C. B. Stewart

Effect of wheat forage maturity and preservation method on forage chemical composition and performance of growing calves fed mixed diets

Three 2.4-ha wheat (Triticum aestivum L.) fields were used to test the effects of maturity at harvest (boot vs. dough) and preservation method (hay vs. silage) on forage yield, chemical composition, and animal performance when fed in mixed diets. Forages were incorporated into 4 diets in a 2 x 2 factorial arrangement of treatments with hominy feed, soybean hulls, and cottonseed meal as the primary concentrate ingredients. In Exp. 1 diets contained 20% wheat forage (DM basis) and were fed to 96 beef calves (n = 48 steers and 48 heifers; initial BW 229 +/- 6.0 kg) in 12 mixed-sex pens. In Exp. 2 diets contained 40% wheat forage (DM basis) and were fed to beef steers (n = 48; initial BW 198 +/- 6.8 kg) in 12 pens. These diets were also individually fed to 32 calves (Exp. 1, n = 16, BW = 187 +/- 9.4 kg; Exp. 2, n = 16 calves, BW = 160 +/- 8.2 kg) to determine DM and NDF digestibility and gastrointestinal tract passage kinetics. Advanced maturity increased (P < 0.01) DM yield, decreased (P < 0.01) CP concentrations, and tended (P = 0.10) to increase nonfiber carbohydrate concentrations, but did not affect (P >or= 0.22) NDF, ADF, or TDN concentrations. Maturity at harvest, preservation method, or their interaction did not affect (P >or= 0.15) ADG when wheat forage was fed as 20 or 40% of the diet. When calves were fed the 40% wheat forage diets, maturity at harvest did not affect (P >or= 0.27) DMI or G:F. Calves fed 40% hay diets consumed more (P = 0.04) feed DM as a percentage of BW than calves fed silage diets, but tended (P = 0.09) to be less efficient. With 20 or 40% wheat forage diets, there were no differences (P >or= 0.13) in passage rate, ruminal retention time, or fecal output due to maturity or preservation method. Digestibility of DM tended (P = 0.07) to be greater for silage than hay diets when fed in 20% wheat forage diets. Dry matter and NDF digestibility of 40% boot-stage wheat forage diets were greater (P < 0.01) than diets containing forage harvested in dough stage. Forty percent hay diets also tended (P = 0.07) to have greater DM digestibility, and NDF digestibility was greater (P < 0.01) compared with silage diets. Although differences in performance were not noted in the present experiments, increased maturity at harvest and preservation as silage can cause differences in DMI and digestibility of DM and NDF in diets containing 40% wheat forage.

CASE STUDY: Effects of interseeding date of cool-season annual grasses and preplant glyphosate application onto a warm-season grass sod on forage production, forage nutritive value, performance of stocker cattle, and net return1

ABSTRACT This research was conducted to determine the effect of a preplant application of glyphosate [N-(phosphonomethyl) glycine] and planting date on the performance of growing beef calves grazing interseeded cool-season annual pastures. Twenty, 0.81-ha bermudagrass [Cynodon dactylon (L.) Pers.]/crabgrass [Digitaria ciliaris (Retz.) Koeler] pastures were planted with soft red winter wheat (Triticum aestivum L. ‘Roane,’ 134 kg/ ha) and annual ryegrass (Lolium multiflorum Lam. ‘Marshall,’ 22 kg/ha) in mid-September or mid-October of 2005 using a no-till drill, with or without an application of glyphosate at 0.77 kg/ha (1.77 L/ha) at planting in a 2 × 2 factorial arrangement of treatments. A variable stocking rate was managed using the put-and-take method. Tester calves (2 heifers and 1 steer; BW = 273 ± 5.4 kg) were used to measure performance, and additional calves were added as necessary to equalize forage allowance among pastures. Daily gains of calves grazing pastures planted in September were 0.28 kg greater (P = 0.03) from April to May than the ADG of calves grazing pastures planted in October. Pastures receiving glyphosate application resulted in greater (P ≤ 0.05) overall ADG and ADG from mid-February to mid-March. Pastures planted in September with glyphosate application produced 109 more (P

Effects of stocking rate, forage management, and grazing management on performance and economics of cow–calf production in Southwest Arkansas1

