696 resultados para Pigeon breeders


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Validation of parentage and horse breed registries through DNA typing relies on estimates of random match probabilities with DNA profiles generated from multiple polymorphic loci. Of the twenty-seven microsatellite loci recommended by the International Society for Animal Genetics for parentage testing in Thoroughbred horses, eleven are located on five chromosomes. An important aspect in determining combined exclusion probabilities is the ascertainment of the genetic linkage status of syntenic markers, which may affect reliable use of the product rule in estimating random match probabilities. In principle, linked markers can be in gametic phase disequilibrium (GD). We aimed at determining the extent, by frequency and strength, of GD between the HTG4 and HMS3 multiallelic loci, syntenic on chromosome 9. We typed the qualified offspring (n (1) = 27; n (2) = 14) of two Quarter Bred stallions (registered by the Brazilian Association of Quarter Horse Breeders) and 121 unrelated horses from the same breed. In the 41 informative meioses analyzed, the frequency of recombination between the HTG4 and HMS3 loci was 0.27. Consistent with genetic map distances, this recombination rate does not fit to the theoretical distribution for independently segregated markers. We estimated sign-based D' coefficients as a measure of GD, and showed that the HTG4 and HMS3 loci are in significant, yet partial and weak, disequilibrium, with two allele pairs involved (HTG4*M/HMS3*P, D'(+) = 0.6274; and HTG4*K/HMS3*P, D'(-) = -0.6096). These results warn against the inadequate inclusion of genetically linked markers in the calculation of combined power of discrimination for Thoroughbred parentage validation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Bordetella avium is an opportunistic pathogen that presents tropism for ciliated epithelia, leading to upper respiratory tract disease in turkeys. This agent has also been associated with Lockjaw Syndrome in psittacine birds, but literatures describing the importance of this agent in such species are rare. The purpose of the present study was to report the first outbreak of B. avium infection in juvenile cockatiels demonstrating the Lockjaw Syndrome in Brazil and to investigate the antimicrobial resistance profile and phenotypic and genotypic characteristics of these strains. Surprising, the strains obtained from five infected cockatiel chicks from three different breeders from different Brazilian states showed a clonal relationship using the Pulsed Field Gel Electrophoresis and Single Enzyme Amplified Fragment Length Polymorphism techniques. The virulence potentials of the B. avium strains were assessed using tracheal adherence and cytotoxic effects on a VERO cell monolayer. (C) 2012 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study of population structure by pedigree analysis is useful to identify important circumstances that affect the genetic history of populations. The intensive use of a small number of superior individuals may reduce the genetic diversity of populations. This situation is very common for the beef cattle breeds. Therefore, the objectives of the present study were to analyze the pedigree and possible inbreeding depression on traits of economic interest in the Marchigiana and Bonsmara breeds and to test the inclusion of the individual inbreeding coefficient (F-i) or individual increases in inbreeding coefficient (Delta F-i) in the genetic evaluation model for the quantification of inbreeding depression. The complete pedigree file of the Marchigiana breed included 29,411 animals born between 1950 and 2003. For the Bonsmara breed, the pedigree file included 18,695 animals born between 1988 and 2006. Only animals with at least 2 equivalent generations of known pedigree were kept in the analyses of inbreeding effect on birth weight, weaning weight measured at about 205 d, and BW at 14 mo in the Marchigiana breed, and on birth weight, weaning weight, and scro-tal circumference measured at 12 mo in the Bonsmara breed. The degree of pedigree knowledge was greater for Marchigiana than for Bonsmara animals. The average generation interval was 7.02 and 3.19 for the Marchigiana and Bonsmara breed, respectively. The average inbreeding coefficient was 1.33% for Marchigiana and 0.26% for Bonsmara. The number of ancestors explaining 50% of the gene pool and effective population size computed via individual increase in coancestry were 13 and 97.79 for Marchigiana and 41 and 54.57 for Bonsmara, respectively. These estimates indicate reduction in genetic variability in both breeds. Inbreeding depression was observed for most of the growth traits. The model including Delta F-i can be considered more adequate to quantify inbreeding depression. The inclusion of F-i or Delta F-i in the genetic evaluation model may not result in better fit to the data. A genetic evaluation with simultaneous estimation of inbreeding depression can be performed in Marchigiana and Bonsmara breeds, providing additional information to producers and breeders.