These forages, however, do not provide quality equal to that of alfalfa and must be supplemented with protein With dwindling water supplies, alfalfa (Medicago sativa L.) and (Anil et al., 1998;Chapko et al., 1991). Hall and Kephart corn (Zea mays L.) producers in the Southern High Plains (USA) seek alternative forages for the dairy industry. At New Mexico State (1991) said that yield and quality of triticale were max-University's Agricultural Science Center at Tucumcari, cereal forage imized slightly before heading in Idaho. Collins et al. monocultures and intercrops with legumes were subjected to two (1990), in Wisconsin, recommended harvesting oat at irrigation treatments during two growing seasons in a Canez fine boot to early head stage for livestock that required sandy loam (fine-loamy, mixed, thermic Ustollic Haplargid). Dry mathigher quality because oat quality would decline after ter (DM) yield of monocultures averaged 3.76, 3.90, 5.55, 5.59, and heading. 3.17 Mg ha Ϫ1 for rye (Secale cereale L.), barley (Hordeum vulgare Quality indicators of cereal forages tend to increase L.), wheat (Triticum aestivum L.), triticale (ϫ Triticosecale rimpaui from the milk to dough stage due to dilution of indigest-Wittm.), and oat (Avena sativa L.), respectively. Cereal forages irriible fiber by the grain (Edmisten et al., 1998b). An gated once in a growing season yielded equally to those watered twice increase in digestible energy is also beneficial to fermenwith average precipitation (2000-2001, 408 mm), but not in a dry growing season (2001-2002, 245 mm) (6.15, 5.41, 1.90, and 3.21 Mg ha Ϫ1 tation and provides more energy for livestock. Thus, for cereal forages irrigated once or twice in

These forages, however, do not provide quality equal to that of alfalfa and must be supplemented with protein With dwindling water supplies, alfalfa (Medicago sativa L.) and (Anil et al., 1998;Chapko et al., 1991). Hall and Kephart corn (Zea mays L.) producers in the Southern High Plains (USA) seek alternative forages for the dairy industry. At New Mexico State (1991) said that yield and quality of triticale were max-University's Agricultural Science Center at Tucumcari, cereal forage imized slightly before heading in Idaho. Collins et al. monocultures and intercrops with legumes were subjected to two (1990), in Wisconsin, recommended harvesting oat at irrigation treatments during two growing seasons in a Canez fine boot to early head stage for livestock that required sandy loam (fine-loamy, mixed, thermic Ustollic Haplargid). Dry mathigher quality because oat quality would decline after ter (DM) yield of monocultures averaged 3.76, 3.90, 5.55, 5.59, and heading. 3.17 Mg ha Ϫ1 for rye (Secale cereale L.), barley (Hordeum vulgare Quality indicators of cereal forages tend to increase L.), wheat (Triticum aestivum L.), triticale (ϫ Triticosecale rimpaui from the milk to dough stage due to dilution of indigest-Wittm.), and oat (Avena sativa L.), respectively. Cereal forages irriible fiber by the grain (Edmisten et al., 1998b). An gated once in a growing season yielded equally to those watered twice increase in digestible energy is also beneficial to fermenwith average precipitation (2000-2001, 408 mm), but not in a dry growing season (2001-2002, 245 mm) (6.15, 5.41, 1.90, and 3.21 Mg ha Ϫ1 tation and provides more energy for livestock. Thus, for cereal forages irrigated once or twice in

A winter grazing/feedlot performance experiment repeated over 2 yr (Exp. 1) and a metabolism experiment (Exp. 2) were conducted to evaluate effects of grazing dormant native range or irrigated winter wheat pasture on subsequent intake, feedlot performance, carcass characteristics, total-tract digestion of nutrients, and ruminal digesta kinetics in beef cattle. In Exp. 1, 30 (yr 1) or 67 (yr 2) English crossbred steers that had previously grazed native range (n = 38) or winter wheat (n = 59) for approximately 180 d were allotted randomly within previous treatment to feedlot pens (yr 1 native range = three pens [seven steers/pen], winter wheat = two pens [eight steers/pen]; yr 2 native range = three pens [eight steers/pen], winter wheat = four pens [10 or 11 steers/pen]). As expected, winter wheat steers had greater (P < 0.01) ADG while grazing than did native range steers. In contrast, feedlot ADG and gain efficiency were greater (P < 0.02) for native range steers than for winter wheat steers. Hot carcass weight, longissimus muscle area, and marbling score were greater (P < 0.01) for winter wheat steers than for native range steers. In contrast, 12th-rib fat depth (P < 0.64) and yield grade (P < 0.77) did not differ among treatments. In Exp. 2, eight ruminally cannulated steers that had previously grazed winter wheat (n = 4; initial BW = 407 +/- 12 kg) or native range (n = 4; initial BW = 293 +/- 23 kg) were used to determine intake, digesta kinetics, and total-tract digestion while being adapted to a 90% concentrate diet. The adaptation and diets used in Exp. 2 were consistent with those used in Exp. 1 and consisted of 70, 75, 80, and 85% concentrate diets, each fed for 5 d. As was similar for intact steers, restricted growth of cannulated native range steers during the winter grazing phase resulted in greater (P < 0.001) DMI (% of BW) and ADG (P < 0.04) compared with winter wheat steers. In addition, ruminal fill (P < 0.01) and total-tract OM digestibility (P < 0.02) were greater for native range than for winter wheat steers across the adaptation period. Greater digestibility by native range steers early in the finishing period might account for some of the compensatory gain response. Although greater performance was achieved by native range steers in the feedlot, grazing winter wheat before finishing resulted in fewer days on feed, increased hot carcass weight, and improved carcass merit.

