This study investigated the performance of steers grazing rhizomatous birdsfoot trefoil (Lotus corniculatus L.) (RBFT) compared to nonrhizomatous birdsfoot trefoil (BFT) in pure stands or when interseeded with endophyte-free tall fescue (Festuca arundinacea Schreb.; TF). Five forage treatments of RBFT, BFT, TF, RBFT+TF, and BFT+TF (four replicate paddocks per treatment) were continuously stocked in spring and fall of 1998 and spring of 1999. Grazing for individual treatments was terminated when pasture mass fell below 900 kg/ha. Average daily gain was greatest (P < 0.10) in pure stands of BFT and RBFT, but total forage production, and thus grazing days, for these treatments was low. Average daily gain for steers grazing BFT+TF and RBFT+TF treatments was not different from (spring and fall 1998) or greater (P < 0.10) (spring 1999) than that for TF. Total forage production of BFT+TF and RBFT+TF was greater (P < 0.10) than that of TF in spring 1998. In fall 1998, BFT+TF produced more (P < 0.10) total forage than either RBFT+TF or TF, and in spring 1999, RBFT+TF had less (P < 0.10) total forage than TF or BFT+TF. Total steer days on mixed pastures were greater (P < 0.10) than that for TF in spring and fall 1998 but not different from those for TF in spring 1999. In all three trials total weight gain/hectare was greater (P < 0.10) for RBFT+TF and BFT+TF than for TF. The RBFT+TF and BFT +TF had greater (P < 0.05) CP than TF in spring and fall 1998 and less (P < 0.05) NDF and ADF in fall 1998. We concluded that either RBFT or BFT could be interseeded with tall fescue to enhance ADG and total steer days.

Condensed tannins in forage legumes can be beneficial or detrimental to ruminant livestock performance, depending on concentration. The objective of this research was to determine condensed tannin concentration in birdsfoot trefoil (Lotus corniculatus L.) without rhizomes (BFT) and with rhizomes (RBFT) from grazed monocultures and mixtures. An additional objective was to investigate possible fluctuation of condensed tannin concentrations through the spring grazing season. In 1997, ‘Norcen’ BFT and ‘ARS‐2620’ RBFT were sown into pastures located at Columbia, MO; pastures were pure stands or mixtures with tall fescue (TF; Festuca arundinacea Schreb). Pastures were grazed in 1998 and 1999, and the BFT and RBFT components were hand clipped every 14 d throughout the spring of 1998 and 1999. Samples were analyzed for condensed tannin concentration by near infrared (NIR) reflectance spectroscopy with calibrations based on the vanillin−HCl colorimetric method. Condensed tannin concentrations of grazed BFT were lower in this study than concentrations reported in other studies. Averaged over both years, BFT contained 11.4 g catechin equivalents (CE) kg−1 DM, and RBFT contained (P < 0.05) three times that amount (38.6 g CE kg−1 DM). Also, condensed tannin concentrations of the BFT component were 100% higher when BFT was grown in a mixture instead of a pure stand (P < 0.10); in 1999, they were 55% higher (P < 0.05). Finally, condensed tannin concentration fluctuated over the spring of 1998 (P < 0.05), but not the spring of 1999. We concluded that condensed tannins in BFT are much lower than in RBFT, that condensed tannins in BFT decrease when grown with a tall fescue companion grass, and that concentrations can fluctuate in the spring as they do in the autumn.

When birdsfoot trefoil (Lotus corniculatus L.) is interseeded into tall fescue (Festuca arundinacea Schreb.) pastures, animal performance often exceeds that expected based on forage samples taken from the pasture. This may be due to cattle (Bos taurus) preferentially selecting birdsfoot trefoil from mixed pastures. Our objective was to investigate the selectivity for birdsfoot trefoil by cattle grazing tall fescue‐birdsfoot trefoil pastures. Treatments were ‘Phyter’ tall fescue sown in a monoculture and in mixtures with ‘ARS‐2622’ and ‘Norcen’ birdsfoot trefoil. Beef heifers fitted with esophageal cannulas grazed pastures in the spring and autumn of 1998 and again in spring 1999. In the tall fescue‐birdsfoot trefoil mixtures, the amount of birdsfoot trefoil on‐offer showed a 73% reduction during the study, but the amount of birdsfoot trefoil in esophageal samples declined by an average of only 22%. Although the percentage of birdsfoot trefoil in mixed pastures often declines over time, its value may be underestimated because animals selectively graze this species when its proportion in pastures is low.

In order to learn more about the feeding value of stovers and straws, seven diets were compared in one experiment and nine in another. The diets in the first experiment were: the upper and lower parts of lucerne (Medicago sativa) hay, the leaves, upper stem and lower stem of maize (Zea mays) stover and the leaves and stem of sorghum (Sorghum vulgare) stover. The diets in the second experiment were: the upper and lower parts of lucerne hay, the leaves, stem and whole stover of millet (Setaria italica), the straw and chaff of wheat (Triticum aestivum), rice (Oryza sativa) straw and sweet potato (Ipomoea batatas) haulm. The diets were fed to sheep to record rate of intake, voluntary intake and in vivo digestibility. The diets were analysed for cell wall (as neutral detergent fibre), crude protein and lignin. Organic matter degradation and cell wall degradation were recorded in nylon bags in the rumen of cattle.The highest rates of intake (6·8–9·6 g dry matter/min) and voluntary intake (75–103 g dry matter/kg W0·75/day) were with sweet potato haulm and the upper, leafy part of lucerne hay. The voluntary intake of millet leaves, wheat chaff and the lower, stemmy part of lucerne hay was moderately high (46–70 g dry matter/kg W0·75/day). Voluntary intake of leaves was higher than that of stems in the case of millet, sorghum and to a lesser extent maize. The lowest rates of intake were with millet stem, sorghum stem and rice straw (1·8–2·4 g dry matter/min). In vivo digestibility of organic matter was highest (59–67%) for the upper part of lucerne hay, sweet potato haulm, the lower part of maize stem and millet leaves. The leaves of maize were less digestible than the stem, while the reverse was the case with millet. Cell wall content was particularly high (74–78% of dry matter) in millet stem, wheat straw and chaff, rice straw and sorghum stem. Lignin content was low (3·6–4·2% of dry matter) in millet leaves, maize leaves and the upper part of maize stem. Organic matter degradation after 24 h incubation in the rumen was highest (80%) in sweet potato haulm and lowest (39–44%) in millet stem, wheat straw and chaff and rice straw. Cell wall degradation after 96 h in the rumen was highest (76–81%) with the leaves of maize, sorghum and millet and lowest (40–59%) with lucerne hay, millet stem and stover, wheat straw and chaff and rice straw.