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Corn gluten meal (CGM) has been used as a supplement for livestock feeding due to its high concentration of digestible nitrogen (N) compounds. Heat damaged CGM (HDCGM), which is not suitable for livestock feeding, may still have value as an organic fertilizer. Objective of the study was to evaluate the impacts of non-feed grade HDCGM on forage production from annual cool and warm season grasses and soil characteristics. Pre-plant incorporated HDCGM at 3 Mg/ha was compared with 4.2 Mg/ha poultry litter (POTL), and 160 kg/ha commercial N fertilizer (COMF), and zero fertilizer (ZERO) for production of the cool-season ‘Prine’ annual ryegrass (Lolium multiflorum), and the warm-season ‘Greentreat’ sorghum × sudangrass (SS) hybrid (Sorghum bicolor). The treatments were repeated at the same site on December 3, 2010 (planted annual ryegrass), May 26, 2011 (planted SS hybrid), October 24, 2011 (planted annual ryegrass) and May 18, 2012 (planted SS hybrid). The HDCGM had 68% more N concentration than POTL, while its P, K, Mg, and Ca were less than half in POTL. The residual N concentration in buried HDCGM and POTL increased in a similar pattern with time in soil. The HDCGM produced less dry matter (DM) of annual ryegrass and SS hybrid than POTL; however, the differences between the two treatments were not statistically significant. All treatments produced more DM in the second than first year. After two years of field test, soil receiving HDCGM contained higher soil organic matter (OM) and N than receiving POTL. Although not as beneficial as POTL for DM production, HDCGM showed potential value as a slow release fertilizer to improve DM production and soil characteristics.

Preservation of forage crops as silage offers opportunity to avoid the high risk of rain-damaged hay in the humid south-central USA. Recent developments with baled silage or baleage make silage a less expensive option than typical chopped silage. Silage has been important in the region primarily for dairy production, but baleage has become an option for the more extensive beef cattle industry in the region. Silage samples submitted to the Louisiana State University Agricultural Center Forage Quality Lab from 2006 through 2013 were assessed for dry matter (DM) and forage nutritive characteristics of chopped silage and baleage of the different forage types from commercial farms primarily in Louisiana and Mississippi. Of the 1,308 silage samples submitted, 1,065 were annual ryegrass (AR) with small grains (SG), the warm-season annual (WA) grasses, sorghums and pearl millet, and the warm-season perennial (WP) grasses, bermudagrass and bahiagrass, providing the remaining samples. Concentration of DM was used to indicate an effective ensiling opportunity, and AR silage was more frequently within the target DM range than was the WA forage group. The AR samples also indicated a high-quality forage with average crude protein (CP) of 130 g/kg and total digestible nutrient (TDN) near 600 g/kg. The cooler winter weather at harvest apparently complicated harvest of SG silage with chopped SG silage lower in both CP and TDN (104 and 553 g/kg, respectively) than either AR silage or baleage of SG (137 and 624 g/kg for CP and TDN, respectively). The hot, humid summer weather along with large stems and large forage quantities of the WA grasses and the inherently higher fiber concentration of WP grasses at harvest stage indicate that preservation of these forage types as silage will be challenging, although successful commercial silage samples of each forage type and preservation approach were included among samples of silages produced in the region.

Sweet sorghum (Sorghum bicolor (L.) Moench) is widely recognized as a highly promising biomass energy crop with particular potential to complement sugarcane production in diversified cropping systems. Agronomic assessments have led to identification of four cultivars well suited for such sugarcane-based production systems in southern Louisiana. Sweet sorghum biofuel production systems are currently being developed, and research producing large sample numbers requiring ethanol yield assessment is anticipated. Fiber analysis approaches developed for forage evaluation appear to be useful for screening such large numbers of samples for relative ethanol yield. Chemical composition, forage fiber characteristics, digestibility, and ethanol production of sweet sorghum bagasse from the four cultivars were assessed. Measures of detergent fiber, lignin, and digestibility were highly correlated with ethanol production (P < 0.01). The best linear regression models accounted for about 80% of the variation among cultivars in ethanol production. Bagasse from the cultivar Dale produced more ethanol per gram of material than any of the other cultivars. This superior ethanol production was apparently associated with less lignin in stems of Dale. Forage evaluation measures including detergent fiber analyses, in vitro digestibility, and an in vitro gas production technique successfully identified the cultivar superior in ethanol yield indicating their usefulness for screening sweet sorghum samples for potential ethanol production in research programs generating large sample numbers from evaluations of germ plasm or agronomic treatments. These screening procedures reduce time and expense of alternatives such as hexose sugar assessment for calculating theoretical ethanol yield.

