caa a22 4500 388060883 CHVBK 20180307125120.0 cr unu---uuuuu 161130e199810 xx s 000 0 eng 10.1017/S135772980000998X doi S135772980000998X pii (NATIONALLICENCE)cambridge-10.1017/S135772980000998X The effects of concentrate energy source on silage feeding behaviour and energy utilization by lactating dairy cows offered grass silages with differing intake characteristics [Elektronische Daten] The effects of concentrate energy source on feeding behaviour and energy utilization, when offered with grass silages of differing intake characteristics, were studied in lactating dairy cows. A total of five silages, which differed in fermentation and intake characteristics, were prepared. Silages A, B and D and silages C and E were harvested from primary regrowths and secondary regrowths respectively of predominantly perennial ryegrass swards. Herbage was ensiled either pre-wilted or unwilted and either untreated or treated with a bacterial inoculant or formic acid based additives. Five concentrates (0s, 25s, 50s, 75s and 100s) were formulated to contain similar concentrations of crude protein, effective rumen degradable protein and metabolizable energy (ME) but using different carbohydrate sources to achieve a wide range of starch concentrations. The silages were offered ad libitum, supplemented with 10 kg concentrates per head per day. In experiment 1, a partially balanced change-over design experiment involving 50 lactating dairy cows was undertaken to examine the effects of concentrate energy source on silage feeding behaviour. Silages A, B, C, D and E were each supplemented with concentrates Os, 25s, 50s, 75s and 100s. Concentrate energy source did not alter (P > 0·05) silage feeding behaviour. The number of meals per day decreased (P < 0·01) as silage dry-matter concentration increased. Experiment 2, a completely randomized experiment involving 18 lactating dairy cows, was undertaken to examine the effects of concentrate energy source on energy utilization with cows offered silages B, C and D. These were supplemented with 10 kg/day of concentrates Os, 50s and 100s. Concentrate energy source had little effect (P > 0·05) on ME intake, energy output or on the efficiency of utilization of ME for lactation (k1). In experiment 3, the effect of concentrate energy source on silage preference was examined in a factorial design experiment involving 12 lactating dairy cows. Silages B, C and D were supplemented with concentrates Os, 50s and 100s. Concentrate energy source did not alter (P > 0·05) silage preference. It is concluded that with silages of differing fermentation and intake characteristics but of similar digestibility, concentrate energy source had no effect on feeding behaviour, silage preference or energy utilization. Furthermore there was no evidence of concentrate energy source by silage type interactions on silage feeding behaviour and preference, or energy utilization. Copyright © British Society of Animal Science 1998 dairy cows nationallicence energy consumption nationallicence energy source nationallicence grass silage nationallicence lactation nationallicence Keady T. W. J. Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down, BT26 6DR Mayne C. S. Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down, BT26 6DR Animal Science Cambridge University Press 67/2(1998-10), 225-236 1357-7298 67:2<225 1998 67 ASC https://doi.org/10.1017/S135772980000998X text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S135772980000998X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Keady T. W. J. Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down, BT26 6DR NATIONALLICENCE 700 1- Mayne C. S. Agricultural Research Institute of Northern Ireland, Hillsborough, Co. Down, BT26 6DR NATIONALLICENCE 773 0- Animal Science Cambridge University Press 67/2(1998-10), 225-236 1357-7298 67:2<225 1998 67 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence SWISSBIB 388060883 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge