Reproduction de : Thèse d'exercice : Médecine spécialisée : Nancy 1 : 2002. / Thèse : 02NAN11018. Titre provenant de l'écran-titre.

<p>The legally binding international declaration of the Convention on Biological Diversity (signed by over 180 countries) recently acknowledged the importance of conserving genetic diversity within livestock species. This study aimed to help Canada assess molecular diversity in its horse and pony (<i>Equus ferus caballus</i>) genetic resources. Here, 24 populations were examined, with special focus on the native Canadian, Mountain and Moorland, and Nordic pony populations, using two well accepted molecular tools. Additional horse breeds and feral populations were also included in this project as some may have influenced the development of the three equine groups of interest. Altogether, 821 individuals were genotyped at 38 microsatellite loci, and 280 individuals were sequenced using a 421 base pair portion of the mitochondrial displacement Hypervariable Region I.</p> <p>Results from the microsatellite analyses indicated that 13.33% of genetic diversity arose from breed differences, whereas 84.60% and 2.07% of diversity arose from within and among individuals respectively. The New Forest and Welsh breeds were found to be the most diverse while having the highest average effective number of alleles and allelic richness (4.31 and 6.01; 4.33 and 5.87 respectively). The Eriskay and Lac La Croix breeds were found to have the lowest average effective number of alleles and allelic richness (2.51 and 3.98; 2.83 and 4.01 respectively). Expected heterozygosities were lowest in the Lac La Croix (0.61) and highest in the Welsh and New Forest (0.74) breeds, whereas observed heterozygosities were highest in the Kerry Bog (0.77) and lowest in the Exmoor (0.57) breeds. The genetic structure and admixture analyses suggested that the most probable number of unique genetic clusters was 21 as opposed to the 24 predefined populations.</p> <p>Results from the mitochondrial sequence data revealed that there were 36 informative sites producing 62 haplotypes, 20 of which were previously unreported. The Connemara was found to have the highest haplotype diversity of the pony breeds (0.89); however, the Highland pony was found to have the highest nucleotide diversity and pairwise difference (0.16 and 6.73 respectively). In contrast, the Fell pony had the lowest haplotype diversity (0.22), and the feral Sable Island population had the lowest nucleotide diversity and pairwise difference (0.01 and 0.29 respectively). Multiple phylogenetic trees were reconstructed and produced similar topologies. In general, the Mountain and Moorland and Nordic breeds were spread among the clades, whereas native Canadian populations were most frequent in the D and E clades. Interestingly, a large portion of ponies were found within the rare E clade as opposed to horses.</p> <p>Information gathered from this project can be incorporated with other available data into pre-existing conservation/breeding programs currently managed by the various breed societies to ensure that the most optimal and sustainable strategies are in place.</p>

<p>The legally binding international declaration of the Convention on Biological Diversity (signed by over 180 countries) recently acknowledged the importance of conserving genetic diversity within livestock species. This study aimed to help Canada assess molecular diversity in its horse and pony (<i>Equus ferus caballus</i>) genetic resources. Here, 24 populations were examined, with special focus on the native Canadian, Mountain and Moorland, and Nordic pony populations, using two well accepted molecular tools. Additional horse breeds and feral populations were also included in this project as some may have influenced the development of the three equine groups of interest. Altogether, 821 individuals were genotyped at 38 microsatellite loci, and 280 individuals were sequenced using a 421 base pair portion of the mitochondrial displacement Hypervariable Region I.</p> <p>Results from the microsatellite analyses indicated that 13.33% of genetic diversity arose from breed differences, whereas 84.60% and 2.07% of diversity arose from within and among individuals respectively. The New Forest and Welsh breeds were found to be the most diverse while having the highest average effective number of alleles and allelic richness (4.31 and 6.01; 4.33 and 5.87 respectively). The Eriskay and Lac La Croix breeds were found to have the lowest average effective number of alleles and allelic richness (2.51 and 3.98; 2.83 and 4.01 respectively). Expected heterozygosities were lowest in the Lac La Croix (0.61) and highest in the Welsh and New Forest (0.74) breeds, whereas observed heterozygosities were highest in the Kerry Bog (0.77) and lowest in the Exmoor (0.57) breeds. The genetic structure and admixture analyses suggested that the most probable number of unique genetic clusters was 21 as opposed to the 24 predefined populations.