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Forage-animal production agriculture is implementing infrastructure changes and management strategies to adjust to increased energy-related costs of fuel, feed grains, fertilizers, and seeds. The primary objectives of this position paper are to assess future research and extension scientific needs in forage utilization, financial support for the discipline, and changing status and number of scientists. A survey questionnaire returned from 25 land-grant universities in the eastern half of the United States rated the top 4 research needs as 1) pasture systems and efficiency of production; 2) interfacing with energy concerns; 3) forage cultivar evaluations and persistence; and 4) environment impacts. Plant-animal future research needs at 11 USDA-ARS regional locations are targeted at sustainable management and improved livestock performance, ecophysiology and ecology of grasslands, environment impacts, and improved technologies for nutritive value assessments. Extension scientists from 17 southern and northeastern states listed the top 3 needs as forage persistence, soil fertility and nutrient management, and pasture systems and efficiency of production. Grant funds currently provide more than 40% of land-grant university research and extension efforts in forage utilization, and scientists estimate that this support base will increase to 55 to 60% of the funding total by 2013. Reduced allocation of state and federal funding has contributed to a reduction in the number of full-time equivalent (FTE) scientists engaged in forage utilization research and extension activities. The current 25 state FTE conducting research number about 2.8 per state. This includes 10 states with >3, ii states with Key words: Extension, forage, pasture, production, research, utilization

A study involving a 2 x 2 x 2 factorial arrangement of treatments was conducted to evaluate effects of hybrid (Pioneer 3335 and 3489), maturity (half milkline and blacklayer), and mechanical processing (field chopper with and without on-board rollers engaged) on intake and digestibility of corn silage. Forty Angus steers (322 [+ or -] 5.2 kg BW) were assigned to the eight silage treatments (five steers per treatment) and individually fed using electronic gates. Diets consisted of 60% corn silage and 40% chopped alfalfa hay (DM basis). Following a 5-d adaptation period, intake was measured for 7 d and subsequently fecal samples were collected for 5 d. Chromic oxide (5 g/d) was fed beginning 7 d before fecal sample collection and digestibility was determined by the ratio of Cr in the feed and feces. Steers were reallocated to treatments and these procedures were repeated, providing 10 observations per treatment. In addition, all silages were ruminally incubated in six mature cows for 0, 8, 16, 24, 48, and 96 h to determine extent and rate of DM, starch, NDF, and ADF disappearance. Processing increased DMI of hybrid 3489 but did not affect DMI of hybrid 3335 (hybrid x processing; P [is less than] 0.06). Total tract digestibility of DM, starch, NDF, and ADF decreased (P [is less than] 0.01) as plant maturity increased. Maturity tended to decrease starch digestibility more for hybrid 3489 than for hybrid 3335 (hybrid x maturity; P [is less than] 0.10). Processing increased (P [is less than] 0.01) starch digestibility but decreased (P [is less than] 0.01) NDF and ADF digestibility, resulting in no processing effect on DM digestibility. There was a numerical trend for processing to increase starch digestibility more for late-than for early-maturity corn silage (maturity x processing; P = 0.11). Processing increased in situ rates of DM and starch disappearance and maturity decreased in situ disappearance rates of starch and fiber. These data indicate that hybrid, maturity, and processing all affect corn silage digestibility. Mechanical processing of corn silage increased starch digestibility, which may have been associated with the observed decreased fiber digestibility. Key Words: Corn Silage, Digestibility, Hybrid, Maturity, Processing

