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Winona, FL, United States

Hersom M.J.,University of Florida | Hansen G.R.,North Florida Research and Education Center | Arthington J.D.,Range Cattle Research and Education Center
Journal of Animal Science | Year: 2010

Dietary constituents can affect cow acid-base physiology and uterine pH. Dietary cation-anion difference (DCAD) has been shown to affect cow acid-base physiology, but the effect on uterine pH has not been demonstrated. The objective of this work was to determine if DCAD [(Na + K + 0.15Ca + 0.15Mg) - (Cl + 0.60S + 0.50P)] could affect cow DMI, acid-base physiology, and uterine pH, and second, to determine if dietary supplements could alleviate any negative effects of DCAD on these variables. In Exp. 1, 21 cows were utilized to determine the effect of a negative DCAD (-0.9 mEq/100 g of DM; low-DCAD) or positive DCAD (+25.0 mEq/100 g of DM; high-DCAD) diet on cow BW, DMI, and pH of blood, urine, and uterine flush fluid. In Exp. 2, 21 cows were randomly allotted to 1 of 3 treatments: control (-3.1 mEq/100 g of DM), molasses (+2.9 mEq/100 g of DM), or molasses+buffer (+25.8 mEq/100 g of DM) to determine if supplemental liquid molasses or liquid molasses with a buffer could alleviate the effects of a negative DCAD, forage-based diet. Cows were individually fed their respective diets for 42 d in both experiments. Cow BW, blood, urine, and uterine flush were collected on d 0, 21, and 42 during both experiments. Cow ADG was not different (P = 0.71) in Exp. 1 or Exp. 2 (P = 0.47). Hay DMI did not differ (P < 0.70) between high-DCAD and low-DCAD cows before d 28, but was greater (P < 0.001) for high-DCAD cows after d 28 in Exp. 1. In Exp. 2, mean hay DMI did not differ (P = 0.39) among treatments. In Exp. 1, a treatment x day interaction (P < 0.05) was apparent for blood, pH, base excess, bicarbonate, pCO2, and urine pH. Blood gas and pH measures peaked on d 21 for high-DCAD and declined from d 0 to 42 in low-DCAD cows. High-DCAD cows had greater (P = 0.08) uterine flush pH compared with low-DCAD cows. In contrast, during Exp. 2 there were no differences (P > 0.14) among treatments for blood, pH, base excess, pCO2, or uterine flush pH. Urine pH exhibited a treatment x day interaction (P < 0.0001). On d 21 molasses supplemented cow urine pH was greater (P < 0.0001) than control cows, whereas on d 42 molasses+buffer had greater (P = 0.01) urine pH compared with control and molasses cows. Dietary cation-anion difference and the use of molasses-based supplements had minimal effect on forage-fed beef cow DMI. However, DCAD has the capacity to alter forage-fed beef cow acid-base physiology and potentially affect uterine physiology. © 2010 American Society of Animal Science. Source

Erickson J.E.,University of Florida | Helsel Z.R.,Rutgers University | Woodard K.R.,University of Florida | Vendramini J.M.B.,Range Cattle Research and Education Center | And 3 more authors.
Agronomy Journal | Year: 2011

Sweet sorghum [Sorghum bicolor (L.) Moench] is a potential bioenergy crop that is capable of high biomass and sugar yields, but production for biofuel in the Southeast is not well understood. The present study examined the effects of planting date (three dates from mid-March to mid-June) on primary and ratoon crop fresh biomass, brix, and estimated sugar yield of three sweet sorghum cultivars ('Dale', 'Topper 76-6', and 'M-81E') grown at three sites from North (29°24′ N) to South Florida (26°40′ N). Across all treatments, primary crop fresh biomass, brix and estimated sugar yields were 70 Mg ha -1, 148 g kg -1, and 5.69 Mg ha -1, respectively. Primary crop yields were greatest for the two earliest planting dates (mid-March to mid-May), and for our southernmost site. The yield potential for ratoon crops was in general only about half as much as the primary crop across all years, sites, and cultivars for the earliest planting date. An exception, however, was ratoon crop yields at the southernmost site, which were in some cases equal to or greater than primary crop yields. Low primary crop brix values were found for all cultivars on the muck soils in South Florida compared to the other two sites, and for M-81E compared to Dale and Topper 76-6. These low brix values were correlated with greater fresh biomass production. Further research is needed on planting dates for optimizing primary and ratoon crop yields along with varietal development with improved ratoon crop yields. Source

Krueger N.C.,University of Florida | Sollenberger L.E.,University of Florida | Blount A.R.,North Florida Research and Education Center | Vendramini J.M.B.,Range Cattle Research and Education Center | And 2 more authors.
Crop Science | Year: 2014