</p> <p>Results from the mitochondrial sequence data revealed that there were 36 informative sites producing 62 haplotypes, 20 of which were previously unreported. The Connemara was found to have the highest haplotype diversity of the pony breeds (0.89); however, the Highland pony was found to have the highest nucleotide diversity and pairwise difference (0.16 and 6.73 respectively). In contrast, the Fell pony had the lowest haplotype diversity (0.22), and the feral Sable Island population had the lowest nucleotide diversity and pairwise difference (0.01 and 0.29 respectively). Multiple phylogenetic trees were reconstructed and produced similar topologies. In general, the Mountain and Moorland and Nordic breeds were spread among the clades, whereas native Canadian populations were most frequent in the D and E clades. Interestingly, a large portion of ponies were found within the rare E clade as opposed to horses.</p> <p>Information gathered from this project can be incorporated with other available data into pre-existing conservation/breeding programs currently managed by the various breed societies to ensure that the most optimal and sustainable strategies are in place.</p>

Since changes in chromosome morphology contribute to the knowledge of evolution as well as to chromosome dynamics, this study looks specifically at one chromosome compared in twelve different species of Perissodactyls: Equus caballus (ECA), E. przewalskii (EPR), Equus africanus somaliensis (EAF), E. asinus (EAS), E. hemionus onager (EHO), E. h. kulan (EHK), E. h. kiang (EKI), E. zebra hartmannae (EZH), E. grevyi (EGR), E. burchelli (EBU), Tapirus indicus (TIN), and Rhinoceros unicornis (RUN). While chromosome morphology studies have been done in some of the extant equids, none have followed the evolution of this chromosome, homologous to Equus caballus chromosome 20 (ECA20), which contains the major histocompatibility complex (MHC). The gene order on the chromosome arm homologous to human chromosome six in most Equidae is reversed with respect to the centromere in comparison to humans. Multicolor fluorescence in situ hybridization was used to show that four probes from ECA20 hybridized to ECA20 (control), SWA5, EAS8, EHO16, EHK14, EKI16, EZH10, EGR11, EBU13, TIN4, and one of RUN12, 14, 15, or 22. The order for the four genes in the horses, zebras, and rhinoceros were as follows: cen-EDN1-MHC-ITPR3-MUT. Hybridization to the ass and tapir chromosomes displayed a possible neocentromere formation. It is apparent the chromosome has gone through several morphological changes while undergoing speciation in the Equidae, yet the overall gene order is conserved.

O Brasil possui cerca de uma dezena de raças de cavalos sendo essas classificadas em locais ou comerciais. As raças que aqui se naturalizaram são descendentes dos animais trazidos pelos portugueses e espanhóis na época da colonização. Cerca de 500 anos após sofrer seleção natural e artificial esses cavalos adquiriram características próprias capazes de se adaptar a ambientes adversos, escassez de alimento, doenças, influência do homem e cruzamento indiscriminado com raças exóticas. Assim, surgiram raças típicas brasileiras dotadas de peculiaridades importantes para as regiões em que vivem. Com isso, o objetivo principal deste trabalho foi o de estimar a variabilidade genética em quatro raças brasileiras de cavalos (Brasileiro de Hipismo, Crioulo, Mangalarga e Pantaneiro) por meio do marcador de DNA microssatélites. Foram utilizados 10 loci de microssatélites que amplificaram para as quatro raças. Em um primeiro estudo, foi estimada a variabilidade genética em 227 animais de três fazendas da região do Pantanal. Um total de 91 alelos foi encontrado. A probabilidade de exclusão de paternidade (PE) para as três amostras conjunta ficou em torno de 99,3%. O conteúdo de informação polimófica (PIC) foi alto, considerado altamente informativo. Os valores de Fis revelaram alto índice de homozigose nas três populações. Pôde-se verificar, por meio de baixos valores de Fst, baixa estruturação para as amostras estudadas sugerindo pouca diferenciação entre as mesmas. Foram utilizados três métodos para detectar gargalo de garrafa. Os resultados sugerem que os animais das fazendas estudadas não passaram por um processo de declínio populacional recente, mas que provavelmente animais da