UTJECAJ RAZINE ENERGIJE OBROKA U SUHOSTAJU I RANOJ LAKTACIJI NA PROIZVODNE REZULTATE VISOKOMLIJEČNIH KRAVA ; EFFECT OF ENERGY LEVEL OF RATIONS IN DRY PERIOD AND EARLY LACTATION ON PRODUCTION OF HIGH YIELDING DAIRY COWS

Istraživanje utjecaja različite razine energije obroka u 50 dana suhostaja ( 1,57 U.H. i 1.93 U.h. ) i različite koncentracije neto energije obroka 105,0% i 115,0% HJ u suhoj tvari obroka u 90 dana rane laktacije, izvršeno je sa 4 grupe Holstein friesian krava s po 11 krava. Krave su hranjene u suhostaju i ranoj laktaciji obrocima različite razine energije: nizak - nizak, nizak - visok, visok - nizak i visok - visok. Hranidba obrocima različite razine energije u suhostaju nije utjecala na proizvodnju mlijeka u ranoj laktaciji. Hranidba krava kompletnim obrocima po volji vece koncentracije neto energije signifikantno je povećala dnevnu proizvodnju mlijeka i 4% MKM (P<0,01) i nesignifikantno ukupnu proizvodnju 4% MKM (P>0,05) u 90 dana rane laktacije. Najmanji utrošak hrane po kg 4% MKM ostvarila je grupa krava obrokom nizak -visok nivo energije. Najslabije iskoristavanje hrane u proizvodnji mlijeka ostvarila je grupa krava s razinom energije visok - visok. Krave hranjene obrocima s visokom koncentracijom energije u ranoj laktaciji trošile su više koncentrata po kg 4% MKM. Krave hranjenje obrocima s razinom energije nizak - visok i visok - visok osvarile su ranije veći vrh proizvodnje mlijeka, što je doprinijelo nesignifikantnom povečanju ukupne proizvodnje 4 % MKM. Na osnovu rezultata istraživanja proizlazi da hranidba s obrocima razine energije nizak - visok u suhostaju i ranoj laktaciji može predstavljati osnovicu za bolje iskorištavanje proizvodnih kapaciteta za mliječnost Holstein friesian krava. ; Effects of different energy levels in rations offered during the 50 days of dry period (1,57 M.R. and 1.93 M.R.) and different concentration of net energy in rations, 105.0 and 115.0% F. U., in dry matter of rations during the 90 days of early lactation, were studied on four groups of HF cows, 11 in each. The cows were ted rations of different energy levels: low - low, low - high, high - low and high - high during the dry period and in early lactation. Feeding rations of different energy levels in the dry period did not influence milk production in early lactation. Feeding cows complete rations ad lib. and with higher concentration of net energy significantly increased daily milk production and 4% FCM (P) and nonsignificantly total production of 4% FCM (P>0,05) during the 90 days of early lactation. The least feed consumption per one kg of 4 % FCM was observed in the group fed low - high energy level. The least utilization of the feed in milk production was observed in the group fed high - high energy level. Cows fed rations with high concentration of energy in early lactation consumed more concentrates per one kg of 4 % FCM. Cows fed low - high and high - high energy levels reached earlier and higher peak of their milk production, which accounted for a nonsignificant increase of total production of 4% FCM. Based on results of testing, it comes out that feeding rations with low - high energy level during the dry period and early lactation represents a basis for i better utilization of production facilities and milk production of HF cows.