The effect of concentrate level on the intake of hays by ewes in late pregnancy

Abstract

ABSTRACTIn two experiments, ewes carrying two, three or four foetuses were offered restricted amounts of concentrates in the range 0 to 1050 g fresh weight per day and hay ad libitum from day 105 of pregnancy until lambing. The replacement rates of concentrates for forage were similar for both Teeswater × Dalesbred and Finnish Landrace × Dorset Horn ewes in experiment 1 (mean −0·63) when the ewes were offered hay which had an organic matter digestibility (OMD) in vitro of 0·56. There was no significant effect of number of foetuses carried on hay intake. As pregnancy progressed, hay intake increased slightly when hay alone was given and decreased at the higher levels of concentrates.In experiment 2, hay intake by Finnish Landrace × Dorset Horn ewes was significantly higher when hay of higher digestibility was offered (0·52, 0·69 and 0·84 OMD) and decreased when higher levels of concentrates were given. Ewes carrying two foetuses ate more than ewes with three or four foetuses particularly when hay was offered as the sole food. Generally, hay intake decreased as pregnancy progressed and this was more evident when concentrates were offered.A predictive equation is given to enable hay intake to be derived from hay digestibility, concentrate level, ewe live weight, number of foetuses carried and week of pregnancy.