EVALUATION OF MIXED RATION STRUCTURE FOR HIGH-YIELDING HOLSTEIN CATTLE

Abstract

The purpose of the research is to investigate mixed ration structure for different phases of dairy cattle lactation. Structure of ruminants' rations mainly determined digestion processes in forestomaches as well as feedstuff intake. Feed particles size is a crucial physical index. It is well known that wet fiber play key role in structural component of cows' ration. One kilo of raw fiber result into 3 hours of chewing activity. Evaluation was performed according to the method developed by scientists of the Pennsylvania State University, USA. Evaluation of feed rations structure is utilized in the USA and EC countries as a quick analysis of the feedstuff value for the dairy cows. Research was performed on two groups of animals being at first and second phases of lactation in 2012 and 2013 at a modern mega farm in Krasnodar Region. Amount of feed particles (size more than 19mm) left on the first layer of separator was 8.1-23.3% while recommended residue quantity should be 6-10% after separation of the feedstuff. Middle layer residues (size 8-19 mm) fluctuated between 27.7-47.8% while recommended ones are 30-50%. Particles less than 8 mm amounted to 39.5-64.8% at the rate of 40-60%. It was stated that feedstuff structure has significant fluctuations during year which affects ration eating and ruminate time of cows.