Information is lacking on the relative performance of small‐grain forage types grown for hay or silage on the High Plains of New Mexico and West Texas. Tests were conducted from 2004 to 2008 at Clovis, NM, to determine long‐term potential of common varieties and blends of species [wheat (Triticum aestivum L.), triticale (xTriticosecale), and oats (Avena sativa L.)] in an irrigated production system. Eleven entries were tested in at least 3 years, including exceptionally wet (2005) and dry (2006) years. In any given year, all crops yielded greater than 2.5 tons of DM, and entry mean annual yields ranged from 4.0 to 5.3 ton DM/acre over the study period. Triticale or blends containing triticale yielded more wet forage than wheat alone. In general, nutritive value of wheat was greater than that of triticale and blends. One triticale entry exhibited similar DM yields and forage quality as those of the wheats. Under irrigation, small grains have the potential to produce acceptable yields of nutritious forage in between summer crops for feeding operations in the region. While wheat may yield less tonnage, it gives greater market flexibility and may better fit into double cropping systems because of its earlier maturity than triticale.

Alfalfa (Medicago sativa L.), a forage crop unique in that it has high potential in terms of both yield and quality, has considerable capacity for animal production when grazed under management that is based on its growth and development. Two grazing experiments, using balanced change‐over designs, were set up to measure the ingestive behavior of beef heifers (Bos taurus) during the first, second, and third hours of grazing sessions on alfalfa pastures established on Maury silt loam (fine, mixed, mesic Typic Paleudalfs). In Exp. I where the herbage mass, in terms of dry matter (DM), was 3.06 Mg ha−1 and the herbage DM allowance was 6.1 kg h−1 per heifer, animals ingested DM at 2.96, 1.88, and 1.56 kg h−1 during their first, second, and third hours of grazing, respectively. The mean rates of biting were 26, 21, and 19 bites min−1 for the same periods. Herbage DM intake per bite declined linearly from 1.96 to 1.54 to 1.36 g for each hour increment in grazing time. Forage utilization was 51, 32, and 27% for the same increments. In Exp. II where the herbage mass (DM) was 1.74 Mg ha−1 and the allowance was 3.4 kg h−1, heifers ingested 2.35, 1.47, and 1.20 kg h−1 during their first, second, and third hours of grazing, respectively. The mean rates of biting were 34, 22, and 18 bites min−1 during the same periods within the grazing session. Herbage DM intake per bite averaged 1.17 g and did not vary within the grazing session. Forage utilization was 75, 47, and 37% during the three consecutive hours within the grazing session. Maximum rates of herbage intake were characterized by larger bites and relatively slow rates of biting. Rates of herbage intake were considerably higher during the first hour of grazing than during the second and third hours. In a 3‐h grazing session, animals consumed 47, 29, and 24% of their intake during the first, second, and third hours, respectively.

