Journal of Animal Science
Effect of winter feeding system on beef cow performance,
reproductive efficiency, and system cos
B. M. Kelln*, H. A. Lardner*†,2, J. J. McKinnon*, J. R. Campbell‡, K. Larson† and D.
Damiran*†
Abstarc :
A 3-yr study was conducted to evaluate the effects of winter feeding systems on beef cow
performance, reproductive efficiency, and system cost. Winter feeding systems were (i) swath
grazing (SG) windrowed whole-plant barley [TDN = 62.4, CP = 13.4 (% DM)] in field
paddocks; (ii) bale grazing (BG) barley hay round bales [TDN = 66.6, CP = 13.1 (% DM)] in
field paddocks; (iii) straw-chaff grazing (STCH) barley crop residue piles [TDN = 46.8, CP = 9.8
(% DM)] in field; and (iv) drylot feeding (DL) barley hay round bales [TDN = 67.9, CP = 13.0
(% DM)] in bale feeders in pens. The study was conducted over 3 production cycles with springcalving beef cows [yr 1 (78 d), n = 180, BW = 630.5 ± 3.9 kg; yr 2 (21 d), n = 180, BW = 598.6
± 7.7 kg; yr 3 (36 d), n = 120, BW = 644.0 ± 5.0 kg]. Cows were allocated swaths, bales, and
crop residue piles on a 3-d basis to manage DMI and feed waste. Dry matter and TDN intakes
were 17 and 23% lower (P < 0.01) in yr 1 compared with yr 2 and 3. Cows consuming SG or
STCH had lower (P < 0.01) DMI compared with BG- or DL-fed cows. Nutritive value of barley
forage in all systems was sufficient, allowing for minimal or no BW change. Bale grazing, SG,
and STCH systems had no effect (P > 0.05) on cow reproductive performance. In yr 1, in the first
21 d, cows maintained BW and BCS with DL compared with SG, BG, and STCH cows.
However, SG, BG, and STCH cows gained BW linearly (r = 0.58, P = 0.09) from d 22 to 76 of
the feeding trial. Cows in drylot pens fed round bale hay gained more BW than did cows in field
paddocks grazing either round bales (P < 0.05; yr 3) or swaths (P < 0.05; yr 2, yr 3). In yr 1 after
78 d, SG cows had lower BW and BCS (P < 0.05) than did DL cows; however, cows in all
systems gained BW in yr 2 and 3. Averaged over 3 yr, winter feeding system costs were 8 and
29% lower for BG and SG, respectively, com pared with the DL system. This research indicates
that bale grazing or swath grazing systems can be effective alternatives to reduce winter feeding
costs.
Key Word :
ale grazing, beef cow, reproductive performance, straw-chaff grazing, swath grazing, winter
system cost
Volume 27, Number 5, October 2011