caa a22 4500 386320721 CHVBK 20180307111625.0 cr unu---uuuuu 161130e198802 xx s 000 0 eng 10.1017/S0003356100003056 doi S0003356100003056 pii (NATIONALLICENCE)cambridge-10.1017/S0003356100003056 The influence of a formulated excess of rumen degradable protein or undegradable protein on milk production in dairy cows in early lactation [Elektronische Daten] Following a 3-week covariance period, 30 group-housed dairy cows were individually given one of three diets from week 4 to week 13 of lactation to determine any possible advantage in milk yield and production of feeding levels of undegradable protein (+UDP) or rumen-degradable protein (+RDP) above the minimum levels (control) proposed by the Agricultural Research Council (ARC, 1984). The three concentrates given were formulated to be of equivalent metabolizable energy (ME, 13·5 MJ/kg dry matter (DM)) concentration and each consisted of rolled barley plus a protein supplement: control (crude protein (CP), 129 g/kg DM) 0·35 kg DM fish meal per day; +UDP (CP, 167 g7kg DM) 1·0 kg DM fish meal per day; and +RDP (CP, 167 g/kg DM) 1+5 kg DM soya per day. For each group the total ‘concentrate' allowance per animal per day was 11·6 kg fresh weight and was given in three equal feeds. Grass silage (CP 122 g/kg DM, ME 106 MJ/kg DM) was given ad libitum. For the control, +UDP and +RDP treatments, respectively, mean grass silage intakes were 8·29, 8·62 and 8·65 kg/day and mean milk yields were 26·6, 26·3 and 26·1 kg/day. These were not significantly different (P > 0·05). Milk fat concentration was lower (P < 0·05) for the +UDP treatment (36·4 g/kg) in comparison with the control (38·6 g/kg) or the +RDP treatment (39·7 g/kg) but no other milk constituent was significantly influenced by treatment. There was a trend for a greater live-weight gain with treatment +UDP (0·81 kg/day) compared with the other two treatments (control 0·50, +RDP 0·51 kg/day) but there were no differences in condition-score change between treatments. In this trial there was no advantage to feeding formulated levels of UDP or RDP above those proposed by ARC (1984). Copyright © British Society of Animal Science 1988 Sloan B. K. Department of Agriculture Rowlinson P. Department of Agriculture Armstrong D. G. Department of Agricultural Biochemistry and Nutrition, The University, Newcastle upon Tyne NE1 7RU Animal Production Cambridge University Press 46/1(1988-02), 13-22 0003-3561 46:1<13 1988 46 ASC https://doi.org/10.1017/S0003356100003056 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0003356100003056 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sloan B. K. Department of Agriculture NATIONALLICENCE 700 1- Rowlinson P. Department of Agriculture NATIONALLICENCE 700 1- Armstrong D. G. Department of Agricultural Biochemistry and Nutrition, The University, Newcastle upon Tyne NE1 7RU NATIONALLICENCE 773 0- Animal Production Cambridge University Press 46/1(1988-02), 13-22 0003-3561 46:1<13 1988 46 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge