Alternative fall and winter feeding systems for spring calving beef cows

Alternative fall and winter feeding systems for spring calving beef cows. Can. J. Anim. Sci. 84: 511-522. This study evaluated the effects of early (EW) and late (LW) weaning on calf post-weaning growth performance and carcass characteristics. It also quantified the effects of EW and LW in combination with three winter feeding strategies on cow growth, reproductive performance and cost of production. EW calves were weaned in late August,, while LW calves were weaned 56 d later in late October. The three cow winter feeding strategies were: (1) traditional (TD), or straw fed ad libitum and barley (Hordeum vulgare L.) silage fed every day; (2) alternate day (AD), or straw fed ad libitum and equivalent amounts of barley silage fed every second day (AD); and (3) swath graze (SG), or swath grazing whole-plant barley, cut in the soft dough stage. The study was conducted over three production cycles (1997/1998, 1998/1999 and 1999/2000). EW calves weighing 213 kg and fed a backgrounding diet (82% barley silage: 18% concentrate) for 56 d, grew 0.36 kg d(-1) (EW = 0.61 +/- 0.02 kg d(-1); LW = 0.97 +/- 0.02 kg d(-1); P < 0.001) slower from early to late weaning than LW calves (210 kg) on pasture nursing their mothers. Over the next 124-128 d, EW and LW calves fed the backgrounding diet grew similarly at 0.95 +/- 0.01 and 0.93 +/- 0.02 kg d(-1), respectively. Both groups of calves also grew similarly during the finishing phase (EW = 1.56 +/- 0.04 kg d(-1); LW 1.53 +/- 0.05 kg d(-1); P = 0.62), such that at slaughter, EW and LW calves were the same age (461 +/- 4 vs. 455 +/- 5 d, P = 0.326) and weight (522 +/- 5 vs. 515 +/- 6 kg, P = 0.390), with similar levels of carcass backfat, yield and quality grade. EW cows weighed 12 to 15 kg more (P < 0.01) in mid-November (first winter feeding), mid-February (pre-calving) and late-May (prebreeding) and tended to have a shorter calving span (49 vs. 62 d, P = 0.07) than the LW cows. Calving interval, calving pattern and cumulative open and cull rates, monitored over three consecutive production cycles, were similar for EW and LW cows. Differences (P < 0.05) in body weight were observed between winter feeding treatments. SG cows had the lowest weight (605 kg) and backfat thickness (4.5 nun) at pre-breeding; AD cows were intermediate (623 kg and 5.1 mm); and TD cows were heaviest (639 kg) with the most backfat (6.4 mm). Calving interval, length of the calving span, calving pattern and cumulative open and cull rates were similar among the winter feeding strategies for cows monitored over three production cycles. Swath grazing required 38.4% less labour than'traditional feeding and 20.9% less labour than alternate day winter feeding. Total cash cost over the first 100 d of winter feeding for the SG winter feeding strategy was $70.00 cow(-1) less than TD (45.5%) and $56.70 cow(-1) less than AD (40.4%) winter feeding strategies. On average, 300 and 314 cow swath grazing d ha(-1) were required to cover the cost of feed in the TD and AD winter feeding strategies, respectively.