THE EFFECT OF ADMINISTRATION OF RAPESEED MEAL TO PREGNANT SOWS ON THERESULTS OF EFFICIENCY IN THE 1ST 3 LITTERS

In the trial carried out on the special-purpose farm of the Research I nstitute of Animal Nutrition at Pohorelice the effect of various sourc es of crude protein in the mixture for pregnant sows was studied. The experimental investigation included 84 sows-crossbreds of the Large Wh ite and Landrace breeds which after end of rearing (approximately at 1 20 kg of live weight) were divided into three identical experimental g roups based on their origin and live weight. According to the starting of the heat were gradually mated by boars (brothers). The feed mixtur e for pregnant sows, instead of 3.9% of soybean meal (group SES), cont ained 4.7% of rapeseed meal (group RES) in the first experimental grou p and 3 % of RES in the second experimental group and 3 % of pea (grou p RES+H). The level of lysine was equalized on the same calculated lev el in all groups. The calculated average daily intake of glucosinolate s - GSL (from mating to 110 days of pregnancy) was 7.259 mMol (RES) an d/or 4.633 mMol (RES+H). It was found out that the replacement of soyb ean meal (SES) by rapeseed meal alone or in combination with pea (RESH) had not any significant influence on live weight of sows in the thr ee first following litters. In spite of it, the weight of born piglets was negatively affected by feeding. Significant influence (P < 0.05) was recorded particularly in the first two litters. Daily intake 1 muM ol of GSL/W0.75 lowers theoretically the weight of born piglet by 0.58 9 g. The level of glucosinolates is probably a main factor which has n egative impact on the weight of born piglets. For this reason we recom mend to use the level of glucosinolates lower than 4,633 mMol for feed ing of sows per feeding day of pregnant sow.