Blackberry (Rubus fruticosas L.) can be a weed in rhizoma peanut (Arachis glabrataBenth.)–grass pastures. Goats (Capra hircus) have provided effective control of Rubus spp. in other environments, but their efficacy has not been tested in legume-grass swards in this context. The objective was to evaluate rotational stocking by goats alone or with cattle (Bosspp.) for blackberry control. Treatments stocked at 2.6 animal units (AU) ha−1 included a cattle-alone control, goats alone, concurrent stocking of cattle and goats, sequential stocking of cattle followed by goats, and sequential stocking of goats followed by cattle. The final treatment was concurrent stocking at a stocking rate of 3.5 AU ha−1. Goats grazed blackberry readily, but cattle avoided it. Blackberry selection was greatest when goats followed cattle sequentially. The blackberry proportion of total biomass increased 10% when cattle grazed alone but was reduced 11% with goats alone and 13% with mixed concurrent grazing at a high stocking rate. Treatments including goats resulted in reductions or smaller increases in blackberry mass than for cattle alone. Goats alone or with cattle resulted in greater removal of blackberry leaf and in reduced height and stem density than cattle alone. Goats reduced the blackberry contribution more than cattle, but it was not eliminated from initially heavily infested pastures across 2 yr of grazing. A greater goat stocking rate or a combination of grazing and mowing may be needed for complete eradication. © Crop Science Society of America. Source

Mullenix M.K.,Auburn University | Sollenberger L.E.,University of Florida | Wallau M.O.,Federal University of Rio Grande do Sul | Rowland D.L.,University of Florida | And 3 more authors.
Crop Science | Year: 2016

‘Florigraze’ rhizoma peanut (RP; Arachis glabrata Benth.) is a persistent forage legume for the US Gulf Coast, but peanut stunt virus (Cucumovirus spp.) reduces herbage accumulation (HA). Less susceptible germplasms and cultivars of RP have been released, but their responses to grazing management are not known. The objective was to quantify aboveground and belowground sward responses to grazing management of RP entries differing in growth habit to explain HA and persistence. Treatments were all combinations of four RP entries (Florigraze, ‘UF Peace’, ‘UF Tito’, and germplasm Ecoturf), two grazing intensities (50 and 75% removal of pre-grazing canopy height), and two regrowth intervals (3 or 6 wk). UF Tito swards were the tallest and Ecoturf the shortest, but Ecoturf had greater herbage bulk density than any entry. Pre-grazing Ieaf percentage was greatest for Ecoturf (61%); there were no differences among the upright entries (56-57%). Ecoturf (0.88) and UF Tito (0.76) had greater post-grazing residual Ieaf area index than Florigraze (0.61). Ecoturf and UF Tito had greater rhizome-root mass (4450 and 4110 kg ha-1, respectively) than Florigraze and UF Peace (3490 and 3170 kg ha-1, respectively). Pre-grazing light interception was greater for the 6- than 3-wk grazing frequency (85 vs. 70%, respectively), and rhizome-root mass followed a similar pattern (3990 vs. 2730 kg ha-1, respectively). Sward structure, leaf, and rhizome-root data explain Iack of differences among entries in HA, excellent persistence of Ecoturf and UF Tito, and generally greater HA and persistence for 6- vs. 3-wk regrowth intervals. © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved. Source

Inyang U.,Range Cattle Research and Education Center | Vendramini J.M.B.,Range Cattle Research and Education Center | Sollenberger L.E.,University of Florida | Sellers B.,Range Cattle Research and Education Center | And 3 more authors.
Crop Science | Year: 2010

Bahiagrass (Paspalum notatum Flügge) is the most used forage for beef cattle (Bos sp.) in Florida; however, damage to bahiagrass pastures by mole cricket (Scapteriscus spp.) stimulated a search for other adapted grasses. The objective of this study was to test the effect of different stocking rates (SRs) on animal performance and herbage characteristics of 'Mulato' (Brachiaria sp.) and bahiagrass pastures. The experiment was conducted in Ona, FL, from May to September, 2007 and 2008. Treatments were three SRs (4, 8, and 12 heifers ha-1) and two forage species (Mulato and 'Pensacola' bahiagrass). There was a linear decrease in herbage mass (from 5.9 to 3.2 Mg ha-1) and herbage allowance (from 2.8 to 0.6 kg dry matter kg-1 liveweight) with increasing SR. Mulato had greater in vitro digestible organic matter concentration than bahiagrass (675 vs. 534 g kg-1) but similar crude protein concentration (130 g kg-1). There was a linear decrease in average daily gain (from 0.49 to 0.22 kg d-1) and a quadratic response of liveweight gain ha-1 as SR increased (190, 353, and 217 kg ha-1 for SRs of 4, 8, and 12 heifers ha-1, respectively). Mulato has potential to be an alternative forage to bahiagrass for beef cattle producers in Florida. © Crop Science Society of America. Source

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