The digestibility and nutritive value of sugar beet top silage for sows

Authors

• Maija-Liisa Salo Department of Animal Husbandry, University of Helsinki, 00710 Helsinki 71
• Elisa Laakso Department of Animal Husbandry, University of Helsinki, 00710 Helsinki 71

DOI: https://doi.org/10.23986/afsci.71937

Abstract

The digestibility of beet top silage made from tops harvested with a mower chopper was determined with five adult, pregnant sows. Two rations of 6 kg/day (Trial I) and 2 kg/day (Trial II) were tested, with the dry matter comprising 48 (I) and 20 % (II) of the total dry matter of the barley-based diet. The average digestibilities of silage were 68.6 (I) and 69.3 % (II) for organic matter and 71.0 (I) and 64.4 % (II) for crude protein. The pepsin-solubility of crude protein was 85 %. The calculated energy value was 2.21 Meal. ME/kg DM, corresponding to 0.60 f.u./kg DM (f.u. =C.7 starch units), and the protein value 142 g DCP/kg DM. The amino acid composition of crude protein of both fresh and ensiled tops was better than that reported for beet tops cut at ground level. The composition changed very little during ensilage. Beet top silage is rich in all required minerals except phosphorus. The oxalic acid converts silage Ca and even extra Ca to an indigestible form, but does not impair the digestibility of Mg. The large amounts of K and Na raise the pH of urine to a high level. The trace element contents of beet tops are well above the established requirements for pigs and the excess is secreted in the faeces.