Profitability of novel endophyte (non-toxic) tall fescue wasn't much different than cool-season annuals, Arkansas researchers say.
The increased costs of annual establishment of small-grain pasture associated with fuel, machinery and labor are eroding profitability of stocker-cattle enterprises. Thus, interest has grown in developing cool-season perennial grasses that are persistent and high quality.
The study was conducted on 60 acres divided into 30, 2-acre paddocks at the University of Arkansas research station near Batesville. Two tall-fescue (Festuca arundinacea Schreb.) cultivars infected with novel endophytes (NE), Jesup infected with AR542 endophyte (Jesup AR542), and HiMag infected with Number 11 endophyte (HM11) were established in September 2002.
Jesup AR542 and HM11 were compared with endemic endophyte Kentucky 31 (KY-31) tall fescue; wheat (Triticum aestivum L.) and cereal rye (WR, Secale cereale L.) planted in September 2003, 2004 and 2005; and annual ryegrass [RG, Lolium perenne L. ssp. multiflorum (Lam.) Husnot] planted in September 2004 and 2005.
Each year, three steers (1.5 steers/acre) were placed on each pasture for fall and winter grazing, and five steers (2.5 steers/acre) were placed on each pasture for spring grazing.
Bodyweight gain/acre of steers grazing NE tall fescue was greater than those of KY-31 and WR during 2003-04, whereas in 2004-05, body weight gain/acre of steers grazing NE and RG did not differ and was greater than that of WR, which was greater than that of KY-31. During 2005-06, body weight gain/acre was greater for steers grazing RG than those of NE and WR, which did not differ. Body weight gain/acre was least for steers grazing KY-31.
Average net return of NE tall fescue was greater than KY-31, but profitability of NE did not consistently differ from cool-season annuals.
Researchers conclude that across the three-year study, NE tall fescue produced net returns of $88.66/acre; this level of profitability would require four years for a new planting of NE tall fescue to break even. Novel endophyte tall fescues offer potential benefits related to decreased risk of stand establishment of annual forage crops, longer growing season and acceptable animal performance.
— Beck et al, 2008, Journal of Animal Science, 86:2043.
Supplementing polyethylene glycol (PEG) to cows on pasture increased their intake of an unwanted Great Plains weed, Utah State University researchers conclude.
Sericea lespedeza (SL) is an introduced legume that can thrive in soils of low fertility and has high concentrations of condensed tannins. It's considered a forage crop in the southeastern U.S. and a weed in the Great Plains. Grazing, rather than insects, is the most viable option for biological control.
Researchers tested their hypothesis that PEG, a polymer that neutralizes the effects of tannins, would increase intake and preference of cattle for fresh cut SL. Sixteen crossbred steers (550 lbs.) were randomly assigned to two treatments: 1) Grain supplement with PEG (PEG-S), and 2) grain supplement without PEG (control).
To assess intake, a trial was conducted with six sample periods, each six days in duration, with steers fed SL and prairie hay (PH) in separate meals. Steers were fasted overnight and fed their respective supplements (with and without PEG) at 8 a.m. Animals were then offered fresh-cut SL from 10:50 a.m. to 3:50 p.m., PH was fed from 4-8 p.m. and animals were without food from 8 p.m. to 6 a.m. the next day.
To assess preference, researchers conducted one-day tests in which steers had simultaneous access to SL and PH on the day following periods 2-6. As with the intake experiment, steers were fasted overnight and fed their respective supplement at 8 a.m., but from 10:50 a.m. to 12:50 p.m., all steers had access to SL and PH simultaneously.
Steers treated with PEG consumed more SL per unit of bodyweight than control steers in periods 2-6. In contrast, controls consumed more PH than steers given PEG. The PEG-S steers consumed more total dry matter (SL and PH) than controls in periods 3, 5 and 6, but not in periods 1, 2 and 4.
SL intake as a percentage of total dry matter intake was greater for the PEG-S steers every day except day 1 and 2 of period 1. Averaged across the five preference tests, PEG-S steers selected a greater proportion of SL than did control steers (39% vs. 9%), and the magnitude of the difference was greater in the later tests. The PEG-S steers had greater ADG than controls (0.97 vs. 0.53 lbs./day).
The results demonstrate PEG supplementation increases intake of and preference for SL. PEG supplementation also may increase SL intake and improve ADG in pastures that contain the plant.
— Mantz, et al, 2009, Journal of Animal Science 87:761.
It isn't necessary to supplement phosphorous (P) to steers grazing Midwest pastures, University of Wisconsin researchers say.
A two-year study was conducted to confirm that managed pastures can provide Holstein steers adequate P to meet their daily requirement. Treatments offered were trace mineralized salt with or without additional P.
In the first year, 80 Holstein steers were assigned to four grazing groups. Treatments were trace-mineralized salt only or a 67:33 mixture of trace-mineralized salt and dicalcium phosphate. Steers rotationally grazed a cool-season grass/legume mixture for 137 days. Fecal bags were placed on three steers from each grazing group over a four-day period to estimate forage dry matter intake (DMI) and forage contribution to daily P intake twice during the grazing season. Analyzed pasture samples contained 3.28 mg of P/g of DM.
During the second year, 72 Holstein steers were blocked into two bodyweight groups and subsequently assigned to one of four pasture groups. Steers rotationally grazed the same forage base as the first year for 126 days. Pasture samples contained 3.27 mg of P/g of DM. No significant differences were detected for body weight, average daily gain or free-choice supplemental mineral intake. Forage provided 126% of the recommended NRC P requirement.
Researchers concluded that P supplementation is generally not necessary for grazing stocker cattle in Wisconsin and several regions across the Midwest because the forage alone contains adequate P to meet growing steers' requirements.
— Brokman et al, 2008, Journal of Animal Science, 86:712.