Gene technology and milk production

The introduction of gene technology to the practice of animal breeding has opened new venues as we enter the 21st century Using DNA based genotyping t he new genetic variants of milk protein genes were identified and basic reg ulatory mechanisms of the lactoprotein gene expression were discovered. Gen omic and cDNA sequences for all major lactoprotein genes were deposited in the GenBank and comprehensive analysis of these data revealed the molecular basis of some quantitative effects which have been reported to be associat ed with particular genetic variants. In addition, comprehensive analysis of the animal genome enabled chromosomal localization of candidate regions be aring quantitative trait loci with effects on milk traits. The possibility to assess maternal and paternal inheritance of desired lactoprotein alleles can be utilised for efficient selection of desired haplotypes. Beside the possibility to change the milk composition through selection of favourable lactoprotein alleles, there is also the chance to manipulate milk compositi on via metabolic pathways, which regulate fat and carbohydrate synthesis. R eduction of the amount of saturated fatty acids and lactose in bovine milk are two interesting tasks for the future in order to adapt bovine milk to t he requirements of modem human nutrition and to make bovine milk acceptable for special groups of consumers. Finally, the availability of recombinant growth hormone induced new technologies of milk production based on prolong ed lactation with high persistence of milk yield.