moisture, and provides both high yields and quality (Karnezos et al., 1994) as well as fixing 82 to 254 kg N Producers in the irrigated steppe of the southern Rocky Mountains ha Ϫ1 yr Ϫ1 (Heichel and Henjum, 1991). Many producers are seeking ways to improve the summer productivity of their established cool-season grass pastures, commonly tall fescue (Festuca arun-have incorporated this species into their irrigated cooldinacea Schreb.). From 1994 to 1997, a study was conducted under season grass pastures, grazing them during the spring irrigation at the New Mexico State University Alcalde Sustainable and fall and harvesting 1 to 2 cuttings of hay during the Agriculture Science Center, in which dry matter yield of monoculture summer to use as supplemental winter feed. However, tall fescue was compared with that of swards containing tall fescue there are some limitations to alfalfa's sustainability in in mixtures with alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus regard to increased inputs to prevent bloat (Karnezos corniculatus L.), cicer milkvetch (Astragalus cicer L.), and kura clover et al., 1994; Majak et al., 1995; Marten et al., 1990; (Trifolium ambiguum M.B.) in a randomized complete block design Peterson et al., 1992), historically poor persistence under with three blocks. Percent tall fescue in the sward and the yield of grazing (van Keuren and Matches, 1988), reestablishtall fescue in mixtures declined from 1994 to 1996 and then increased ment only by seeding, and autotoxicity in reestablishin all mixtures except tall fescue-kura clover in 1997. Dry matter yields of alfalfa and cicer milkvetch increased until 1996 then declined, ment (Melton et al., 1988). For these reasons, interest in while birdsfoot trefoil equilibrated in 1996 and 1997 and kura clover alternative forage legumes is building and, while several continued to increase. Combined dry matter yields followed a trend have been shown to be well adapted to the higher precipsimilar to that of the legume yields except that, in 1996 and 1997, itation areas of the eastern USA (Heichel and Henjum, yields of the tall fescue-cicer milkvetch mixture were comparable to 1991; Hoveland and Richardson, 1992; Taylor and those of monoculture tall fescue, which were 5.76 and 6.72 Mg ha Ϫ1 for Smith, 1998) and to the drier but cooler climates of the 1996 and 1997, respectively. Over the life of the study, tall fescue-cicer central and northern Great Plains and Rocky Mountains milkvetch yielded less than one-half that of tall fescue-alfalfa while of the USA and Canada (Berg, 1990; Farnham and

Intercropping legumes with nonlegume crops has shown benefits in improving dry matter (DM) yield, but additional information is needed when crop mixtures are ensiled. This study assessed the fermentation characteristics of forage corn silage {Zea mays L.) (CS) and forage sorghum silage [Sorghum bicolor (L.) Moench] (FS) when mixed with different proportions of lablab bean [Lablab purpureus (L.) Sweet] (LB). Corn, FS, and LB were grown in separate fields at two locations in 2009. At each location, crops were cut and chopped separately and taken to the laboratory for ensiling. Six mixtures were handmade on a percentage fresh weight basis for each CS-LB and FS-LB combination, including (i) 100:0, (ii) 90:10, (iii) 75:25, (iv) 50:50, (v) 25:75, and (vi) 0:100.For each mixture, a 1-L glass jar (mini-silo) was filled with 500 g of fresh material, with four jars per treatment. Forage in mini-silos was fermented for 60 d at room temperature (25°C). Analysis was conducted for nutritive value and fermentation characteristics. The greatest impact of mixing LB with CS or FS was on crude protein (CP) and acid detergent fiber (ADF) concentrations, with no significant impact on neutral detergent fiber (NDF). Averaging across CS and FS, CP concentration increased from 87 to 173 g kg-'' and ADF concentration from 253 to 306 g kg-^ as LB increased from 0 to 75% in the mixture. Increasing LB in the mixture also increased other constituents, such as pH and lactic and acetic acid concentrations. Adding LB to CS or FS for silage can have a positive effect on the final nutritive value, but additional research is needed to assess the impact in cattle.

Forage sorghum [Sorghum bicolor (L.) Moench] and sorghum & sudangrass (S. bicolor var Sudanese) hybrids may produce as much dry matter yield as corn (Zea mays L.) for silage but with less water. Planting sorghum forage with annual legumes could increase digestibility and crude protein (CP) concentration, making the mixture more suitable for dairy cow rations. The objective of this study was to assess dry matter (DM) yield and nutritive value of brown midrib (BMR) sorghum forage grown as a monoculture or in combination with selected annual legumes. BMR100 (a forage sorghum) and PS210BMR (a photoperiod sensitive sorghum & sudangrass) were planted with four annual legumes: cowpea [Vigna unguiculata (L.) Walp.], lablab (Lablab purpureus L.), soybean (Glycine max L.), and tepary bean (Phaseolus acutifolius A. Gray). Lablab was most complementary with sorghum for forage. The lablab‐sorghum mixtures contained more CP with no consistent effect on neutral detergent fiber (NDF) and acid detergent fiber (ADF) compared to monoculture sorghums. This finding opens another possibility to produce good quality forage that could be used as an alternative forage crop to corn in the Southern High Plains.