Investigation of culling practices on a dairy farm

Absztrakt

Main aim of cattle breeding is to keep cattles with high productivity in production as long as possible. Thus length of productive lifetime can be increased. Culling is a complex decision. During that age, phases of lactation cycle, milk production, reproduction attributes and health stage all have to be taken into account. Optimal timing is important at culling as too early or too late culling results in economic loss.  Culling decision is influenced by economic factors as well such as quantity and price of milk, price of culled cow, purchase price and raising cost of heifer. Many heifer have to be settled into production so all heifer which is suitable for reproduction has to be kept for breeding. As a result of this, all heifer that is healthy in context of reproduction biology has to be taken into breeding. Investigations of this study were made on a Hungarian dairy cattle farm. There is untied system on the farm. Cattles are grouped based on production level and stage of lactation. Daily milking number is three. Culling reasons were analysed in the first three lactations. Based on investigated data, 1175 cow were culled during five years which means 235 cows annually. There were differences between culling reasons. Udder health problems were the main reasons of culling. These presented 30% of the total cullings with 348 individuals. Several individuals were culled without fertilisation in the given lactation. The reason of this could be that the cow did not get pregnant again or other diseases and injuries occurred during lactation period. Most diseases occurred in the first 25 days of second lactation.