A polyol mixture or molasses treated beet pulp in the silage based diet of dairy cows: I. The effect on the feed utilization, milk yield and blood values

This study investigated the effect of a polyol mixture or molasses treated beet pulp on the feed utilization, milk yield and blood values. 24 cows were divided into 3 groups. Hay was given at 2 kg/d, silage ad lib. and concentrate mixture at 78 kg according to the milk yield. The control group had grain (barley-oat) concentrate mixture, the molasses group had grain supplemented with 29 % dried molasses beet pulp and for the polyol group grain was supplemented with 25 % dried beet pulp treated with mixture of sugar alcohols. A 2 weeks standardisation period was followed by 12 of comparison. 12 of the cows were also in a digestibility trial in the later part of the comparison period. Feed intake was heavily reduced in the molasses group and hence the milk yield was significantly lower (P < 0,05) than in the polyol or control groups (19,5, 21,2 and 21,2 kg FCM/d). The mean consumption of polyols was 483 g/d and that of sugars from the molasses beet pulp was 410 g/d. The feed utilization was significantly lower (P < 0,05) in the control group than in the polyol or molasses groups. The consumptions of f.f.u./kg FCM were correspondingly 0,407, 0,375 and 0,373. Digestibility of nitrogen free extracts was significantly higher for the polyol group than for the control group (81,4 and 78,1 %). For molasses group digestibility of NFE was 78,5 %. Digestibility of OM was correspondingly 76,2, 73,6 and 74,3. Rumen butyric acid formation was higher in the polyol group than in the molasses or control groups, although the differences were not statistically sinificant. The blood and plasma parameters studied were haemoglobin, PVC, ketone bodies in blood, glucose, total protein, urea-N and uric acid in plasma. Plasma urea-N was higher (P < 0,01) in the control than the polyol or molasses groups. In glucose or ketone bodies concentration there were no treatment induced differences.