Some effects of formaldehyde treatment of hay or silage and level of barley intake on the production of crossbred lambs fed in pens

Abstract

Hay and silage treated with formaldehyde were compared with untreated hay and silage during in vivo studies of digestibility, and in growth studies where the forages were fed with and without barley to 6-month-old crossbred lambs. In the growth study there were 20 treatment groups (four forage types offered ad libitum x five barley levels 0, 100, 300, 500 and ad libitum g day-1). Sheep were fed for 6 and 12 weeks for groups fed silage and hay respectively following which animals were slaughtered. On a digested basis, barley contributed from 0 to 76 per cent of digested energy intake. Lamb growth rate varied between 0 and 150 g day-1 and was linearly related to intake of digested DM. Growth rates were above 100 g day-1 where barley constituted 60 to 70 per cent of this intake. Silage and hay with digestibilities of 62 to 65 per cent barely maintained sheep liveweights when fed as a sole diet. The sheep ate more hay than silage and treating the forage with formaldehyde did not significantly increase intake or growth rate.