Thesis (doctoral)--Universität, Giessen, 2003. / At head of title: "Aus dem Institut für Tierzucht und Haustiergenetik der Justus-Liebig-Universität Giessen." Includes bibliographical references (p. 163-201).

Call number: LD2668 .T4 1955 B65 / Master of Science

Thesis (M.Sc. (Zoology)) --University of Limpopo, 2010 / Refer to document

No description available.

Vis daugiau žmonių renkasi mažų veislių šunelius, kurie puikiai tinka ankštuose butuose. Mažų veislių šunelius įsigyja vieniši žmonės – kompanijai, kiti kaip žiurkgaudžius, kai kurie vietoj „skambučio“, bet daugiausia įsigyja kaip aksesuarą. Jorkšyro terjerai šiuo metu yra viena populiariausių šunų veislių Lietuvoje. Nuo 1992 metų iki 2007 metų lapkričio 11 dienos Lietuvos kinologų draugijos šunų veislių knygoje užregistruota: Jorkšyro terjerų veislės šunų 1045; Australijos šilkinių terjerų 10; Rusų žaisliukų užregistruota 343 (iš jų trumpaplaukių 175, o ilgaplaukių 168); Čihuahua 275 (iš jų trumpaplaukių 53, o ilgaplaukių 222). Įregistruotų veislynų skaičius iki 2007 metų lapkričio 11 dienos: Jorkšyro terjerų veislės 66; Australijos šilkinių terjerų 1; Rusų žaisliukų užregistruota 25 (iš jų trumpaplaukių 14, o ilgaplaukių 11); Čihuahua 22 (iš jų trumpaplaukių 5, o ilgaplaukių 17). Parenkant ir poruojant veislinius šunis labai svarbu jų giminingumas. Giminingas veisimas gali turėti tiek teigiamų, tiek ir neigiamų pasekmių populiacijai. Gali padidinti proporciją homozigotų, turinčių reikalingą požymį. Kaip neigiama pasekmė yra tai, kad padidėja paveldimų recesyvinių ligų - inbrydingas padidina homozigotiškumo, tuo pačiu ir ligos, tikimybę. Iš nagrinėtų Estijos dviejų Australijos šilkinių terjerų veislynų „Magik šou“ ir „Volitans“ Australijos šilkinių terjerų kilmės dokumentų giminingo poravimo atvejų nerasta. Išnagrinėjus trijų Lietuvoje esančių Jorkšyrų terjerų veislynų... [toliau žr. visą tekstą] / More and more people choose small dogs breeds, because these dogs perfectly suit for the small apartments. Lonely people choose small dog breeds as well – as a company, rat – catchers, instead of “door – bell“, or very often as an accessory. Yorkshire Terrier recently is one of the most popular dogs breeds in Lithuania. From 1992 till 11th of November, 2007 in the dogs breeds’ book in Lithuanian Cynological Society there were registered: 1045 Yorkshire Terriers,10 Australian Silky Terriers, 343 Russian Toy dogs (175 shorthaired and 168 longhaired ones), 275 Chihuahua (53 shorthaired and 222 longhaired ones). There was this number of breeding grounds registered till 11th of November, 2007: 66 of Yorkshire Terriers, 1 of Australian Silky Terriers, 25 of Russian Toy dogs (14 shorthaired and 11 longhaired), 22 of Chihuahua (5 shorthaired and 17 longhaired). Selecting and mating pedigree dogs it is very important to pay attention to their relationship. Mating relative dogs can have positive results to the population as well as negative ones. It can increase the proportion of homozygote having a required feature. A negative side is a possible increase of recessive diseases – inbreeding increase the possibility of homozygotism, and at the same time increase the possibility of diseases. In the investigated cases in two Estonian breeding grounds for Australian Silky Terriers, no relationship mating was found in the pedigree documents. Pedigree documents investigation was made in three... [to full text]