Fazenda Nova Esperança estariam passando por um processo de estruturação. Um outro estudo de variabilidade genética incluiu, além da raça Pantaneira, outras três raças brasileiras de cavalos: Crioulo, Brasileiro de Hipismo (BH) e Mangalarga. Os mesmos 10 loci de microssatélites também foram utilizados. Todos os loci amplificaram nas quatro raças, com a exceção de AHT17 em BH e Mangalarga. A raça que apresentou maior variabilidade alélica foi a Pantaneira (n = 91) seguida pelas raças Crioula (n = 81), BH (n = 57) e Mangalarga (n = 41). O coeficiente de endogamia (Fis) apresentou valores altos para as quatro raças. Por meio da estimativa Fst pôde-se inferir que a raça Mangalarga é a mais divergente entre as raças estudadas. Através do programa Structure, foi observado que Pantaneiro, Crioulo, Brasileiro de Hipismo e Mangalarga estão estruturadas em quatro distintas raças. / Brazil has around ten horse breeds, which are classified as local or commercial horses. The breeds established here are descendant from the animals brought by the Portuguese and Spanish colonization. After 500 years of natural and artificial selection, these horses acquired their own adaptive characteristics to adverse environments, lack of food, diseases, human influence, and random breeding with exotic breeds. Thus, the main objective of this work was to estimate the genetic variability of four Brazilian horse breeds (Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga) by microsatellite markers. Ten microsatellite loci have been used and amplified in the 4 breeds. On a first study, the genetic variability was estimated in 227 animals from three farms around the Pantanal region. A total of 91 alleles were found. The paternity exclusion probability (PE) to all 3 samples was around 99.3%. The polymorphic information content (PIC) was high, and considered to be informative. The Fis values showed high levels of homozygosity in all three populations. It was verified, through the low values of Fst, low structure of the samples studied, suggesting slight differentiation among them. Three methods to detect the bottleneck effect have been used. These results suggest that the animals from the studied farms did not go through a recent population decrease in numbers, however animals from the Fazenda Nova Esperança may be going through a structure process. On a second study, besides the Pantaneiro, genetic variability was also estimated in others three Brazilian horse breeds: Crioulo, Brasileiro de Hipismo (BH) and Mangalarga. The same 10 microsatellite loci were used. All loci amplified in the four breeds, except for the AHT17 in the BH and Mangalarga. The breed that presented higher allelic variability was Pantaneiro, followed by the Crioulo, BH and Mangalarga breeds. The endogamy coefficient (Fis) showed high values on the four breeds. Through the Fst estimate, it was observed that the Mangalarga breed is more differentiated among the studied breeds. Through the Structure software, it was observed that Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga are structured in four distinct breeds.

BRITO, Jéssica de Carvalho. Digestibilidade aparente dos nutrientes e características físico-químicas das fezes de equídeos alimentados com feno de tifton. 2016. 39 f. Dissertação (Mestrado em Zootecnia)-Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Aline Mendes (alinemendes.ufc@gmail.com) on 2017-01-16T21:09:27Z No. of bitstreams: 1 2016_dis_jcbrito.pdf: 738911 bytes, checksum: b21e8de2629c7e9fe53992fdce2fae33 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-01-16T21:14:58Z (GMT) No. of bitstreams: 1 2016_dis_jcbrito.pdf: 738911 bytes, checksum: b21e8de2629c7e9fe53992fdce2fae33 (MD5) / Made available in DSpace on 2017-01-16T21:14:58Z (GMT). No. of bitstreams: 1 2016_dis_jcbrito.pdf: 738911 bytes, checksum: b21e8de2629c7e9fe53992fdce2fae33 (MD5) Previous issue date: 2016 / The horses and donkeys are different species of horses that have physiological characteristics that need to be understood for better accomplishment of food management and food nutrients utilization Thus, the objective was to compare and evaluate the voluntary food intake and the implications on the physico-chemical characteristics of the stool, production of short chain fatty acids and apparent digestibility of a diet consisting of hay Tifton 85 in equine and asinine species. Twenty animals were used, ten quarter mile race horses and ten Pêga breed asses, distributed in a completely randomized design with two treatments of ten repetitions, being the animal the experimental unit. It is considered as treatments the two species analyzed. The animals were fed with Tifton 85 