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A contribuição da adubação verde com leguminosas para melhoria do solo e produção agrícola depende em primeiro lugar da produção de biomassa e da sua composição química, que variam em função da espécie, região e estação de cultivo. Objetivo do presente trabalho foi avaliar a composição química da biomassa produzida por adubos verdes no Vale do Ribeira, São Paulo, Brasil. Para tal, foi conduzido um experimento em Pariquera-Açu-SP, no ano agrícola 2006/2007, em blocos casualizados, com quatro tratamentos (três adubos verdes e vegetação espontânea) e cinco repetições. Aos 30, 60, 90 e 120 dias após a semeadura, foram coletadas amostras em 1 m² da parte aérea das plantas e determinada a matéria fresca e seca, bem como a composição da biomassa. Crotalária, guandu e mucuna produziram, em ordem decrescente, as maiores quantidades de biomassa e foram mais eficientes do que a vegetação espontânea. A biomassa produzida pelos adubos verdes apresentou qualidade superior à produzida pela vegetação espontânea. Crotalária e guandu apresentam maior proporção de matéria seca acumulada no caule que possui baixo teor de N, alta relação C/N e L/N, variáveis que tornam a decomposição dos resíduos mais lenta. A análise particionada da matéria seca permite indicação mais precisa da composição química dos resíduos e a previsão da disponibilidade dos nutrientes no solo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Abstract: Background: Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons. Results: Adult pigeons kept under a skeleton photoperiod were assigned to six different groups. Homogenates of the hippocampus obtained at six different times-of-day were used for NOS analyses. Both iNOS activity and nNOS cytosolic protein concentrations were highest during the subjective light phase and lowest in the subjective dark phase of the circadian period. ANOVA showed significant time differences for iNOS enzymatic activity (p < 0.05) and for nNOS protein content (p < 0.05) in the hippocampus. A significant daily rhythm for both iNOS and nNOS was confirmed by analysis with the Cosinor method (p < 0.05). The present findings indicate that the enzymatic activity of iNOS and content of nNOS protein in the hippocampus of pigeons exhibit a daily rhythm, with acrophase values occurring during the behavioral activity phase. Conclusions: The data corroborate the reports on circadian variation of NOS in the mammalian hippocampus and can be considered indicative of a dynamic interaction between hippocampus-dependent processes and circadian clock mechanisms.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons. Results: Adult pigeons kept under a skeleton photoperiod were assigned to six different groups. Homogenates of the hippocampus obtained at six different times-of-day were used for NOS analyses. Both iNOS activity and nNOS cytosolic protein concentrations were highest during the subjective light phase and lowest in the subjective dark phase of the circadian period. ANOVA showed significant time differences for iNOS enzymatic activity (p < 0.05) and for nNOS protein content (p < 0.05) in the hippocampus. A significant daily rhythm for both iNOS and nNOS was confirmed by analysis with the Cosinor method (p < 0.05). The present findings indicate that the enzymatic activity of iNOS and content of nNOS protein in the hippocampus of pigeons exhibit a daily rhythm, with acrophase values occurring during the behavioral activity phase. Conclusions: The data corroborate the reports on circadian variation of NOS in the mammalian hippocampus and can be considered indicative of a dynamic interaction between hippocampus-dependent processes and circadian clock mechanisms.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Asignatura. Etología de los recursos pesqueros (Licenciatura Ciencias del mar)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Scopo del lavoro della presente tesi è stato quello di valutare la prevalenza di Chlamydiaceae, ed in particolare Chlamydia psittaci, in una popolazione aviare con caratteristiche sinantropiche quale il colombo di città (Columba livia var. domestica) dell’areale veneziano. Per evidenziare il patogeno sono state utilizzate metodiche sierologiche, d’isolamento e biomolecolari tradizionali. Contestualmente, mediante tecnologie molecolari innovative, quali microarray ed MLVA (Multilocus VNTR Assay) sono stati valutati i genotipi di C. psittaci e le eventuali altre specie di Chlamydia presenti in tale popolazione. Inoltre, si è proceduto ad una classificazione delle lesioni anatomo-patologiche ed ad una loro correlazione con la presenza del patogeno. I risultati dimostrano che la prevalenza di C. psittaci nella popolazione oggetto dello studio è del 10%. Durante tale studio è stata dimostrata la presenza di un ceppo di C. psittaci atipico, in quanto non classificabile con le attuali tecniche a disposizione. La genotipizzazione dei ceppi di C. psittaci conferma la presenza nel colombo di città del genotipo B, E ed E/B, che solitamente risultano essere coinvolti con minore frequenza in episodi di infezione umana. Inoltre sono stati dimostrati alcuni ceppi classificati come Chlamydia spp., in quanto le metodologie applicate e le conoscenze attuali non permettono ulteriori distinzioni, prospettando la possibilità di un nuovo ceppo. Infine, attraverso l’analisi dei dati raccolti durante la prima fase di campionamenti e successivamente confermati durante la seconda fase, siamo riusciti a strutturare un sistema di selezione, basato su caratteristiche funzionali ed anatomopatologiche, che permette di selezionare in sede necroscopica i colombi molto probabilmente infetti, permettendo conseguentemente una migliore organizzazione e gestione dei campioni di interesse contenendo nel contempo i costi ma mantenendo elevati gli standards diagnostici.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis is about plant breeding in Early 20th-Century Italy. The stories of the two most prominent Italian plant-breeders of the time, Nazareno Strampelli and Francesco Todaro, are used to explore a fragment of the often-neglected history of Italian agricultural research. While Italy was not at the forefront of agricultural innovation, research programs aimed at varietal innovation did emerge in the country, along with an early diffusion of Mendelism. Using philosophical as well as historical analysis, plant breeding is analysed throughout this thesis as a process: a sequence of steps that lays on practical skills and theoretical assumptions, acting on various elements of production. Systematic plant-breeding programs in Italy started from small individual efforts, attracting more and more resources until they became a crucial part of the fascist regime's infamous agricultural policy. Hybrid varieties developed in the early 20th century survived World War II and are now ancestors of the varieties that are still cultivated today. Despite this relevance, the history of Italian wheat hybrids is today largely forgotten: this thesis is an effort to re-evaluate a part of it. The research did allow previously unknown or neglected facts to emerge, giving a new perspective on the infamous alliance between plant-breeding programs and the fascist regime. This thesis undertakes an analysis of Italian plant-breeding programs as processes. Those processes had a practical as well as a theoretical side, and involved various elements of production. Although a complete history of Italian plant breeding still remains to be written, the Italian case can now be considered along with the other case-studies that other scholars have developed in the history of plant breeding. The hope is that this historical and philosophical analysis will contribute to the on-going effort to understand the history of plants.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: ‘pay-to-stay’ PS, ‘risk avoidance’ RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy. Methodology/Principal Findings Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, ‘punishment’ by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS). Conclusions/Significance We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were inconsistent with RB.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background In cooperative breeders, subordinates generally help a dominant breeding pair to raise offspring. Parentage studies have shown that in several species subordinates can participate in reproduction. This suggests an important role of direct fitness benefits for cooperation, particularly where groups contain unrelated subordinates. In this situation parentage should influence levels of cooperation. Here we combine parentage analyses and detailed behavioural observations in the field to study whether in the highly social cichlid Neolamprologus pulcher subordinates participate in reproduction and if so, whether and how this affects their cooperative care, controlling for the effect of kinship. Methodology/Principal Findings We show that: (i) male subordinates gained paternity in 27.8% of all clutches and (ii) if they participated in reproduction, they sired on average 11.8% of young. Subordinate males sharing in reproduction showed more defence against experimentally presented egg predators compared to subordinates not participating in reproduction, and they tended to stay closer to the breeding shelter. No effects of relatedness between subordinates and dominants (to mid-parent, dominant female or dominant male) were detected on parentage and on helping behaviour. Conclusions/Significance This is the first evidence in a cooperatively breeding fish species that the helping effort of male subordinates may depend on obtained paternity, which stresses the need to consider direct fitness benefits in evolutionary studies of helping behaviour.