The extensive cow-calf industry in the Gulf Coast Region of the southeastern USA is based on pastures of warm-season perennial grasses, which often provide insufficient forage availability and/or nutritive value in late summer. Several species of summer-growing legumes have potential to increase nutrient availability for nursing calves through creep grazing. Selected warm-season legumes were evaluated at multiple locations across Louisiana. At each location, a treatment with 10% of the pasture area planted to legume was compared to a bermudagrass control treatment. Objectives were to assess both plant and animal factors influencing potential for creep grazing to increase calf weaning weight. Iron-and-Clay cowpea was widely adapted and suited to grazing defoliation although not tolerant of flooding. Aeschynomene was particularly well adapted to silt loam and silty clay loam bottomland soils but was not readily grazed when woody stems developed before stocking. Calves had to learn to utilize creep areas and consume unfamiliar legume species. Both pasture and animal characteristics affected response to legume creep grazing. At the Hill Farm Research Station, the combination of young cows and pastures with limiting nutritive values produced low weaning weights (200 to 215 kg) and resulted in weaning weight increases of from 5 to 7 kg from creep grazing. Benefits were not detected from creep grazing at other locations where calf weaning weights were higher. Creep grazing can contribute to calf weaning weight when forage grazed by the cow herd does not allow calves to attain their genetic potential, however, intensive management is required.

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is the major insect pest of bermudagrass, Cynodon dactylon (L.) Pers., in the Southeastern USA. Somaclonal variation in bermudagrass has produced distinctly divergent susceptibilities to fall armyworm under controlled conditions. Plant persistence, productivity, forage quality characteristics, and response to fall armyworm were assessed in field plots at Rosepine, Louisiana from 1995 through 1999. Forage quality characteristics were assessed each year, and natural infestations of fall armyworms were monitored in 1998 and 1999. Most of the somaclonal lines were similar to their parent cultivar in forage yield and quality, and none was consistently superior. Differences in forage quality characteristics among the bermudagrass lines were detected in 1996 and 1997, with little difference among lines in 1998 and 1999. All lines assessed were infested and sustained damage from natural infestations of fall armyworm larvae. Thus despite acceptable forage productivity and quality of most lines, expression of fall armyworm resistance under these field conditions was not detected. This lack of difference under field conditions, despite distinct resistance of some lines under controlled conditions, may primarily be due to either insufficient production of compounds deterring the insects for detectable effects under field conditions or loss of expression of the somaclonally acquired traits even with vegetative reproduction.

Ninety-six Brahman crossbred steers (187 ± 3.9 kg) were used to evaluate protein supplements in corn-silage growing diets for 140 d. The following treatments were used: 1, control (7.9% crude protein (CP)); 2, urea (10.3% CP); 3, dehydrated alfalfa (10.0% CP); or 4, soybean meal (SBM) (10.6% CP). Steers were then fed a common finishing diet (80% corn) with 13.4% CP for 120 d. Steers fed the control diet had lower levels of plasma-urea nitrogen, consumed less feed, gained less weight and utilized feed less efficiently than those fed supplemented diets (P

Digestibility, intake and performance trials were conducted with cattle to evaluate the effects of physical and chemical treatments on the nutritive value of sugarcane (Saccharum officinarum) bagasse. The four treatments in the digestibility trial were: 1, untreated raw bagasse; 2, steam-pressure treatment with a continuous flow digester (SP); 3, steam-pressure treatment plus pelleting (SPP); 4, steam-pressure treatment, 3% anhydrous ammonia and pelleting (SPA). Steam-pressure treatment and pelleting, both with and without ammoniation, increased voluntary feed consumption (P −1) and feed-to-gain ratios for the four diets were as follows: 1, 0.91 and 8.78; 2, 1.10 and 8.39; 3, 1.12 and 7.72; 4, 1.15 and 7.98. Treatment means did not differ (P > 0.05). SPP bagasse was compared with bermudagrass pellets and corn silage in growing diets for cattle. Ninety-six Brahman crossbred steers (167 kg) were allotted to 12 groups of eight animals (four pens per treatment) for 134 d. SPP bagasse pellets depressed gains and feed conversion ratio (P −1) and feed-to-gain ratio for SPP bagasse pellets, bermudagrass pellets and corn silage diets were 0.42 and 12.90, 1.02 and 7.65, and 0.94 and 5.87, respectively. This investigation demonstrated that feeding pelleted bagasse at 15% of the diet did not reduce performance of finishing cattle fed a high-grain diet. However, when growing cattle were limit-fed a grain-based supplement with free access to bagasse pellets, bermudagrass pellets or corn silage (approximately 70% of the diet), gains and feed efficiency were significantly (P