hay (85.72% DM, 12.88% CP, 73.74% NDF, 32.59% ADF and 2.25 Mcal GE/kg) at will, and it was evaluated the ability of voluntary intake. After six days of adaptation to experimental conditions, it was carried out four days of total stool collection. During the collection period, at 6h feces were collected for measurement of pH and buffering capacity (BC) as well as the color evaluation and stool consistency. During the collection period, the feces were homogenized for removal of a sample for the analyzes of dry matter (DM), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and gross energy (GE). Digestibility coefficients were calculated for DM, CP, NDF, ADF and GE. Blood samples were collected on the last day of the digestibility trial, at 0, 3 and 6 h after feeding for analysis of short-chain fatty acids (SCFA), which were also analyzed in the stool. Donkeys showed consumption of 1.12 kg DM/BW statistically smaller (P <0.05) than equine (1.60 DM/BW). It was observed higher digestibility coefficients (P <0.05) to asses for DM (61.60%), CP (67,18%) NDF (54,17) and the ADF (50,00). There was no statistical difference for pH, color and consistency of stools among the species studied receiving diet composed only with bulky. The BC of donkeys was more efficient for BC6 (9.12 mmol/L) and BC5 (22.62 mmol/L) than horses (6.07 and 14.38 mmol/L, respectively). It was observed that donkeys produce more acetic acid (33.81 mmol/L) with a unique fodder diet, but they exhibit lower levels of this SCFA in the blood (1.00 mmol/L) compared to the horses (1.27 mmol/L), which shows less absorption of acetate in the cecum-colic region. The asses have consumption capacity of hay Tifton85 less than equine, but shows higher digestibility of nutrients and increased buffering capacity of short-chain fatty acids formed during fermentation. / Os equinos e asininos são espécies diferentes de equídeos que possuem particularidades fisiológicas que precisam ser entendidas para melhor realização do manejo alimentar e aproveitamento dos nutrientes dos alimentos. Sendo assim, objetivou-se comparar e avaliar o consumo voluntário de alimento e as implicações sobre as características físico-químicas das fezes, produção de ácidos graxos de cadeia curta e digestibilidade aparente de uma dieta composta por feno de Tifton 85 nas espécies equina e asinina. Foram utilizados 20 animais adultos, sendo dez equinos da raça quarto de milha e dez jumentas da raça Pêga, distribuídas em delineamento inteiramente casualizado, com 2 tratamentos de 10 repetições, sendo o animal a unidade experimental. Considerou-se como tratamentos as duas espécies analisadas. Os animais foram alimentados com feno de Tifton 85 (85,72 %MS; 12,88 %PB; 73,74 %FDN; 32,59 %FDA e 2,25 Mcal EB/kg) à vontade, e avaliada a capacidade de consumo voluntário. Após seis dias de adaptação às condições experimentais, foram realizados quatro dias de coleta total de fezes. Durante o período de coleta, às 6h foram recolhidas as fezes para medição do pH e capacidade tamponante (CT), bem como a avaliação de cor e consistência das fezes. Durante o período de coleta, as fezes foram homogeneizadas para retirada de uma amostra composta para a realização das análises de matéria seca (MS), proteína bruta (PB), fibra em detergente ácido (FDA), fibra em detergente neutro (FDN) e energia bruta (EB). Foram calculados os coeficientes de digestibilidade para MS, PB, FDN, FDA e EB. Amostras de sangue foram coletadas no último dia do ensaio de digestibilidade, às 0, 3 e 6h após a alimentação para análises de ácidos graxos de cadeia curta (AGCC) que também foram analisados nas fezes. Asininos apresentaram consumo de 1,12 Kg MS/PV menor ao dos equinos (1,60 Kg MS/PV). Observou-se maiores coeficientes de digestibilidade (P<0,05) na espécie asinina para MS (61,60%), PB (67,18%), FDN (54,17) e FDA (50,00). Não houve diferença estatística para os valores de pH, cor e consistência das fezes entre as espécies estudadas recebendo dieta composta somente com volumoso. A CT dos asininos mostrou-se mais eficiência para CT6 (9,12 mmol/L) e CT5 (22,62 mmol/L) que os equinos (6,07 e 14,38mmol/L, respectivamente). Observou-se que os asininos produzem mais ácido acético (33,81 mmol/L) com uma dieta exclusiva de forragem, mas apresentam menores níveis desse AGCC no sangue (1,00 mmol/L) em comparação aos equinos (1,27 mmol/L), o que demonstra menor absorção na região ceco- cólica de acetato. A espécie Asinina possui capacidade de consumo de feno de Tifton85 menor que a equina, mas demonstra maiores coeficientes de digestibilidade dos nutrientes e maior capacidade tamponante dos ácidos graxos de cadeia curta formados na fermentação.

