title: Performance of growing lambs fed two levels of concentrate with conventional or macerated timothy hay.
abstract: Thirty-two Outaouais male lambs were used in a 2 x 2 factorial design to compare growth and carcass characteristics of lambs fed conventional and macerated hay at two levels of concentrate. Timothy hay was harvested with either a prototype mower-macerator or a conventional mower-conditioner. Hays offered for ad libitum intake were fed with isonitrogenous supplements containing either 400 g of commercial concentrate or a mixture of 100 g of commercial concentrate and 158 g of canola meal. Lambs were fed from an initial weight of 22 kg to a slaughter weight of 43 kg. Feeding the highest level of concentrate tended to decrease hay intake but increased DMI and ADG. Feeding macerated hay had no effect on DMI, digestibility, ADG, and gain:feed. There was an interaction (P < .08) between type of conditioning and feeding level of concentrate for carcass weight, dressing percentage, and muscular conformation of hind leg roast. In general, the highest values were obtained for lambs fed the higher level of concentrate. Efficiency of ME utilization 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.
authors.affiliation: Sheep Research Farm, Agriculture and Agri-Food Canada, La Pocatière, QC, Canada.
authors.forename: H V
authors.initials: HV
authors.lastname: Petit
authors.forename: G F
authors.initials: GF
authors.lastname: Tremblay
authors.forename: P
authors.initials: P
authors.lastname: Savoie
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004032:Diet / Q000592:standards*; D004063:Digestion / Q000502:physiology*; D004435:Eating / Q000502:physiology; D005511:Food Handling / Q000379:methods*; D008297:Male; D006109:Poaceae; D011897:Random Allocation; D012756:Sheep / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology