ENSILAGE CAPACITY OF INTERGENERIC HYBRIDS OF GRASSES, RED-CLOVER AND THEIR SIMPLE MIXTURES

Over two years' period (19922 to 1993) the ensilage capacity of intergeneric hybrids of grasses, tetraploid varieties of red clover and their two components' simple mixtures was observed. The trial was conducted at the co-operative farm Zajezova (500 m a. s. l.) on large plots of area 150 m(2) per each variant with the aim produce the sufficient amount of forage for in vivo digestibility trials with wethers. The seed rates for intergeneric varieties of grasses, red clover and grass/clover mixtures were 35, 15 and 15 + 8 kg/ha, resp. All swards were established in September 1991. The following doses of mineral fertilizers were used: 40 kg P and 80 kg K in spring + 50 kg N/ha for grasses. The same N-dose was used also after the 1st cut. The following intergeneric hybrids of grasses - varieties Felina, Hykor, Becva and Perun, tetraploid red clover - varieties Vesna, Kvarta and Radegast were used. Composition of grass/clover mixtures is given in Tabs I, II. The swards were cut in the same period: beginning of ear emergency of grasses. Immediately after cutting the mean sample of all variants were taken. Dry matter, crude protein, crude fibre, ether extract and ash contents were analyzed (according to CSN 46 7007). On the basis of analyzed nutrients the content of nitrogen-free extract and organic matter were calculated. Ensilage capacity was determined by the ratio of monocarbohydrates + water soluble carbohydrates: crude protein (S/CP ratio). The results proved that carbohydrate content was strongly and significantly higher in the 1st than in the 2nd cuts in intergeneric hybrids of grasses. Even more important was the difference in monocarbohydrate content. In significantly higher content of carbohydrates in the Ist cut in varieties of tetraploid red clover caused that the differences in carbohydrate content in grass/clover mixtures were only slightly significantly higher in comparison with the 2nd cut. A strong correlation dependence was found between carbohydrate content and cuts (r = -0.6106(++)). Crude protein content was getting higher in the 2nd cut in all groups but the differences were not significant. This was confirmed also by insignificant correlation dependence (r = 0.1498). Ensilage capacity coefficient in intergeneric hybrids of grasses, tetraploid varieties of red clover and their simple mixtures was significantly higher in the Ist cut, what is confirmed also by strong correlation dependence (r = -0.4900(++)). It can be concluded that the fermentation process of intergeneric hybrids of grasses will be the most-favourable in the Ist cut. The same tendency can be found for tetraploid varieties of red clover if the forage was prewilted. If the technology of prewilting is not used then the fermentation process will be influenced by low dry matter content. The similar situation is also with simple grass/clover mixtures.