O Brasil possui cerca de uma dezena de raças de cavalos sendo essas classificadas em locais ou comerciais. As raças que aqui se naturalizaram são descendentes dos animais trazidos pelos portugueses e espanhóis na época da colonização. Cerca de 500 anos após sofrer seleção natural e artificial esses cavalos adquiriram características próprias capazes de se adaptar a ambientes adversos, escassez de alimento, doenças, influência do homem e cruzamento indiscriminado com raças exóticas. Assim, surgiram raças típicas brasileiras dotadas de peculiaridades importantes para as regiões em que vivem. Com isso, o objetivo principal deste trabalho foi o de estimar a variabilidade genética em quatro raças brasileiras de cavalos (Brasileiro de Hipismo, Crioulo, Mangalarga e Pantaneiro) por meio do marcador de DNA microssatélites. Foram utilizados 10 loci de microssatélites que amplificaram para as quatro raças. Em um primeiro estudo, foi estimada a variabilidade genética em 227 animais de três fazendas da região do Pantanal. Um total de 91 alelos foi encontrado. A probabilidade de exclusão de paternidade (PE) para as três amostras conjunta ficou em torno de 99,3%. O conteúdo de informação polimófica (PIC) foi alto, considerado altamente informativo. Os valores de Fis revelaram alto índice de homozigose nas três populações. Pôde-se verificar, por meio de baixos valores de Fst, baixa estruturação para as amostras estudadas sugerindo pouca diferenciação entre as mesmas. Foram utilizados três métodos para detectar gargalo de garrafa. Os resultados sugerem que os animais das fazendas estudadas não passaram por um processo de declínio populacional recente, mas que provavelmente animais da Fazenda Nova Esperança estariam passando por um processo de estruturação. Um outro estudo de variabilidade genética incluiu, além da raça Pantaneira, outras três raças brasileiras de cavalos: Crioulo, Brasileiro de Hipismo (BH) e Mangalarga. Os mesmos 10 loci de microssatélites também foram utilizados. Todos os loci amplificaram nas quatro raças, com a exceção de AHT17 em BH e Mangalarga. A raça que apresentou maior variabilidade alélica foi a Pantaneira (n = 91) seguida pelas raças Crioula (n = 81), BH (n = 57) e Mangalarga (n = 41). O coeficiente de endogamia (Fis) apresentou valores altos para as quatro raças. Por meio da estimativa Fst pôde-se inferir que a raça Mangalarga é a mais divergente entre as raças estudadas. Através do programa Structure, foi observado que Pantaneiro, Crioulo, Brasileiro de Hipismo e Mangalarga estão estruturadas em quatro distintas raças. / Brazil has around ten horse breeds, which are classified as local or commercial horses. The breeds established here are descendant from the animals brought by the Portuguese and Spanish colonization. After 500 years of natural and artificial selection, these horses acquired their own adaptive characteristics to adverse environments, lack of food, diseases, human influence, and random breeding with exotic breeds. Thus, the main objective of this work was to estimate the genetic variability of four Brazilian horse breeds (Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga) by microsatellite markers. Ten microsatellite loci have been used and amplified in the 4 breeds. On a first study, the genetic variability was estimated in 227 animals from three farms around the Pantanal region. A total of 91 alleles were found. The paternity exclusion probability (PE) to all 3 samples was around 99.3%. The polymorphic information content (PIC) was high, and considered to be informative. The Fis values showed high levels of homozygosity in all three populations. It was verified, through the low values of Fst, low structure of the samples studied, suggesting slight differentiation among them. Three methods to detect the bottleneck effect have been used. These results suggest that the animals from the studied farms did not go through a recent population decrease in numbers, however animals from the Fazenda Nova Esperança may be going through a structure process. On a second study, besides the Pantaneiro, genetic variability was also estimated in others three Brazilian horse breeds: Crioulo, Brasileiro de Hipismo (BH) and Mangalarga. The same 10 microsatellite loci were used. All loci amplified in the four breeds, except for the AHT17 in the BH and Mangalarga. The breed that presented higher allelic variability was Pantaneiro, followed by the Crioulo, BH and Mangalarga breeds. The endogamy coefficient (Fis) showed high values on the four breeds. Through the Fst estimate, it was observed that the Mangalarga breed is more differentiated among the studied breeds. Through the Structure software, it was observed that Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga are structured in four distinct breeds.

O Brasil possui cerca de uma dezena de raças de cavalos sendo essas classificadas em locais ou comerciais. As raças que aqui se naturalizaram são descendentes dos animais trazidos pelos portugueses e espanhóis na época da colonização. Cerca de 500 anos após sofrer seleção natural e artificial esses cavalos adquiriram características próprias capazes de se adaptar a ambientes adversos, escassez de alimento, doenças, influência do homem e cruzamento indiscriminado com raças exóticas. Assim, surgiram raças típicas brasileiras dotadas de peculiaridades importantes para as regiões em que vivem. Com isso, o objetivo principal deste trabalho foi o de estimar a variabilidade genética em quatro raças brasileiras de cavalos (Brasileiro de Hipismo, Crioulo, Mangalarga e Pantaneiro) por meio do marcador de DNA microssatélites. Foram utilizados 10 loci de microssatélites que amplificaram para as quatro raças. Em um primeiro estudo, foi estimada a variabilidade genética em 227 animais de três fazendas da região do Pantanal. Um total de 91 alelos foi encontrado. A probabilidade de exclusão de paternidade (PE) para as três amostras conjunta ficou em torno de 99,3%. O conteúdo de informação polimófica (PIC) foi alto, considerado altamente informativo. Os valores de Fis revelaram alto índice de homozigose nas três populações. Pôde-se verificar, por meio de baixos valores de Fst, baixa estruturação para as amostras estudadas sugerindo pouca diferenciação entre as mesmas. Foram utilizados três métodos para detectar gargalo de garrafa. Os resultados sugerem que os animais das fazendas estudadas não passaram por um processo de declínio populacional recente, mas que provavelmente animais da Fazenda Nova Esperança estariam passando por um processo de estruturação. Um outro estudo de variabilidade genética incluiu, além da raça Pantaneira, outras três raças brasileiras de cavalos: Crioulo, Brasileiro de Hipismo (BH) e Mangalarga. Os mesmos 10 loci de microssatélites também foram utilizados. Todos os loci amplificaram nas quatro raças, com a exceção de AHT17 em BH e Mangalarga. A raça que apresentou maior variabilidade alélica foi a Pantaneira (n = 91) seguida pelas raças Crioula (n = 81), BH (n = 57) e Mangalarga (n = 41). O coeficiente de endogamia (Fis) apresentou valores altos para as quatro raças. Por meio da estimativa Fst pôde-se inferir que a raça Mangalarga é a mais divergente entre as raças estudadas. Através do programa Structure, foi observado que Pantaneiro, Crioulo, Brasileiro de Hipismo e Mangalarga estão estruturadas em quatro distintas raças. / Brazil has around ten horse breeds, which are classified as local or commercial horses. The breeds established here are descendant from the animals brought by the Portuguese and Spanish colonization. After 500 years of natural and artificial selection, these horses acquired their own adaptive characteristics to adverse environments, lack of food, diseases, human influence, and random breeding with exotic breeds. Thus, the main objective of this work was to estimate the genetic variability of four Brazilian horse breeds (Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga) by microsatellite markers. Ten microsatellite loci have been used and amplified in the 4 breeds. On a first study, the genetic variability was estimated in 227 animals from three farms around the Pantanal region. A total of 91 alleles were found. The paternity exclusion probability (PE) to all 3 samples was around 99.3%. The polymorphic information content (PIC) was high, and considered to be informative. The Fis values showed high levels of homozygosity in all three populations. It was verified, through the low values of Fst, low structure of the samples studied, suggesting slight differentiation among them. Three methods to detect the bottleneck effect have been used. These results suggest that the animals from the studied farms did not go through a recent population decrease in numbers, however animals from the Fazenda Nova Esperança may be going through a structure process. On a second study, besides the Pantaneiro, genetic variability was also estimated in others three Brazilian horse breeds: Crioulo, Brasileiro de Hipismo (BH) and Mangalarga. The same 10 microsatellite loci were used. All loci amplified in the four breeds, except for the AHT17 in the BH and Mangalarga. The breed that presented higher allelic variability was Pantaneiro, followed by the Crioulo, BH and Mangalarga breeds. The endogamy coefficient (Fis) showed high values on the four breeds. Through the Fst estimate, it was observed that the Mangalarga breed is more differentiated among the studied breeds. Through the Structure software, it was observed that Pantaneiro, Crioulo, Brasileiro de Hipismo and Mangalarga are structured in four distinct breeds.

