyme AluI. In total 229 boars of various breeds were genotyped. The frequency of allele A was estimated at 0.62 and allele B at 0.38. Genotype AA was found at a frequency of 0.45, AB at 0.35 and BB at 0.20. We found associations between PRLR genotype and ejaculate volume, sperm concentration, percentage of live sperm, and number of live sperm in the ejaculate (P < 0.01).
4

Interferon and its immunological role in ruminant reproduction

88%
Chelmonska-Soyta A.
Archivum Immunologiae et Therapiae Experimentalis
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2002
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vol. 50
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issue 1
47-52
EN
Interferon tau (IFN-tau) is an key cytokine in maintaining pregnancy in ruminants. It is produced by the ruminant conceptus around the time of implantation. IFN-tau belongs to the type I interferon family but, unlike the other members of this group, it is not virus inducible and its expression is temporal and restricted to the trophoblast cells of the ruminant conceptus. The main target of the paracrine action of this cytokine is the endometrium. It changes the prostaglandin metabolism and secretory function of the cells by upregulating the secretion of several proteins. It also presents immunomodulatory action towards leukocytes by changing their proliferative responses and cytokine production. This cytokine activity in reproductive biology and immunology has been intensively explored for the last ten years. It has been regarded as a potential tool in improving the performance and biotechnological processes in ruminant reproduction. Additionally, its high antiviral potency and low cytotoxicity in comparison with IFN-tau has placed this cytokine in the group of possible therapeutics in human and animal medicine.
5

Reproduction biotechnology of farm animals

75%
Smorag Z.
Biotechnologia
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2002
|
issue 4
30-40
EN
This paper presents the most important research and application of biotechnology of farm animals reproduction: semen sexing, embryo in vitro production, embryonic and somatic cloning and transgenesis.
6

Application of reproduction biotechnology methods in animal biodiversity conservation

75%
Gajda B., Smorag Z.
Biotechnologia
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2007
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issue 4
55-65
EN
This article presents the potential and prospects for the use of selected reproduction biotechnology methods in animal biodiversity conservation programs. The first part focuses on biotechnological methods related to male reproduction such as artificial insemination, semen cryoconservation, sexing and spermatozoa sorting. The second part discusses biotechnological methods related to female reproduction such as superovulation, in vitro production and transfer of embryos, cryoconservation of oocytes and embryos, embryo sexing, cloning and transgenesis.
7

Achievements in biotechnology of animal reproduction over the past 20 years - case studies

63%
Smorag Z.
|
EN
Animal reproduction biotechnology is an area of fast development with possibilities of practical applications not only in breeding, but in pharmacy and biomedicine as well. Its growth has been achieved thanks to the results of last decades of the previous century in embryology, endocrinology, and molecular biology. The paper contains very brief description of the achievements of NRIAP Department of Animal Reproduction Biotechnology during the last 20 years in mammalian sex regulation, cryobiology of gametes and embryos, in vitro production of embryos, cloning and animal transgenesis.
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