Deactivation of condensed tannins in Acacia cyanophylla Lindl. foliage by polyethylene glycol in feed blocks: Effect on feed intake, diet digestibility, nitrogen balance, microbial synthesis and growth by sheep

摘要: Abstract Unmolassed feed blocks were used as supplement of Acacia cyanophylla Lindl. (acacia)-based diets. They made, on the basis crude weight, with olive cake (42.2%), wheat bran (26.7%), flour (10.7%), quicklime urea (4.4%), salt (4.4%) and a mineral vitamin (0.9%). Polyethylene glycol (PEG, mol. wt. 4000) was introduced in these at five increasing levels (0 (control), 6, 12, 18 24% ingredient mixture before moulding) to deactivate acacia condensed tannins. The dietary treatments (levels PEG) evaluated simultaneously each diet tested 6 yearling male Barbarine sheep (average initial weight 19±1.5 kg) rams 47±3.0 kg). Animals held individual pens metabolism cages, respectively. adapted experimental conditions for 10 21 days, respectively commencement measurement periods. Freshly cut foliage distributed ad libitum block permanently available trough. Feed intake daily gain measured yearlings during 60-day period. intake, vivo digestibilities, nitrogen balance microbial synthesis using urinary excretion allantoin consecutive days. Dry matter (DMI) ranged from 13.7 16.5 g/kg W 0.75 15.5 24.3 rams. PEG had no effect intake. DMI by given without low (37.7 39.9 , rams). Supplementation containing either or increased 25, 50, 56 45%, 22, 71%, Providing rate digestible organic (DOMi) 3.4, 4.3, 9.4 18.2 protein 17, 23 36 g/day, higher greater N retention allantoin. Estimated (g/kg DOMi) 37, 94, 135 153% PEG, clear-cut improvement nutritive value acacia-based diets following supply resulted linear increase growth sheep. optimum responses retention, yield obtained 18% which corresponded consumption about g/day. It concluded that may be carrier improving tannin-rich