1 Texas A&M AgriLife Research and Extension Center, Stephenville, TX, USA. stephenville.tamu.edu 2 Universidade Federal Rural de Pernambuco, Recife, PE, Brazil. www.ufrpe.br 3 Instituto de Investigacao Agraria de Mocambique, Maputo, Mozambique. www.iiam.gov.mz 4 Louisiana State University Agricultural Center, Homer, LA, USA. www.lsuagcenter.com 5 The Samuel Roberts Noble Foundation, Ardmore, OK, USA. www.noble.org

Big bluestem (Andropogon gerardii Vitman) indiangrass Sorghastrum nutans (L.) Nash] and switchgrass (Panicum virgatum L.) are widely recognized as valuable forage and conservation species in the Great Plains and the upper South. These species occurred in natural fire-maintained longleaf pine (Pinus palustris Mill.) woodland ecosystems from southeast Texas eastward. Recent interest and even recommendations of cultivars of these species have been developed in the Louisiana longleaf pine area. Genotype origin of these species is known to affect adaptation. Adaptation of the cultivars Kaw big bluestem, Lometa indiangrass, Osage indiangrass, Blackwell switchgrass, and Alamo switchgrass to the Louisiana Coastal Plain was assessed under a natural stand of longleaf pines and in full sun at Rosepine, La. Plots were seeded in 1995, and stands were monitored through the spring of 1998. Only Alamo switchgrass and Lometa indiangrass under the pines produced sufficient stands for harvest. Production potential was greatest for Alamo switchgrass with the highest annual yield of 5,580 kg ha-1 from 2 harvests in 1996. Herbage production of 1,500 kg ha-1 did not differ between Alamo switchgrass and Lometa indiangrass in the second year of harvest when harvested in June and September for 2 consecutive years. The longleaf pine overstory apparently provided a competitive advantage during establishment, since weeds dominated plots in full sun. The 2 cultivars from southern latitudes, Alamo switchgrass and Lometa indiangrass, were superior in establishment, productivity, and stand survival. Aggressive competition from dense-growing subtropical grasses was detrimental during establishment and following defoliations. DOI:10.2458/azu_jrm_v53i1_pitman

Wiregrass (Aristida stricta Michx.)-dominated communities characterize extensive areas of South Florida that have been subjected to burning and uncontrolled grazing for decades. We evaluated the effects of deferment from grazing on species composition and herbage mass of these rangelands. Treatments were 1-ha exclosures that were closed to grazing December to March, closed April to July, closed August to November, always closed, or always open. All treatments were burned biennially. Herbage mass of preferred grasses was greater (P < 0.05) after 8 years in exclosures that were always closed (avg. 110 kg ha-1) compared with other treatments, which were not different (avg. 65 kg ha-1). Herbage mass of preferred grasses increased by 10 kg ha-1 year-1. Shrub biomass was greater in the treatment that was always closed (2,370 kg ha-1) compared with other treatments avg. 1,855 kg ha-1), and biomass increased quadratically over years. There were no effects due to treatments or years on biomass of wiregrass, other less desirable grasses, grasslike species, or forbs. Frequency of occurrence of preferred grasses was not affected by treatment and averaged 41%. Although preferred grasses were relatively abundant, neither their biomass nor frequency of occurrence increased on a scale relevant to management for cattle production when protected from grazing. This biennially burned, seasonally flooded, infertile wiregrass range is not highly responsive to grazing or deferment from grazing, hence responses may not justify the inputs required for more intensive grazing management.

Creeping bluestem (Schizachyrium stoloniferum) was grazed every 6O-days to 15 or 30-cm stubble heights during the following 4 periods (seasons): (1) June, Aug., Oct. (JAO); (2) Oct., Dec., Feb. (ODF); (3) Feb., Apr., June (FAJ); (4) year-long (YL). Average diameter (37 cm) of piants grnzed in JAO and YL to lS-cm stubble was less (PC 0.05) than piants (43 cm) grazed to 30 cm. There was no difference in diameter of piants grazed to 15 and 3O-cm stubble in ODF and FAJ (45 cm). Tiller density was influenced by stubble height only in 1982 and 1983 when density for the 15 cm stubble averaged lll/m2 vs. 142/m2for the 3O-cm stubble. Tiller density in 1980,1982, and 1983 was less (X0.05) in JAO and YL treatments (109/m’) than in ODF and FAJ (167/mz). Forage dry matter yield in 1979-80 and 1982-83 depended on stubble height and seasons. Avenge yield at H-cm height was greater for the FAJ treatment (1,700 kg/ha), similar for JAO (910 kg/ha) and ODF (910 kg/ha) and lowest for YL (660 kg/ha), but yield was simiIar at aii seasons (510 kg/ha) at 3O-cm stubble. Crude protein and IVOMD were influenced more by grazing time within a season than by seasons or stubble height. Poorest quality forage was at the beginning of the seasons (especially ODF and FAJ treatments). Best quality came from regrowth. Winter or spring grazing resulted in better stands of creeping bluestem than summer or year-long grazing.