Physical properties and fermentation profile of maize silage on large farms in Croatia

Maize silage is the main forage for ruminant livestock in Croatia. Production of substances determines quality of ensiling during the process and, therefore, has an impact on nutritive value, consumption, and health of cattle. Since in Croatia there is no systematic research of ensiling quality, this study aimed to determine quality parameters values of maize silage from large farms in continental Croatia during the spring of 2016. In total 33 samples of maize silage were representatively sampled by taking silage from the entire cross-section of the silo. Selected quality parameters included dry matter (DM) and ash contents, pH and titratable acidity, water holding capacity, particle size of the whole silage and separated grains, and aroma according to the "Sil-All for corn silage" (Danstar Ferment Ag, Switzerland). Nearly half of the analyzed samples had DM content outside the optimal range (300 – 400 g*kg-1). The pH value of silages was within the optimal range (3.5 – 4.2) which indicated that the active phase of ensiling was properly done. However, two-thirds of samples had an undesirable aroma which indicated changes of fermentation products occurred during the stable phase. Titratable acidity of tested silages, with a range from 11.61 to 128.93 meqv. NaOH*100 g-1 DM, indicated their different buffering properties in the rumen. Water holding capacity varied from 4.4 to 8.57 g*g-1 DM and this range implied variable fiber content in analyzed samples. Grain content in silages ranged from 23.86 to 45.05% whereas its geometric particle size was in a range from 2.15 to 4.3 mm. When considering particle distribution of whole silage on PSPS (Penn State Forage Particle Separator) sieves, a half or more than half samples had content on individual sieves outside the optimal ranges. In conclusion, maize silages on large dairy and fattening farms in continental Croatia are very variable in quality and, in many parameters, of lower quality than the standards implying that more attention must be given to the silage production procedures.