The Perenič organic farm has about 40 dairy cows, mostly of the Brown Swiss breed.
In March 2023, we started nutritional management for dairy cows according to the
model of Orešnik (1996) and carried it out until May 2023. The results of the ration
change were monitored using AT4 control. The ration consisted mainly of grass silage
from the first and second cut and hay. The analysis showed that the home-grown
roughage was of rather poor quality and especially of low protein content. The ration
lacked energy (for 2 kg of milk), so we added more maize and reduced the amount of
lucerne in the new ration, we also added more mineral vitamin supplement and salt. The
average milk yield before the diet was 22.19 kg, in April 22.22 kg and in May 25.03 kg.
Milk yield from roughage was 12.99 kg/day before management, decreased to 11.82 kg
in April, and increased to 14.63 kg/day in May due to the much better quality of the new
roughage. Concentrate feed per kg of milk increased from 210 g in March to 230 g in
April and then decreased to 200 g in May. Energy utilisation was 109.9 % before
management, dropped to 100.0 % in April, and increased to 115.2 % in May. This
indicates that the nutrition management of dairy cows on Perenič farm was not precise
enough.
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