Sociality is widespread across the animal kingdom and explanations for its incidence and persistence are numerous. Whilst various drivers of sociality have been identified and tested, controversies remain and we are still far from a complete understanding of the mechanisms underlying social structure. Here I use a combination of field observations on a free-living population of feral horses Equus caballus and laboratory behavioural experiments on the Pacific beetle roach Diploptera punctata to investigate the drivers of sociality in these species. I explore four key aspects of sociality: the influences of kinship on sociality and social development, the strength and persistence of social bonds, the relationship between inbreeding avoidance and dispersal and the potential influence of individuals on social structure. Whilst kinship is a major driver of social structure in most mammalian species, I present evidence in Chapter Three that horse society is not structured by levels of kinship; however, in Chapter Five, I show that kinship levels to potential mates are significant in female dispersal choices in this species. In Chapter Eight, I provide evidence for significant effects of kinship to companions upon social and physical development in D. punctata, indicating a clear potential benefit of kin-based associations. The stability of social bonds can have substantial effects upon social structure. In Chapter Three, I show that the bonds between female horses show significant stability and are formed independently to kinship levels, a rare result in a non-primate species. I also provide evidence consistent with the hypothesis that these bonds are driven by male harassment. Similarly, in D. punctata, I find in Chapter Eight that female clustering occurs within resting aggregations and that the most likely explanation is the avoidance of male harassment. I therefore propose that this driver of female sociality may be a highly prevalent force structuring animal societies. Inbreeding depression has been demonstrated in a variety of species and contexts. Here I show in Chapter Five that in horses, female dispersal is likely to be influenced by kinship levels with potential mates. In Chapter Four, I then show that more heterozygous males have a higher reproductive success, most likely due to their ability to utilise a larger home range. Finally, local population structure can be highly influenced by individual association choices and behaviour. In Chapter Two, I show that in horses, mothers may allow their sons to postpone dispersal by the maintenance of stronger mother-son bonds, permitting an extended period of social learning. In Chapter Seven, I demonstrate that consistent inter-individual variation in personality traits exists in D. punctata which is stable across life stages, despite age effects on the strength of boldness. This is a source of variation which may be extremely important for decision-making social groups. My main conclusion from this work is that male harassment is often a key driver of sociality which may frequently be overlooked. I also demonstrate that the effects of kinship are far-ranging but not omnipresent. This thesis therefore makes a major contribution to our understanding of the mechanisms underlying animal sociality and presents clear potential avenues for future research.

