The influence of development phase, cut and degree of wilting on parameters of chemical composition, proteolysis and quality in lucerne silage

Abstract

Different phases of plant development (beginning of bloom - 10% flowers, midbloom - 50% flowers), two growth cycles (II and IV cut) and two levels of biomass wilting (DM = 320 gkg-1 and 410 gkg-1) on changes in chemical composition, proteolysis and quality of lucerne silage were investigated in this experiment. Experiment was set as statistical model 2×2×2 (2k). Based on the results of chemical analysis it is confirmed that in earlier cut lucerne silages there was more crude protein, ammonia and soluble nitrogen , and less crude fiber (p lt 0.05). Lucerne silages from IV cut were very little different from silages from II cut in nutrient content and quality parameters. Wilting lucerne to the highest level of dry matter reduced total fermentation and proteolysis (p lt 0.05). At the same time there were no significant differences in chemical composition of silages (p>0.05), unless protein. On the basis of this investigations it can be concluded that ensiling of lucerne in latter phases of plant development, with higher degree of wilting, produces silages with better quality parameters, but also with significantly lower nutritive value. Therefore the use of various methods of induction and stimulation of lactic acid fermentation is recommended for lucerne mass cut in earlier development phases - with the aim to obtain maximum nutrients and best quality.

U radu je ispitivan uticaj različitih faza razvića (početak cvetanja - 10% iscvetalosti, sredina cvetanja - 50% iscvetalosti), dva ciklusa korišćenja (II i IV otkos) i dva stepena provenulosti biomase, odnosno sadržaja suve materije (SM = 320 g/kg i 410 g/ kg) na promene parametara hemijskog sastava, proteolize i kvaliteta silaže lucerke. Eksperiment je postavljen po statističkom modelu 2×2×2 (2k). Na osnovu rezultata hemijskih analiza utvrđeno je u silažama ranije košene lucerke veći sadržaj proteina, amonijaka i rastvorljivog zota i manji sadržaj sirove celuloze (p lt 0,05). Silaže lucerke iz IV otkosa su se minimalno razlikovale u pogledu sadržaja hranljivih materija i parametara kvaliteta u odnosu na silaže lucerke iz II otkosa. Provenjavanje lucerke do većeg nivoa suve materije je dovelo do redukcije fermentacije i proteolize (p lt 0,05). Pri tome nije bilo statistički značajnih razlika u pogledu hemijskog sastava silaža (p>0,05), izuzev proteina. Na osnovu izvedenih ispitivanja može se zaključiti da se siliranjem lucerke iz kasnijih faza razvića, uz veći stepen provenjavanja, postiže bolji kvalitet silaža, ali se signifikantno smanjuje hranljiva vrednost. Zbog toga se preporučuje primena različitih metoda indukcije i stimulacije mlečnokiselinskog vrenja za materijal košen u ranijim fenofazama, kako bi se dobila maksimalna hranljiva vrednost i maksimalan kvalitet.