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Herens cows have been treated at the Clinic for Ruminants, University of Berne, more frequently for fertility problems than other breeds. The aim of the study was to overview the reproductive performance of the Herens breed by analyzing data sets of the Herens Breeding Book and of the Animal Traffic Database of Switzerland. In addition, a questionnaire was sent to the breeders concerning aspects of management and care to identify a possible influence on the reproductive performance of the animals. Based on 4988 lactations starting in 2003, an average interval of calving to first insemination of 86 days a calving to conception interval of 146 days and an inter calving period of 431 days could be calculated. Conception rate resulted in 39.1%, the fertility index was 1.87 and 6.5% of all cows were culled because of fertility problems. Half of the breeders owned 4 or less cows. The most important reason for keeping Herens cows was cow fighting. Traditional alpine pasturing and cow fight rules resulted in a seasonal calving with 80% of the births taking place between October and December. The calving month and seasonal calving were the most important reasons for a prolonged calving to conception interval.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The remnant population of Balkan lynx Lynx lynx martinoi is small, isolated and highly threatened. Since 2006 a conservation project has surveyed its status and promoted its recovery in Albania and Macedonia. Eurasian lynx are often associated with conflicts of an economic or social nature, and their conservation requires a focus on the people sharing the landscape with the species. In this study we adopt methods and conceptual frameworks from anthropology to explore the local knowledge and perceptions of lynx among rural hunters and livestock breeders in the western mountains of the Republic of Macedonia in south-east Europe. The main finding was that local people rarely saw or interacted with lynx. As the level of interactions with this species is very low, the lynx doesn?t appear to be a species associated with conflicts in Macedonia. There was also a general lack of both scientific and local knowledge, which has led to somewhat negative attitudes, mainly based on myths and rumours. Poaching of lynx and their prey seem to be the main barriers to lynx conservation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Predation pressure has long been considered a leading explanation of colonies, where close neighbors may reduce predation via dilution, alarming or group predator attacks. Attacking predators may be costly in terms of energy and survival, leading to the question of how neighbors contribute to predator deterrence in relationship to each other. Two hypotheses explaining the relative efforts made by neighbors are byproduct-mutualism, which occurs when breeders inadvertently attack predators by defending their nests, and reciprocity, which occurs when breeders deliberately exchange predator defense efforts with neighbors. Most studies investigating group nest defense have been performed with birds. However, colonial fish may constitute a more practical model system for an experimental approach because of the greater ability of researchers to manipulate their environment. We investigated in the colonial fish, Neolamprologus caudopunctatus, whether prospecting pairs preferred to breed near conspecifics or solitarily, and how breeders invested in anti-predator defense in relation to neighbors. In a simple choice test, prospecting pairs selected breeding sites close to neighbors versus a solitary site. Predators were then sequentially presented to the newly established test pairs, the previously established stimulus pairs or in between the two pairs. Test pairs attacked the predator eight times more frequently when they were presented on their non-neighbor side compared to between the two breeding sites, where stimulus pairs maintained high attack rates. Thus, by joining an established pair, test pairs were able to reduce their anti-predator efforts near neighbors, at no apparent cost to the stimulus pairs. These findings are unlikely to be explained by reciprocity or byproduct-mutualism. Our results instead suggest a commensal relationship in which new pairs exploit the high anti-predator efforts of established pairs, which invest similarly with or without neighbors. Further studies are needed to determine the scope of commensalism as an anti-predator strategy in colonial animals.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The socio-economic structure of the breeding farms of Franches-Montagnes horses (FM) in Switzerland is evaluated on the basis of an investigation carried out in 2002 by the Swiss FM breeding federation. Questionnaires were sent to 3500 of its members and the results include data from 968 breeding enterprises, housing a total of 3965 FM. The quality of the husbandry of FM varies according to factors such as the altitude and the geographical situation of the farms and studs. Socio-economic parameters, such as the role of FM in the business, their use (breeding, driving, riding) and the age and level of professional education of the owners may also have an effect on standards of husbandry. The results show that the owners for whom FM represent a source of income more frequently keep their horses in standing stalls, but give them more time to exercise at liberty than the horses belonging to amateur breeders. Younger and better educated breeders are more likely to house their animals in groups.