In this thesis I examine the population ecology of wild horses (Equus caballus) in the Australian Alps. Wild horses were first introduced into the Alps over 150 years ago. Paradoxically, they are a feral animal impacting on the environment, but are also a cultural icon. Managing wild horse populations is contentious and needs to be founded on knowledge of their population ecology. This is the first study of its kind in the Australian Alps and therefore has a broad focus. Four general areas were addressed: distribution, estimation of abundance and density, population dynamics and the influence of brumby-running. The study was conducted between 1999 and 2002 inclusive in the Australian Alps national parks, which form a contiguous protected area in south-eastern Australia from the Australian Capital Territory (ACT) in the north, through New South Wales (NSW) and into Victoria in the south. The current distribution of wild horses in the Australian Alps national parks is patchy. There are five major discrete populations in NSW and Victoria with the northern most population in Kosciuszko National Park (NSW) bordering on the ACT. A review of published material and oral history reveals historic influences on distribution. The presence of each population is associated with introductions by people. The distribution of some populations expanded after introductions and many have fluctuated over time. Distributions have been contained or reduced through control by people, natural events such as snow and drought and by geographical barriers. Park managers eliminated a population of wild horses in the ACT in the 1980s. Distributions have expanded in areas without active management (notably northern Kosciuszko National Park) and are likely to continue expanding under a policy of no management. In February and March 2001, abundance and density of wild horses were estimated by helicopter aerial survey in areas where the mapping showed horses to occur. This was the first time that these parameters have been estimated empirically. I compared three different aerial survey techniques (strip, mark-recapture and line transect) based on relative accuracy and precision and found that line transect analysis gave the highest, most precise estimate. Given that aerial surveys usually underestimate abundance, this method was also likely to be the most accurate. Mark-recapture over a 50m wide strip gave a similar result but lacked precision. Strip and mark-recapture techniques performed poorly over 200m strips because animals were missed. Numbers observed dropped off dramatically beyond the 50m strip. Line transect analysis (for both observers combined) gave an estimate of 5010 (+/- 1408SE) horses while mark recapture over 50 metres gave an estimate of 4915 (+/-2733SE). These estimates correspond to a density of 1.8 horses km-2 over the area surveyed (2789km2). The results suggest that aerial surveys of large mammals using a wide strip width (200m) and mark recapture analysis may seriously underestimate population density. The population dynamics and demography of wild horses were estimated at three sites, Big Boggy, Cowombat and Currango, every spring and autumn over 3 years. The sites were spread widely across the Alps with the aim of obtaining a broad understanding of population dynamics. The survey used Pollock�s robust design and natural markings were used to identify individuals. There was a seasonal spring peak in population size at Big Boggy with no clear seasonal trend at the other two sites. Mean wild horse densities determined at Big Boggy (2.01km-2) and Currango (2.13km-2) were not significantly (p<0.5) different to the density calculated in the aerial survey, whereas density was significantly higher at Cowombat (6.4 km-2). Census techniques were of limited use in estimating annual population growth rate because of low precision. Demographic analysis showed that none of the populations were increasing at the maximum intrinsic rate (l = 1.2), and the Big Boggy and Cowombat populations may be stable (l = 1.0/yr). There was an apparent trend of food limitation across the sites. Body condition was positively related (p<0.01) to pasture biomass. The Currango population was increasing (l = 0.09) associated with higher recruitment, body condition and pasture biomass than in the other two populations studied. The Cowombat population had the lowest annual finite rate of increase (l = 1.03), and horses at this site were in the poorest condition and pasture biomass was lowest. The Big Boggy population was intermediate between the two. Annual adult survival was constant in all populations at 0.91. Survival in the first three years of life was more variable with the average at each site ranging from 0.63/yr to 0.76/yr. An average of 0.26 female foals was born per adult female per year. Sensitivity analysis showed that population growth rate is most sensitive to changes in adult survival, followed by fecundity and then survival in the first three years of life. The dynamics observed at each site was representative of the demography of wild horses in other parts of the world and is typical for large mammalian herbivores. Brumby-running is a form of harvesting that is currently being used to control wild horses in the Alpine National Park (Victoria) and is soon to be trialled in Kosciuszko National Park (NSW). The effectiveness of brumby-running has not been assessed prior to this study. Data collected by the Alpine Brumby Management Association and predictive modelling were used to examine the influence of brumby-running on the wild horse population in Alpine National Park. Brumby-runners remove about 200 horses per year with a preference for young animals and adult females. More horses are caught in autumn (61/yr) and least in summer (30/yr) (p<0.05). Brumby-runners do not appear (p>0.05) to target horses in poor condition. One skilled brumby-runner caught an average of 1.16 horses/day, while his companions caught an average of 0.55 horses/day. Brumby-runners show behaviour analogous to social carnivores. Predictive modelling suggests that brumby-runners could suppress the population of wild horses in Alpine National Park similar to the effects of predators, or human harvesting of other large mammals. Selecting young animals in the harvest reduces the impact of harvesting on the population compared to unselective harvesting, while selecting adult females increases the predicted impact. There are several management recommendations based on the findings of this thesis that address concerns for both environmental impact and the cultural value of wild horses. The distribution of wild horses should not be allowed to expand further, and the size of the wild horse population should be prevented from increasing further. Other management recommendations that are more complex involve reducing some populations so that the level of environmental impact they are causing is acceptable. This requires a definition of �acceptable impact.� Finally managers should consider eradicating smaller populations.