caa a22 4500 388060468 CHVBK 20180307125119.0 cr unu---uuuuu 161130e199808 xx s 000 0 eng 10.1017/S1357729800009759 doi S1357729800009759 pii (NATIONALLICENCE)cambridge-10.1017/S1357729800009759 Supplementation of grass silage-based diets with small quantities of concentrates: strategies for allocating concentrate crude protein [Elektronische Daten] Fifty-five multiparous Holstein-Friesian cows were used to evaluate the short- and long-term effects of varying the crude protein (CP) content of concentrates offered at a low level (5 kg/day) along with ad libitum access to a high quality grass silage. Three dietary treatment groups in lactation weeks 4 to 22 received concentrates containing either 156 (L), 247 (M) or 338 (H) g CP per kg dry matter; from weeks 13 to 21, half of the L animals changed over to the H concentrate and vice versa so that there were five treatment groups (LL, LH, MM, HL and HH). Feeding M or H compared with L increased silage voluntary intakes (P <0·05) and the yields of milk (P <0·05), fat (P < 0·05) and protein (P < 0·01). Milk protein concentration increased with level of concentrate CP (P < 0·05). Pattern of concentrate CP supply (comparison ofLH, MM and HL) had no significant effect on intake or yields of milk and milk solids across the experiment (weeks 4 to 21), though cows gained less weight on treatment HL than on LH (P <0·05) or MM. Intake, milk and component yields were all markedly affected by a change in concentrate CP at week 13; there were positive effects of additional CP (LL v. LH) and negative effects of reduced CP (HH v. HL) on silage intake (P <0·05), as well as milk yield (P < 0·001), milk protein yield (P < 0·001) and milk protein concentration (P < 0·001). Responses to increased concentrate CP were of a similar magnitude in early and midlactation; extra concentrate CP can recover depressed yields and concentrations of milk protein in established lactation. Production responses to concentrate CP involved a concomitant increase in silage voluntary intake. Copyright © British Society of Animal Science 1998 dairy cows nationallicence concentrates nationallicence food intake nationallicence grass silage nationallicence milk production nationallicence protein nationallicence Aston K. Institute of Grassland and Environmental Research, Trawsgoed Research Farm, Trawsgoed, Ceredigion SY23 4LL Fisher W. J. Institute of Grassland and Environmental Research, Trawsgoed Research Farm, Trawsgoed, Ceredigion SY23 4LL McAllan A. B. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB Dhanoa M. S. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB Dewhurst R. J. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB Animal Science Cambridge University Press 67/1(1998-08), 17-26 1357-7298 67:1<17 1998 67 ASC https://doi.org/10.1017/S1357729800009759 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S1357729800009759 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Aston K. Institute of Grassland and Environmental Research, Trawsgoed Research Farm, Trawsgoed, Ceredigion SY23 4LL NATIONALLICENCE 700 1- Fisher W. J. Institute of Grassland and Environmental Research, Trawsgoed Research Farm, Trawsgoed, Ceredigion SY23 4LL NATIONALLICENCE 700 1- McAllan A. B. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB NATIONALLICENCE 700 1- Dhanoa M. S. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB NATIONALLICENCE 700 1- Dewhurst R. J. Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB NATIONALLICENCE 773 0- Animal Science Cambridge University Press 67/1(1998-08), 17-26 1357-7298 67:1<17 1998 67 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge