H.A. Lardner

Effect of winter feeding system on beef cow performance, reproductive efficiency, and system cost1

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 spring-calving 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 0.05) 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, compared with the DL system. This research indicates that bale grazing or swath grazing systems can be effective alternatives to reduce winter feeding costs.

Effect of maturity at harvest on yield, chemical composition, and in situ degradability for annual cereals used for swath grazing

The objective of this study was to determine how harvest maturity of whole-crop cereals commonly used in swath grazing systems in western Canada affects yield, chemical composition, and in situ digestibility. We hypothesized that the increase in yield with advancing maturity would not offset the decline in digestibility and, thus, the yield of effectively degradable DM (EDDM) would decline with advanced stages of maturity. Four replicate plots of barley (Hordeum vulgare L.; cv. CDC Cowboy), millet (Panicum milliaceum; cv. Red Proso), oat (Avena sativa L., spp.; CDC Weaver), and wheat (Triticum aestivum L.; cv. 07FOR21) were grown, with a subsection in each replicate harvested at 4 different maturities: head elongation, late milk, hard dough, and fully mature. At each stage of maturity, the wet and DM yields, and chemical composition (DM, OM, NDF, crude fat, and nonfiber carbohydrates; NFC) were determined. Whole-crop samples were ground (2-mm screen) and weighed into nylon bags (pore size of 53 ± 10 µm), and duplicate incubation runs were conducted by crop type. For each incubation run, nylon bags were randomly allocated (randomized by field replication, stage of maturity, and incubation time) to 1 of 7 heifers (32 bags/heifer during each run). Degradation rates were determined using a first-order kinetic model and data were analyzed with stage of maturity as a fixed effect and plot as a random effect. The DM, OM, and NFC yields increased linearly for barley and oat (P < 0.001), and increased quadratically for millet and wheat (P ≤ 0.025). Neutral detergent fiber yield increased linearly for barley (P = 0.005) and quadratically for millet, oat, and wheat (P = 0.044). There were no changes in CP yield observed for barley, millet, or oat with advancing maturity, but there was a linear increase observed for wheat (P = 0.002). The NFC concentration increased linearly for barley, millet, and oat (P < 0.001), and quadratically for wheat (P < 0.001), whereas the EDDM concentration decreased quadratically for millet, oat, and wheat (P = 0.003). The degradation rate of NDF decreased linearly with advancing maturity (P ≤ 0.014) for millet, oat, and wheat, but was not affected for barley (P = 0.13). The yield EDDM increased linearly for barley and oat (P < 0.001), and increased quadratically for millet and wheat (P ≤ 0.025). These findings suggest that harvesting whole-crop annual cereals at the hard dough and mature stages may maximize the yield of EDDM.

Comparison of alternative backgrounding systems on beef calf performance, feedlot finishing performance, carcass traits, and system cost of gain1

A 3-yr experiment was conducted to evaluate the effects of swath grazing forage barley (Hordeum vulgare; cv. Ranger) or foxtail millet (Setaria italica; cv. Golden German) compared with grass-legume hay fed in drylot pens on

Effect of beef heifer development system on average daily gain, reproduction, and adaptation to corn residue during first pregnancy1

Postweaning heifer development systems were evaluated at 2 locations in a 4-yr study for their effect on performance and subsequent adaptation to grazing corn residue as a pregnant heifer. In Exp. 1, heifers were blocked by BW and randomly assigned to graze winter range (WR) or graze winter range and corn residue (CR). In Exp. 2, heifers were assigned to graze winter range and corn residue (CR) or graze winter range and placed in a drylot (DL). Artificial insemination and natural mating were used at breeding on the basis of location. In Exp. 1, heifers developed on corn residue tended (P = 0.11) to have reduced ADG compared with WR heifers. Subsequently, BW at the end of the 82-d corn residue grazing period tended (P = 0.09) to be lower for CR compared with WR heifers. However, the proportion of heifers attaining puberty before the breeding season and pregnancy rates were similar (P ≥ 0.29) for CR and WR heifers. Developing heifers on winter range tended (P = 0.09) to reduce heifer development costs

Effects of supplementing spring–calving beef cows grazing barley crop residue with a wheat–corn blend dried distillers grains with solubles on animal performance and estimated dry matter intake1

36/pregnant heifer compared with CR heifers. In Exp. 2, DL heifers had greater (P < 0.01) overall ADG during development compared with CR heifers, resulting in greater (P < 0.01) prebreeding BW for DL heifers compared with CR heifers (355 vs. 322 ± 9 kg). At pregnancy diagnosis BW remained greater (P = 0.02) for DL compared with CR heifers (423 vs. 406 ± 7 kg). Corn-residue-developed heifers had increased (P = 0.03) AI conception rates compared with DL heifers (78% vs. 67% ± 6%). However, there was no difference (P ≥ 0.21) in percent pubertal before the breeding season or final pregnancy rates for CR and DL heifers. Developing heifers on corn residue reduced (P = 0.02) heifer development costs