The Elsenburg Merino flock has been divergently selected for the ability of ewes to rear multiple offspring since 1986. Updated genetic trends for reproduction are reported for the Elsenburg Merino resource flock. The objective was to determine whether genetic trends estimated previously for the Elsenburg Merino Resource flock changed significantly with the introduction of genetic material from the industry to the high (H) line. All analyses included the full pedigree file, consisting of 6547 individuals. Heritability estimates were 0.08 ± 0.02 for number of lambs weaned and 0.11 ± 0.02 for corrected weight of lamb weaned. The ewe permanent environment variance was estimated at 0.09 ± 0.02 and 0.11 ± 0.02 for number of lambs weaned and for corrected weight of lamb weaned, respectively. Genetic trends for the H and low (L) lines were divergent (P < 0.05) for all reproduction traits during the period prior to the observed breakpoints. Progress for number of lambs weaned in the H line stabilised after 1999 while a decline in response for weight of lamb weaned in the H line occurred after 2003. The change points may result from reduced selection intensity during the formation of reciprocal crossbred lines, or the introduction of unrelated industry sires in the H line. The pedigree was analysed and inbreeding trends computed for the H and L lines with the aim to test the significance of inbreeding within the lines. The software packages used for the statistical analyses were ENDOG v4.8 and POPREP web analysis software. The average inbreeding coefficients (F) were 1.47% and 0.73% for the divergently selected H and L lines. The rate of inbreeding (ΔF) per generation was 0.5% for the H line and 0.6% in the L line. The overall rates of inbreeding per generation were different in the H and L lines but within acceptable levels. The L line, however, showed an unwanted recent increase in inbreeding that will need to be considered in future. Since 2003, part of the Elsenburg Merino breeding flock was subjected to structured reciprocal within-breed crossing. Lamb survival traits and ewe reproductive performance of purebred (H and L) and reciprocal crosses (HxL and LxH) were evaluated using least squares analyses. Levels of heterosis were also assessed. The mean survival of the two crossbred lines was notably superior to the midparent value in absolute terms, although the contrast did not reach statistical significance (P = 0.098). Further research is required to establish whether this within breed heterosis for lamb survival can be exploited to decrease lamb losses. Reproduction, number of lambs born (NLB) and number of lambs weaned (NLW) in the H line was higher than in the L line (P < 0.05) while the two crossbred lines were intermediate and different from both the H line and the L line (P < 0.05) from the analyses of annual reproduction and overall “lifetime” reproduction across three lambing opportunities. Individual heterosis for annual reproduction was estimated at 2.2% for NLB, 13.8% for NLW and 8.5% for corrected weight of lamb weaned (TWW), with the estimate for NLW reaching significance (P < 0.05). Corresponding estimates for total production over three lambing opportunities were 8.7% for TNLB, 19.1% for TNLW and 13.8% for TTWW, with the estimate for NLW reaching significance (P < 0.05). Ten RAPD markers were used to study molecular divergence between the H and L lines. Phenotypic data on the lifetime reproduction of ewes born in 1999 and 2000 indicated that reproduction in the H line ewes was markedly higher than that of L line contemporaries (P < 0.01). The RAPD assay, conducted on 15 ewes from each line, used eight primers and produced 87% polymorphic loci. The mean coefficient of genetic differentiation between lines (Gst) was estimated to be 0.25. In conclusion, the H and L lines were shown to be divergent for genetic trends and levels of inbreeding. The derived estimates of heterosis may also be used to infer divergence between the lines and significant molecular divergence proven using RAPD assays. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

In this study the genetic diversity in Turkish native sheep breeds was investigated based on microsatellite DNA loci. In total, 423 samples from 11 native and crossbreed Turkish sheep breeds (Akkaraman, Morkaraman, Kivircik, ivesi, Dagli&ccedil / , Karayaka, HemSin, Norduz, Kangal, Konya Merinosu, T&uuml / rkgeldi) and one Iraqi breed (Hamdani) were analyzed by sampling from breeding farms and local breeders. After excluding close relatives by Kinship analysis, the genetic variation within breeds was estimated as gene diversities (HE), which ranged between 0.686 and 0.793. The mean number of observed alleles (MNA) ranged between 5.8 and 11.8. The allele frequency distribution across Turkey showed no gradient from east to west expected in accordance with the Neolithic Demic Diffusion model. The differentiation between different samples of Akkaraman, Dagli&ccedil / and Karayaka breeds was tested by FST index. Akkaraman1 sample from the breeding farm was significantly (P&lt / 0.001) different from the other two Akkaraman samples. Deviation from HW expectations observed for Akkaraman1, ivesi, Morkaraman and HemSin breeds. AMOVA analysis revealed that most of the total genetic variation (~90%) was partitioned within the individuals. In parallel to this observation, when factorial correspondence analysis and shared alleles distances were used to analyze the relationship between the individuals of the breeds, there was no clear discrimination between breeds. Moreover, NJ tree constructed based on DA genetic distance, and PC analyses were used to analyze among breed differentiation. Delaunay Network drew 4 genetic boundaries (two of them being parallel to geographic boundaries) between breeds. All the results indicated that Kivircik was the most differentiated breed. Finally, Mantel Test and Bottleneck analysis did not reveal a significant result. Kivircik breed, among all native Turkish breeds, was found to be the genetically closest to the European breeds based on the loci analyzed. The genetic variation in Turkish breeds was not much higher than that of European breeds, which might be a consequence of the recent sharp decrease in sheep number.

