Amino acid flow at the abomasum in twin-suckling ewes at pasture and the effect of a fishmeal supplement

摘要

Fourteen twin-suckling ewes with rumen and abomasal cannulae grazed a ryegrass/clover sward (C; n = 7) or the same sward but with a 500 g/h/d protein supplement (S; n = 7). The trial was designed as a cross-over with two 14 day adaptation periods followed by two five day sampling periods (Days 43-48 and 63-68 after lambing). All ewes were treated with anthelmintic 14 days after lambing. Flow of amino acids (AA) at the abomasum and dry matter (DM) intake were measured during both periods using intra-ruminally infused markers. Diurnal variation in AA flow peaked between 12:00 and 15:00 h and was greatest in the supplemented ewes. Flows of AA were increased by supplementation; Essential AA, +16 %; 128 to 148 g/d, Sulphur-AA, +21.2 %; 3.3 to 4.0 g/d, Branched-chain AA, +15.9%, 47.8 to 55.4 g/d. There was evidence for a lower faecal egg count in supplemented animals, being 670 vs 46 epg, respectively, in C and S groups, (P = 0.08) 21 days after anthelmintic treatment. This work provides information on the extent of enhancement of the supply of amino acids associated with ability to limit the peri-parturient increase in faecal egg count and provides a basis for the development of supplements.