Effects of a subacute ruminal acidosis model on the diet selection of dairy cows
In: Journal of dairy science, Jg. 85 (2002), Heft 12, S. 3304-3313
Online
academicJournal
- print, 35 ref
Zugriff:
Two experiments were conducted to study the effects of a subacute ruminal acidosis (SARA) model on diet choice in dairy cows. In the first experiment, 25% of the ad libitum dry matter intake (DMI) of the total mixed ration (TMR) was replaced with wheat-barley pellets (WBP, 50% ground wheat, 50% ground barley). Rumen pH was measured continuously via in-dwelling probes in 4 mid to late lactation cows. This diet change reduced rumen pH by 0.14 ± 0.02 pH units (mean ± SE) and increased time below pH 6.0, from 319 ± 36 min-1 to 641 ± 36 min-1. Hence, the nutritional model successfully induced SARA. The second experiment determined if inducing SARA increases the feed preference for long alfalfa hay compared with alfalfa pellets. The 2 wk of inducing SARA were separated by 1 control wk. Four cows on either SARA and control diets were given a choice of 2 feeds, 2 times per d, for 30 min. The preference ratios (PR = Amount of Hay consumed/Amount of Hay + Pellets consumed) for alfalfa hay during two SARA weeks was greater (0.85 ± 0.03) compared with the control week (0.60 ± 0.03). In SARA weeks, average rumen pH was 0.23 ± 0.03 units lower, and time below pH 6.0 and 5.6 was higher compared to control. These results suggest that when given a choice of feeds, dairy cows alter their diet selection to attempt to attenuate SARA.
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Effects of a subacute ruminal acidosis model on the diet selection of dairy cows
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Autor/in / Beteiligte Person: | KEUNEN, J. E ; PLAIZIER, J. C ; KYRIAZAKIS, L ; DUFFIELD, T. F ; WIDOWSKI, T. M ; LINDINAER, M. I ; MCBRIDE, B. W |
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Zeitschrift: | Journal of dairy science, Jg. 85 (2002), Heft 12, S. 3304-3313 |
Veröffentlichung: | Savoy, IL: American Dairy Science Association, 2002 |
Medientyp: | academicJournal |
Umfang: | print, 35 ref |
ISSN: | 0022-0302 (print) |
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