caa a22 4500 386319944 CHVBK 20180307111622.0 cr unu---uuuuu 161130e198810 xx s 000 0 eng 10.1017/S0003356100003305 doi S0003356100003305 pii (NATIONALLICENCE)cambridge-10.1017/S0003356100003305 Performance of young steers offered stack-treated ammoniated hay or untreated hay with or without a supplement [Elektronische Daten] An experiment was designed to establish the growth response of young housed steers to the feeding of stack-ammoniated low-quality hay, and to a range of different supplements for 16 weeks, and any carry-over effects during the following 24 weeks at pasture. Ammoniated hay was offered alone (TA), or with daily supplements of either 0·75 kg barley (TLB), 1·50 kg barley (THB), 0·1125 kg fish meal (TF), 0·75 kg or 1·50 kg of a barley-based concentrate (TLC and THC, respectively). Untreated hay was offered with either urea (UU) or with a daily supplement of 0·75 or 1·50 kg concentrates (ULC and UHC respectively). Ammoniation increased the total nitrogen concentration of the hay from 13·4 to 24·2 g/kg dry matter, and resulted in a small increase in the organic matter digestibility measured in vivo (0·597 to 0·653), compared with that measured in vitro (0·572 to 0·667). Digestibilities of the fibre fractions, measured in vivo, were also increased by ammoniation (0·626 to 0·734, 0·637 to 0·761, 0·678 to 0·771 for acid-detergent fibre, neutral-detergent fibre and cellulose, respectively). Intakes of hay were reduced by supplementation, with the exception of TF, although total intakes were increased. During the housed period, live-weight gains of steers given ammoniated hay were 0·58, 0·71, 0·81, 0·69, 0·80, 0·86 kg/day for treatments TA, TLB, THB, TF, TLC, THC, respectively. The live-weight gains of steers offered the untreated hay were 0·49, 0·66, 0·87 kg/day for treatments UU, ULC, UHC, respectively. There was no carry-over effect of treatments on live-weight gains over the grazing season (mean 0·66 kg/day). It is concluded that when high levels of supplementation are available, no benefit is to be gained by ammonia treatment of ihe hay. However, without supplementation stack ammoniation of hay produces a marked improvememt in performance, compared with the addition of urea at feeding. Copyright © British Society of Animal Science 1988 Gibb M. J. AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR Baker R. D. AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR Animal Production Cambridge University Press 47/2(1988-10), 223-229 0003-3561 47:2<223 1988 47 ASC https://doi.org/10.1017/S0003356100003305 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0003356100003305 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gibb M. J. AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR NATIONALLICENCE 700 1- Baker R. D. AFRC Institute for Grassland and Animal Production, Hurley, Maidenhead SL6 5LR NATIONALLICENCE 773 0- Animal Production Cambridge University Press 47/2(1988-10), 223-229 0003-3561 47:2<223 1988 47 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence SWISSBIB 386157308 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge