Search results for "Breed"
showing 10 items of 697 documents
Population genetic structure of the butterflyMelitaea didyma(Nymphalidae) along a northern distribution range border
1996
The population genetic structure of the butterfly Melitaea didyma was studied along the northern distribution range border in Central Germany by means of allozyme electrophoresis. Individuals were sampled from a total of 21 habitat patches from four regions, and two provinces. Sampling was designed to estimate local vs. regional differentiation. High levels of variability were found, He= 0.14-0.21. The mean expected sample heterozygosity from one region, Mosel, was significantly lower than from the Hammelburg region, He= 0.17 and 0.19, respectively. Two hierarchical levels of genetic differentiation were found. Within regions individuals sampled from different patches behaved as belonging t…
Breeding strategy and morphological characters in an urban population of blackbirds, Turdus merula
2001
Pairing patterns in monogamous birds are thought to be the consequence of mutual mate choice by males and females for characters linked to individual quality in the opposite sex. Although this may result in assortative pairing for a single character, there may be no simple match between male and female phenotype if the traits linked to individual quality are sex specific. For instance, in several passerine species, females tend to select males on the basis of territory quality or characters that may reflect health or vigour, whereas males benefit from pairing with females in good condition that breed early because early breeding increases reproductive success. We investigated pairing patter…
Generation of homozygosity and genome fixation in pea (Pisum sativum L.)
2013
Pea cultivars are nearly homozygous and thus homogeneous when they are released. The traditional method of selfing is slow and inefficient, taking up to ten generations of inbreeding following a cross to achieve a high level of homozygosity. Current single-seed-descent (SSD) methodologies enable a maximum of three generations per year to be developed in pea. Doubled haploidy and an in vitro based modified SSD technology have been utilised in many important crops for the rapid achievement of homozygosity, and thus acceleration of the breeding process. In pea, due to the lack of robust protocols, none of these technologies is routinely used in a breeding program. The aim of this study was to …
Measuring technical efficiency of Greek red suckler cow breed's farms in Central Macedonia region using a data envelopment analysis model
2022
This study aims to estimate the technical efficiency (TE) of a randomly selected sample of red Greek suckler cow breed farms in the area of Central Macedonia and identify the most technically efficient characteristics of cow-calf operations. Moreover, this work wants to verify the impact of local and European policies in support of the sector on the estimated efficiency. The research investigates the technical efficiency of 64 suckler cow farms by using the data envelopment analysis (DEA) method. Findings reveal that the most efficient farms were larger, with higher gross revenue, and higher cost of fixed capital than non-efficient farms. In addition, the cost of variable capital, which dir…
Rumicetum palustris (TIMÁR 1950) W. FISCHER 1978, new plant community from Bidentetea tripartiti R. Tx., LOHM. ET Prsg 1950 class in SW Poland
2016
Natural water reservoirs are very valuable floristic sites in Poland. Among them, the most important for preservation of biodiversity of plant communities are lakes, rivers, oxbow lakes and fishponds. The long-term process of human pressure on habitats of this type caused disturbance to their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of last two hundred years, led to systematic disappearance of localities of many plant communities. Rumicetum palustris (Timár 1950) W. Fischer 1978, of Bidentetea tripartiti R. Tx., Lohm. et Prsg 1950 class, has been described for the first time in Hungary and Germany. This …
Gnaphalio uliginosi-eleocharitetum acicularis Passarge 1999, new plant community in Poland
2017
Zbiorniki wodne są bardzo cennymi miejscami florystycznymi w Polsce. Wśród nich najważniejsze dla zachowania różnorodności biologicznej flory są stawy rybne. Długookresowy proces oddziaływania ludzkiego na tego typu siedliska powodował zakłócenia w ich równowadze biologicznej. Zmiany w systemie wodnym, rozwój przemysłowy i chemizacja rolnictwa, zwłaszcza w okresie ostatnich dwóch stuleci, doprowadziły do zaniku wielu gatunków roślin oraz zbiorowisk roślinnych. Zespół Gnaphalio uliginosi-Eleocharitetum acicularis Passarge 1999 z klasy Isoëto-Nanojuncetea Br.-Bl. et Tx. 1943, po raz pierwszy został opisany w Niemczech. Rośnie na piaszczystych lub mulistych brzegach rzek, starorzeczach i w sta…
Anther culture in Citrus clementina: a way to regenerate tri-haploids
2005
Abstract. Regenerants from anther culture of Citrus clementina Hort. ex Tan. cvv. Nules, SRA 63, and Monreal were obtained in different experiments from 1994 to 2002. Genetic analysis of 37 such regenerants was carried out using 4 microsatellite markers that were heterozygous in the parental genotypes. The results showed that in all cases but one the regenerants carried only one or the other allele of the parental genotype, and were therefore homozygous and produced through a process of gametophytic embryogenesis. Ploidy analysis by flow cytometry of 94 regenerants showed that as many as 82% of them were tri-haploids, rather than haploids or doubled-haploids as expected, with other ploidy …
The influence of somatic cell count on sheep milk composition and cheese-making properties
2005
Somatic cell count (SCC) is an important tool for monitoring intramammary infections in dairy cows. However, systematic generalization of this decision rule is not easy in small ruminants. Determination of SCC in sheep milk is important for the processors of milk (indicator of quality), for breeders (mastitis indicator) and could be useful for selection as well. SCC value can be affected by some non-infective factors such as breed, stage of lactation, parity, type of lambing, type of milking, etc. (Bergonier et al., 1994), as well the health status of the udder (Fruganti et al., 1985; Ranucci et al., 1988). In addition, EC Directive 92/46, which regulates the production and commercialisatio…
Maternal antibody transmission and breeding densities in the Black-headed Gull Larus ridibundus
2004
1. The offspring of avian species, especially those of colonial breeders, are exposed to a number of pathogens immediately after birth. The chick's immune system is, at that early stage still immature and inefficient. As a consequence, diseases can have a strong impact on chick survival.2. The ability of mothers to transmit passive immunity in terms of antibodies of their own acquired immunity to their chicks is probably an essential pathway to enhance the chick survival. Since the production of antibodies is costly, females are expected to adjust the transmission of passive immunity to the local disease environment.3. We found that in Black-headed Gulls (Larus ridibundus L.) yolk antibody …
Mother Knows Best: Dominant Females Determine Offspring Dispersal in Red Foxes (Vulpes vulpes)
2011
Background: Relatedness between group members is central to understanding the causes of animal dispersal. In many group-living mammals this can be complicated as extra-pair copulations result in offspring having varying levels of relatedness to the dominant animals, leading to a potential conflict between male and female dominants over offspring dispersal strategies. To avoid resource competition and inbreeding, dominant males might be expected to evict unrelated males and related females, whereas the reverse strategy would be expected for dominant females. Methodology/Principal Findings: We used microsatellites and long-term data from an urban fox (Vulpes vulpes) population to compare disp…