|
|
Heredity of polledness in cattle
HEGROVÁ, Kateřina
Most cattle breeds were originally naturally horned. The horns were used as a tool of defense and a manifestation of dominance in the herd. With increasing pressure to increase the efficiency of breeding and increase the safety of both animals and care-givers, horned cattle are being dehorned. However, this does not correspond with welfare requirements. In 2009, the complete genome of cattle was sequenced, which started a series of researches in the field of heredity. Genetic manifestations of horns or polledness are controlled by the autosomal locus polled, located on chromosome pair BTA1, characterized by two alleles, for the dominant P allele representing polledness, and for the recessive allele p for horns. In cattle we encounter 4 mutations of these alleles Celtic, Frisian, Mongolian and Guarany. Manifestations of polledness are also influenced by alleles for the presence of scurrs Sc and sc, or alleles for the manifestation of the so-called African horns Af and An. Thanks to the testing of individuals using microsatellite markers or the SNP method, it is possible to mark genetically polled individuals and thus help breeders to expand hornless breeds.
|
|
|
The analysis of efficiency and fertility with regard to presence of horns in dairy cow herd
TOMANOVÁ, Jana
For quite a long time there is trend of de-horned cattle supported in our country and in the whole developed world especially for safety of farmers and animals. Despite of this fact, especially in organic breeds, there are quite often these two forms together in one herd. The aim of this thesis was to evaluate the efficiency and fertility of Holstein cows with regard to presence of horns. Observation of a herd of Holstein cattle took place from April 2010 to September of 2011 at Bemagro, a.s. The priority of this ecologically farming company is to preserve horns in the herd. A total amount of 100 cows was observed, from which 50 of them was de-horned and the equal amount was horned. There were indicators of fertility measured (service period and insemination interval) as well as indicators of milk production (the amount of milk, content of fat, proteins and lactose).
|
guest ::
