Feeding potential of summer grain crop residues for woolled sheep in the south-eastern Transvaal Highveld. I. Availability of crop residues and sheep mass changes

Abstract

In a two-year study, the value of crop residues of lupins, dry beans, soybeans, sunflower, sorghum and maize for wintering sheep was evaluated. The amounts of residues arid weeds present at the start and end of grazing were estimated by means of quadrat samples. Maize cobs were picked up. Amount of residues and the ratio of grain to straw at the start of grazing differed in the two seasons and differences occurred between crops. Weeds were an important source of feed. The extent of utilization of total dry matter and individual components varied between crops and components. The crop residues were each grazed by 10 mature Dohne Merino wethers/ha. Midrib wool samples were collected in the second season. The sheep initially gained and then lost mass. They were removed from the trial when they had reached the starting mass. Sheep on dry, bean residues gained least during both seasons. Sheep on sorghum residues had the highest average ADG of 98 g over the two seasons, while sheep on soybean residues gained disappointingly with an ADG of only 47 g. Grazing periods differed between seasons. The total length of the grazing period was much the same between crops, except for dry beans where it was markedly shorter. Clean yield percentage was about 61% and did not differ between residues. The wool growth rate of sheep on all crops except on lupins was similar and varied from 0,24 to 0,28 g / d /100 cm². Sheep on lupins had a wool growth rate of 0,53 g / d /100 cm²..

In 'n studie oor twee jaar is die waarde van oesreste van lupiene, droebone, sojabone, sonneblom, sorghum en mielies geevalueer. Die hoeveelheid reste asook onkruid is met aanvang en beeindiging van beweiding bereken volgens kwadraatmonsters. Mieliekoppe is opgetel. Die hoeveelheid reste en die verhouding van graan tot strooi aan die begin van beweiding het in die twee seisoene verskil en verskille het ook tussen gewasse voorgekom. Onkruid was 'n belangrike bron van voer. Die mate van benutting van die totale droe materiaal en die onderskeie komponente het tussen gewasse en komponente verskil. Die oesreste is deur tien volwasse Dohnemerinohamels/ha bewei. Midribwolmonsters is in die tweede winter geneem. Beweiding is gestaak nadat die skape na piekmassa, weer dieselfde mass a as hul aanvangsmassa bereik het. Skape op drol!boonreste het gedurende beide seisoene die minste in massa toegeneem. Skape op die sorghumreste het die hoogste gemiddelde GDT van 98 g oor die twee seisoene getoon, terwyl skape op die sojaboonreste telleurstellend gevaar het met 'n GDT van slegs 47 g. Weiperiode het tussen die twee seisoene verskil. Totale lengte van weiperiode' was ongeveer dieselfde tussen gewasse, behalwe vir dronbone waar dit heelwat korter was. Persentasie skoonwol was ongeveer 61% en het nie tussen gewasse verskil nie. Die wolgroeitempo van die skape op al die gewasse, behalwe op lupiene, het gewissel vanaf 0,24 tot 0,28 g/d/100 cm².. Skape op lupiene het 'n wolgroeitempovan 0,53 g/d/100 cm². getoon.

Keywords: Crop residues, utilization, sheep mass changes, wool production