Feed intake variation in crossbred lambs applied to livestock production

Spirulina supplementation, and lamb sire breed and sex effects were investigated using 24 lambs in a 3 x 4 x 2 balanced experimental design, representing: 3 sire breeds (Dorset, Merino, White Suffolk), 4 Spirulina levels (CONTROL, LOW, MEDIUM, HIGH), and 2 sexes (ewes, wethers). Lambs were supplemented Spirulina daily and had ad libitum access to Lucerne hay. Daily consumption of Lucerne hay was monitored, with data transformed into feed models: residual feed intake, residual liveweight gain, standardised daily feed intake (SDFI), feed conversion ratio, daily feed intake (DFI). Spirulina level and sex were found to have no independent effects on lamb feed intake (P>0.05). Merino sired lambs feed intake was lower than their crossbred counterparts using SDFI and DFI values (P<0.023). And, Merino ewe lambs consumed more Lucerne hay than wethers (P<0.05). These findings could prove useful when balancing feed resources to match Spirulina supplementation and lamb breeding management goals.