The fat and protein content of the sheep milk under different conditions

In Hungary the Hungarian Combing Merino has been and still is the most common sheep breed. In order to increase the milk production traits, especially the milk components, several crossings were made. In an experiment lasting three years the fat, protein and dry matter contents of the milk produced by ewes belonging to different genotypes: Merino, (Merino x East-Friesian) F1, (Merino x Langhe) F1, (Merino x Sarda) F1, (Merino x Pleven) F1 and (Merino x Awassi) F1 were studied. The test milkings of the ewes were carried out fortnightly, twice a day. From the study the following conclusions could be drawn: (i) the East-Friesian F1 ewes produced the largest amount of fat, protein and dry matter in their milk; followed by Langhe F1, Sarda F1, Pleven F1, Awassi F1 and Merinos in the ranking; (ii) the improvement in conditions gave an increased yield of the studied traits; and (iii) the pre-selection of Merinos on the basis of milk production should be made prior to the start of crossbreeding considering to increase the milk production traits

Economic necessity for developing the milk sector

The Merinos dominating in the Hungarian sheep industry and the profitability of sheep production is not as high as would be necessary. Economic analysis was made to find out the possible break-even points. According to the results, the increase of milk production might be the key to solve this problem, but some conditions should be considered. Regarding the data presented the possible conclusions might be summarized as follows: Enlarging the stock without improving the phenotypic background is not profitable. This method will lead to a deadlock. The utilization of milk breeds under the present conditions could be realized: (i) if the costs of changing the breeding animals could be covered from other sources, since national sources are not available; (ii) if the attitude of the managers and employees of milk sheep farms could change; and (iii) if the price of milk was reasonable and the state purchase prices could reach the average prices of the EU (1 Euro/litre)

Development and Validation of 58K SNP-Array and High-Density Linkage Map in Nile Tilapia (O. niloticus)

Despite being the second most important aquaculture species in the world accounting for 7.4% of global production in 2015, tilapia aquaculture has lacked genomic tools like SNP-arrays and high-density linkage maps to improve selection accuracy and accelerate genetic progress. In this paper, we describe the development of a genotyping array containing more than 58,000 SNPs for Nile tilapia (Oreochromis niloticus). SNPs were identified from whole genome resequencing of 32 individuals from the commercial population of the Genomar strain, and were selected for the SNP-array based on polymorphic information content and physical distribution across the genome using the Orenil1.1 genome assembly as reference sequence. SNP-performance was evaluated by genotyping 4991 individuals, including 689 offspring belonging to 41 full-sib families, which revealed high-quality genotype data for 43,588 SNPs. A preliminary genetic linkage map was constructed using Lepmap2 which in turn was integrated with information from the O_niloticus_UMD1 genome assembly to produce an integrated physical and genetic linkage map comprising 40,186 SNPs distributed across 22 linkage groups (LGs). Around one-third of the LGs showed a different recombination rate between sexes, with the female being greater than the male map by a factor of 1.2 (1632.9 to 1359.6 cM, respectively), with most LGs displaying a sigmoid recombination profile. Finally, the sex-determining locus was mapped to position 40.53 cM on LG23, in the vicinity of the anti-Müllerian hormone (amh) gene. These new resources has the potential to greatly influence and improve the genetic gain when applying genomic selection and surpass the difficulties of efficient selection for invasively measured traits in Nile tilapia

SNP genotyping reveals substructuring in weakly differentiated populations of Atlantic cod (Gadus morhua) from diverse environments in the Baltic Sea

Atlantic cod (Gadus morhua) is one of the most important fish species in northern Europe for several reasons including its predator status in marine ecosystems, its historical role in fisheries, its potential in aquaculture and its strong public profile. However, due to over-exploitation in the North Atlantic and changes in the ecosystem, many cod populations have been reduced in size and genetic diversity. Cod populations in the Baltic Proper, Kattegat and North Sea have been analyzed using a species specific single nucleotide polymorphism (SNP) array. Using a subset of 8,706 SNPs, moderate genetic differences were found between subdivisions in three traditionally delineated cod management stocks: Kattegat, western and eastern Baltic. However, an FST measure of population differentiation based on allele frequencies from 588 outlier loci for 2 population groups, one including 5 western and the other 4 eastern Baltic populations, indicated high genetic differentiation. In this paper, differentiation has been demonstrated not only between, but also within western and eastern Baltic cod stocks for the first time, with salinity appearing to be the most important environmental factor influencing the maintenance of cod population divergence between the western and eastern Baltic Sea

Application Of Molecular Genetic Methods For The Identification Of Booroola (Fecb) Mutation Carriers In The Hungarian Prolific Merino Breed

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