PERFORMANCE OF GROWING LAMBS FED 2 LEVELS OF CONCENTRATE WITH CONVENTIONAL OR MACERATED TIMOTHY HAY

Thirty-two Outaouais male lambs were used in a 2 x 2 factorial design to compare growth and carcass characteristics of lambs fed conventiona l and macerated hay at two levels of concentrate. Timothy hay was harv ested with either a prototype mower-macerator or a conventional mower- conditioner. Hays offered for ad libitum intake were fed with isonitro genous supplements containing either 400 g of commercial concentrate o r a mixture of 100 g of commercial concentrate and 158 g of canola mea l. Lambs were fed from an initial weight of 22 kg to a slaughter weigh t of 43 kg. Feeding the highest level of concentrate tended to decreas e hay intake but increased DMI and ADG. Feeding macerated hay had no e ffect on DMI, digestibility, ADG, and gain:feed. There was an interact ion (P < .08) between type of conditioning and feeding level of concen trate for carcass weight, dressing percentage, and muscular conformati on of hind leg roast. In general, the highest values were obtained for lambs fed the higher level of concentrate. Efficiency of ME utilizati on for gain was similar among treatments. These data suggest that the benefits of macerated timothy hay and higher amounts of concentrate on carcass quality are additive.