Kikuyu (Pennisetum clandestinum) pasture for sheep. 2. Production and nutritional status of ewes with or without lupin (Lupinus albus) supplementation

摘要

Abstract Kikuyu pasture was grazed continuously for 12 months by 20 dry and 40 producing South African Mutton Merino (SAMM) and Merino ewes at a stocking density of 23 ewes ha?1. Supplementary sweet lupin seed was supplied to one group of producing ewes of each breed during pregnancy and lactation at a rate of 0.5% of the liveweights of the ewes. Rumen fluid samples for the determination of pH, volatile fatty acids (VFA), and ammonia‐nitrogen (NH3‐N) were collected from rumen‐fistulated wethers corresponding to the periods of late pregnancy and early lactation of ewes. Rumen NH3‐N concentrations (8.7 mg 100 ml?1 and 5.4 mg 100 ml?1) were low during both periods of sampling. Rumen VFA concentrations (12.3 mmol 100 ml?1 and 9.2 mmol 100 ml?1)were within normal ranges. Supplementation significantly increased blood urea concentration of ewes. Supplemented ewes lost less weight than the unsupplemented ewes (P ≤ 0.02) during the experimental period. Pregnancy (P ≤ 0.001) as well as lactation (P ≤ 0.0001) reduce...