Studies Regarding the Development of Two Genetic Lines of Holstein Friesian Cows Differing in Mature Live Weight

Abstract

To achieve optimal profitability in dairy production the type of cow farmed must be suitable for the production system operated. Matching the right type of dairy cow to the dairying will become more important in the future as dairying systems became more diverse. This paper uses first results from current Simnic Holstein Friesian comparison trial to project the type of cows that will best complement the systems that are developing today and in the future. In 2004 the experimental herd of Holstein Friesian cows at ARDS Simnic Craiova provided the foundation cows to develop two lines of cows differing in mature weight. Multiparous cows from the base herd were blocked by parity, milk solids yield and live weight. Within each block, the heavier cows were inseminated with semen material from bulls with higher breeding value for live weight, and the lighter cows were inseminated with semen material from bulls with low breeding value for live weight. The 2 lines developed were „the genetic line of Simnic Holstein Friesian with heavy live weight” (HF Simnic GVM) and „the genetic line of Simnic Holstein Friesian with light live weight” (HF Simnic GVm).