Effects of dietary n-3 polyunsaturated fatty acids and ... - FINS

1 st WorkshopXIII International Feed Technology SymposiumBoth in 2003 and 2004, to prepare whole plant maize silage, hybrids NS SC 663 andZP SC 677 were planted. In addition, in production of whole plant maize silage, alltechnological operations were implemented.In 2003, maize was harvested and silage prepared from 25 August to 1 September,and in 2004 between 30 August and 6 September. Silage was prepared in the milkywaxyphase of maize ripening.A chemical analysis for the content of moisture, raw proteins, raw fat and ash wasdone using the Weende method. The chemical analysis for the content of neutral(NDF) and acid (ADF) detergent fibers the Van Soest method was used.The chemical analysis for total content of lactic, acetic and butyric acid was doneusing the Wigner Magasanic method.RESULTS AND DISCUSSIONHaving in mind that in both years virtually identical agritechnical measures wereapplied, it can be concluded that the large differences in yield in 2003 and 2004, forboth cultures, were caused by extreme differenced of precipitation in the monitoredperiod. In the exceptionally dry 2003, yields were drastically decreased, and in therainy 2004, yields were up to two times higher than in the preceding year (Table 1).Indexes in Table 1 show that yield decrease in the dry 2003 was less pronounced forsudan grass than for maize, i.e. that sudan grass proved to be more resistant to thedraught than maize.Table 1. Achieved yield of fresh green mass (t/ha)SpeciesYear2003 2004Maize 15,2 32,4Sudan grass 41,8 66,7IndexRealized yields are one of the two most important indicators of suitability of a culturefor producing animal feed. Table 1 shows that, according to this indicator, sudangrass, especially in unfavorable years, has significantly higher yields, recommendingan increase of its share in the planting structure in order to increase production ofanimal feed (silage). The second most important indicator of suitability of a culturefor producing animal feed is its chemical composition, which directly influences thequality of feed (in this case silage) prepared from that culture. The quality ofprepared silage directly influences both the level of consumption of dry matter peranimal, and the level of utilization of consumed dry matter. Table 2 presents thequality of prepared whole plant maize silage and sudan grass silage in 2004.255