Intake, digestion, and N metabolism in steers fed endophyte-free, ergot alkaloid-producing endophyte-infected, or nonergot alkaloid-producing endophyte-infected fescue hay1

Abstract

A digestion and N balance trial was conducted to compare effects of traditional endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte infected (NE; MaxQ; Pennington Seed, Inc., Madison, GA) Jesup tall fescue (Festuca arundinacea Schreb.) hay on digestion and N retention in steers. Hay composition (DM basis) was as follows: E+ (10.8% CP, 59.9% NDF, and 29.4% ADF), E- (11.8% CP, 58.5% NDF, and 28.4% ADF), and NE (11.6% CP, 58.6% NDF, and 28.3% ADF). Eight Polled Hereford steers (initial BW 240 +/- 9 kg) were used in a replicated, 3 x 3 Latin square design, with an extra steer allotted to each square. Steers were fed ad libitum for 14 d, followed by a 9-d adaptation to restricted intake (based on the animal with the lowest ad libitum intake for the square) and a 5-d fecal and urine collection. Water intake (20.2 L/d) and urine output (7.40 L/d) did not differ (P > 0.10) during the collection period. Plasma prolactin concentration was less (P < 0.05) for steers on the E+ hay (8.83 ng/mL) than for those on the E- hay (18.03 ng/mL) and intermediate for steers on the NE hay (12.65 ng/mL). Endophyte-infected hay differed (P < 0.05) from E- and NE in ad libitum DMI (5.02 vs. 5.62 and 5.61 kg/d, respectively) and ad libitum DMI as a percentage of BW (1.86 vs. 2.06 and 2.06%, respectively). Restricted DMI during the fecal and urine collection was lower (P < 0.05) for E+ hay than for E- (5.04 vs. 5.24 kg/d), and NE was intermediate (5.19 kg/d). Dry matter digestibility was lower (P < 0.05) for E+ compared with E- and NE (62.3 vs. 67.0 and 65.9%, respectively). Digestibility of ADF was lower (P < 0.05) for E+ than for E-, and was intermediate for NE (61.5, 66.0, and 63.9%, respectively). There were no differences for NDF, cellulose, or hemicellulose digestibilities among hay types. Crude protein digestibility was higher (P < 0.05) for E- and NE than for E+ (54.3 and 52.5 vs. 48.1%, respectively). Nitrogen retention was lower (P < 0.01) for E+ than for E- or NE (15.6 vs. 22.7 or 23.0 g/d, respectively). Hay type did not influence plasma urea N, urine urea N output, or urine urea N as a percentage of urinary N. Results from this study indicate that E+ tall fescue hay was lower in ad libitum DMI, DM digestibility, and N retention than NE or E- hays with similar chemical composition. Hay from NE and E- fescue had nearly identical composition, and did not differ for any variable measured.

Physiological and digestive effects of Neotyphodium coenophialum-infected tall fescue fed to lambs1

“…Apparent DM (P = 0.48), ADF (P = 0.62), and CP (P = 0.89) digestibilities were not different between treatment groups (Table 2), which agrees with Stamm et al (1994), although it should be noted that DM digestibility was numerically 4 percentage units greater for E− than for E+. Matthews et al (2005) reported lower DM, ADF, and CP digestibilities in animals consuming an endophyte-infected diet compared with those on an endophyte-free diet. The difference in the effect of ergovaline on nutrient digestibilities could be related to the quality of the different feeds.…”

“…Early work typically classified treatments as infected vs. noninfected tall fescue with no analysis for ergopeptide alkaloid levels (Fiorito et al, 1991;Paterson et al, 1995). When alkaloids were tested, the treatment levels of ergopeptides varied greatly, ranging from 0.12 mg/kg of ergovaline (Matthews et al, 2005) to 2.43 mg/kg of ergovaline (Aldrich et al, 1993) in the high treatments. Higher ambient temperatures and heat stress can cause a greater change in rectal temperature for animals consuming endophyte-infected diets when compared with endophyte-free diets (Hannah et al, 1990;Gadberry et al, 2003).…”

“…The difference in the effect of ergovaline on nutrient digestibilities could be related to the quality of the different feeds. Matthews et al (2005) fed a higher quality diet with hay being the source of alkaloids and reported DM digestibilities of 62.3% for E+ and 67.0% for E−. The digestibilities reported by Stamm et al (1994;48.8% for E+ vs. 46.0% for E−) or Within a row, means without a common superscript letter differ (P < 0.05).…”

Intake, Digestibility, and Nitrogen Balance of Steers Fed Gamagrass Baleage Topdressed at Two Rates of Nitrogen and Harvested at Sunset and Sunrise

“…At the end of the 5‐d collection, the composite frozen samples were oven‐dried (55°C), weighed for dry matter (DM) determination, ground in a Wiley mill to pass a 1‐mm screen, thoroughly mixed, subsampled, and stored at room temperature until analyzed. Total urine was collected each of the 5 d for N balance determination as described by Matthews et al (2005), except 6 M acetic acid was used to maintain urine pH below 6.0.…”

Effect of Feeding Fescue Seed Containing Ergot Alkaloid Toxins on Stallion Spermatogenesis and Sperm Cells

“…The reported fiscal impact of ergot alkaloids is in the tens and hundreds of millions of dollars. The greatest clinical and financial impact is in the beef industry, with cattle being affected with a number of pathologies (Burfening 1973;Peters et al 1992;Porter and Thompson 1992;Aldrich et al 1993;Dyer 1993;Porter 1993;Hill et al 1994Hill et al , 2000Oliver et al 1994;Cheeke 1995;Schneider et al 1996;Stuedemann et al 1998;Schultze et al 1999;Schnitzius et al 2001;Parish et al 2003;Matthews et al 2005;Realini et al 2005;Wang et al 2009). The symptoms in cattle include increased respiration rates, increased rectal temperatures, salivation, nervousness and rough hair coats, decreased weight gains and decreased overall performance in beef steers (Hoveland 1993).…”