Feeding potential of summer grain crop residues for woolled sheep in the south-eastern Transvaal Highveld. II. Selection of material and intake

Abstract

Dohne Merino wethers grazed crop residues of lupins, dry beans, soybeans, sunflower, sorghum and maize at a stocking rate of 10 wethers/ha. Three wethers in every treatment were oesophageally fistulated and during sampling periods the other seven were fitted with faecal bags. Oesophageal and faecal samples were taken during the same period every second week. Oesophageasl samples were separated into grain and straw (including weeds) to determine the grain:straw ratio and were analysed for dry matter (DM), organic matter (OM), crude protein (CP) and in vitro digestible organic matter (IVDOM). Digestible organic matter and protein intake of sheep generally decreased with time as grain availability declined. At commencement of grazing the nutritional value of the residues was sufficient for sheep to increase mass. Crude-protein intake decreased with time and should be supplemented to sustain production .

 Dohnemerinohamels het die oesreste van lupiene, droebone, sojabone, sonneblom, sorghum en mielies teen 'n belading van 10 skape/ha bewei. Drie van die hamels in elke groep was slukdermgefistuleerd en gedurende monsternemingsperiodes het die ander sewe hamels missakke gedra. Slukderm- en mismonsters is gedurende dieselfde periode elke tweede week geneem. Slukdermmonsters is in graan- en strooikomponente( insluitend onkruid) verdeel om die gran: strooiverhouding te bepaal en is vir droe materiaal (DM), organiese materiaal (OM), ruprotei'en (RP) en in vitro organiese materiaal verteerbaarheid( IVOMV) ontleed. Verteerbare organiese materiaal-en protei'eninname het oor tydafgeneem soos die hoeveelheid graan beskikbaar afgeneem het. Met aanvang van beweiding was die voedingswaarde van die oesreste hoog genoeg vir massatoename by die skape. Proteieninname het oor tyd gedaal en moet aangevul word om produksie te onderhou.

 Keywords: Sheep, crop residues,digestible organic matter intake,protein intake