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

Over two years' period (19922 to 1993) the ensilage capacity of interg eneric hybrids of grasses, tetraploid varieties of red clover and thei r two components' simple mixtures was observed. The trial was conducte d 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 am ount of forage for in vivo digestibility trials with wethers. The seed rates for intergeneric varieties of grasses, red clover and grass/clo ver mixtures were 35, 15 and 15 + 8 kg/ha, resp. All swards were estab lished in September 1991. The following doses of mineral fertilizers w ere 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 intergeneri c hybrids of grasses - varieties Felina, Hykor, Becva and Perun, tetra ploid red clover - varieties Vesna, Kvarta and Radegast were used. Com position of grass/clover mixtures is given in Tabs I, II. The swards w ere cut in the same period: beginning of ear emergency of grasses. Imm ediately after cutting the mean sample of all variants were taken. Dry matter, crude protein, crude fibre, ether extract and ash contents we re analyzed (according to CSN 46 7007). On the basis of analyzed nutri ents the content of nitrogen-free extract and organic matter were calc ulated. Ensilage capacity was determined by the ratio of monocarbohydr ates + water soluble carbohydrates: crude protein (S/CP ratio). The re sults proved that carbohydrate content was strongly and significantly higher in the 1st than in the 2nd cuts in intergeneric hybrids of gras ses. Even more important was the difference in monocarbohydrate conten t. In significantly higher content of carbohydrates in the Ist cut in varieties of tetraploid red clover caused that the differences in carb ohydrate content in grass/clover mixtures were only slightly significa ntly higher in comparison with the 2nd cut. A strong correlation depen dence was found between carbohydrate content and cuts (r = -0.6106(++) ). Crude protein content was getting higher in the 2nd cut in all grou ps but the differences were not significant. This was confirmed also b y 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 th e Ist cut, what is confirmed also by strong correlation dependence (r = -0.4900(++)). It can be concluded that the fermentation process of i ntergeneric hybrids of grasses will be the most-favourable in the Ist cut. The same tendency can be found for tetraploid varieties of red cl over if the forage was prewilted. If the technology of prewilting is n ot used then the fermentation process will be influenced by low dry ma tter content. The similar situation is also with simple grass/clover m ixtures.