The objective this research was to determine the effect of application of multiple grazing management practices at 2 stocking rates (SR) on the productivity and economics of the cow-calf enterprise in the Southeastern United States over a 4-yr period. Pasture management systems included: continuous grazing management at a moderate SR (0.8 ha/cow; CG) without additional forage management, rotational grazing management at a moderate SR (0.8 ha/cow (MR) with addition of stockpiled bermudagrass [ (L.) Pers.] and complementary cool season annuals, and rotational grazing management similar to MR but with a high SR (0.4 ha/cow; HR). Stockpiling in MR and HR was managed by fertilization of 0.2 ha/cow of bermudagrass in early August with 168 kg ammonium nitrate and deferring grazing until November. Wheat (; 112 kg/ha) and annual ryegrass ( Lam.; 28 kg/ha) were interseeded (0.2 ha/cow) in HR and MR with a no-till drill in the fall. Cow and calf performance and economics data were analyzed by ANOVA using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) and pregnancy percentage was analyzed using the GLIMMIX procedure of SAS; pasture was the experimental unit and year was the random block. Hay feeding days decreased ( < 0.01) from 107 ± 10.9 d for CG to 37 ± 10.9 d for HR, which was further reduced ( = 0.01) to 15 ± 10.9 d for MR. Pregnancy percentage did not differ ( = 0.20) among treatments. Weaning BW in CG (237 ± 7.3 kg) tended ( = 0.09) to be greater than in MR (227 ± 7.3 kg) and were greater ( < 0.01) than in HR (219 ± 7.3 kg). However, total weaning BW per hectare was 89% greater ( < 0.01) for HR compared with CG and MR, which did not differ ( = 0.31). With rotational stocking, there was the opportunity to harvest excess forage as hay in both MR and HR with a net value of US

The Effects of a Modified Glucomannan on the Performance of Stocker Cattle Grazing Endophyte-Infected Tall Fescue1

52.90/ha ± 25.73 and

Effect of species of cool-season annual grass interseeded into Bermudagrass sod on the performance of growing calves

15.50/ha ± 25.73, respectively. Net returns per hectare did not differ ( = 0.30) between CG (

Chemical composition and in situ dry matter and fiber disappearance of sorghum × Sudangrass hybrids

429 ± 63.0/ha) and MR (

Evaluation of Tall Fescues for Stocker Cattle in the Gulf Coastal Plain1

479 ± 63.0/ha) but were increased ( < 0.01) by 107% by HR (

Effect of crabgrass (Digitaria ciliaris) hay harvest interval on forage quality and performance of growing calves fed mixed diets.

1,024 ± 63.0/ha). Using rotational grazing, stockpiled bermudagrass, and complementary cool-season annual grasses can drastically reduce winter feed requirements and simultaneously increase carrying capacity and net return.

Effect of mature body weight and stocking rate on cow and calf performance, cow herd efficiency, and economics in the southeastern United States

To evaluate a modified glucomannan to mitigate fescue toxicosis, 45 steer calves (BW = 281 ± 7.0 kg) grazed nine 2-ha pastures of endemic endophyte-infected tall fescue (Festuca arundinacea) for 133 d begininning in March of each year (2 yr; 5 steers/pasture). The 3 treatments were nonsupplemented (control), self-fed liquid supplement (QLF Inc., Dodgeville, WI; SUP), or SUP containing the glucomannan (FEB-200, Alltech Inc., Nicholasville, KY; MGL). Target intake of the supplements was 0.9 to 1.4 kg/d so that MGL would deliver 10 to 20 g of glucomannan daily. Steer BW was measured every 28 d, supplement intake was measured every 7 d, and behavior was monitored every other Thursday. Data were analyzed as a mixed model, with treatment as the fixed effect and year and pasture as random effects. Least squares means were separated using contrasts. Over the 133 d, MGL steers gained BW (0.54 kg/d) more quickly (P = 0.03) than SUP steers (0.41 kg/d), but ADG of SUP steers did not differ (P = 0.94) from that of control steers (0.50 kg/d). On d 133, BW of the supplemented cattle did not differ (P = 0.96) from that of control steers; the BW of MGL steers was 6% greater (P ≤ 0.03) than that of SUP steers. The control steers spent a greater (P < 0.05) percentage of time grazing than the SUP steers. Overall, there were no observed benefits for liquid-feed supplement with steers grazing endemic endophyte-infected tall fescue, but the inclusion of glucomannan to the supplement seemed to enhance BW gain.