Metabolic and endocrine responses of lambs fed Acremonium coenophialum-infected or noninfected tall fescue hay at equivalent nutrient intake

Abstract

Ten Hampshire x Western wether lambs (means weight = 30.1 kg) equipped with ruminal and abomasal cannulas were fed either low-Acremonium coenophialum (AC) Kentucky-31 (less than 1% infected) or high-AC G1-307 (greater than 95% infected) varieties of tall-fescue (TF) hay of similar nutrient composition in a completely randomized design. Lambs were housed in metabolism crates at 21 +/- 1 degrees C and fed 552 g DM/d of ground hay at 0800 and 2000. A 10-d adaptation preceded 7 d of sample collection. Levels of water and DM voluntarily consumed by the low-AC group during the adjustment period were held constant for both treatment groups throughout the collection period by intraruminal insertion of unconsumed DM and water. Fixed water intake markedly reduced voluntary water intake but it alleviated previous depressions in voluntary DM intake in lambs fed high-AC. Mean daily respiration and heart rates, rectal temperature and hematocrit were not affected (P greater than .10) by treatment. Compared with high-AC, lambs fed low-AC retained a greater (P less than .10) amount of N (1.8 vs 1.1 g/d) and a greater (P less than .10) percentage of their N intake (16.4 vs 9.9%). Abomasal total and bacterial N flow and ruminal digestion of cell wall components were not affected (P greater than .10) by treatment. Total tract digestion of DM, NDF and ADF was lower (P less than .01) for high- than for low-AC. Serum prolactin concentration was higher (P less than .10) for lambs fed low- than for those fed high-AC TF, but serum cortisol and thyroxine concentrations were not affected (P greater than .10) by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of Nitrogen Fertilizer and Endophyte Infection on Ecophysiological Parameters and Mineral Element Content of Perennial Ryegrass

“…Hunt et al (2005) and Rasmussen et al (2007) found endophyte infection lowered soluble protein content of ryegrass. In contrast, other researchers did not find any difference in CP concentrations between EI and EF plants (Fiorito et al 1991; Newman et al 2003). In this study, we did not find any effect of endophyte infection on CP content.…”

Effects of elevated CO2, nitrogen and fungal endophyte‐infection on tall fescue: growth, photosynthesis, chemical composition and digestibility

“…5), but there were no differences in either NDF or ADF. Fiorito et al . (1991) found a difference in both NDF and ADF, but the interpretation of these results is problematic because they used different cultivars to obtain endophyte‐infected (G1‐307) and endophyte‐free (KY‐31) plants.…”

“…However, there is little difference in these fractions for endophyte‐infected plants. Fiorito et al . (1991) did not find any difference in CP concentrations between cultivars differing in endophyte‐infection (but see earlier comments about the difficulty in interpreting these results).…”

Anti-quality factors associated with alkaloids in eastern temperate pasture

“…Chestnut et al (1991) found no difference in organic matter digestibility of E+ and E-tall fescue in steers and Harmon et al (1991) found no endophyte effect on dry matter and nitrogen digestibility in steers. Others, however, found that diets containing E+ tall fescue had reduced dry matter and organic matter digestibility in sheep (Hannah et al 1990, Fiorito et al 1991, Westendorf et al 1993, cattle (Aldrich et al 1993a), and rats (Larson et al 1991), which could be ambient temperaturedependent (Hannah et al 1990).…”