C omparison of grazing oat and pea crop residue versus feeding grass-legume hay on beef- cow performance, reproductive efficiency, and system cost 1

38/pregnant heifer compared with DL-developed heifers. A subset of pregnant heifers from both experiments grazed corn residue fields in late gestation. As pregnant heifers grazing corn residue, WR heifers (Exp. 1) tended to have reduced ADG compared with CR heifers (0.34 vs. 0.43 ± 0.08 kg/d, P = 0.07). Furthermore, in Exp. 2 CR heifers had greater (0.41 vs. 0.30 ± 0.22 kg/d) ADG grazing corn residue as pregnant heifers compared with DL-developed heifers. Calving date, dystocia score, and calf birth BW were similar (P ≥ 0.15) between development systems in both experiments. There appears to be a potential learned grazing behavior for heifers developed on corn residue allowing them to better adapt to grazing corn residue as pregnant heifers compared with WR and DL heifers.

Effect of development system on growth and reproductive performance of beef heifers

ABSTRACT A 2-yr study was conducted to determine the effects of supplementing wheat–corn blend dry distillers grains with solubles (DDGS) on beef cow performance and estimated DMI of barley crop residue. Each year, 25 ha of forage barley (cv. Ranger) was seeded and managed for weed control. In fall, the crop was swathed and combined to collect straw-chaff crop residue in 13-kg piles. The field was further subdivided into six 4-ha paddocks for grazing using portable electric fence. Forty-eight spring-calving Black Angus beef cows (BW = 598.2 ± 4.2 kg) were stratified by BW and days pregnant and randomly allocated to 1 of 3 supplement treatments (2 replicates): (1) 100% DDGS (70:30 wheat:corn blend; WCDDGS); (2) 50% WCDDGS plus 50% rolled barley grain (50:50); or (3) 100% rolled barley grain (control; BAR) while winter grazing barley strawchaff piles [TDN = 45.4, CP = 8.6 (% DM)]. Cows were allocated crop-residue piles on a 3-d basis. Cow BW, BCS, and rib and rump fat were measured at the start and end of the trial, and cow BW was corrected for conceptus gain based on calving data. Supplementation strategy did not influence (P > 0.1) forage intake. Supplementation of 100% WCDDGS or a 50:50 blend of WCDDGS and barley grain resulted in greater (P

The effects of spring versus summer calving on beef cattle reproductive and growth performance in western Canada

Spring-calving nonlactating pregnant Angus (Bos taurus) cows (yr 1, n = 90, BW = 637.6 ± 5.8 kg; yr 2, n = 78, BW = 671.2 ± 8.1 kg; yr 3, n = 68, BW = 669.4 ± 6.6 kg) were managed in 1 of 3 replicated (n = 3) wintering systems: (i) grazing oat residue [OATG; TDN = 58.6, CP = 6.7 (% DM)] piles in field paddocks; (ii) grazing pea residue [PEAG; TDN = 50.9, CP = 11.1 (% DM)] piles in field paddocks; and (iii) drylot (DLPF) pen feeding grass–legume round bales [TDN = 54.5, CP = 10.4 (% DM)] in bale feeders. The study was conducted over 3 production cycles, and cows were allocated crop residue and bales on a 3-d basis to manage utilization and feed waste. Forage utilization was less (P < 0.05) in PEAG (33.4 ± 4.3%) and OATG (44.9 ± 5.9%) systems than in the DLPF (90.0 ± 1.63%) wintering system. Dry matter intake of cows varied (P < 0.05) among systems; cows consuming PEAG or OATG had less (P < 0.01) DMI compared with DLPF cows. Nutrient (CP, TDN) intake was greatest (P < 0.05) for DLPF cows and least for cows in the PEAG system. Cows grazing PEAG residue lost BW (11 kg) from d 1 to 20; however, BW change during the entire trial period (63 d) was positive (4 kg) for PEAG cows but less (P = 0.01) than OATG (27 kg) or DLPF (66 kg) cows. Calf birth weight was least (P = 0.03) for OATG cows than DLPF cows, 39 vs. 42 kg, respectively. On average, total costs for the OATG and PEAG winter feeding strategies were

Impact of calving seasons and feeding systems in western Canada. I. Postweaning growth performance and carcass characteristics of crossbred steers

0.77 and

The effects of spring versus summer calving on beef cattle economic performance in western Canada

0.59 cow/d less than the DLPF (