Author/Editor		Rajčevič, M; Jazbec, I; Ponikvar, M
Title		Oskrbljenost visokoproduktivnih krav z energijo med poletnim krmljenjem na paši
Translated title		Energy supply in highly productive cows during the summer feeding regime on pasture
Type		članek
Source		Zb Vet Fak Univ Ljublj
Vol. and No.		Letnik 30, št. 2
Publication year		1993
Volume		str. 191-8
Language		slo
Abstract		The aim of the present research was to study the nutritional status in a herd with 200 highly productive cows during summer grazing. The consumed nutritive matters of a ration, concentration of urea in milk and serum and total serum proteins (TSP) were taken as criteria. In May, June, July and September 15 cows in the post-partum period were included in the research. Cows were grazing day and night and in the stable they recived 2-3 kg hay, 8-9 kg maize silage, 3 kg beet pulp and 2.5 kg concentrates. The chemical composition of feedstuff, of rnilk, urea in the milk, urea in the blood serum and TSP were determined. The results were statistically evaluated by the T-test. The following are correlations between the average consumed nutritive matters per ration and concentration of urea in the milk serum and TSP: in May the significant correlation appears between consumed proteins and urea in the milk (r = -0.529*), in June between NEL and urea in the serum (r = 0.623) and in September between NEL and urea in the serum (r = 0.632) and in September between NEL and TSP (r = 0.424). Under the conditions of our trial, in which there was neither a significant surplus of proteins nor significant deficiency of energy, no correlations between the nutritive matters of the ration and concentration of urea in milk and serum have been found. But indeces such as content of protein in milk and urea in milk and serum indicate a lacking balance of nutritive matters in the consumed ration.
Descriptors		CATTLE ANIMAL FEED MILK UREA SILAGE UREA ENERGY METABOLISM