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Evolution of litter size in hystricomorph rodents
Cingelová, Alexandra ; Dušek, Adam (advisor) ; Špoutil, František (referee)
The suborder Hystricomorpha is an ideal model group for the study of rodent life-history evolution due to its wide distribution, great diversity of inhabited ecosystems and social systems. By tracking several factors, it was possible to determine the key factors that influenced litter size during evolution. The data set contained 75 of the total 292 species of the suborder. The average litter size, female and male body size, level of sexual dimorphism, level of sociality, type of reproductive system, level of parental care, presence of multipaternity, type of habitat and food were assigned to each species based on the information obtained from the available literature. The analysis included a statistical part calculated using general linear mixed models, and a phylogenetic part including parsimonious mapping of characters onto the phylogenetic tree and linear regression using phylogenetic independent contrasts. Social factors like degree of sociality, sexual dimorphism and reproductive system significantly influenced litter size at birth. Multipaternity also had an influence, but less than the first three factors. Ecological factors, food and environment, had no effects unless they were combined with the effect of family. It is therefore possible to assume that ecological factors have influenced...
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Optimization of litter size in rodents
Cingelová, Alexandra ; Dušek, Adam (advisor) ; Sedláček, František (referee)
Optimization of litter size can be defined as adjustment of litter size according to actual environmental conditions or condition of mother to reach a compromise between the maximum number of offspring and their individual fitness. Rodents are an ideal taxon to study this topic because of their enormous interspecific variability in life strategies across the whole order. The variation in litter size among rodent species was influenced by countless ecological and social factors during their evolution. These include the geographical location of the breeding populations, various life and reproductive strategies such as r-/K-strategy, the presence of altricial or precocious offspring, various ways of life, the presence of water in the environment, predation rate, hibernation, and sociality. Litter size can be adjusted already before fertilization, for example by choosing a partner, by timing reproduction, condition, age and social status of the mother. Genetic factors affecting litter size are, for example, MHC glycoprotein polymorphism and t-haplotype. Reduction of the litter size may occur before insemination by influencing the ovulation rate, female reproductive hormone levels and exposure to the stressors, during implantation by selective abortion, and postpartum by infanticide, siblicide, and...
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Analýza reprodukčního potenciálu dospělých samic prasete divokého
Podlipná, Jiřina
Diploma Thesis focuses on adult wild boar females and analysis of their reproductive potential based on data obtained on drives during main reproduction period (August to January) at 30 areas of interest throughout the Czech Republic in years 2014–2017. Average value detection of Gonadosomatic Index (GSI) out of gravid female wild boars 0,0097 and out of all samples 0,0071. Rut period based on the age of fetuses is from October to January and expected dates of birth are determined by shifting the length of pregnancy towards the rut period with a peak in March. The litter size has just low correlation with the weight and very low with the age, average litter size in adult wild boar females is 6,1 youngsters for hoggets and 6,3 youngsters for wild sows. Average embryonic mortality reaches 13 %. The total sex ratio of piglets is 1:1,08 (M:F), the sex ratio of piglets for hoggets is 1:1,13 and for wild sows 1:1. The resulting finding of this analysis is, that there is no significant difference between the average litter size of hoggets and wild sows, so it is recommended to regulate the number of adult wild boar females year-round irrespective of age of the individuals.
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Vyhodnocení významu výživného stavu prasat divokých na jejich reprodukci
Miškeřík, David
The main aim of this thesis is to describe relationship between the physical state of wild boars and their ability to reproduce. The study is focused exclusively on wild boars of feminine gender. The sows were firstly examined in relationship to the certain biotope and consequently according to the particular age groups. The core of the research was to confirm or refute whether the litter size is influenced by nutrition of the sows. The samples of the research were gathered in various locations of the Czech Republic, mostly in Bohemia and in the surroundings of Brno. Subsequently, the samples were processed and analysed in a laboratory. The collected data were organized and statistically evaluated. Microsoft Excel was used for processing and graphical presentation of the given data. The outcome of the research confirmed the relation between age, amount of body fat and litter size. The thesis also proved that food abundance supports bigger litter sizes of wild boars.
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Problematika chovu vysoce plodných prasnic
Chudá, Magdalena
Bachelor thesis concerns with issues of highly fertile sows. The thesis describes the current level of reproduction of sows in the Czech Republic and its welfare implications. It also deals with specific factors affecting litter size such as sow nutrition and exposure to stressors, risk of giving birth to a large number of piglets, anatomy of the mammary gland of a highly fertile sow and the quality and quantity of colostrum and breast milk. The thesis is also focused on other chosen factors affecting the prosperity of piglets such as gestation and intrauterine crowding, placental nutrition, birth difficulties, low birth weight, and establishment of the teat order. Further more, the work describes methods of management of sow breeding and rearing piglets, which improve their lives and welfare. These include tooth reduction, split suckling, cross–fostering, nurse sow system, split weaning, supplementary feeding of milk and artificial breeding of piglets in incubators.
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Optimization of litter size in rodents
Cingelová, Alexandra ; Dušek, Adam (advisor) ; Sedláček, František (referee)
Optimization of litter size can be defined as adjustment of litter size according to actual environmental conditions or condition of mother to reach a compromise between the maximum number of offspring and their individual fitness. Rodents are an ideal taxon to study this topic because of their enormous interspecific variability in life strategies across the whole order. The variation in litter size among rodent species was influenced by countless ecological and social factors during their evolution. These include the geographical location of the breeding populations, various life and reproductive strategies such as r-/K-strategy, the presence of altricial or precocious offspring, various ways of life, the presence of water in the environment, predation rate, hibernation, and sociality. Litter size can be adjusted already before fertilization, for example by choosing a partner, by timing reproduction, condition, age and social status of the mother. Genetic factors affecting litter size are, for example, MHC glycoprotein polymorphism and t-haplotype. Reduction of the litter size may occur before insemination by influencing the ovulation rate, female reproductive hormone levels and exposure to the stressors, during implantation by selective abortion, and postpartum by infanticide, siblicide, and...
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