No description available.

The aim of this study was to compare the growth performance and incidences of health disorders of the Drakensberger breed to the collective total of all other beef breeds in feedlots. The objective was to conduct a meta-analysis on the performance, health and centralised growth data (Phase C) of all cattle breeds from different regions in South Africa. The intention was not to compare different breeds with each other but only the Drakensberger breed to other breeds and crossbreeds generally found in feedlots. Results from Phase C performance tests at the centres, as well as historical growth and health data were gathered from a number of feedlots. Data from feedlots were only accepted when individual animal records were kept; classification was according to breed type; and when Drakensbergers were present in the particular feedlot. The aim was to utilise historical records of up to ten years per feedlot. After initial processing and elimination of outliers, a meta-analysis was performed on the growth data. Each feedlot was analysed separately, followed by a final meta-analysis, which incorporated results from all the feedlots. It included 497 798 head of cattle from 5 feedlots, with a separate analysis on Phase C performance test data, comprising of 6139 animals from 4 Agricultural Research Council (ARC) test centres. Health data from 2 feedlots, comprising of 24 819 animals, along with Phase C performance test data from 2 ARC test centres, including 1746 head of cattle, were analysed. The variables included in the analysis were: average daily gain (ADG), feed conversion ratio (FCR), mortality and morbidity ratios and type of disease or disorder. In addition to determining the individual effects of breed, sex, season, year, region and diseases, possible interactions amongst these factors were investigated. The meta-analysis on the feedlot performance and Phase C performance tests revealed that other breeds had a higher (P < 0.01) ADG than Drakensbergers. No difference was observed between Drakensbergers and other breeds within gender and within season. The meta-analysis on Phase C performance test data showed no significant difference in FCR between Drakensbergers and other breeds. A feedlot study, including 23 554 head of cattle, has shown that Drakensbergers have a higher rate (P < 0.01) of respiratory disease occurrence during the winter season than other breeds. Likewise, results from the ARC test centre in Irene, consisting of 1553 animals, reveal that the occurrence of respiratory diseases was less (P < 0.01) in other breeds than in Drakensbergers. However, there seem to be no significant differences in the occurrence of metabolic disturbances and other diseases between Drakensbergers and other breeds. Although a statistical difference of only 20 grams per day (P < 0.01) in ADG were found between Drakensbergers and other breeds in feedlots and test centres, the biological and economical effect would most probably be insignificant. The large dataset of close to 500 000 cattle also contributed to such a small weight difference being significant. The majority of the contributing feedlots stated that their record keeping lack accuracy and do not comprise of a complete set of health data. Readers are therefore advised to interpret the health data analyses with caution as the analyses are not representative of the actual health status of cattle in the feedlot industry, simply because accurate data does not exist. / Dissertation (MSc(Agric))--University of Pretoria, 2013. / Animal and Wildlife Sciences / unrestricted

Although the Afrikaner and Black-headed Persian were used in several previous studies for upgrading with Karakul rams, this study looked at how fast progress could be made to produce good quality marketable pelts as well as producing ewe material to increase Karakul ewe numbers. Market requirements have also changed in the past years. After three generations of upgrading it was found that, especially in colour inheritance, faster progress was made as in previous studies with just a small percentage of spotted animals (1.3 % in the F₃-generation). All economic important pelt traits (pattern, hair quality, texture, lustre and curl type) improved significantly from the F₁ to the F₃ generation and it compares well with the control group (pure bred black and white Karakul). The type of rams that gave the best results with upgrading, were the less developed type with good hair quality and good pattern forming characteristics (watered-silk and shallow watered-silk). Pelt types improved from the F₁ which were under average and of poor quality to higher quality pelts which received above average prices on auctions for the F₂ and F₃ generations. It appears that the Afrikaner and Black-headed Persian can both be used with success in an upgrading program, all depending on what colour breeding (black or white) there is a need for. / Dissertation (MSc (Agric) (Animal Science))--University of Pretoria, 2007. / Animal and Wildlife Sciences / MSc (Agric) / Unrestricted