Abstract:
5A EFFECTS OF NaOH TREATMENT OF FORAGE AND ADDITION OF CONCENTRATES ON RUMEN R. M. DIXON* and R. PARRA* Two possibilities to increase the intake of digestible energy by cattle given law quality forage are alkali treatment of the forage and supplementation with concentrates, but associative effects may reduce intake and digestibility of fibre (Berger & &. 1980; Herrera & &.1981). Three fistulated Zebu steers (286-344 kg) were given mature Penti4ti PW)XL&W?J forage either freshly chopped or after treatment with 5% NaOH + 1.25% urea (DM basis), each with or without 3.6 kg DM/d of (90 % maize flour residue + 10% cottonseed meal). Rates of DM digestion (T$ of 8 feeds were determined using nylon bags and rumen liquid samples were taken before and at 4 and 8 h after the daily feed to determine pH and ammonia N. TABS 'I Forage intake (kg DM/d) and rumen digestion in steers fed 4 diets Intake of forage was decreased (P 4 0.07) by both NaOH treatment and concentrate supplementation. The rate of DM digestion was significantly different (SEM 1.4, PCO.05) between each of the feeds with the exception of sorghum grain and maize flour residue. NaOH treatment increased rate of IIM digestion, but feeding NaOH treated forage did not affect rate of DM digestion or rumen pH. Addition of concentrate reduced pH after feeding, and reduced rate of DM digestion of maize cobs (2 NaOH) by 57% and of the other feeds by 20%. The results. are consistent with. the frequently observed depression in intake and fibre digestion with concentrate supplementation. NaOH treatment of forage reduced intake but was not associated with a detrimental effect on rumen fibre digestion. BERGER,L.L., KLOPFENSTEIN,T.J. and BRITTON,R.A. (198O)J.Anim.Sci. 50:745* HERRERAaF.J FERREIRO,M.,ELLIOT,R.and PRESTON,T.R. (1981) .Trop.Anim.=od.6:178 = ')r Instituto de Producci& Animal, Facultad de Agronoda, Universidad Central de Venezuela, Maracay, Venezuela.