To assess the effects of feeding high-oil corn on carcass characteristics and meat quality, 60 yearling steers were fed high concentrate diets containing either control corn (82% of diet), high-oil corn (82% of diet), or high-oil corn at a concentration that was isocaloric with the control diet (74% of diet). After being fed for 84 d, steers were slaughtered. At 72 h postmortem, carcass data were collected and rib sections from five steers grading U.S. Choice and five steers grading U.S. Select from each treatment were collected, vacuum packaged, and aged for 14 d. Three steaks (2.54 cm thick) were removed from each rib for Warner-Bratzler shear force measurement, sensory appraisal, and fatty acid composition analyses. Data were analyzed with treatment as the main effect for the carcass data and treatment, quality grade, and two-way interaction in the model for the longissimus data. The two-way interaction was nonsignificant (P [is greater than] 0.05) for all variables tested. No differences were detected (P [is greater than] 0.05) in carcass measurements except for marbling scores and quality grades, both of which were greater (P [is less than] 0.05) for carcasses from steers fed the high-oil corn. Overall, 78% of steers fed the high-oil corn graded U.S. Choice compared with 47% for the control and 67% for isocaloric group. Shear force and sensory properties of the longissimus were not different (P [is greater than] 0.05) among treatments. Steaks from U.S. Choice carcasses rated higher (P [is less than] 0.05) for tenderness and tended to rate higher (P [is less than] 0.10) for juiciness. Feeding the isocaloric and high-oil diets increased (P [is less than]0.05) linoleic acid, arachidonic acid, and the total PUFA content of lipid extracted from the longissimus. Saturated fatty acid percentage was lowest (P [is less than] 0.05) for high-oil corn and highest (P [is less than] 0.05) for control, with isocaloric being intermediate. Feeding high-oil corn increased (P [is less than] 0.05) pentadecyclic acid, margaric acid, and total odd-chain fatty acid content. Feeding high-oil corn in finishing beef cattle diets enhanced intramuscular lipid deposition and increased unsaturation of fatty acids of the longissimus. Key Words: Beef Cattle, Corn, Carcass Quality, Fatty Acids

Sixty crossbred beef steers (initial BW = 412 kg) were used in a 83-d finishing study to determine the effect of feeding dry rolled high-oil corn on performance and total-tract digestibility of finishing diets. Steers were allotted by weight to the following dietary treatments: 1) control corn (C; 82% normal corn, 12% triticale silage), 2) high-oil corn (HO; 82% high-oil corn, 12% silage), and 3) high-oil corn formulated to be isocaloric to C (ISO; 74% high-oil corn, 20% silage). Total lipid content was 4.9% (DM basis) for normal corn and 7.0% for high-oil corn. Steers were individually fed using electronic gates. Quantity of feed offered and refused was recorded daily. Fecal samples were collected on d 63 to 66 of the trial to determine digestibility. Chromic oxide was fed as an indigestible marker for 7 d before fecal collection began. Planned contrasts of HO vs C and ISO vs C were used to assess treatment differences. Dry matter intake was greater for steers fed C vs HO (P [is less than] 0.01) or C vs ISO (P [is less than] 0.01), but daily gain and feed efficiency were not affected (P [is greater than] 0.05) by treatments. Digestibility of DM, OM, starch, and GE was greater (P [is less than] 0.05) for the HO diet than the C diet, but lipid digestibility did not differ among treatments (P [is greater than] 0.05). The combined effect of greater GE content and digestibility resulted in greater (P [is less than] 0.01) DE content for the HO than for the C diet. Calculated DE of the corn was 8.3% greater (3.74 Mcal/kg; P [is less than] 0.01) for the HO diet and 6.5% greater (3.67 Mcal/kg; P [is less than] 0.01) for the ISO diet than the corn in the C diet (3.25 Mcal/kg). Dry matter and GE digestibility did not differ (P [is greater than] 0.05) between the C and ISO diets. Steers consuming ISO had greater (P [is less than] 0.05) starch digestibility than steers fed the C diet. Although HO had higher DE, DE intake was similar (P [is greater than] 0.05) for HO and C due to lower DMI for HO. These results indicate that available energy is greater from high-oil corn than from typical corn, but depressed voluntary feed intake prevented performance improvements and resulted in equal energy intakes between high-oil corn and typical corn diets. Key Words: Corn, Digestibility, Energy, Growth Performance, Oil

Abstract: Since the late Miocene, plants using the C4 photosynthetic pathway have increased to become major components of many tropical and subtropical ecosystems. However, the drivers for this expansion remain under debate, in part because of the varied histories of C4 vegetation on different continents. Australia hosts the highest dominance of C4 vegetation of all continents, but little is known about the history of C4 vegetation there. Carbon isotope ratios of plant waxes from scientific ocean drilling sediments off north‐western Australia reveal the onset of Australian C4 expansion at ~3.5 Ma, later than in many other regions. Pollen analysis from the same sediments reveals increasingly open C3‐dominated biomes preceding the shift to open C4‐dominated biomes by several million years. We hypothesize that the development of a summer monsoon climate beginning in the late Pliocene promoted a highly seasonal precipitation regime favorable to the expansion of C4 vegetation. [ABSTRACT FROM AUTHOR]